Diary February 2016
Dear Lord, there are some tragic people out there! I got into a world of trouble last time I wrote because, apparently, I didn’t care enough about my dog! That will be why he lived the life of luxury and got away with murder for thirteen years, will it? But it seems I failed to weep and wail and cry enough when he finally karked it. That’d be because it was his time and I was rightly proud of the great life I gave him. So we soon got a new pup, named her Meg, and she’s become my new companion of an evening when I stroll out for a last one but I fear mankind is losing his ability to understand his former best friend. Only the other day I found myself foul of a barmaid who unfailingly winds Meg into a frenzy for no good reason. She smooched and cajoled from the other side of the bar until the innocent animal kicked over its training thus far and hurtled across the bar trailing string in her wake, which I instantly used to recover little Meg before administering a swift (though painless to a dog) slap across the chops to discourage further transgression. Off she went obediently back under the table but oh, was I the villain! I was ‘cruel’ apparently. There’s yet more. I met a bloke in the pub some months back, an older chap who’d had a mutt called Bruce that had died about six years earlier and at the time he’d decided against any more dogs. Fair enough. I could see him struggling with a vibrant young animal that may well outlive him but then he told me he’d had a change of heart and a new pup was about to join the family. What had caused this turnaround, I asked… and you know when the answer is so removed from anything you might’ve expected that you wonder whether gasping incredulity would be less offensive than an obviously failed effort to suppress it? “We thought enough time had passed so as not to offend Bruce’s memory…” Such people should be permanently disbarred from ever owning any sort of pet! Let’s just establish a few basics here, the first being that dogs are not four-legged children! They are pack animals recently descended from wolves and domesticated for their herding instinct. Other natural behaviour that we humans like to exploit is that, when living in a pack and having munched down a bellyful of the former weakest beast in the herd, doggy doesn’t just get up and curl down a steaming Mr. Whippy under his mates’ noses. He’d not dare… so instead he retires a polite distance because his mates would bite his bottom if he didn’t, which is how come we can easily train our best friend to whimper at the door rather than curl said Mr. Whippy down in the middle of the living room during Strictly. And this leads neatly to another requirement of the doggy mentality. They like to know who’s in charge. Imagine if you turned up for work on Monday morning and your boss wasn’t sure whether or not to be your boss. No decisions or guidance, no leadership, only a biscuit and do as you please. Yeah, it would be great for a day but after that you’d want to know what was to be done before the company went bust and you were all off to the benefits office. Dogs like to have a master, it’s a basic requirement of their genetic programming and when they cross the line their genetic programming also warns them that the alpha-male doesn’t voice his dissatisfaction with a written warning – he has big gnarly teeth – yet the world remains full of wishy-washy dog owners being told what to do by their own pets. Then there’s the stuff people think dogs need when in fact they don’t. I also keep ducks and I get fed up with people saying, ‘but ducks need water’. Ducks do not need water at all! Admittedly they like water very much but if you don’t give them any, apart from for drinking of course, you don’t get fatalities, you only get dry ducks. Likewise, if you don’t walk your dog ten miles a day in all weathers it won’t die it’ll just slob around the house watching telly with you. Think about this, in the wild they don’t scoff down their share of disembowelled buffalo then immediately burn off all the calories thus provided by walking about for no good reason. Admittedly, give a duck a rain shower and it will use only its furiously chattering bill to create a pond with a canal system and some lovely water features where your lawn used to be and, yes, get your dog used to going for a walk every day and it’ll hold you to it even if it’s snowing but both are entirely optional. So why do people humanise their pets and give them feelings they don’t have? It’s like those who bleat about the terrible cruelty of keeping dolphins in captivity. Go swim with dolphins in a hot place and see just how glum they look as they wow you with a trick or two then chuff down a herring they didn’t have to chase halfway across the Pacific. Happier and less endangered animals are difficult to find. Conversely, you’ll not find the bleaters traipsing the prairie, spear in hand and living in a wigwam either. Not a chance… they live in brick boxes with food brought to their door, a vet on standby and InstaFilmdownloadyFantasylandCloudBollocks for entertainment. Animals are intuitively clever – humans are thick as mince… I may perhaps illustrate this point by reference to rugby, which seemed somewhat prevalent last year and is, so far as I can tell, the only game to glorify a confirmed sports cheat! Now then, whereas I’ve had the misfortune of being subjected to much footballfoolery over the years, not on purpose, mind you, but because down the pub it’s often difficult to avoid some moron yelling at the green glow; but recently I’ve seen the folly that is rugby, very puzzling behaviour. The story goes