New Begining

At last, we can begin to start afresh with all the laffin-gas webstuff.

From now on, all new info, updates and adventures will be posted here.

All the archive history follows...

HERTFORDSHIRE UNIVERSITY VISIT

It’s always amazing how it pays off to get out and about with the car. Going to events and shows where the car is on static display give us a chance to chin-wag with the public while we’re not in the middle of all the challenges of actually running her. When I’m about to get in the car, I’m usually not in the mood to be chatting with members of the public.

Static shows always turn up interest from knowledgeable and well connected people as well as the many many youngsters who just want to get close to a rocket and ask as many questions as we can answer. David usually spends most of the day getting youngsters in and out of the car, so that they can have the experience of feeling what it’s like to sit in such a crazy piece of kit.

On Wednesday we took the car to the University of Hertfordshire at the request of Ray Wilkinson, a senior lecturer at the School of Automotive Engineering. Ray also runs their Rocket Labs, which I think must be unique in the UK. We met Ray earlier in the year while we were at the Rockets and Space event at Waltham Abbey. One thing leads to another…

As soon as we pulled up in the Transporter, students appeared, which was very handy, as we immediately roped them in to help with unloading the car, extra rockets and components and all the other stuff we had brought to be examined.

What a bright, entertaining and invigorating group of enthusiastic young people! We didn’t stop all day, answering questions, explaining systems, taking useful comments and observations on board. There was a steady stream of folk getting in and out of the car, operating the controls and getting pictures taken.

The great thing was the fact that Automotive, Engineering and Rocketry students and Staff all got involved. This meant every aspect of the car, rockets, systems, chassis, running gear, aerodynamics, were all the subject of very knowledgeable discussion. The students weren’t the only ones in learning mode – there was quite a bit of very useful input that will be most helpful.

Ray took us both on a tour of some of the facilities at the University. For a couple of back-yard builders with a small machine shop and what seemed like loads of tools and equipment, it was like being in the ultimate toy-shop. Two wind tunnels, massive autoclave, lovely CNC machine-shop, professional standard Rocket testing equipment, materials stress labs, the list of great kit seemed endless.

We had taken our test rig and various rocket components, including one of our High Pressure Accumulators, so that Ray and his students could test our rocket systems under laboratory conditions. We discussed the possibilities of a series of development tests exploring variables of fuel types and oxidiser flows. Hopefully, Ray will be able to work this in with his regular teaching programme. It would be of tremendous help to us.

We also discussed the possibility of a co-operation in designing and building the next car. David and I have already started on this project, but it is very much in its infancy, so it’s a perfect time to get others involved. The new car is going to be built around a pristine carbon-fibre Champ-Car tub, which is already sitting in our workshop. We want to get away from traditional dragster space-frame construction and move on the composites for the entire chassis. The car will look very different to ‘laffin-gas’, with the cockpit much further forward, a much longer and lower rear section, F1 style running gear (modified for straight-line application) and six rockets. This car will capitalise on all the lessons learned from ‘laffin-gas’ (which has always been an experimental test-bed) and take the Hybrid Rocket Car to a new level. As systems have been developed and evolved, it is now obvious that, to get the most out of the technology, it’s time to design from scratch using all the data that ‘laffin-gas’ has generated. This doesn’t mean the end of ‘laffin-gas’, however, as we still want to show her true capability and keep on developing her potential.

A six-rocket car is probably a bit much for use on the ordinary drag strip. The new car will be run on longer tracks (airstrips) and be going after variety of performance records. We are presently in discussion with Ray and his colleagues to see how we can co-operate in this new adventure. Watch this space!!

NEW ROCKET-CAR WORLD RECORD

A few months ago, a guy called Tony Lovering got in touch. He wanted to build a rocket-powered radio-controlled model car and was interested in using Nitrous Hybrid technology. He wanted to know if we would be willing to give him some tips to help him on his way. After a good conversation on the phone, we invited Tony to come and see our car and we offered to share the things we had learned and developed for the full-sized manned car that we operate. Tony arrived and we went over the whole project, showing Tony all the bits and pieces involved.

Yesterday, Sunday 13th September, Tony ran his Hybrid Rocket powered car, ‘BLACK KNIGHT’ at the ROSSA UK Speed Championships, held at Shakespeare County Raceway.
(ROSSA: Radio Operated Scale Speed Association).

The ‘BLACK KNIGHT’ achieved a terminal speed of 163.58mph! Rocket powered cars represent a new class for ROSSA, but, having reviewed the ROSSA records, this represents a NEW OUTRIGHT WORLD RECORD for any radio controlled scale vehicle!

We say to Tony: ‘Bloody Well Done’.

Over the months, Tony has been building a single rocket, scaled-down version of our rockets and piston accumulator technology, with a series of trials and tests taking place along the way. After each test, we discussed the results and tried to help out by imparting what we know. Tony had a few failures, but he learned from each test, and his perseverance paid off last Saturday with a spectacular run.

The video of that run can be seen on YouTube at http://www.youtube.com/watch?v=RYujWn9WNXQ

Tony very kindly sent us an email on the same day:

Thanks for all your help. As you can see from the video there is much more to come

Thanks again

Tony

Tony, you’re very welcome.

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10/09/09

12:02:26 pm, by carolynne , 420 words, 10 views
Categories: Day to day

FRANKENSTEIN OPERATES!

This weekend (Saturday 12th September), the car will be on display at Sywell in support of ‘Young Aviators’ Day’. As it has always been part of our mission to get young people interested in engineering and related stuff, we are very happy to be taking part

For over two years, I’ve been threatening to cut the car in half! As our understanding has developed and systems have evolved, the space around the throttles and valves in the chassis has become very crowded. After the last test, we stripped out most of those systems for a general overhaul and clean-up. With rockets out and the chassis sitting bare, we decided that the time for radical surgery had arrived.

The plan was to add half a metre to the area of the chassis where all the ‘worky-bits’ are situated. With the car on stands, leveled and ready, David picked up the cutting tool and prepared to go for it. At that moment, there was a bright flash of lightening and an instant, shattering clap of thunder – no really - a big thunderstorm kicked off right overhead! Apocalyptic eh?

We’ve put in a new triangulated section of chromolly steel, adding just under half a metre. John Shakeshaft brought his mobile equipment and tig-welded the whole thing back together as strong as ever.

Then we had to replace or extend all the control connections, as everything was now too short. Throttle cables, electrical connections, ‘chute cables, brake lines all had to be done. Suffice to say, the job is finished and she’s back in one piece, looking a lot longer!

The extra space has allowed us to re-position the pressure vessels much lower in the chassis, adding to stability and safety and greatly improving the general looks of the car.

Geoff Caswell of ‘Caswell Engineering’ and ‘Flexrite/Chemgine’ is supplying us with all new stainless and PTFE double-braided hosing and connections as well as other 316 stainless fittings to improve the flows and safety of the systems. This is a huge help, as these are the absolute best you can get, and the most expensive!

A rumour has circulated back to us (as they always eventually do) that we blew up a rocket at our last test. We didn’t. In fact we damaged nothing of any importance as the safety systems did the job they were designed to do.

As soon as the new kit from CASWELL is in the car, we’ll be back out. I'll keep you all posted.

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20/08/09

12:44:31 pm, by carolynne , 453 words, 18 views
Categories: Day to day

SECOND SYWELL TEST

I’m writing this while everything is fresh in my mind.

What a fantastic day of testing at Sywell Aerodrome. We have so much to thank Michael Bletsoe-Brown and all the crew at Sywell for making the most fabulous facility available for our tests. We owe Sywell big-time, and we will definitely repay the debt with a super performance on that great runway.

The plan had been to test one rocket first –if all went well with that one – we’d fire three. As with most experimental projects, the plan changed as we went along. I made an error, misreading a pressure gauge, during the first fueling exercise. The result was that we got gas under the piston in the supply accumulator, and the rocket quenched on opening the main throttle.

Back to the old bus we went, and we decided to repeat the single rocket test, this time wearing my reading glasses!! She fired beautifully on the one rocket with mutli-dancing diamonds on view in the exhaust jet. Success!! The new cooling set-up had worked on what turned out to be the hottest day of the year.

We had two rockets left un-fired in the car, so we decided to fuel them both up and see how she went. One was pressurised to 950psi and one to 1,000psi, just to get a variable we could observe. The first rocket fired beautifully, the second underwent pressure-shock in the hoses and valves in the input side of the rocket, damaging an expensive valve and blowing out the ‘Fike’ burst-disc on the output of the accumulator. On hearing the bang, I lifted my foot and the car shut down safely. Thank you Fike! The explosion protection did its job. The rocket and accumulator were both perfectly intact. And we have found the pressure-shock threshold for a Nitrous Hybrid using piston accumulators. It’s 950 psi. Anyone planning on using this set-up, whether in models, or on a larger scale, please take note!! This is serious safety information that should be taken very seriously.

We now know that all our systems are working as designed, that we can do this in silly-hot conditions, and we can do it safely!

The car (once we’ve fixed the slight damage) is now ready to do her stuff.

After over four years of build and development of a novel technology, we are there. I can’t tell you how good that feels.

It must be beer o’clock!

PS We've had a chance to do some more analysis of exactly what occured. Any one who wants the low-down on the mechanics of the compression-shock event should contact Carolynne via the website remebering to put your email address in your email.

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19/07/09

05:38:58 am, by carolynne , 782 words, 23 views
Categories: Day to day

Testing in Heaven

Friday’s weather forecast was, to say the very least, not good.

Michael Bletsoe-Brown had very kindly allowed us to arrange a private test on the new concrete runway at Sywell. He’d had the track swept, two of our team members had taken holiday days off work, and commitments had been made. Under any other circumstances, we would have canceled the test as thunderstorms and high winds were predicted.

As this was a purely a systems test and not an attempt to go for a quick run, it made sense to see what we could get done.

We got to Sywell a little after nine in the morning and got the chiller running to get ready for fuelling. While the Nitrous was getting cold we walked the runway to have a close look and pick up any debris. We found a few small flint-stones, but, apart from that, the surface was perfect. We put out distance makers at 330yds and 440yds.

The original plan had been give her a good hard burn and shut off at 1,000ft. The wicked cross-wind ruled that out. In fact it did us a favour by making us really concentrate on the systems testing. So we went for plan ‘B’, which was to get her going and for me to play with the throttle to see how much control we had and how quickly the rockets would cycle.

