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The Bloodhound Project 23. FROM COLD WAR TO CAR

23. FROM COLD WAR TO CAR

Monday, 18 October, 2010

If you seriously intend to propel a car – such a crudity as an actual four-wheeled car – to Mach 1.4, whilst also wishing it to remain in contact with the surface of the planet at all times… why, guess what?

You are not a normal person.

At first glance you might be an incurable optimist – but if you exhibit symptoms of same, the BLOODHOUND team will politely say; “Thank you for coming in. Please close the door on your way out. Have a nice day”.

Optimists – no.

Adventurers – yes. Very, very high-technology adventurers. Capable of summoning all the latest weapons of science and engineering. Every aspect must be very much more advanced aerodynamically than anything which has ever gone before. It must be very much lighter than its predecessor, ThrustSSC. And the engines must be much more powerful than of yore. Everything about it must be new.

Well, anyway, most of it…

I’ll come back to that.

All the systems in BLOODHOUND are awesome. And all the systems in BLOODHOUND fall into one of three categories in my personal lexicon.

Category One is those areas of which I understand not one iota. This category is depressingly bulky, including as it does the electronics, telemetry, and Computational Fluid Dynamics (CFD). Oh, I know what they’re aiming to achieve; but I have only the haziest notion of how they are achieving it. I have this mental vision of the electronic folk waiting until everyone else has gone off to the pub and then donning Wizards’ hats and sitting around a seething cauldron stirring computer chips, plasma do-dangles, and for all I know a few eyes of toads and some calcified bat’s droppings. I do not mention this to the genii involved lest they give me that gentle smile reserved for the village idiot.

Category Two is those bits I understand reasonably well – the jet engine, cockpit ergonomics, human factors with relation to G, dynamic and aerodynamic stability, where to locate the ashtray, etc.

And Category Three is certain arcane elements which might appear easy enough to grasp in the first place, but seem to sort of grow in complexity the more you look into them.

Like the rocket. In fact especially like the rocket. And its associated systems.

From stand-off nuclear bomb to global peace mission: BLOODHOUND's rocket fuel pump, developed from the Blue Steel missile

One of which systems is now being carefully placed on the table in this conference room by Daniel Jubb, the rocket man. Its shape – the system, not Daniel – is slightly reminiscent of an ammonite fossil. It is not big – maybe 18 inches (45 cm) in diameter. It is not heavy. It weighs 51 lbs (23 kg) so even Daniel – who is slightly built, most of his body-mass having gone into his brain – can carry it without apoplexy. Conor La Grue, who is slightly built by King Kong standards, could probably tuck it under one arm and amble off to John O’Groats with it.

This is the pump for the rocket fuel, or rather oxidant. The High Test Peroxide (HTP) pump. Sitting right here on the table and doing its best to look innocuous and much like any other centrifugal turbo-pump…

 

Not like any other pump

It is not like any other centrifugal pump. It is not like practically any other pump in the world. And, although new within the meaning of the act, it in fact has a rather black 50-year history. No – I’ll re-phrase that. It does not so much have a black history as a sadly hideous history.

We’ll come back to that, too.

All rockets are remarkable. And of all rockets, the Falcon hybrid (solid fuel and liquid oxidant) for BLOODHOUND is possibly the most remarkable of all for decades. (see Of rockets and thinking, From Outside the Box Jan ’09). The Falcon is a one-off. There are much bigger liquid-fuelled rockets used for space shuttles and ICBM’s and the like, and much smaller solid-fuel ones used for missile weaponry. But in this application…?

In this application the Falcon is unique. By space-launch standards it is small – but by any other yardstick it is HUGE. The largest hybrid rocket ever created in Britain, and probably in all of Europe. Rockets have been used before on surface vehicles – especially Land Speed Record cars – but nothing, nothing ever, on this scale. This is by far, far and away the most powerful rocket ever to be used to power a land runner. On a scale of one to ten it is a bit like bolting a Formula One engine into your lawnmower and then being surprised when it hacks off a molehill and comes up with a soil sample from Western Australia. Even now, after two years of association with BLOODHOUND, I find it difficult to get my head around the sheer power of this rocket.

The Eurofighter EJ200 engine, possibly the most efficient jet in the world in terms of weight / size / thrust, produces 20,000 lb of thrust on full re-heat. The Falcon rocket will say ‘Hah!’ to that and produce 27,500 lbs of thrust. Making the total power of BLOODHOUND 47,500 lbs of thrust.