that once upon a time some poor footballist got fed up of kicking the ball (he should have just gone home at that point) but instead he cheated in fine style by picking it up and running with it under his arm and somehow the idea has caught on. Unfortunately, however, a chance was missed for it to offer improvement over its parent pastime leaving it with all the basic failings plus some. Its practitioners still don short trousers and play in Siberian conditions when the grass, which clearly has more intelligence, has rightly chosen to hibernate and even the zillions of squigawatts wantonly burned so they can see what they’re doing won’t get it going again. Then there’s the fact that about two thirds of said grass may as well be dug up and thrown away because all everyone does for an hour an and a half is plodge around in the middle until the dreary homeostasis is momentarily lost and some of the tribesmen dash for one end or the other. There’s more… they say rugby is a game for men yet it seemed to me little more than a smorgasbord of thigh-groping, cuddling and mud-wrestling practiced by boys in short trousers interspersed with a team effort to jam their heads up each other’s bottoms whilst the referees skipped about in cerise pink! But what I found absolutely jaw-droppingly stupid was that for the best part of an hour and a half, rather than run in pointless circles like the footballists, the rugbyists quite literally spent it falling over! Honestly, they stood up and three seconds later they were over again. I seriously wondered at first whether it was a couple of those wheelchair teams trying to do it without their wheelchairs. Occasionally, they would all stop and gawp skywards as some outlying players kicked a leather egg back and forth overhead but soon it fell short, landed in the middle and they all promptly fell over again. On one occasion someone had the presence of mind to kick the thing then run after it so he was spared the falling over but soon enough someone else picked it up and he fell over instead. If nothing else it was hilarious watching them all flopping about like landed fish and predicting with sub-second accuracy when the next meatball would get a mouthful of grass, but ten minutes of such silliness was enough for one lifetime. I just cannot imagine a pastime where the rules never change, the scenery is always the same and it just drudges endlessly year on year the same as it always was. Two years of sponsons was bad enough but they’re done leaving our latest challenge that of ridding ourselves of all that spar and sponson nonsense. It was cluttering half of our workshop and was much better employed wowing visitors to the museum, where I gather it has been very successful and popular. Rumour also has it that some die-hard Bluebird anoraks have even had to finally accept that the mock-up from Across The Lake isn’t in fact full sized when faced with a genuine pair of sponsons. But in disposing of all that hardware we were beset by yet more of the world’s absurdity. You see, what we needed was a nice big van to do the moving so we went to our usual rental company where we know the boss and asked if we could please rent one as we’ve done many times – only this time we went with our Bluebird Project heads on and our Bluebird Project credit card. “Sorry, lads, you need an account or your own name on the card.” I looked at him incredulously, wondering whether he’d suffered some sort of traumatic brain injury since we’d last spoken. He seemed not to remember me. I reminded him who we were but didn’t need to, he’d not received that TBI, he just had mental indigestion from having swallowed the rule book. “Nothing to worry about,” he explained, “There’ll be lots of things on line with your home address just point me at a few.” Erm, I think there isn’t! The upshot was that we had to go through a complicated set of machinations via several of our companies just to rent a van from someone we knew and always rented vans from! I spent the next half hour in the office demonstrating to anyone who would listen that for a hundred quid or so it was perfectly possible to hire a living, breathing human being, no questions asked, to do pretty much whatever the hell you liked with – but a van? Not a chance. Grrrr! But never mind, we completed the job and returned in triumph to find that some things hadn’t changed. There’s still, for example, the ‘when’ brigade who bemoan the lack of immediate results but we’ve always had those. That’s an easy one, though. They never call and offer to come and help so they have no voice. We even had someone with a shortage of cranial synapses suggest we abandon the entire effort as conceived back in November 2001 and just bodge what we have back together so we can stuff it in the museum. This individual just hadn’t grasped that it’s only the sheer audacity and ambition of bringing the machine back to life that’s chimed with British industry, supporters and public alike and made any of this possible. I’d invite this person to write a letter to the cream of industry and the multitude of enthusiasts around the globe who’ve chipped in so far. Dear Sirs, As an impatient, greedy ignoramus I wish never to see this goose lay any golden eggs and would instead prefer that it’s wheeled out in whatever condition it may be at the earliest in order that I may profit from it immediately. Yours faithfully. Mr. & Mrs. N. Arrowmind. Sorry, folks – this is just going to take as long as it takes and there’s not a damn thing anyone can do about it except maybe join in and help – hinder and it’ll only take longer. The programme is as follows…
Rebuild the boat.