This was the first time we would run rockets with chilled Nitrous. Watching the weather radar, we decided to start fuelling just before noon. What a difference having cold gasses! We were able to get much of the fuel in by gravity pour and, when the pump was needed, the pumping went steady and reliable. It’s still hard work having to pump against the pre-filled nitrogen, but safety really requires that we do it this way.

When we were ready, we rolled her on to the runway and let the folks at Sywell know we were ready to test, so that they could observe. Sywell’s crash tender was on the spot, fully crewed. We had a quick discussion to go over the safety info we had previously provided, and all was ready.

I got strapped in and Fred gave the radio instructions. She fired quickly on the pilot nitrous, which ran for two seconds, and I went to the main throttle. She blew out. We just didn’t get enough heat in the rockets.

We’d brought spare rockets, so we decided to swap the rockets out and have another go, as there was still plenty of fuel in the car.

An hour later, we ready to test again. This time we decided to let the pilots burn for four seconds and open the main throttles very gently to get her burning. This time she lit – but not really well, I backed the main throttles off and had another go and she hooked up, gave a good blast that gave me a kick in the pants, and then the fuel was gone.

We got the car back to the transporter, the sky darkened and the heavens opened with a spectacular thunderstorm. Luck was with us this time!!

We’d accomplished everything we wanted from the test. We’d learned that the increased liquid density of the chilled nitrous meant we were struggling to deliver enough start-up gas (not hard to fix!), we’d got her to burn well when we tried again, and we’d proven out the chilling and fuelling method.

What was really great was the totally relaxed atmosphere of a proper private test, where there was no pressure to perform for the public. No start-time to meet, no performance anxiety. It was just like static testing down at the farm with the added ability to get her in motion.

We’d also made some great new friends at Sywell. Michael Bletsoe-Brown enjoyed observing what we were doing and has invited us back to test again, basically until we are ready and happy to do a proper high-speed run on that marvelous runway.

The team met up in the bar at the ‘Aviator’ (what luxury – a pint of ‘Pride’, lovely surroundings and seating that swallows you whole) and we did our usual de-brief. As the only variable we had changed, was the chilling of the gasses, the conclusion was to increase the pilot volume by enlarging the inputs to get the rockets hotter more quickly.

Many, many thanks must go to Michael Bletsoe-Brown and his people at Sywell. My only regret is that we had had to go through the last couple of years without the use of such a brilliant place to test.

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06/07/09

10:28:49 pm, by carolynne , 802 words, 25 views
Categories: Day to day

Rockets, Rockets and More Rockets

Our visit to the Royal Gunpowder Mills, to take part in their ‘Rockets and Space Weekend’ was a great experience. What a great site, beautiful setting, fantastic history and a superb permanent rocket collection that is a must-see. A big ‘thanks’ must go to Lynne and all her people for putting on such an excellent event. For the first time in the life of our project we were able to mix and talk with a group of rocket experts and enthusiasts and actually felt part of that community. There were many knowledgeable people with backgrounds in military and civilian rocketry and many, many enthusiastic amateurs and modelers. We had a chance to get a close-up look at lots of different types of rockets and we listened to many differing theories and opinions – many of them at odds with one another, and all equally convinced of the correctness of their own positions. Yes, we learnt much.

We got to see the designs, models and actual rocket parts of the HTHP hybrid destined for the ‘Bloodhound’ LSR car and many of the different small-scale hybrids that are being flown by professionals and amateurs.

We think we were, on the whole, well received. Though we don’t know what was said when we weren’t in listening range! Our piston accumulators, our four rocket system and our bio-fuel ‘wick’ fuel grain were all very novel to the community. It would appear that we have done quite a few things that are truly innovative and have advanced the possibilities of ‘hybrid’ rockets.

One thing that did stand out is the undeniable reality of what we are doing. The car isn’t just a ‘design’ or a ‘plan’ or a graphic artist’s idea of what it’s all going to be one day. Our car was there – real, with tyres you can kick, rockets you can touch, tests and runs you can see on Youtube. The other thing that made us different is that ours is a manned rocket with all the safety implications and harsh realities of being a piloted vehicle carrying human cargo! As far as we can tell, it’s also the most powerful rocket car presently actually running and being used anywhere on the planet. If this isn’t the case, I’ll happily withdraw that statement. But as far as we honestly know, our project is unique. It’s also one of the most powerful hybrid rocket set-ups around.

We were offered testing facilities and various forms of technical assistance that will be very useful. The rocket professionals all seemed to be of the opinion that we were doing things well and with proper regard to safe operation, ‘though none of them expressed a wish to have a drive in her!

Last week we met with Michael Bletsoe-Brown of Sywell airport, right here in Northants, with a view to possibly testing on their new 1300metre concrete runway. We had brought the car along for the people at Sywell to have a good look for themselves. We parked the bus on the apron and got the car out onto the concrete so all could have a good look. We had arrived on a day when the British Aerobatics Team were practicing, so we were surrounded by a bevy of very powerful little aeroplanes and a bunch of crazy pilots – rockets are right up their alley!!

Michael very kindly arranged for me to inspect the new runway. It is a work of art! With special ballast in the mix, it has no need for large expansion joints and has been laid with amazing precision. The result is a wide, smooth surface that is ideal for high-speed testing. We have yet to arrange precise times, but suffice to say, our dream of having a private testing facility has now come true. I hope to have further talks with Michael later this week, to make firm arrangements and also to see what we can do to help promote what is probably the finest general aviation airport in Europe.

David and I have always liked Sywell, with its fabulous art-deco architecture and it’s amazing history, and we have donated a few artifacts to it’s aviation museum. So we are delighted to be able to be associated with such a jewel of a place.

The new refrigeration unit has now been tested successfully, and we can now get our gases down to less than 10deg C in a couple of hours. That solves our warm-weather fuelling problems. So now we’re ready for the next test run. It will either be at Sywell, in the next couple of weeks, or at good old Shakey at their Mini Festival this coming weekend (11th/12th July). We’ll keep you all posted on that.

The adventure continues…..

BE THE BULLDOG!!

After the last newsletter, where I talked about struggling with high ambient temperatures, we received two emails, one from Dick Keller (which was most inspirational) and one from Knut Soderquist, (which was typically to the point).

Dick told us to develop counter-measures and ‘Be the Bulldog!!’, while Knut told us that we had to deal with the heat as the show must be able to go on regardless of the prevailing conditions.

We’ve been told! (Again).

We’ve welded a very sturdy structure into the transporter to carry the gas cylinders, enclosed it, insulated it, and included a chiller, with the cold air ducted over the bottles and re-circulated inside the cabinet. We now have a secure and safe refrigerator for the gas and N2O.

Now we’ve got pistons in the car’s pressure vessels, we have to bear the safety aspects very much in mind. Dropping a piston at pressure on top of N2O gas is a very dodgy thing to do. So we have to pressurise the Nitrogen side first with enough pressure to keep the N2O liquid as it goes in. The hotter the day (and, therefore, the hotter the N2O) – the higher is the required pressure. The strain put on the pump and compressor can just get to be too much.

We can now chill the N2O (and the Nitrogen) to near freezing, which deals with this problem.

We’ve also put in a more powerful gas-ram to operate the start-up N2O system.

So now it’s time to test again at the track. That will be in the next two or three weeks.

In the meantime, we’re taking the car to the Royal Gunpowder Mills at Waltham Abbey for the 4th of July weekend, to take part in their festival of rocketry, which should be a real blast! There’ll be lots of enthusiastic model rocketeers and some very knowledgeable rocket pro’s in attendance, along with the firing of many rockets. There was some discussion about firing one of ours – but the lack of sufficient safety perimeter for such a large rocket knocked that idea on the head.

It should be a super and hugely entertaining event. If you’re in the region – why not pop along?

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01/06/09

06:44:42 am, by carolynne , 375 words, 36 views
Categories: Day to day

TOO HOT TO TANGO

Our on-track test didn’t go well.

We’ve been stopped by wind, rain and even snow before, but this time – it was just too hot!

It was 85degF under the tent. This meant we had to pump in nitrous against an 800psi nitrogen pressure. The poor old compressor really struggled to keep up with the demands of the nitrous pump. It took the best part of an hour to get only 8lbs in each accumulator.

We’d used space blankets to keep everything as cool as possible until the moment of fuelling but it didn’t really help. We had a start-time of between 1:00 and 2:00pm, which, from a temperature point of view, really couldn’t have been worse!

Every system was tested and cycled in the pits and it was all working. Just before we left for the start-line, Bev Battsford (Shakey’s pairing-lane Supremo, who'd very kindly volunteered to help us out on the day as a team member) warned us that it was over 100 deg.F, on the track, and at the end of the pairing lane. This was really too hot for the car. We’d come this far so we gave it a go.

When the word came over the radio to switch on the pilot nitrous – nothing happened. The ram and valve set-up that lets the starter nitrous in didn’t operate.

We got her back to the pits, let her sit in the shade, disconnected the pilot hoses from the rockets and tried the system. It worked. It looks like the heat had made it all go tight.

Very disappointing- again.

It was, after all, just a test of many new parts- all of which behaved themselves very well. A test we would have preferred to conduct in private.

On the bright side – the car was very gas-tight and everything held up well.

We’ll try again on a cooler day – with a more powerful ram on the pilot system.

I want to say a very big ‘thank you’ to the guys at Shakey, my wonderful team, and especially to Bev, who is recovering from orthopaedic surgery, but still helped immensely by bringing us safely to the start line, as she has done so many times before.

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23/05/09

06:24:42 am, by carolynne , 228 words, 56 views
Categories: Day to day

AND THE ROCKET IS FINE

A promised, here are the results of internal examination of the rocket:

We knocked the rocket apart yesterday. The fuel grain showed that the central cardboard tube was almost entirely consumed and the outer almost entirely intact. This is exactly the same result as previous examinations of fired rockets. The nozzle was also intact, with no sign of erosion on the hard edges. No evidence of any heat-effect or damage to any aluminium components.

A newly refurbished rocket has now gone back in the car, so there are four rockets, in the car, ready to go.

Over the next few days we are doing some work to improve the ballistic protection behind the cockpit and we're making and installing a better and stronger bash-plate underneath the pressure vessels and throttles.

We now must test this all at the track - we've made tentative arrangements with Shakey to do this on the 30th/31st May at the 'Yanks' Event. This has yet to be confirmed by the track officials.

We will not be out to demonstrate full terminal speed at this test. We just want to see a good, powerful run to 3/4 track and then assess the way she stops.

We'll keep you posted.

Team member, and Mac supremo, Will Campbell has now put together a 'facebook' page for Laffin-Gas, with reports, pictures and videos. See you on there!