Let me put this into perspective. Let me remind you of one of the most successful airliners in the world, the Boeing 737. There are more than 6,000 Boeing 737’s flying today, with more variants than you can shake a stick at. Taking an average, they have an MTOW (Maximum Take-Off Weight) of 68 tonnes, and carry about 150 people at a cruise speed of Mach 0.74.

BLOODHOUND has slightly more power than the average Boeing 737.

The bald words don’t seem to convey this. Allow me to try again. Here we have a land-born car with the power of a Boeing 737 but less than a tenth of the weight. Carrying one man.

And aiming to nearly double the 737’s cruise speed. And doing it on the ground.

This is the requirement for getting to Mach 1.4 in a car. This is the tax which is levied to overcome supersonic drag at ground level.

Which brings us back to the rocket – the vital rocket. The rocket designed by Daniel Jubb and his Falcon Project team specifically for BLOODHOUND.

 

A Thrumblefugdit and the need to know…

Except that the Falcon team didn’t know it was for BLOODHOUND until just before BLOODHOUND went public. Up until then they had never even heard of BLOODHOUND. The Boss, Daniel, drew up the specifications for the 6 inch research models and the final 18 inch monsters – and didn’t tell them what it was all for. And they didn’t ask.

I literally feel my jaw dropping as Daniel matter-of-factly tells me this.

They… didn’t… KNOW..?

“No, no. For the first couple of years, before the car was announced, they thought it was for a space-plane of some sort. But they didn’t know. That’s quite normal.”

Normal. Normal…?

I slowly close my jaw. Because yes, in the defence industry it is pretty normal. Scientists, and indeed component manufacturers, frequently work in the dark – sorry, in compartments. Sam the Scientist may well be tasked with drawing up a bifurcated Thrumblefudgit with a calibrated yaffling dogget. He may well work on it for a couple of years. And he may well never be told whether it’s going into a Joint Strike Fighter or a cryogenic decrapulator for deployment in the highest diplomatic circles. Not being a dodo – and you don’t want your Thrumblefudgit designed by a dodo – Sam the Scientist will undoubtedly make an educated guess at the purpose of the thing; but he might be wrong. In the Falcon team’s case the assumption of a space-plane was perfectly reasonable – after all, nobody’s gonna be wanting a device like this in a torpedo or a combine harvester or a car fer Chrissake, now are they…?

There is a certain fine irony in this. BLOODHOUND is now the most open high technology project in the world. The contrast to secret military-type research could not be greater. Yet for the first couple of years BLOODHOUND was definitely secret – it being as you might say important to keep the gob shut until you had something concrete to open it about, even if ‘concrete’ only actually existed in cyberspace at that time. And so the military need-to-know habit sort of kicked in…

Well, well…

Anyway – to return to the rocket. To get this colossal performance there is one overriding difficulty. No, I’ll re-phrase that. There are quite a number of overriding difficulties, but one that kind of overrides all the other overrides – viz; the requirement to shovel HTP down its throat into the rocket chamber at a quite staggering flow-rate and pressure.

Take flow-rate. Whatever it is that shovels the HTP has to shift nearly 1,000 litres of it. In 20 seconds.

To put it another way, the Falcon pump must be capable of emptying the entire contents of the average car petrol tank in ONE second. Not to mention the fact that HTP has a specific gravity of 1.35, and therefore weighs very nearly twice as much as petrol…

Well, okay – problem. But in fact there are any number of pumps which will do that. A considerable number of fire engine water pumps powered by little 100 hp engines will do better, in fact. So not a big problem…

Um… well, not until you hit on the other half of the requirement. That the HTP will be coming from a tank already pressurised to 25 psi by inert nitrogen – nearly twice atmospheric pressure – and that downstream of the pump you need it to enter the rocket chamber at a pressure of 1,100 psi – 76 bar, or 76 times normal atmospheric pressure.

Aaah…

Now it’s a problem, because all pumps operate on a sort of trade-off. You can either have very high flow-rate or very high pressure – but you can’t have both. Well… you can of course, but by now the whole plant’s become more than slightly substantial, and requires a very hefty fire engine indeed to drag it around. Or, say, a power station.

And you would actually like the pump to weigh 51 lbs.

Big, big problem. No, actually – HUGE problem. And one which has bedevilled all liquid-using rocketry for the past 70 years. Because 99.9 per cent of rocketry has always been for space vehicles or missiles, and all space vehicles and missiles share a common requirement – that everything on board must be as light as humanly possible, and then re-designed again and again to add even further lightness.

Which is why the design of a rocket-fuel pump can easily take as much time as the development of the rocket itself. A decade is by no means unusual. But BLOODHOUND did not, and does not, have a decade or anything like it. Nor did it – and nor does it now – have anything remotely like the squillions available on a defence budget, even a defence budget currently so squeezed that the RAF are thinking of ordering 500 Tiger Moths just to stay airborne.

