June 2010

Whatever has happened to our milk?

Remember when you were a kid and the milkman left bottles on the doorstep and on cold mornings you could pop off the foil lid and the cream was so thick it wouldn’t pour?

And that was only on days when the blue tits hadn’t pecked through and nicked the lot. There was something endearing about small, blue and yellow birds getting up before you and stealing your breakfast – at least I thought so – and in the days when we recycled properly the empty bottles were then rinsed then refilled with fresh cow-juice squeezed straight from Ermintrude’s tits then given no more than a quick heating up according to a process laid down by M. Louis Pasteur to make sure there wasn’t too much listeria in the world.

I was sent to the little village store the other night for milk, something I never buy, only to discover that the do-gooders have assumed control of our moo-sauce too. Like light bulbs it seems you can now only get washed-out, fake milk. They call the blue-topped stuff whole milk but it bloody isn’t because someone has thieved the cream before the birds could even get a sniff and it only gets worse as the product they still call milk gets progressively more watery until you’d be forgiven for thinking they’d harvested quite the wrong bodily fluid. So-called, ‘whole milk’ is only missing its cream – though they charge you the whole price – but they do likewise for green-topped, semi-stolen milk that’s had the cream plus most of the rest of the good stuff taken out until you reach the red-topped slop that you could keep a goldfish in without too much trouble. Don’t forget, though, that they then sell you back what they’ve removed in your best interests in a hundred other dairy products then tell you not to eat it because it’s bad for you.

What’s actually bad for you is sitting about taking no exercise but try getting out on your bike for half an hour and the health and safety maniacs will have you dressed like a Christmas tree in fluorescent green with twinkling lights. The ethos these days seems to be that we need an environment, whether at home or in the workplace, where clumsy morons can hurl themselves at danger and bounce off unscathed protected by their gloves, glasses, boots and shortly, probably, full-cotton-wool-jackets…

The maniacs call me all the time in my office to ask who looks after health and safety within my organisation to which I reply, “We do.”

Then they rub their hands with glee and knowingly inform us that what we really need is a boy, straight out of school, having swallowed the latest manual on how fools can avoid injury while diving headlong into a combine harvester, to come and show us how it’s done.

“We use a somewhat outmoded though highly effective model,” I explain. “It’s called… (and I drag this part out for best effect) ‘common sense’. Ever heard of it?”

They tend not to like that very much.

I mean, divers don’t strap on their diving knife so they can charge blindly amongst old fishing nets, do they. It’s a get out of jail card if all your experience, planning and precautions don’t quite keep you out of bother (and for flicking your underwear over the side once safely back on the dive boat). So is it really safer to erect a million-foot-high scaffold with crash-mats and sky-hooks to change a lightbulb when your subject isn’t proficient in balancing safely on a rickety chair in the first place?

Angle grinders are my favourite. The maniacs tell us we should wear eye protection at all times yet not one of them can demonstrate how to use one safely without eye protection. Work amongst a group of blokes with grinders and it’s not their eyes you’ll get into bother over. You’ll only sprinkle their mug of tea with iron filings once before you learn to combine safe grinding practice with neighbourly consideration at which point your eye glasses become a secondary layer of protection instead of treating the symptoms of unsafe working practices. I invariably invite the H&S busybodies to come and run a training course in working off a ladder, balancing on chairs and angle-grinding without wrecking your mate’s cuppa and then show us how gloves, glasses and boots can contribute that little bit extra. It beats them every time.

And here’s another thing… they can never tell you what type of grinder ejects what type of projectile while working any given material and which are the bad ones so here’s a health and safety lesson born of long (and often painful) experience.

Bits of hot, abrasive grinding disc are quite nasty because they hit your cornea with a lot of residual heat and stick but they’re quite smooth and don’t scratch too badly whilst being easily removed with a cotton bud. Shards of stainless steel stick too and they’re anything but smooth so your eye protests angrily within seconds but they too can be quickly swept away with a cotton bud so long as you’re careful to lift them away as you go to avoid any scratching. For real anguish what works best is a high-velocity shaving of cast iron. They’re usually needle-sharp and red hot so they stick into your eyeball and weld themselves there with the heat. The trick with splinters in the eye is to shift them immediately. You can trail to A&E where you’ll be seen after all the overdosed druggies have been mollycoddled back into society but by then it’s too late. Once your eyeball gets angry all you’re going to get, apart from agony, is anaesthetic so you leave the hospital looking like a pirate, orange dye that makes the world look like it’s lit with sodium vapour lamps and a total stranger jabbing at the offending piece of shrapnel with a cotton bud just as you could’ve done yourself two hours earlier. One of those cast iron spikes can even mean scraping your eye with the blade of your Swiss Army Knife… that takes a little more resolve, but with a bright light, a mirror and a steady hand it works every time. Aluminium splinters are totally harmless, by the way, because they cool quickly in flight, have little mass and therefore little energy and never stick so they can be quickly blinked out.