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20/05/09

09:42:30 am, by carolynne , 905 words, 28 views
Categories: Day to day

Landmark Test Result

After six months of serious problem solving, engineering, safety testing and expenditure, today was the day to put it all on the line and conduct a live-fire test.

That’s a very nervous moment. It has taken several days to get the team all lined up, get all the necessary in place, and be ready to get it done. But more than all that there has been almost five years of hard effort spent on doing something which has never been done before with any degree of success or reliability. If this firing doesn’t go – the whole project is screwed.

We’d thoroughly discussed fueling protocol, both within the team and with our American mentor (who works on the Delta and Atlas Launchers), Dana Vandersaal (thanks Dana!).

We went for the slowest, most cumbersome (but definitely safest) method we could devise: Nitrogen first, to liquefaction pressure for the Nitrous Oxide, and then pump the NOS in to weight. This is the best way to avoid pressure shock.

I’ll post all the full technical data in a few days, but suffice to say the fuel load was light and the push-pressure quite low.

She burned like a good ‘un! We’ll probably have to choke her down!

It’s all been captured on video, and we’ll get them posted as soon as we can.

The car is definitely a go-er.

THE TECHNICAL STUFF:.

As usual, we want to share our acquired knowledge and data with all who may find it useful.

The last time we had the car at the track we failed to get full ignition on the start line. Trouble-shooting showed that al control systems were working as they should. The only difference between that set-up, and the one that had previously fired so well, was that we had sloped the nitrous vessels in the car, in an attempt to overcome the effects of forward (horizontal) G. It hadn’t worked.

After much calculation and experimentation we arrived at using pistons inside the vessels to maintain a complete physical separation between the gas and liquid. This prevents the lateral movement of the liquid N2O and prevents ‘blow-through' of Nitrogen (Which extinguishes the rockets).

In earlier blogs, you can read the saga of the development, manufacture and testing of these new ‘accumulator’ vessels.

In order to conduct a meaningful test it was essential to start with the exact set-up that had failed to perform last time out. The only difference had to be the addition of pistons. This meant that we had to fire a rocket in the car with all other possible variables constant, hence the firing of a single rocket, in the car down at the farm.

The Nitrogen side of the accumulator we were using was first charged to 650psi, which, at the ambient temperature on the day, would ensure that the Nitrous would stay liquid as it was introduced.

Each accumulator now has its own discrete pressure guage to allow us to monitor the increase in Nitrogen pressure as the N2O is pumped in.

We pumped in 8lbs of liquid N2O, looking for two seconds of ‘pilot’ ignition burn, and 3-4 seconds on main throttle. Nitrogen pressure had stabilized at 800psi, which is about 200psi lower than we normally use. After a little discussion it was decided to run at that pressure as we weren’t really concerned (in this test) with power output, rather actual full-throttle ignition.

When the car was chained down in position and all bodies (except mine, of course) were out of harms way, I performed a radio-instructed start sequence, exactly as we do it at the track.

The rocket fired beautifully. Just over two seconds on pilot and nearly five on mains. I closed the throttle with some N2O still in the system. This means that we are using the Ntrous much more effieciently than before. The team all thought that, despite the low state of tune, it was the most powerful in-car burn we had yet achieved. Sitting in the car while the burn was going on, I could have no opinion save the observation that the car had lurched forward with much more power than I was expecting from one rocket.

Reviewing both videos of the test, I now concur with the team. It appears that the piston have provided vastly more efficient delivery of N2O.

External inspection of the rocket showed that it had completely retained its structural integrity, it was only mildly warm to the touch, and it appears that the nozzle has settled into its taper by about 0.5mm. We will open the rocket up and give all the internals a thorough inspection. If there are any marked differences to previous firings, these will be passed on.

The rocket we used had been sitting around with an oil-soaked fuel grain for about six months. I wasn’t sure what effect this would have on performance. First appraisal says – no effect at all. This is a very useful result as it means we can stock-pile rockets ready for use rather than having to prepare them on the week of use.

This was truly the last hurdle. We are now confident that we can reproduce this firing at the track with all four rockets. Now I have to learn to stop the damnthing!!

Video of the test can be viewed on www.youtube.com/laffingastv

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02/05/09

08:12:22 am, by carolynne , 573 words, 34 views
Categories: Day to day

Friday May 1st:

Team Member Kim and I took four completed piston accumulators to Nottingham for pressure testing and certification at Jackson Keay Gas Cylinder Services. We weren’t wearing steel toe-caps so we weren’t allowed onto the shop floor to observe the testing up close. I stood at an office window overlooking the factory and watched as the bottles went on to the hydrostatic rig. It was a nervous half hour as I watched the bottles being filled with water and then hooked up to the compressor lines. We wanted them certified to 120bar, which is the standard for nitrous bottles and almost twice our maximum operating pressure. The big test gauge went up to 120 bar and stayed there. No leaks, no bangs, no breakages. The bottles were taken off the rig and stamped with the Jackson Keay cipher.

We’ve passed!

Jackson Keay are the foremost pressure vessel safety company in the UK, testing vessels for the likes of BOC and Air Products. You simply can’t have a more impeccable certificate than one from Jackson Keay. I’ve got to thank Fred Ayres, Neil and all the people at Jackson Keay for helping us out. For what has to be called a ‘nominal fee’, they have disturbed a busy production-line on three occasions to help us get through this vital process. They have been genuinely enthused about our little project and without them, well, we would have been well and truly stuck in the mire.

We got the accumulators home, popped them on the bench and shot the pistons up and down a few times with compressed air, just to make sure nothing had got jammed-up in the testing process. Now we’ve got to get them in the car, add all the plumbing and make sure there are no leaks.

We’ve added the over-pressure protection so kindly provided by FIKE but, even so, we’ve reviewed our fueling procedure to ensure that there is no risk of pressure-shocking the nitrous as it goes in. A light pre-charge with Nitrogen to provide damping is called for and that is what we’ll do.

The next step is to get the car down to the farm and fire one rocket in the car, to make sure everything works as predicted. We can’t see why it wouldn’t work, but hard experience has taught us to test everything. If that goes well, i.e. one rocket does a full burn, then it’s off to the track for a four-rocket burn in motion. We have that test penciled in for Shakespeare Raceway on the 16th-17th of May. I must emphasize that this run will be purely a test – not a performance. There is still much to learn about the actual power, getting the car stopped safely, and the amount of control the throttles give us.

After a hard off-season getting these accumulators built and tested, it’s back to the fun stuff of actually firing rockets!

A very big ‘THANK YOU’ must also go to Geoff Caswell of Caswell Engineering whose sponsorship and direct engineering assistance has been vital. The huge threads for the caps needed very precise cutting, which we simply couldn’t do on our old (and somewhat worn) lathe. Geoff came to the rescue by doing the thread cutting on one of his excellent CNC lathes and the result was a beautiful fit. Thanks Geoff!!

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IF AT FIRST…

The mark one accumulator has now been pressure tested. Oh dear! The welded flanges parted company from the vessel. Fortunately it was a hydrostatic test so there was no drama, just a sad exit of a flow of water. On examination, the actual weld material was fine but there was a crystalline substrate that had formed at the penetration boundary. It was, after all, an experiment, and now we know that the bottles don’t like even the best of welding.

David has been hard at work in a freezing workshop manufacturing Mark Two. This time we’ve gone for threaded construction as we know that the bottles hold a thread very well. A large cap made from high-grade billet aluminium is now screwed on to a fine thee-inch thread on the bottle. We now have to add the piston and the internal stops to prevent point-loading on the vessel and it’s back to the testers at Jackson Keay, who have been extremely helpful. David is very expert in the machine-shop and mechanical construction is an area of expertise – neither of us can make any claim to be experts at welding dissimilar metals!

The very cold weather has slowed us down a lot, so we’re behind schedule. Nothing new there then. We’ll be taking the new construction for testing in the next week or so and, if all goes well, David will press on with the other three accumulators.

We’ve had an interesting email from the NASA White Sands Testing Establishment, offering advice and consultation following on from the article we wrote about the explosion at Scaled Composites’ testing facility. It is very welcome and it does show that our efforts are being followed by some very serious people. Ever since that tragic accident in the Mojave Desert, we have had to back-track, consult, and re-design to ensure that our operations are as safe as possible. The addition of the accumulators is central to this.

Suppliers have come forward with specialist lubricants and explosion protection that have made it possible for us to move forward. Many others that we have contacted cannot get it together to make a promised phone call! In such hard times as these, it is a bit gob-smacking that the business-as-usual culture of lousy customer service still seems to be the norm in the U.K. We know that an order from us will not make or break any company, but the world is watching us now, and you’d think that, with the entire engineering sector under real pressure, there might be an effort to improve customer relations and to take advantage of any P.R. opportunities that might come up. The survivors of this recession will be the firms that make a real effort, and the ones where complacency reigns supreme can expect to end up on the scrap-heap.

We will be joining our American friends at Alconbury on March 5th to display the car and take part in their annual U.S.A.F. Motorcycle Safety Event. It’s good to see our American guests taking safety on our roads so seriously and we are delighted to assist in their efforts. As these folk can rightly claim to be the fastest bunch on the planet, we’re really looking forward to rubbing shoulders with some serious jet-jockeys.

The rest of our schedule for the coming season is still very sketchy as we don’t know exactly when we’ll be ready to have another go in public, but we are hopeful to be on track by late April or early May. We’ll keep you all posted.

Those of you who are reading this in our newsletter will be getting some photos of the new kit. Unfortunately the guys who did our website forgot to give us a facility to upload photos – and now they’re no longer in business. We’ll get the website sorted out soon (we hope!) but in the meantime, if you want pics, please sign up to our newsletter via the website.

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30/11/08

11:05:11 am, by carolynne , 844 words, 81 views
Categories: Day to day

Accumulating Knowledge

Well, we’ve messed around with the bladders and, several weeks ago, came to the conclusion that while the theory is fine, the practicalities aren’t. The material we can use just isn’t up to the job.

So the problem of a physical barrier between the Nitrogen and the liquid nitrous was still with us.

A few months ago, we started looking into high-pressure accumulators and spoke with the people at Hydac, and one of their dealers about their excellent diaphragm accumulators. They are definitely up to the job. Unfortunately the standard ones are made from steel, which Nitrous will corrode, and which are far too heavy for our application. The purchase of lightweight aluminium versions was way beyond our finances.