So think, head…

And what Dan Jubb thought was to go back into history. Had anybody ever before produced a pump that might meet the Falcon rocket requirements…?

And the answer was, yes – or more or less yes. And this is where the evil bit comes in.

In the 1950’s, the Cold War between Russia and NATO was deadly, deadly serious. To a generation of British and Commonwealth citizens who had just lived through WWII, the mere thought of another kind of oppression called Communism was more than enough to cause hands to fly to sword-handles. Britain almost beggared herself to stay in what was then called the Arms Race. The top cards in the Arms Race were of course nuclear weapons, and Britain created the V-force – the Vulcan, Valiant and Victor bombers – to deliver nuclear bombs as required.

Nobody – to be fair, nobody on either side except for a few megalomaniacs – actually thought this was vastly sensible. But that was the way it was, back then. And the way it continued until the most appropriately named MAD situation came about – MAD being Mutually Assured Destruction, which basically means that if you fire 50 nukes at me I’ll fire 100 back at you, and we’ll solve the ideological dispute by reducing the entire planet to a lifeless ball of irradiated rubble which glows silently in the dark. It finally took the man I personally regard as the greatest statesman of the late 20th century, Mikhail Gorbachev, to break the spiralling ring of poison.

But scientifically there were huge advances, as there always are in modern warfare whether you call it hot, cold or tepid. One of them arose from a certain British war committee who concluded that Russian SAM (Surface To Air) missile technology was developing at such a rate that any V-bomber intending to free-drop a nuclear present on Moscow was likely to receive a SAM in the bread-basket before it got within 50 miles of the joint. So the answer to this must be a missile, or stand-off bomb, whereby your Vulcan gets to 100 miles from the target, presses a button, and the missile, with its own guidance system, launches from your belly and streaks off ahead at Mach 3.0, leaving the SAM’s gasping in its wake. A sort of supersonic, robotic Kamikaze. You the Vulcan then turn at maximum G and run away like f***, er, like a fox.

 

From Red Snow and Blue Steel cometh a BLOODHOUND

Hence the stand-off missile programme code-named Blue Steel, initiated in the mid-‘50’s. Built by Avro, Blue Steel carried a 1.1 megaton Red Snow air-burst thermonuclear warhead, and was powered by a two-chamber liquid-fuelled Stentor rocket created by Armstrong Siddeley. It was not a particularly successful missile, being over-ambitious for its time and delivered several years late. It was also distinctly un-loved by V-bomber crews engaged in the other-worldly bats’ cave existence of QRA – Quick Reaction Alert – where you lived in your eerie hangar with your bomber for 48 hours at a time, permanently togged-up and ready to go within a very short time of the scramble light going on.

Living cheek by jowl with a 1.1 Megaton nuclear warhead capable of killing a million people does not make for an easy head on the pillow however sanguine of temperament a man might be. And if that was not tension enough there was always the lengthy and hazardous business of fuelling-up Blue Steel with kerosene and the much more capricious hydrogen peroxide…

There were 53 fully armed – what the RAF call ‘live round’ – Blue Steels produced, plus another 20 or so experimental units. Mercifully for the world, no Blue Steel was ever fired in anger, and the thing was scrapped in 1970 as Polaris took over as Britain’s nuclear deterrent.

This happened 13 years before Daniel Jubb was born.

But in rocketry, as in so many things in life, wisdom cometh not only from what you know, but also who you know. And Dan Jubb knew one John Scott-Scott, a legendary and revered figure in the wholly arcane world of rocket pump designers, now energetically retired in a bit the same way that Ron Ayers is allegedly ‘retired’. Jubb discussed the Falcon requirement with Scott-Scott, and Scott-Scott suggested the Stentor oxidant pump as a candidate. And he would know, because back when he was Daniel’s age he actually worked for Armstrong Siddeley on the Stentor pump.

So from hideous war machine to the to the world’s fastest car…?

Er… well, not entirely. Because – certainly back then – when a nation scrapped a weapon they didn’t mess about – they scrapped it. Gawd knows what they did about the warheads, but the Blue Steels just sort of evaporated, all except for a few practice rounds which ended up in museums. The design drawings were burnt. Nine years of research – and you could maybe warm your hands on the fire in the grate for 10 minutes.

Including the Stentor pump specifications. Almost, anyway.