Run her on water, any water, in a series of proving trials.
Donate our work to the museum to be displayed forever in her home.
That’s the deal and it’s not negotiable. Not that we’ve exactly dawdled since our last big push. There’s so much going on that I’m dizzy with it! Let me see – what have we been up to? Well, having binned off all that sponson stuff to the other side of the country, we were left free and clear to start on the boat’s systems. We have the steering and linkages, fuel and electrics, engine and start system and many many small widgety bits to get fitted and working but first we had a height issue. When we set about installing the front spar and sponsons we really needed the boat quite high so we could fine tune her in pitch and roll so we left the back end in the rollover jig stanchion, which is necessarily high to allow the boat to clear the floor when rolled, and built the lifting jig for the front with the four screw-jacks under it, remember?
That rig allowed us to set up the forward structure to absolute perfection, most likely better than ever it was, but it has one fundamental failing when it comes to fitting the systems – the boat is too high to let us drop an engine into the hole. It’s also pretty much immovable and the time has been that we wanted to shove the boat out of the way so we could use the floor space for something else. To get around this we firstly dug out the old recovery cradle we used back in 2001 to get the wreck out of the lake. It’d been quietly awaiting its next role in a corner of the yard all this time.
It was designed with reference to Ken’s original launch and recovery cradle but with about six feet missing off the front for obvious reasons. It was made nice and low so we could get the boat onto it in the least amount of water and our tape measures told us that if we put the boat on it in the workshop we’d have a comfortable amount of room to crane an engine in. Job-one was to grow it a little and also provide a means to get the boat onto it so we made this.
It’s the missing six feet with some other points of note. It’s on wheels for starters. We allowed ourselves 30mm of ground clearance and the castors are of such weight-rating and numbers that we can use this conveyance for the final assembly to a complete, two and a half ton boat when the time comes. You’ll notice also the little cutouts in the longitudinal bars about halfway along. These are so we can put a pair of lifting beams under the boat then draw them out when not in use so as not to bash our knees. We put a similar cutout in the main part of the cradle.
Then all we had to do was to glue the two pieces together.
As the missus pointed out – that’s quite an erection! You may also notice an additional set of castors on the side chopped from a deceased shopping trolley recycled once already to move sponsons about – we waste nothing – so that the thing can be turned on edge and manoeuvred into tight spaces. Mike glued on a 25mm plywood top and we were ready to pop a hydroplane on top.
With a little practice we got the hang of lifting the boat with four small chain-blocks and with her dangling from the ceiling we rolled her new moving dolly underneath.
See how the lifting beams and the cutouts work…
And finally – Ta-dah… Bluebird on her new dolly. And just to give an idea, building that lot and getting the boat onto it took us about three weeks by the time we designed the mounts for the castors and had them laser cut from 5mm steel, sent for the castors, lifting blocks and moving sleds for the overhead beams and ordered in the steel for the beams themselves, and that’s without the fabrication work and labour to do all the moving. But it’s done now so we can crack on.
Where to begin… Well the time had finally come to throw an engine into the hole. The last time there was an Orph’ in there was about ten years ago when the old one was removed so we could get among the frame. We’d already done a fair amount of prep’ work on our intended running engine ahead of this momentous occasion by rebuilding and refitting as many parts from the original as it was practical to use. Donald’s original tacho-generator, for example.