The only alternative was to build accumulators ourselves. We decided that free-floating pistons were an arrangement that we could manufacture in our own machine-shop. Diaphragm construction was out of the question for us. This is a big step, and safety of operation must always be to the fore in our design and operation. Whatever we build has to be tested at pressures well above those that would actually be used in service.

The first accumulator is now well on its way. We’ve had John Shakeshaft weld a very sturdy flange around the outside of one of our 220bar vessels and cut the vessel across the centre of the flange. David is now working on the ally piston we’re going to use to free-float between the gas and liquid. We’re using 3,000psi hydraulic seals in the system. As we operate at around 1,000psi (75bar) there’s a good margin for safety and reliability. Before any high-pressure gas goes anywhere near it, the accumulator will be subjected to an independent hydrostatic test to ensure its integrity at well above our service pressure.

With a solid barrier, such as a piston, in the system, our over-pressure protection has had to be reviewed, as we need protection on both sides of the piston. Fortunately the people at Fike, (an international engineering and manufacturing firm specialising in explosion protection) have come though for us and are providing (at their cost!!) the finest burst discs and holders. There will be one on the output end of each of our pressure vessels and one disc will be sacrificed as part of the hydrostatic testing. To the folks at Fike, we must say a very big THANK YOU!! Especially to one very bright lady engineer (we like lady engineers!) - Yvonne and to Keith, the manager with some real marketing vision. We do hope that we can continue this collaboration. Needless to say, there’ be a FIKE logo on the car and we’ll be there to asssit in their PR and promotional efforts. For anyone interested in what they do and what they can supply, please take a look at: www.fike.co.uk/contactus.htm .

If all goes well, and we’re happy that the construction is more than adequate, we’ll be doing a single-rocket test in the car to ensure that all works as it should in relation to the rest of the systems in the car. There’s no doubt that the piston will do the job of partitioning the gas from the liquid in theory, but there is no substitute for practical experimentation.

While we're thanking people: A big 'thank you' to Geoff and Sue Caswell of Rushden engineering company; G. Caswell Engineering, who've come on board as a Development Partner and started by donating a beautiful TOS milling machine that has already made our lives so much easier. The Caswells make super high-quality stainless-steel fittings for process industries and for medical applications. So we now have a source for those bits of 316 stainless that we keep seeming to need! It's great to have support from people who are committed members of our local community.

The body of knowledge we have employed has been the result of very expensive and time-consuming development by lots of folk. We have always acknowledged Charles Berg’s efforts – it was because of Charles’ openness and willingness to share what he knew, that we even got started on our car. Charles has continued to give input as time has gone on, as have others all over the planet. For our part, we too have discovered and developed lots of useful stuff which we have been happy to share with anyone with an interest in hybrid rocketry. The accumulation of this knowledge is a community affair, and long may it continue.

This sharing would be stifled if any of us in this community fail to acknowledge the input, work and expense of others. We are happy to share – but get a little miffed when someone comes to our house, gets the low-down on all that we’ve learned and then claims he figured it all out for himself. Use the knowledge by all means - we all stand on the shoulders of others. To acknowledge that is model behaviour, to claim it for your own is plagiarism.

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05/11/08

04:11:47 pm, by carolynne , 363 words, 104 views
Categories: Day to day

You just never know

A couple of weeks ago the media were full of the new Richard Noble project: "Bloodhound". 1,000mph in a land vehicle would be no mean feat. I was interested to see the government backing citing 'getting youngsters enthused about science and engineering'. I'm all for that.

We've just learned the hard way that an economy cannot live long on a diet of consumer credit and shopping. At some point, someone has to create the real wealth that pays the shopping bill. For the UK, this means high value-added engineering and science. We can't compete with the low labour costs of the Far East in mass-manufacture so we must concentrate on the high-end products and science. Yet we know that science has become the poor relation in the school curriculum, very often being taught by teachers who have little or no science or engineering backgound, who have been press-ganged into teaching the subject.

When we are at the track with the car, we're always surrounded by youngsters asking great questions and getting utterly enthusiastic. So we contacted local schools and people involved in education, offering to take the car to their school and let the children enjoy a science lesson based around the car. To our dismay, not one school ever got back to us.

So, when the 'Bloodhound' project hit the news, I contacted the local BEEB to vent our frustration. They did a story for the regional programme, that barely touched on the educational issue but it was a fairly well done little piece.

Then a couple of press agencies got in touch - then an article went out in The Mail Online, and Metro. They didn't quite get the facts right - the media never do. So we never claimed to have 8,000lbs of thrust -HONEST!!

Now the whole world wants to know about laffin-gas and that's great for us. But it's not what we were really after. We want to connect with the youngsters and let them see what fun and adventure can come from science and engineering. The youngsters, we are sure, will do the rest. So, schools, teachers, technical colleges - get in touch and we'll be there!

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21/08/08

07:35:34 pm, by carolynne , 1800 words, 322 views
Categories: Day to day

THE BIG BOYS SCREW UP

About three years ago a bloke blew up a rocket car at Santa Pod. It wasn't our car. We had nothing to do with it. Since then we haven't been able to run there. We are based three miles from Santa Pod and we have to drive to another track, Shakespeare (which is a great place), in order to be able to carry on our project. I only mention this because it's an example of how someone else, that you have absolutely nothing to do with, can screw up, and thereby mess with your life (a bit like a drunk driver!).

That's all pretty minor stuff really. What 'Scaled Composites' and 'Virgin Galactic' have been up to is truly jaw-dropping. They killed three people, seriosuly injured three more, and then refused to tell anyone exactly what had actually happened. The offical California 'Health and Safety Report' has never been published, even though 'Scaled' were fined $28,000 for violations. Of course, when you realise that 'Scaled Composites' is controlled by Northrop Grumman (a true Aerospace/defence giant) all becomes clear. God, I wish we had that kind of pull.

By refusing to publish the relevent data, 'Scaled' have put everyone involved in Hybrid Rockets in a jam. Did something happen that we haven't designed for? Should we stop until we get the facts? What if someone gets hurt? Their screw-up, our problem!

The following two items are the recent Press-Release from 'Scaled' and a letter sent, by myself, to a couple of leading journals. (What's the betting they'll ignore it?)

SCALED COMPOSITES, LLC

August 1, 2008

The rocket oxidizer cold-flow test accident of 26 July 2007 at Scaled Composites was a devastating event. It caused the death of three co-workers and serious injuries to three more. It produced untold grief and turmoil for immediate families and friends of those killed and injured, as well as to the Scaled family. All of our lives were changed that day.

It should go without saying that we were completely surprised by this accident, as we had conducted numerous tests, without incident, on similar systems including the SpaceShipOne rocket motor. The body of knowledge about nitrous oxide (N2O) used as a rocket motor oxidizer did not indicate to us even the possibility of such an event. However, because this serious and unanticipated accident had occurred, we had to look back at what had happened and where we go
from there.

After doing our best to take care of the families and each other, the first order of business was to work with Cal OSHA in its investigation of the accident. Cal OSHA took through the end of January this year to complete its investigation. The agency did not determine a cause for the accident. We are continuing to work with Cal OSHA. In doing so, we hope to support Scaled’s needs as well as the ongoing efforts of others in this developing industry.

In addition to the OSHA investigation, we put in place our own Accident Investigation team, composed of 11 members from the industry and from Scaled, with a collective rocket development and testing experience of over 200 years. Scaled also worked with NASA to
conduct basic materials incompatibility testing. Based on the findings of this Accident Investigation team, Scaled has implemented a variety of improvements to enhance the safety of the N2O hybrid rocket motor.

The improvements and plans include:

Conducting increased compatibility testing between N2O and any materials that contact it in the tank and eliminate incompatible materials in the flow path;

Revising cleaning procedures to further minimize the risk of contaminants in the system;

Replacing the composite liner in the N2O tank with a metal tank liner;
Diluting N2O vapor in the tank with Nitrogen or another inert gas to decrease its volatility and/or act as a pressurant;

Designing additional safety systems for the N2O tank to minimize the danger due to tank overpressure; for example, a burst disk feature; and Increasing the amount of testing during the development program to demonstrate that these design changes, and any improvements to system components, prevent the sequence of events that led to the accident.

Finally, we have formed an Advisory Board comprised of rocket industry experts to oversee theimplementation of our improved designs and procedures going forward. These procedures, aswell as the improved test site safety procedures that we hope to develop with Cal OSHA, will greatly enhance program safety for the future.

The industry will be provided with any pertinent materials compatibility data and/or testing protocols we develop as we move forward.

RISKY BUSINESS

Space Ship One – the Virgin Galactic Challenger is an amazing project.

A small rocket powered ship is taken to altitude by one of Bert Rutan’s innovative aircraft, built specicaly for the job, and then the rocket-ship powers off into sub-orbital space. It is designed to offer the experience of space-flight to the general public, and is being promoted by that Paragon of all Promoters; Richard Branson and his ‘Virgin’ brand.

'Scaled Composites' is the company, founded by Bert Rutan, that is doing this great project. These were the guys who built the aircraft which circum-navigated the globe, and many other fabulous pioneering aircraft. There is no way such a small operation could fund a space-flight project, so Bert sold a controlling interest to Northrop Grumman, one of the aerospace giants. There’s always a down-side to such a move, as big corporations do not operate by the same rules as the little guys.

A little over a year ago, there was an explosion at the Mojave Desert centre, in California, where the work is taking place. Three people were killed and several more injured. This happened during a ‘routine’ fueling test, where the oxidizer for the rocket (in this case Nitrous Oxide) was being transferred, from a storage tank, into the pressure vessel for the rocket. Subsequently 'Scaled Composites' were fined $28,000 for violations of health and safety rules. (which would seem to many a paltry amount for three dead and three badly hurt). The California OSHA (the local health and safety authority) report was never published. On the first of July this year, 'Scaled Composites' issued a press-release concerning this incident. The last line of the release states:
“The industry will be provided with any pertinent materials compatibility data and/or testing protocols we develop as we move forward.”

Scaled Composites are not the only people working in the field of high-powered Hybrid Rockets (the type of rocket being used), so sharing of information is the responsible and ethical thing to do. Well done Scaled Composites! Well - not quite!

The press release contains no useful information as to exactly what occurred, what materials, methods and protocols were being followed nor the source of ignition. No engineering or scientific data has been released. The Health and Safety report has been withheld. Three people were killed. That experience should, at the very least, translate into a sharing of knowledge that would enhance the safety of others working in the field.