So John Scott-Scott did not have the design drawings. But what he did have, incredibly, was an actual Stentor pump (now in the Rolls Royce Heritage Trust Collection in Derby). Turns out that when Britain shut down Blue Steel they weren’t quite as careful as they imagined. And Scott-Scott saw a Stentor pump in a rubbish skip, thought; ‘Seems a shame to leave that there’, and promptly nicked same. Which is why there is one left.

Well, fine and dandy. But having a pump in your hand is not like having the design specs on your drawing board. You can measure the various component parts of the pump in your hand – but you have no idea whether they are at the high end or low end of the design tolerances. You don’t know the hydrostatic loading on the seals. You don’t know the material specs. All you’ve got is the pump in your hand…

Designing from this is called ‘reverse-engineering’, which is a very great deal more difficult than it sounds.

Which resulted in Jubb, Scott-Scott, Ron Ayers and Richard Noble descending on one Dr Michael Fopp, the energetic Director General of the RAF Museums at Hendon and Cosford. This resulted in access to RAF Hendon’s quite incredible archives – and lo, there under Blue Steel were the fuel pump specs…

Or some of them.

In fact, little more than the material specs – but having the material specs is a lot better than nothing. So then the trail led to the Public Records Office, where they found still more…

To cut a long story short, they found enough information to enable Dan Jubb, with the help of John Scott-Scott, to re-design – or adapt the design of – the Stentor pump to exactly match the requirements of the Falcon for BLOODHOUND.

“That saved us five years of research”, Dan tells me calmly.

I have given up jaw-dropping so just stare at him. “Five… years?”

 

This sort of pump is – not usual. Forget your fire-engine power…

“Oh, yes”. The B 52 moustache smiles at me gently. “This sort of pump is not… er, usual”.

I look at it. Sitting here on the table, looking innocent. Weighing 51 lbs (23 kg). And capable of shifting a tonne of HTP in 20 seconds at 1,100 psi.

No. Not usual…

I happen to know that this ammonite houses a five-blade stainless steel rotor – or to be accurate, impeller. Which is a whole seven-and-a-quarter inches (18.3 cms) in diameter.

Not a usual pump. Not, in fact, the most advanced pump in rocketry by any means these days – but not a usual pump.

But of course there is a snag. Perhaps not so much as a snag but an inevitable demand of physics. If you’ve created such a – well, I can only call it a sort of micro-pump – to do all this without flying apart at about half the demand, then you are going to have to rotate it quickly.

At 11,000 rpm, to be exact. Even 12,000 rpm should you need to crank up the rocket impulse late in the development programme.

Which requires a great deal of power. An almost incredible amount of power. In fact, 620 bhp.

620 hp to drive an impeller seven inches – 18 cms – in diameter.

Which is almost unbelievable to me. But the physics are the physics – that’s the way it is. And, ahem and pardon me, that innarf going some. Especially if you end up needing 12,000 rpm which will require no less than 800 bhp…

The original Stentor pump was powered by a ‘cold’ rocket (HTP going through a catalyst-pack) driving a single-stage turbine which could produce 1,000 hp. Sadly, Halfords didn’t seem to have one, and trying to reproduce same from scratch would mean that BLOODHOUND might run in 2015 on a good day.

So it had to be a race-car piston engine. So the decision went to a 12 cylinder MCT engine to drive this pump.

Except that now the deal with MCT has sort of crumbled, for reasons I won’t bore you with. Leaving, since the crumbling took a long time, the rocket testing programme well behind schedule, since there is only a limited amount of point in testing the rocket if you are not also testing the fuel-delivery system at the same time.

Stalemate. A damming-up of research. Hitch. “Hell’s nuisance”, as Richard Noble would say.

But now, I can reveal, BLOODHOUND has signed up with a new engine sponsor. With the ink not yet dry on the contract I cannot expose their identity until the official announcement – well, I could of course, but if I told you I’d have to kill you. Suffice it to say that this manufacturer is a household name in – well, I can’t say. But they are very well experienced in creating engines which produce a great deal of power indeed. I personally suspect, ‘tween you and I, that they might have been a tiny tad miffed at first at the idea of their world-class racing engine being regarded as an APU (Auxiliary Power Unit) in BLOODHOUND. But if that’s so – and I hasten to add the above is only a personal guess from Outside The Box – they have got over it, and are now providing not only engines and replacement engines but also full technical back-up to amalgamate the electronic engine controls with those of BLOODHOUND. Which for me is firmly back in Category One.

Not many motors around which are capable of this.

Watch this space. And wait for the eerie shriek from the Mojave desert which will announce the Falcon’s first full-power run with the whole pump system operating. Which you’ll probably be able to hear in East Cheam…