This little gizmo makes the signal to drive the rev-counter and was rebuilt by Barry Hares as well as adapted to fit the later engine. The original oil tank went back on too.
If you look closely between the upper two pipes (blanked with the fingers from rubber gloves) you can see a small dent, and if you look at archive pic’s of the boat in 66 you can see the same dent. No idea what caused it but it’s as original as the tank itself. On went the bits until our engine was pretty much built and looking very like the 701 Orph’ that came out.
We were to remove the fuel system at the last minute because it’s inaccessible under the engine once it’s in and we had some work we could carry on with on the bench so with that done, we rigged our lifting gear and… ta-dah!
Looks good, eh? Well it did eventually once we’d worked out where it fouled the engine mounts, considered what we might have to pare away from the stainless firewall that normally separates the hot from the cold ends of the engine then found photographs to prove that this was necessary back in 66 too before we actually did the paring. Until then the engine was up and down like the underclothes of a lady of the night. But soon we had it happily in its mounts and it was time to move on but not before putting a small ghost to rest. You see, there’s a small engine mount right up at the front that, should it fail, well, the engine would get loose, displace its inlet trunk, flame out and a terrible accident may ensue. So, after much research, and a little help from unmentionable quarters we were able to perfectly reproduce the forward mount and this time it won’t be hammered to death at high speed on rough water until it snaps.
It holds the front of the engine and sets the thrust-line.
It may look simple enough but, believe me, it isn’t. It’s a collection of odd sizes and threads – some of them left-handed so an extra thank you goes to Barry for reproducing it absolutely faithfully. That’s the engine in the hole for the moment so what else was pressing? How about the electrics? There wasn’t much chance of Checkie getting on while we had sponsons in the way and all hands to getting them ready and out of the way but now they’re gone…
Our resident wirologist, Checkie, can be found simply by following the nearest bundle of brightly coloured wires to where he’s scheming and planning his next move. Those who have followed the Bluebird saga for any length of time will have come across Fred Blois’ book on the many incarnations of the boat entitled ‘Rainbow Coloured’. The story goes that he once asked Ken what colour the wiring was under the instrument panel and the answer, reputedly offered with some asperity, was to become the title of Fred’s book, but guess what – when the old wires were identified, period replacements sourced and assembled into a perfect copy of the original…
They are rainbow coloured! And here’s another little detail – I’m really catering for the anoraky disposition today. When the inlets imploded in 66, possibly due to the mismatched tacho indictor and generator tricking the team into overrating the engine (though the resident Bristol Siddeley engineer, Mr Pearson, may well have seen and avoided this) they had to be chipped free of all that bodge and paint and sent off to be made stronger and in with that task was the added complication of the entire forward wiring harness running through the intakes since day-one and needing shifting. They could probably have un-wired everything at the pointy end and teased the bundle backwards but they didn’t – they chopped it in two then, with the inlets away being beefed up, they rewired it lower in the hull so as to keep it below the inlets making the final join with a length of choc-block connector affixed to a lump of wood.
Now we never did discover exactly where it was mounted because it fell free of the mud and debris that came up with the left-hand cockpit wall but it was in there somewhere just forward of F-15, which as we all know by now is the back wall of the cockpit. We have a chunk of the wiring forward of it with clear evidence that the ends had once been screwed into the choc-block then violently torn out so we can place it with fair accuracy because we know how long that wiring is and how it was routed so all Checkie had to do was see about putting it all back, but here’s the best part. In a joint effort between our resident museum conservator, Loubie-Lou, and Checkie, they mended the original, made it electrically sound and conserved the chunk of wood too.
The only concession to the fierce maintenance of originality in the wiring dept. (apart from new wires, of course) is the addition of some fuses. Bluebird had none originally and with an extensively bodged 24v system it’s a miracle she didn’t go up in flames so Checkie has added these to his inventory of bits and bobs.