I must disclose a personal interest at this point. I am also involved in the development and application of powerful Hybrid Rockets. In their report, 'Scaled' identify certain ‘new’ safety procedures, including the use of inert gas and over-pressure protection. We’re a very small operation, yet we worked out that these steps we’re needed three years ago, before we took the step of firing any rockets. So, as big as their operation is, mistakes have been made, and now commercial secrecy prevails (as per usual), at a big Aerospace Corporation. I have the greatest of respect for Bert Rutan. He is probably the finest aerodynamicist working today, and I’m sure this secrecy is not down to him.

It is the normal practice, in scientific circles, to share data. Especially when that data is pertinent to the safety of other scientists. In fact, it is considered to be basic ethics. Northrop Grumman have decided not to do this. They seem prepared to allow others to take risks that could well be avoided, by witholding the one good thing that may have come out of the tragic loss of three lives; information.

In the press release they also state:
“It should go without saying that we were completely surprised by this accident, as we had conducted numerous tests, without incident, on similar systems including the SpaceShipOne rocket motor. The body of knowledge about nitrous oxide (N2O) used as a rocket motor oxidizer did not indicate to us even the possibility of such an event.”

Whoa there! The 'body of knowledge' certainly predicted the possibility of such an event. Many other engineers working with Hybrids will confirm. What they should have said was “We didn’t know”. One wonders what else 'they didn’t know' and what else they still don’t know. This matters because they haven’t figured out the root cause of the event. The impression left is that they truly haven't a clue. If all the data relating to the incident were to be shared, perhaps there are others who can figure out exactly what happened. Unfortunately that possibility is not to be allowed.

The accident demonstrates that, like the rest of us, 'Scaled Composites' is fallible and not in the least omniscient. We are now to trust that, as they continue to operate in their own splendid isolation, they will not get it wrong again. One is reminded of how Morton Thiokol made a commercial decision that cost the lives of a Space-Shuttle crew. (I should explain that Morton Thiokol built the solid-fuel rocket boosters that leaked and blew up the 'Challenger' as she launched. Engineers warned that the weather was too cold for the seals and that a catastrophe would follow. Senior mangement made the 'business' decision to let the launch go ahead. The rest is history.)

We have tried to contact Scaled Composites on several occasions in an effort to share data in the spirit of scientific co-operation. They have never replied. Not even with a ‘No thank you’. They are obviously too big and too clever to talk to the likes of us. Oh, up to this date, despite fueling and firing dozens of rockets, we haven’t blown anything up. (YET!)

This commercial secrecy is unforgivable and unethical. It is also criminally dangerous.

I, for one, would be just a tad nervous were I to be on board when that rocket fires up. Knowing what you now know, would you pay a couple of hundred thousand quid for a ticket to ride?

Big organizations such a NASA have demonstrated, on more than one occasion, that commercial consideration comes before life and limb. Here we go again.

Carolynne Campbell
Chief Designer
Laffin-gas Xperimental Hybrid Rocket Car Project

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04/08/08

08:30:24 am, by carolynne , 1150 words, 112 views
Categories: Day to day

Rocket Royalty on a Flying Visit

Sometimes getting things wrong can give wonderful results. When I first put the laffin-gas.com website together, I included a short ‘potted’ history of rocket cars. I wanted to give proper credit to those who had come before. It was full of inaccurate information, as the sources I had used were also full of inaccurate information. The result was lots of emails –some from true anoraks, some from nutters threatening retribution and some (very few), from people who actually knew what they were talking about. A few weeks ago one such message popped up: “Gary Gabelich didn’t own or build Blue Flame, he was a hired driver,” from Dick Keller.

Even I knew who Dick Keller was – he’s the man who built just about all of the big peroxide rockets and many of the cars they went in: X1, Pollution Packer, Blue Flame, Vanishing Point and many more! I replied, thanking him for getting in touch and putting us right. A correspondence followed on from that, with Dick giving little hints and tips and encouraging comments. Then Dick tells me that he’s coming to Manchester in late July, and perhaps we could meet up. I jumped at the chance. This man knows more about rockets and cars and aerodynamics and fluid dynamics and…. This was an opportunity I could not miss.

It turned out that Mr. Richard A. Keller III (RAK III !!) was competing in the European Masters track cycling championships at the Manchester Velodrome, representing Ireland, and he had a day off between races, and that he would like to come and see the car!

If Dick Keller was taking the time out to see our project, it was only good manners that I should take the time to see what he was up to on the cycling track. So, last Tuesday, I set off from Northants to go to the Manchester Velodrome and watch the man race. I arrived in time to see three very fit men on bicycles thrashing round the track, elbows and shoulders flying, in a knock-out to get to the semi-finals of the 70+ sprint race. The winner? Richard Keller of Ireland. I spent the afternoon watching great names of cycling giving it maximum welly around the track and very entertaining it was. I even got video of one of Dick’s races. Dick took time out for a quick lunch and we chatted about cycling as we munched on disgustingly healthy stuff, and made arrangements for the following day’s trip to see the car.

I met Dick for breakfast at his hotel and we set off for Northants. The drive down was amazing with Dick telling about Blue Flame, his other cars and all the various colourful, sometimes dodgy, characters from the early days of drag racing and the heyday of thrust cars. Sprinkled throughout the conversation was a litany of personal friends of Dick’s that was a Who’s-Who of the time: Chuck Suba, Art Arfons, Walt Arfons, Don Garlits, Craig Breedlove, Sammy Miller, Andy Green, Bert Ruttan… and through it all a self-effacing matter-of-fact demeanour – just a mad cyclist telling the tales of his adventures without ‘bigging anything up’. This guy had been right in the middle of all those amazing things we’ve only read about.

Hubby David introduced himself as we got through the door, on went the kettle as Dick looked out through the patio doors at the waiting beast. He was out the door before I could pour his cup of tea. It was a bit like waiting outside the Headmaster’s study as he inspected the car from one end to the other, muttering to himself as he went. I gave him a couple of minutes and we followed him out.

He took us through the car from front to back – and his entire initial interest was its safety features – no discussion of rocketry – just safety. This wasn’t entirely surprising as Dick has seen a few people die in rocket cars – all of them good friends of his.

First the steering column – was it designed to collapse? What kept it from spearing the driver? (Referred to as ‘Precious Cargo’). After a little further inspection and discussion the steering was given the ok. It went on - every detail that affected safety. In the end the headmaster’s instructions were to put in a much stronger blast shield, sort out a better inclinometer, modify the parachute mountings and put shrouds around the nozzle area. His reasoning in all cases couldn’t be faulted and it came from direct, sometimes fatal, experience. Keller’s will be Done!!

Only then did discussion turn to rocketry and fluid dynamics. Now we were going to get a critique from a guy who’d worked on Saturn and designed and built all the early H2O2 rocket motors for cars. We went through everything, nozzle sizing and design, volume to surface-area ratios, fuel delivery and shut-off capability, the bio-fuel concept and why four rockets instead of one big one. Having looked at the hardware, Dick took a look at testing videos. The verdict? She’ll do the 300mph once we’ve got the gas separation sorted! In the opinion of the man whose opinion really matters, we were not barking up the wrong tree and our development was close to fruition. What a relief. If Dick Keller had thought we were not going to make it, he would have said so, in the nicest possible way, of course, but there’s no bullshit to be had from him.

Then Dave Coleman of Quarter Mile High showed up with his cameras and we were able to record a discussion/interview. Can’t wait to see the result! Hopefully QMH will make an edited version available to the public as it will be quite an historic documentation of the views and experience of the most famous rocketeer of them all.

During the filming, David Rose and Fred Thomas also appeared and we were all able to chat and ask questions for another hour before it was time to get Dick back to Manchester and to his first love – thrashing bicycles to death!

We learned so much in such a short space of time and, I hope, found a new friend and collaborator. It’s not often you get to know someone who is head and shoulders above the rest in his field. It’s taken several days for it all to sink in and now we’ve got a load of work to do to comply with the Headmaster’s safety instructions. If you don’t listen to one who really knows, then you are truly an idiot.

Oh! The cycling! Richard Keller of Ireland’s final medal tally in the European Masters:
3 Silver and 1 Bronze medals out of four events participated in. Not bad for a seventy-year-old bloke!!

NOSTALGIA, CONUNDRUMS AND A GREAT WEEKEND

It’s been the normal practice to post a report in the week after a trip to the track. It’s taken longer this time because we were doing our best to solve a mystery. Every time we diagnose things at the track, we get home, look at the evidence and come to a different conclusion. We were all convinced we had developed an electrical gremlin and spent hours at the track trying to track it down. Glenn Stockton and I went over all the systems, testing everything early on Sunday morning and we did find a dodgy switch. Thinking that we had found the Gremlin, we got the car ready, took her to the start line and fire her up. Just like the two tests the day before, she blew out just as I opened the main throttles.

Back at the pit, three of us said ‘the only thing we’ve changed is the angle off the bottles’.
None of us really thought that it was the problem but Glenn suggested looking into putting bladders in. It turns out that the bottle angle was the problem – no gremlin!!

So it’s a problem: Put the bottles back upright and she’ll launch fine but there’ll be a problem with nitrogen blowing through as she starts to pull G. Leave them angled and she’ll blow out on the line. It’s got to be bladders. We’ve contacted a couple of firms who deal in this stuff and custom made bladders are on the way. Bladders enable us to completely separate the N2 from the liquid N20, allowing the clean delivery of Nitrous at any bottle angle at under any Range of G force. The question is – can we make them hold up at the operating pressures we have to use? We think we can – only testing will show for sure.

We’ve got to get them installed and do some testing before going back to the track for a full on-track test.

Was the weekend a bad one? No. The whole team was very encouraged by the exercise. We’d been able to be part of the NSRA’s super event, with a very knowledgeable and supportive crowd. We’d got three tests in, in one weekend, which was a first and very, very productive in terms of learning things quickly. The team had turned the car around and got her ready each time with no sweat and proved that we could make start times over a weekend. Yes we burned a lot of nitrous and a lot of money, but it was probably the best outing yet.

When she’s ready, we’ll be back!!

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20/06/08

08:30:06 am, by carolynne , 285 words, 86 views
Categories: Day to day

150 LBS OF NITROUS SHOULD DO THE TRICK!

With 150lbs of Nitrous, eight rockets, spare pyros and a full crew, laffin-gas is going for it at the NSRA Nostalgia Nationals at Shakespeare County Raceway on the weekend of 28th/29th June.

The season, so far, has been plagued by rain, snow, wind and events beyond the team’s control that have, so far, stymied our attempts to get in a full-pass on full power. We are now making sacrifices to the Weather Fairies (they’re real, you know) in hopes of clear weather and a fair chance at getting her down the track.