A pair of period, Lucas fuse holders sneaked in under the start frame. They’ll be a nightmare to access once the boat is complete but that’s intentional so as not to spoil the original look. The wiring is one of those things that will have to slowly grow into the boat so there’s still a fair amount to do. For example the juice can’t be supplied to the boost pumps, fire system or starter overspeed control until those parts are in the hull so we’ll just have to take it as it comes at us. Or, rather, Checkie will… The schedule now is that we install all the systems while we can shove our grubby mitts through the sides of the boat before stripping it all out again, popping the boat back on the rollover jig to rivet on all the outer panels and the floors then the last act will be placing her back on the moving dolly for the final fit-out. But there’s one system that may be left in from now because it doesn’t really get in the way of anything we have left to do and that’s the steering. It’s a simple enough setup. Up at the pointy end is a steering box of the worm-drive and quadrant-gear variety manufactured by Burman. We know they supplied the bits for two reasons. One is that they are listed as a sponsor in the 1954 launch pamphlet and there’s not really anything else on the boat that they could have made. The second is that the mounting points in parts we recovered from the lake match up perfectly with those of a Burman box of that era. The original was lifted by Futch’s divers then lost to history. It is currently ‘whereabouts unknown’ and, though a few images exist, we’ve never pinned down exactly what model it was. It may even have been a special but it’s very similar to one from a Morris J-series van and, better still, the gear ratio for that box matches the figures scrawled by Ken on a sheet of graph paper so many moons since when calculating the steering loads. Mike turned up just such a box from somewhere and Barry Hares, or as he’s known these days, ‘Clever Barry’, rebuilt it for us. Better still, it just happens to fit onto the mounts provided. It’s uncanny… See in the pic’ below that piece of box section cut off at forty-five degrees at its top end that the steering box is attached to against the F-20 bulkhead? That’s an original part that bolts to an angle on the other side of the bulkhead, which is then fixed at both ends into the mounts for the front spar and that’s why we have it – it departed the accident trailing on the end of the gubbins carried away by the front spar.
The drop-link on the left then connects to a short push-pull shaft back to a contrivance smack in the way of the driver’s left leg that converts a push to a pull and a pull to a push, if you get my drift. A sort of a horizontal seesaw arrangement designed by a Mr. Norris that we tried to build to his sizes in order to keep his gear ratios correct then cursed him fluently for several days until we discovered that, despite every instinct we possessed, it was in fact possible to build it and make it work to his design. He was a clever bugger! We began with bits of wood and scraps of tin…
Then we progressed to a modified Renault water pump – yes, we know it’s French, sorry, Donald.
Then, once it all played the game, we built this beautiful thing…
Machine work by Barry Hares, Fabrication by Mike and I might have thrown a weld or two onto it. It’s based on a single grainy photo of its predecessor coming out of the lake in the hands of divers plus the existing rivet pitches and bolt fixings on the frame tubes – it was a proper detective job working out what went where. Inside the cockpit it perfectly mimics what little of it you can actually see and what could be seen allowed us to further guess at how it was put together. Our only concession was that we made it extra-double bulletproof.
There’s a cover to go over it, of course, but it’s a good as we could possibly make it. But you knew all of this. Our next challenge was to get the push-pull-pull-push all the way to the blunt end about twenty feet backwards so as to get the rudder moving and that was yet another trip into the unknown. The old steering shaft was shot through with holes and largely seized in its bearings by the time we began stripping the boat for real in 2006. It was sort of free when we recovered the wreck because, as we towed her up the lake suspended beneath the sealed lift-bags, she began to oscillate most uncomfortably until we sent Zaid over the side with a giant spanner to centre the rudder. It did the trick and she came quietly after that but a few years in storage and Rob had to spend several weeks extracting the old shaft.
The bearings, on the other hand, along with many of the fittings were in remarkable condition so it followed that if we just had a new shaft made up we could simply slot it all together again, add a piece at the front where bits were missing and we’d be back in business.
There next followed one of those drawn out detective jobs that consume many hours for which we receive no credit at all. The problem was that the shaft, which measured 15 thousandths of an inch less than an inch in diameter, defied all our efforts to identify what it was originally made from. Something had clearly been ground down into our steering shaft but no type of stock tube or pipe that we could find would match the inside diameter, the resultant wall thickness after grinding and the obviously very tough material it comprised. We sectioned a piece of the original that had been especially well preserved inside the left-hand cockpit wall…
…and checked everything all over again. Many hours were spent poring over catalogues, old and new, and crawling in filthy-dirty corners of stockists’ warehouses with a digital Vernier until we discovered that it was a ridiculously obscure, imperial, cold-drawn, seamless hydraulic pipe that, as you have probably already surmised, wasn’t stocked by anyone in our quadrant of the galaxy. We sent for a couple of lengths from Alpha Centauri, but that was only part of the story. Next we had to get it down to a very precise diameter along its entire length with great accuracy and that’s where Green & Preece Grinding came to our aid. http://www.green-preece-grinding.co.uk/default.asp What we now needed was a process called ‘centreless grinding’ in which the workpiece isn’t held at either end but runs instead between a set of wheels rotating at different speeds, one of which is abrasive so that the diameter of a long piece of material may be gradually brought to size with a number of passes. It’s all a bit witchcrafty… First-off I measured each bearing to see what sort of variation we had and to make a note of the smallest diameter we had to cater for. Every manufactured part has a tolerance, or a slight variation usually expressed as +/- and our bearings, though very accurate, were no exception. Most were bang-on the inch but we had two at 0.998” or two-(thou)sandths of an inch undersize. I called Green & Preece, spoke to the boss-man and explained who we were and what we hoped they could help us with and he agreed to help immediately but there was a problem. We’d measured the original shaft and it was 15 thou’ undersize of the bearings, or 0.985” but that would normally be a very rattly fit in a bearing. I explained that the boat twisted and flexed and there was a possibility that the steering might nip up in extreme conditions without the requisite clearance but no – he wasn’t having this 15-thou undersize thing at any price. He’d give me 2-thou, take it or leave it, and our shaft would be ground to 0,998” whether we liked it or not. He was right, of course. But that’s the size of two of my bearings, I argued, but it made not a hap’orth of difference and soon enough our gleaming new steering shafting arrived ground to absolute perfection. Now, considering that we got three, eight-feet lengths of centreless-ground hyd’ pipe, you’d imagine there’d be some detectable variation somewhere but, despite trying very hard to find anything different, it all measured 0.9980” from one end to the other. I was more than a little impressed! We did have the small problem of the two bearings that measured size-for-size with the shafting but a quick spin up on the lathe and some lapping-paste later and they were sliding nicely and BFG lost no time in getting some steering parts thrown together.
The linkage on the end is original. It was built with taper pins so Barry procured some replacements and using a little heat, he shrunk them into fresh holes drilled and taper-reamed to perfection. Once set they get a tremendous hold and then, for that belt and braces confidence, the ends were peened with hammer and dolly to make sure they’re never getting out again.
It’s a very nice repair of the original.
Only the final fettling to do now – some bearings to true up and get running smoothly and the steering will be complete. Of course, as with any rebuild of anything, the time it takes to get 90% of the work done is about equal to the time you’re going to need to find the next 9%, which is how long it’s going to take to find the final 1% so at least a third is done. Same goes for the hydraulic system. We got much of this in hand many years ago because we needed support from aerospace and, as an industry, it’s like a big, bubbling planet with a most unpredictable climate. One week you can get the help you need, the next the company has been sold to another aerospace giant or a redundancy package has come along causing all the old hands who’ve known how to set up your mechanically driven hydro- worzel sprocket with their eyes closed for the past thirty years to move to the Caribbean leaving behind only horribly clever youngsters who can design a communications satellite on their smartphones but who live a long time after 1954. Bluebird’s hydraulic system is basically one of the control surface circuits spannered out of the Gnat and thrown into the boat complete. How it works is this… At the heart of the system is a radial piston pump made by Lockheed and driven by the engine gearbox that slurps in hydraulic oil then shoves it around a circuit at 3000psi. It lives its life in an unending contest with a thing called an accumulator because the problem is this. If you’re throwing your Gnat around