The people at the NSRA (National Street Rod Association) have kindly invited us to their rather special event and have even allowed and exception to their ‘No Rear-Engined Cars’ rule, (our rockets are in the back of the car!!).

About twenty five years ago, David was working in a foundry and he made some castings of on old NSRA plaque. We found three of them during a clear-out of David’s workshop and two have been donated to the NSRA. We expect one may appear as the centerpiece of a special Twentieth Anniversary Trophy to be presented at the event. Amazing how these things happen, isn’t it?

We’ve made a few modifications to the car, to make the controls a little more forgiving and to ensure a reliable supply of gas to the air-ram that gets the burn going. Now it’s really got to be show-time!

How fast will she go? We really don’t know. But, if the way she went off the line at the first meeting of the year is anything to go by, a full pass at full power should be pretty quick!

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06/05/08

07:41:43 am, by carolynne , 432 words, 87 views
Categories: Day to day

NO GO ON THE BANK HOLIDAY

I must be a prophet! In my last press release I ended with a cautionary note:

“This is drag racing and even the best cars don’t go every time and the weather can always interfere.”

What a spot-on forecast.

We arrived on Friday for Set-up to be ready for a run on Saturday. We were scheduled to run at the end of the day’s qualifying sessions. All the crew were there and we were ready to go. Just as we were about to put the gasses into the car, a racer put his car through the starting lights and went into the barrier. That closed the track for the rest of the day. The Saturday run was off!

Sunday – it rained. They dried the track – then it rained. And so-on and so-on. Later in the day the truck carrying the track drier did a graceful pirouette and crashed into the guard-rail wrecking the track drier. Sundays run was off!

David and I returned home for a decent night’s sleep in our own bed, and headed back to the Raceway early on Monday morning. The weather was fine leaving home, but as we neared Shakespeare, the heavens opened.

We sat around all morning. The track wasn’t dry and ready until 2:00pm. Ahead of us were a couple of hundred racers, all as desperate as us to get a run in. The organisers were franticly attempting to fit a full day’s racing into the next four hours and, frankly, it all got a bit shambolic. We need an hour’s notice to gas-up and ready the car. The notice didn’t come. When we finally got a go-ahead, we gassed up and ended up waiting for an hour in the pairing lane. The car is not designed to sit and wait once it is fueled.

We went to the line, fired the pyros, and the pilots did not come on. We’d lost pressure in the air system that operates the pilot valves. No run! And no time to return to the pit, replace the pyros (which we can do in about 40mins) and try again. Racing was over.

We were gutted, but then so were a couple of hundred other racers, including guys who’d come all the way from Sweden and accomplished nothing. There were many grim faces in the pits.

Ah well! That’s Drag Racing!!

We’ll be back out in a couple weeks at a less frenetic event, hopefully with the weather Gods smiling upon us, and we’ll get her down the track.

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29/04/08

07:16:22 am, by carolynne , 372 words, 72 views
Categories: Day to day

READY FOR BLAST-OFF AT SPRINGSPEED

We’re off to Shakespeare County Raceway this coming weekend for a full-fuel burn down the track.

The first track test of the year was inhibited by lousy weather, (sleety with a strong cross-wind) so we only attempted a short burn. The car went off very strongly, but blew though the Nitrous sooner than we had anticipated for the amount of fuel we’d put in the car.

The last two weeks have been very, very busy while we tore the fuel system apart, re-mounted all the gas cylinders at an angle of 40deg and re-jigged all the high-pressure hoses to fit the new configuration. The result is now pressure-tested and working fine and the car looks much better with a lower and neater profile behind the cockpit. More importantly the set-up now allows for forward ‘G’ much better and will make much better use of the Nitrous.

Rockets are now sitting in the oiling rig, soaking up a few litres of bio-fuel and there are loads of last-minute jobs still to do.

‘Springspeed’ is the first major event of the year at Shakespeare with hundreds of racers competing in everything from frightening ‘Fuel Altereds’ and heavy American V8 monsters to Lightening fast drag-bikes. So for us, there is real pressure to perform and perform well.

After successful winter testing, and a very positive first outing, our confidence is fairly high, but this is drag-racing and it’s a very unpredictable sport. Even the best cars don’t go every time and the weather can always interfere, so we will need a bit of luck for everything to go well.

Knut Soderquist (One of the most successful Top-Fuel owners, who helped Carolynne in the early days building the chassis) paid us a visit last week. He is very excited about the car. “One good run is all you need now” he told us, “There are people from Lithuania to Thailand who want to book you car.” If anyone in drag-racing can deliver international bookings, it’s Knut. So no pressure there, then!

We hope to see all our supporters at the track – not just to see us, but to expose them to a fantastic weekend of top quality non-stop action at Shakespeare.

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15/04/08

05:15:19 pm, by carolynne , 274 words, 69 views
Categories: Day to day

AND NOW FOR THE TECHIE BIT!

We were surprised by how quickly the Nitrogen blew through the N2O on the last run.
David Rose pointed out the effect of the forward ‘G’ on the level of the liquid surface in the bottles. Doh!!

Back home and digging out the ‘O’ level physics, I drew a few force diagrams. At 1G the surface slopes to 45deg, at 2G it slopes to 72.5 deg.

No wonder the Nitrogen pushed past so quickly! Now we’re modifying the car and angling the bottles in the chassis. The ideal angle would be 27.5deg from horizontal. In order to accomplish that, we would have to lengthen that area of the chassis. Not too big a job on its own, but when we consider the wiring, controls, parachute cables and all the other stuff involved, we’ve decided to compromise.

The bottles are being mounted at 40deg. from the horizontal. This means that, at 2G, the surface of the liquid will slope across the bottle at 32.5deg. This we can live with by compensating with an over-fill of the N2O.

The result should give us a much longer full-power burn, using an acceptable quantity of Nitrous. We aren’t happy with the idea of leaving several pounds of nitrous behind and then having to vent it to atmosphere. N2O is a nasty greenhouse gas and venting several pounds after every run is not really acceptable. So we’re devising a recovery system to return unused nitrous to storage and minimize the need to vent.

Right now, the car is in pieces while we work on the modifications. Ah the joys of asn experimental car!

A SNOW DODGING START

Saturday April 5th 2008, Shakespeare County Raceway.

It was sleeting as we arrived in the transporter and blowing a strong and very cold north wind. The rest of the team was already there and we got the car out, covered her up, climbed back into the bus, closed all the doors and put the heater on.

It was already obvious that there would be no fast run today. There’s a break in the weather, so Rachel and Will took off the top panels and hub-caps ready for Glenn Stockton to give her his usual thorough scrutineering job. There were a few new bits and modifications done over the off-season and I went over everything with Glenn. As usual, he picked up a couple of small items that needed rectification. You don’t get anything dodgy past HIM!

Then the rain/sleet returned. Conversation is the transporter turned to “Do we run, don’t we run.” The unanimous decision was, “we’ve come this far, let’s at least get her on the track, if we can, and do a launch to prove the ignition in track conditions.”

Another break in the weather, the sun appears and we can see the track crew working their socks off trying to get the track ready. Susie and David Rose put a small (for us) dose of nitrous in the car, while Rachel, Susie and Will went through the safety check-list.

Once the gas is in the car, we only have a couple of hours before the pressures start to drop, so now we really need the weather to hold up. Here comes the rain… a heavy shower sends us back into the old race-bus.

It takes an hour before the track re-opens and we decide to go for it right away. As we push the car into the fire-up lane, the P.A. announces “Treaded tyres only on the track”. That tells us that the track conditions are not suitable for a high speed run. A launch would be safe enough, though.

The crew pushes me to the line, final radio check, and Dave Rose gives me the thumbs-up.

Fred comes on the radio, car switched on and, on Fred’s commands, I initiate the ignition sequence. “Pilots, Pilots, Pilots” comes over the radio. I turn the switch and feel her light up well. “Go,Go,Go,” Throttle full forward and she leaves strongly, by sixty feet I can feel the power dropping as the Nitrogen starts to push through the small amount of Nitrous in the bottles, I let her run to half track, and shut her down, coasting through to the end.

She’d done exactly we expected. There was no damage to any of the rockets or structures in the car and absolutely no mess on the track. I was a bit crestfallen that I hadn’t been able to give her a full blast, but everyone else was very happy. We’d got a good launch, proved the car in race conditions and we hadn’t blotted our copybook.

As we got back to the pits, down came the weather again. It turns out that we’d taken our only opportunity of the weekend as Santa Pod-like snow descended on Sunday. That was lucky!

We’re talking with Jerry Cookson at Shakespeare about the date of the next run, when, weather permitting, we’ll fill her up to the brim and really have a go.

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27/02/08

11:30:50 am, by carolynne , 278 words, 83 views
Categories: Day to day

Southern Manufacturing and FIRST RUN OF THE YEAR

Firstly, many, many thanks to Phil Valentine, Adrian Jones and all the folks at Southern Manufacturing Show for making us so welcome and being so helpful. They even removed a wall so we could get the car into the hall! We had a fantastic space, which became the 'village green' for the show.

Reaction to the car and to our technology was superb. Being amongst so much superior British engineering with our home-grown project, and to be taken so seriously was a real compliment.

Was it worth it? Absolutely! I would recommend this kind of show to other racers. Being the only car really helped us to stand out and get our message across. Sometimes we racers get too caught up in our own little world and don't expand our horizons. The Autosport show is fine - but one gets lost amongst all the other racers and cars.

You also get exposed to a base of potential sponsors that otherwise you would never meet. Lots of firms have offered parts and services to help the project and with the build of the new car.

FIRST RUN!!

Our first chance to test the new pilot ingnition set-up, that performed so well in tethered testing, will be on 5th and 6th April at good old Shakespeare Raceway.

We're not sure yet if the run will be on Saturday or Sunday. It depends on both the weather and the team's other commitments.

We'll be going for a full burn of all four bio-fuel rockets and a good parachute test.

The car is ready to show some real performance this year and all the action will be at Shakespeare so don't miss it!

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18/12/07

03:33:53 pm, by carolynne , 118 words, 107 views
Categories: Day to day

Southern Manufacturing Exhibition 6/7 FEB 2008

The car and the team are going to be on show at this expo at Farnborough in February. It's mid-week show, so we're giving plenty of advanced warning!! you can find all you need to know at www.industry.co.uk .

We're bringing on board some new Development Partners (to be announced as soon as deals are done and dusted.

The guts of the NEW CAR - laffin-gas2 will also be on show. The next generation car will be a big leap forward from the present machine and will be built in the next few months, hopefully almost entirely out of composite materials!!