the sky you need several jacks working to make control surfaces waggle hither and thither and this would normally need a lot of oil whizzing about, which in turn would need a big pump and all the associated weight. So, the fix is to store reservoirs of pressurised hyd’ oil in various places about the plane that can be drawn upon in moments of need and this is achieved, in the Gnat’s case, using a cylinder about the size of a large Thermos flask with a piston inside. On one side of the piston is high-pressure nitrogen and because gas is compressible it acts as a big spring that pushes the piston to the other end of the cylinder. But over there oil is being pushed just as hard the other way by the pump forcing the piston back again and further compressing the nitrogen. It’s no different to the tin of underarm slop you spray on of a morning so that by close of play in the office you don’t smell like a camel-rider’s jock-strap. Liquid in a cylinder with pressurised gas... Press the tit and out comes the liquid. Only difference being that there’s no piston dashing up and down your tin of Lynx. That’s the basics of how the energy is stored but left unsupervised all we’d have is 3000psi oil pressure on one end and a pocket of terrified nitrogen cowering at the other so to keep it in check there’s a thing called a cut-in/cut-out damper and what happens is that having decided what oil pressure is needed to, for example, to shove an aileron about, you put gas at that pressure at one side of the piston then set the maximum oil pressure allowed into the other side to about the same so the piston sits in happy equilibrium. Then, when you push your lever to wing about the heavens, your aileron, instead of trying to gulp oil straight from the pump, sucks it from the accumulator instead with the gas helping it on its way to give your plane instant reactions, expanding the gas it goes with its pressure falling. Then, soon as that happens, a second valve opens allowing the accumulator to take a toot of 3000psi oil from the pump to replenish itself pushing the gas back into its corner ready for next time. Get the idea? Put an accumulator and cut-in/cut-out valve on each control surface and undercarriage leg and you can get away with a small pump pushing a relatively small oil volume in circles waiting for the accumulators to draw on the supply as needed. So what do we have so far? Our pump spinning merrily keeping our accumulator topped off and any unused oil heading back to a header tank to be de-aerated, cooled and prepped for another spin on the merry-go-round... It now follows that if we tap our water-brake into the accumulator we can use the pressurised oil to shove the ram up and down but the forces are pretty big. At 150mph, which Bluebird could easily attain on her proving trials, should Ted extend the brake, there’d be something like three-quarters of a ton trying to rip the whole contrivance off the transom and when Donald was using it around 300mph the forces would be four times that! So the ram must be pushed plenty hard in either direction and this necessitates being able to deliver oil above or below the seals on the piston rod. To achieve this they added a ‘selector valve’ as used all over the Vulcan, which basically allows oil to go one way or another depending on the flick of a switch in the cockpit and this is where the system departs from the Gnat setup. In the aircraft, if your engine packs up, you can still push and pull on rods and linkages and fly the plane. In fact, a great friend of mine flies 737s for a living and he can manually haul one of those about with no hydraulics should the need ever arise so a minuscule Gnat ought to be no problem. So, when the motor stops, the accumulators just bleed the pressure down, return the oil to the header tank and park the pistons at the empty, oil end. But a fat lot of good that would be in the boat because there’s no manual means to shove the brake down and even if there was it would be too slow and beyond human strength. That’s where the Vulcan valve comes in because what it does is trap the pressurised oil in the accumulator to allow the brake to be extended with no engine and this is why we think the brake was uncommandedly extended when we lifted the wreck rather than through any attempt by Donald to get out of trouble – but maybe we’re wrong. There were also many minor parts that must be persuaded back into life like a charging point for the nitrogen fill, a line-filter for the oil and various ancillary valves, not to mention every last connection, many of which we knew would leak when asked to hold back high pressure fluids after a half-century hiatus, but we were more than ready to persevere with it. We tackled the parts of the system one at a time. Our pump was fished out of the bilges with a chunk of Orph’ gearbox still hanging off it. The magnesium gearbox was long gone but when it fizzed away the pump dropped into the mud beneath with its insides largely filled with oil so it was in pretty good nick, all things considered.
We pulled it down and gave it a clean-up. There was some minor water staining inside that we gently polished off with Crocus cloth but that was about it. Our old allies, Kearsley Airways, gave us some spares that were not so good for flying but perfect for ground-running and we gave the pump a top to bottom rebuild.