Weather, and Authorities, permitting; well be doing a run on the fantastic Farnborough runway!!

Stay posted.

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05/11/07

01:44:47 pm, by carolynne , 741 words, 314 views
Categories: Day to day

Tethered Test 03-1107

Having experienced ‘blow-out’ of rockets in the car when opening the main throttles, we examined the differences between the in-car systems and the systems we use in static-rig testing of single rockets.

The car contains safety systems to ensure responsible operation on the track, which are unnecessary in static testing, so these were examined in detail. The solenoid valves for instant shutdown had been used in the test-rig, although not every time, and from going over our records, we found that the test rig performed reliably with or without the solenoid valve. Other safety systems did not directly impact on the actual rocket systems in the car, but gave the driver and crew finer control of events. This meant that we could discount the safety systems as a cause of the blow-outs.

Further examination of the differences between what we were doing in rig-testing and in the car, showed a major difference in the pilot ignition system. In the rig, we use a small ball-valve drawing from the main nitrous supply, just prior to the main throttle. In the car we have been using a supply from a single bottle and distributing the N2O to the four rockets by means of a manifold. We had previously observed that, though the manifold is designed for equal distribution, it was not feeding pilot N2O equally to all four rockets. On one run, earlier in the year, the car had gone on two full burning rockets and main ignition was not achieved on all four. The normal solution for this, in hydraulic systems is to use flow-controllers to balance the system. We had put flow controllers on all four outputs from the manifold and achieved an even distribution. It was only since we had installed these flow-controllers that the blow-outs appeared.

The manifold and flow-controllers were identified as the only critical difference between the test-rig and the in-car systems. We decided to reproduce the test-rig in the car, meaning, four discrete N2O systems, each with one pilot valve and one main throttle valve feeding from one bottle to one rocket.

We had arranged to perform a static tethered test of the new systems in the car, in a reproduction of start-line conditions on the previous Wednesday. Unfortunately, despite having ordered the N2O well ahead of time, our supplier informed us on the day of the test, that he could not supply the gas. We were unable to perform the test that week. Steve, at Motorshack, came to the rescue by supplying the gas at short notice, but the static test was not going to get done that week.

We decided to take the car to Shakespeare Raceway that weekend and test the new systems at the track. Unfortunately bad weather stopped us for the very first time.

Today we performed the tethered test down at the farm in Grendon. Carolynne suited up and got into the car which was restrained by heavy chains to the rear and a balancing tether to the front. We simulated the actual start-line procedures using radio commands and all the usual set-up and fuelling methods. The only difference between an actual run and this test was the tethering of the car.

All four rockets ignited strongly on the pilot gas and Carolynne was instructed to throttle up. All four rockets switched over to main throttles and burned at full power for a little over six seconds.

After the firing, the car was examined for any structural effect. All four rockets were intact with no sign of leakage and all four graphite nozzles were also intact. The structure holding the rockets in the car was also entirely intact, with no measurable distortion to end-plates, cross-braces or chassis mounting points, thus demonstrating that the structure of the car is well capable of handling the effects of four rockets running strongly.

As has been demonstrated by other designers, it is not difficult to get rockets to fire in a car, but doing it with adequate safety systems and with the engineering standards required to maintain structural integrity requires quite advanced and careful engineering design and execution. We are happy that we have now demonstrated that this car is both safe for track operation, and capable of reliable high-speed performance.

We now have a working and reliable four-rocket hybrid rocket car.

Fuel used:
8lbs N2O per rocket.
800psi N2 in the push system.
Cardboard liners soaked 75% with Bio-fuel.

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04/09/07

07:11:57 am, by carolynne , 428 words, 117 views
Categories: Day to day

Development and testing

After every track test, the whole team stops off at the pub just up the road from Shakey and we go over what happened. After the last test (where we lit four rockets but they burned with very low energy), we all decided to park the car until the fuel problems were solved.

I'd discussed the problem of the sheer unpredictability of the cardboard fuel grain with Glenn (safety supremo at Shakey). I'd suggested going back to plastic liners. Glenn was against the idea and he had a good point. The plastic goes well but it's dirty, smokey and leaves little strings of plastic all over the track. So the next idea was to try soaking the cardboard in cooking oil. (Bio-Fuel!)

We knew that this would be powerful, but it was an unknown quantity. It meant a whole series of single-rocket static tests (expensive!!) to get on top of the new fuel combination. The last report tells of our first test. If we'd used that set-up, we would probably have blown the back off the car!!. So we've done a series of tests varying the nitrous flow and the amount of bio-fuel we put in. Now we've got manageable rockets that will be safe in the car and they're very tuneable, with a thrust range of between 1,000lbs and 2,000lbs per tube.

We can now go as fast (or as slow) as we wish.

Glenn had also expressed concers about the very narrow rear track. If we had a blow-out, or, for any other reason, the car got seriously sideways it would probably roll over. He was right and we agreed with him. So while we've been developing the new rocket, we've widened the rear track by over a foot and added super hard shock absorbers. This means the car is much more stable laterally, we can run on less-than-perfect surfaces and are no longer limited to running purely on good drag-strips.

Now we've got our fingers crossed that our old race transporter will pass its MOT, 'cos we can't get the car and all the kit to the track without her!

Next time out. we'll be taking eight rockets. We'll be going for two runs at the event. Rockets can be swapped out very quickly, though they are a lot of work to build up. So we're going to get them all fueled and ready well ahead of time and just to a simple swap-over at the track.

You can see a vid of a static test (a really good one!!) one www.myspace.com/laffingasrocket.

Bio fuel is awesome

The last run showed us the disadvantages of cardboard as a fuel-grain. The high-density tubes we have wound for us are surprisingly strong when packed very tightly into the aluminium casing and the stuff burns fairly well. In the run before last, when we only properly lit two rockets, we made the 1/8th mile in 4.6 secs. There is one big drawback and that is the susceptibility to damp conditions. We’ve known for a long time that the cardboard grows and shrinks very noticeably depending on how it’s been stored. Even in apparently dry conditions like the workshop, tubes will not want to fit inside one another and the cut length will vary. We’ve resorted to keeping the tubes we want to use next in the living room next to the radiator. These tubes slide together nicely and retain their cut length. However, they pick up damp very quickly, even when inside apparently sealed assembled rockets. One day is enough to seriously affect the performance.

Other rocketeers have commented that the presence of moisture shouldn’t make a difference and the resulting steam should add to the rocket pressure. This doesn’t seem to be the case. Firstly, the damp prevents the rockets from getting up to temperature, making the ‘steam-effect’ impossible to achieve. Secondly, the rocket pressure is self regulating as the higher the internal pressure, the slower the flow of input gas. If the rocket pressure equals the gas pressure, no gas can flow. Pressure, while important, is not the only factor in performance. The more important factor is energy. A non-combustible such as water can only detract from energy production. It is the energy in the rocket that creates the internal shockwaves and generates the hypersonic flow at the nozzle, the higher the exhaust velocity, the higher the thrust.

We have now constructed and twice tested a rocket with a new fuel grain set-up. The rockets were loaded with concentric cardboard tubes as before and then filled with cooking oil and allowed to stand for 48 hours. We had already experimented with cardboard and oil to see how well the oil soaked in. It soaked thoroughly. We had also turned a blow-torch onto a soaked piece of cardboard and observed the oil boiling to the surface, so we were reasonably confident that we would have a ‘wick-effect’ inside the rocket. On the first test, the initiating firework detonated, rather than burned, and ignition failed. As we were set up with gas in the fuel rig, we ignited the rocket by putting a firework in from the nozzle end. This is not a satisfactory arrangement as it was reasonable to expect the ignition only to be partial. The rocket did light and went on to main input jet, only for us to run out of fuel in the rig.

Two days ago, we repeated the experiment. This time we did achieve full ignition and the rocket ran on full power for 6.5 secs. It was three or four times as loud as any rocket we had previously tested. The diamond shockwaves in the jet were more than double in size and there were more of them. There is no doubt (though we lack the measuring equipment to accurately confirm this) that the rocket was two to three times more powerful than anything we had previously tested. This indicates a thrust of 2-3,000lbs.

On inspection of the test rig and rocket, in situ, it was discovered that the test-rig endplates (10mm steel) were both severely bowed, and that the rocket end-caps had both moved by 5mm. In spite of this movement, the sealing system had held up as there was no blow-by and no damage to the rocket casing or end-caps. On dismantling the test rig, we discovered that all the input connections had been vibrated loose and the rocket nozzle, whilst still retained in its outer holder, had fractured.
The cause of all this damage could not have been internal pressure, as the input gas pressures has been kept to our test standard. The bowed endplates must, therefore, be the result of the intensity of the internal shockwaves having a ‘hammer effect’ on the ends on the rocket.

This rocket was more powerful than we could use in a set of four in the car. 8-12,000lbs of thrust in an 850lb car is too much for operation on a quarter mile strip.
We can, however, reduce the rate of input of N2O by various means and reduce power to a more useful and manageable level.

The implications of these experiments are that we can now overcome the problem of damp, as an oil soaked rocket will not be susceptible, and that we can produce as much power as we could possibly require.

We have given some thought to external damping devices to absorb the hammer effect on the rocket ends. Further experiments are now needed to tune the gas flow and to test shock-absorbers.

This rocket set-up has the potential (when constructed with superior materials) to be extremely powerful and controllable. I believe it could have significant military and aviation applications.

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30/05/07

07:05:42 am, by carolynne , 248 words, 200 views
Categories: Day to day

Four Rockets LIT, but No Power!

There's a new vid on youtube.com/laffingastv. You can see the last run there. It was disappointing in that we didn't get the power out of the rockets, but pleasing because we've finally cracked the problem of lighting all four reliably. Why such low power? We took the rockets apart and found considerable moisture in the cardboard fuel grain. We'd encountered this before and proviously dealt with it by keeping the rockets indoors, in the central heating, until the last moment. This time we'd built them well in advance and put them in the car, relying on sealing the nozzles and inserting some 'Timbilt' boot dryers (fabric tubes full of silica gell). Mistake!! The boot dryers are great at drying wet biking boots (highly recomended) but the gell was not able to overcome the moisture hungry nature of the cardboard. Result: very cold burn, no real pressure in the rockets and running out of fuel at half track. If you look at the previous run, we actually went a lot quicker on two rockets! You could see the diamond shock-waves in the exhaust jet on that run... no diamonds this time. This can only be owned up to as a mistake. Back to keeping the rockets in the house for the next run!!
We've also been experimenting with a much more powerful fuel grain... cooking oil! We've got one more static test to do to ensure the rockets can take the pressure, then we'll publish the results.

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19/05/07

06:33:16 am, by carolynne , 124 words, 116 views
Categories: Day to day

a.m. Saturday May 19th

We're getting ready to load up the transporter and take the car over to Shakey ready for tomorrow's run. We want to get back in time to watch the cup final, so it's a very early start. We've done as much as we can to ensure a full four-rocket burn... but as you all know, every time this car goes to the track it's an adventure into the unknown!!
We got another lovely email from Ky Michaelson, complimenting us on our 'good work' and wishing us luck. It means a lot coming from Ky. (For those who don't know, Ky built the Conklin Comet rocket car which is still the fastest thing ever in a quarter mile.)
So fingers crossed...the adventure continues
Carolynne

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09/05/07

10:41:55 am, by carolynne , 98 words, 164 views
Categories: Day to day

Full Pass on the 19/20th May

We'll be back At good old Shakey on the 19th and 20th, going for a full pass on four rockets. We're pretty confident it will all happen properly, but, as we're still testing - you never know!! Lots of new stuff has been done to get more reliable ignition with bigger better fireworks and flow balancing for the start-up. There'll be a film crew there to catch the action. You can see footage of the last run and of Carolynne explaining some bits about the car on youtube.com/laffingastv.
Please come along and support us!!
See you there!

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08/04/07

05:07:28 pm, by carolynne , 62 words, 129 views
Categories: Day to day

Contact Info

Unfortunately, we've had to make it more difficult to 'leave a comment' on this blog. After a series of trojan horses and sheer vandalistic attacks (sad isn't it?), access has been restricted. We still want to hear from you 'tho! So, if you want to leave a comment, PLEASE SEND IT TO OUR CONTACT INFO ON THE MAIN WEBSITE AND WE'LL RESPOND!!

Here wo go again!!

Having spent the off-season re-designing, re-engineering and re-wiring the car, we found ourselves at Shakespeare for the first test of the year. We were hoping for a quiet little testing day…so, I think, were most of the large number of teams out for their start-of-the-year shakedown. So it was busy and we were testing in public, again. (bugger!)

An all-new throttle control system has been installed which gives us full throttle control, (not easy with rockets!!) we’d gone up to 24 volt systems with capacitor discharge to fire the pyros (to avoid the voltage drops that plagued us last year) and generally applied all that we’d learned during last season. So there shouldn’t be any unknowns, right? Wrong! We had ordered the same fireworks as last year, opened the box and out came something completely different. They were noticeably smaller. We checked and double-checked and were assured they were the same. Oh no they weren’t, the manufacturer had changed them and our supplier hadn’t been informed.
It was now too late to go on the hunt for a more powerful substitute. So a new unknown was thrown in at the very last moment. AH the joys of Rocket Science!

The team is now a well-oiled machine, and the car was made ready and gassed up with no input from me. Glenn Stockton came along for his usual thorough scrutineering job and all the new systems were explained and demonstrated.

Serious butterflies in the old tummy as I walked down to the start, not because I was particularly worried about the drive, but very worried about the effectiveness of the pyros. A failure now would really hurt the project. They did struggle, only lighting three rockets. She still went like stink. So when we get four lit it should be an interesting ride.

I shut off just past halfway, as I am still learning about the car at speed and we promised to take it carefully. She really pushed hard, and the further and faster she goes the more she accelerates… quite the opposite of a traction car.

So a good, mostly successful, start to the year and, of course, we were delighted.

Now we’re working on some bigger and hotter pyros, the last link in the chain. Next time out? Hopefully we’ll get a full pass on four rockets. And that should be a very quick run!

After three very hard years, laffin-gas is showing what she can do… and it’s going to be a great show.

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15/03/07

10:04:02 am, by carolynne , 154 words, 114 views
Categories: Day to day

Laffin Gas supports HEADWAY

A note to let you all know that we will be supporting 'Headway', (the brain injuries trust) this year. My husband David suffered quite a bit of damage as a result of his many brain ops to remove a tumour. He attends the local Headway in Irthlingborough twice a week and it has been a fantastic help to us both. Recently featured in the BBC drama about head injury, Headway is a fantastic organisation that does wonders for people with life-changing injuries. The folks who attend are Members, not clients, and they are treated with great respect. As a carer, myself, the respite and knowledge I have gained from Headway has been vital.
So we'll we displaying the Headway logo on the car, and making the car available for Headway fund raising events during the year. I'm sure everyone involved in our sport will be happy to help us to help Headway.
cheers
Carolynne

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06/03/07

10:18:56 am, by carolynne , 138 words, 101 views
Categories: Day to day

"It's bin a long cold lonely winter".... and a busy one!
We've spent the time applying all the things we learned from last year's testing. A new throttle system now allows us to have full throttle control of the car and allows us to stage properly. All the control systems have been revised, replaced, upgraded and re-wired by Dave Rose and our new team member Andy Monk (see him in the 'people' section). So we're pretty sure that reliability will not be a problem this year and we can start to get some serious speeds out of the beast!
Geoff Martin and Buddie came round and re-certified the chassis, so we're SFI'd once more. A couple of private static tests are scheduled for March and we hope to be at Shakespeare on April 1st for a decent run.

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04/11/06

07:58:25 am, by carolynne , 128 words, 256 views
Categories: Day to day

Ky Michaelson gets in touch!

We've been lucky enough to get some emails from Ky Michaelson, the builder of the 'Conklin Comet', a rocket dragster in which Kitty O'Neil ran a qurter mile in 3.235 secs with a speed of 412mph. This was at the El Mirage airforce base in the Mojave desert. It's not on a dragstrip, true, but it is the fastest ever quarter mile... and done by a female.
Ky says " I've been building hybrid rockets since 1995 and I believe you are on the right track. You might even break Kitty's record". That's some record and certainly can't be attempted on a drag-strip. What a generous gentleman Ky is!
His website can be found a www.the-rocketman.com. I think this guys knows more about rockets than anybody I've come across.

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31/10/06

08:44:51 am, by carolynne , 366 words, 202 views
Categories: Day to day

Last Saturday we had more adventures! The difficulty with rockets is there's very little chance of a quick fix and another go. Once the fireworks in the heart of the rockets have gone off, they have to be replaced either with a second set of ready-to-go rockets or by opening them up, replacing the fireworks and rebuilding the rockets. All pretty much impossible when you're only out for a one-day test. With a less exotic car..it's often back to the pits for a quick fix and off you go again. With rockets everything simply has to work all at once.
The first problem we had was the failure of a very expensive special battery that powers most of the ignition systems. We backed the car off the line, nicked the battery out of Susie's little honda and checked all was working. Then (because the fireworks hadn't been lit and the gas had not been released (lucky!!) we had another go. This time she lit on the pilot gas. I pushed the throttle forward and the truly hefty throttle cable parted company from the throttle plate. I couldn't release the main gas. Attempt over!
Yes we were disappointed. But again we learned something. Each time we test we eliminate possible failures and, so far, we have never repeated an error. so it was all useful stuff!
Now the season is over and the car is being stripped down and fully reconditioned for next year.
I want to thank all the folks who've worked so hard. Firstly my brilliant team, David, David, Rachel, Susie and Vinnie, who have all kept motivated and positive and whose teamwork and good spirits have been a joy to be around. Thanks also to my dear brother Bob, who's helped with image, racing supplies and all kinds of 'connections' from his formula-one background.
Also a special 'THANK YOU' must go to all the people at Shakespeare County Raceway, for both their professional and thorough attention to safety and their generous support of our efforts. And thanks to all our fans!
The car may be going on display at some engineering and motorsport shows over winter. We'll keep you all posted.
cheers
Carolynne

'ere we go

The weather forecast has improved and all looks good for a run today (Saturday). It's a long drive in the race bus to get to Shakespeare from here. We've cycled and tested, gone over checklists and we're going for a good full throttle launch this afternoon. Staging is difficult for us as we have a long ignition sequence which can only just be made to fit in the 15 seconds that the lights allow. Even so we're going to try for a properly recorded run this time.

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26/10/06

08:40:23 am, by carolynne , 54 words, 136 views
Categories: Day to day

weather for Saturday's run

We've been watching the weather forecasts. As of yesterday it was 'showers Saturday, fine Sunday'. As of this morning it has changed to 'fine Saturday'. We're loading up the transporter and installing the rockets... but if it changes back to 'showers Sat' I'm afraid the test will be cancelled.
fingers crossed! Watch this space.

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21/10/06

09:18:24 am, by carolynne , 296 words, 122 views
Categories: Day to day

re-building the Rockets

Every time we do anything with this car, we learn something new. This time we learned that if you let the rockets sit undisturbed for a couple of weeks (after they've been run) they don't want to come apart!!
When a rocket tube has been used, it has to be stripped down to replace the fuel grains (cardboard tubes!!), the internal seals, and the firework that ignites the whole thing. This is when we get the chance to see how the construction has held up. There is always the odd little burn-through at the first line of defence in the seals, but, as usual, the second and third seal surfaces were intact. We also slice a fuel grain along its length to see the burn pattern. You get very little for the first 20cm, then very even along the rest of the length. Even the ignition wiring is burnt away and has to be replaced.
We normally strip the rockets down within a day or so of running them, but life had taken over and they'd sat for two weeks. Getting the end-caps off took a lot more effort than usual. Usually we can just drift the liners out, this time we had to set up a rig to winch them out of the ally tubes. Then we discovered that the same rig is ideal for installing the new liners...they went in tight and smooth. It's vital that the cardboard fits tightly to the outer case, or the gas pressure in the rocket will split it..and nitrous just loves burning ally!!
Anyway the rockets are built and sitting in the front room to keep the damp air away from them.
If any-one is interested in having a go at making rockets...get in touch...

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19/10/06

01:30:08 pm, by carolynne , 39 words, 1828 views
Categories: Day to day

Many many thanks must go to Matthew Augier of DPS for his great work on our website. The service has been friendly, quick and accurate. Any other racers..event organisers... traders..might want his link:
www.dps.uk.com

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12:16:25 pm, by carolynne , 72 words, 222 views
Categories: Day to day

Halloween run

Saturday the 28th of October will be our first full throttle test at Shakespeare raceway..
If you've got a little person with you, we'll try to give you a chance to get a pic of him/her in the car! (Depending on how busy the pit is!!)
There'll be a fireworks display, a huge bonfire, and lota of other great cars showing off. Check it all out at:
www.halloweenshowdown.co.uk/