There now – you’d not get that lesson from the H&S lot any more than they’d admit how painful a ball of molten welding spatter trapped in your steel-capped boot can be or how fragments can ricochet off the frame of your safety spec’s and hit you squarely in the eyeball anyway.

One thing though. Always wear your glasses when drilling hard stuff. Exploding drill bits are bloody dangerous!

Our health and safety prospects will improve soon, however, now that the daylight thieves have moved the clocks again. Just as we entered the bleakest winter since 1978 the fools wound our timepieces the wrong way to extinguish all hope of seeing our way home in the snow but now that spring is here they’ve given us our hour back when, let’s be honest, we don’t really need it. And – there’s now talk of us moving the clocks in the obvious direction next year and adopting double summertime by 2012. This could signify a loose particle of common sense that’s fetched up in the right place, or it could as easily be that they don’t want their Olympic running and jumping, spear-throwing contest going short of daylight…

Soon the sunlit evenings will be long and the grass will grow like the weed it is whereupon the footballists will hang up their boots and millions of kilowatts will be saved across the nation as cricketists don long pants and jumpers to leg it hither and thither in the blazing, summer sunshine. It’s in the sensibly warm summertime that the serious business of Formula One swings into action again.

Now there’s a proper sport, one which evolves year on year, where sponsors’ millions serve to move mankind forwards and feed the developing technologies of everything from crash survivability to fuel economy back to the populace. A sport where someone is actually in charge to enforce rules, punish those who transgress and ban refuelling making the first race of the year into a sad procession of overweight petrol tankers. It was dreadful but at least Rob finally had a chance to get even for all our digs at his chosen sport…

*

For almost five years now I have been teased in the workshop on a Saturday afternoon as I switch on my ball chasing wireless to warm up the valves to listen to my beloved team get beat once again. Apparently I should be into F1 for real excitement.

So it came to pass that sipping my tea one Sunday morning and channel hopping I happened upon this fascinating sport.

First few laps I thought were quite exciting but then the race ended. Or so I thought

..But no they had been racing to see who had the fastest car so he could start first in the real race? Surely it would be fairer for the guy with the slowest car to go first or even have a head start. Never mind, off they go again to the delicate screeches of Merriment Walker

And Stirling Sienna is in the lead with a thousand laps to go.

900 laps to go and Sienna still leads.

At this stage I went to 112 to catch the end of Bewitched. (I have always had a thing about Elizabeth Montgomery)

Turns out I missed the most exciting bit which has unfortunately been removed from the sport.

THE PITSTOP???????

And Sienna pulls in for fuel, Excitement mounts as we watch to make sure he uses the diesel pump and not unleaded. Cost him £340.00 to drain the tank last time and almost certainly cost him the race. He is eyeing up the mars bars on the rack and oh no he has gone for the snickers. Must be the Geordie pump attendant cos when Sienna asked for some air he was given another 10 litres of fuel. Ready to go but there seems to be a problem. He’s refusing to leave the pits. Only been given single greenshield stamps, needs triple for a bottle of fizzy stuff to squirt at the end.

And he is eventually off to join the rest of the little cars for the boring bit.

Now you might think that that would be enough excitement for one day, and I wouldn’t blame you in the least, anyone would.

But no siree, Bob. These pit stops are a double edged sword.

While Stirling was in getting his fuel and a Ginsters pasty for the journey, my little mate from earlier with the crappy slow car. Who had to start last???? has caught up and seems for some reason to be ok for fuel and sucky sweets so doesn’t need to stop. Probably knows its only £1.14 a litre further down and he can use his premier card. And so we return to the commentary with Merriment Walker.

And Sienna is edging forward trying to rejoin the flow of traffic as Robs little mate in the crappy, little slow car who had to start last? tootles toward him. Will he flash him out? NO he has tootled straight past with a two fingered salute

Stirling is furious as he eventually gets out he knows that all of the overtaking lanes have cones on them so no one can overtake anyone any more. But wait Rob’s little mate in the crappy, little slow car who had to start last? has pulled into a lay-by and has disappeared behind the hedge Stirling flies past him and over the line. Another fine victory for the man with the fastest car who started first.

So, to recap. We have a sport where the handicap system puts the slowest bloke at the back. The only way to overtake is if someone needs a pit stop and the powers that be take out the pit stops. What chance does my little mate have against Stirling who is starting first not stopping and no one can get past?

If I have missed something, lads, please explain before 3pm Saturday when I will be warming me valves up for a proper sport.

*

…no, Rob you haven’t missed anything, on that occasion at least, but the second race in Australia was an absolute cracker with lots of overtaking, pits tops and not a ball in sight.

In the meantime we’ve been working hard on our own brand of motorsport.

One of the reasons we’re rebuilding an old Orpheus is that it’s all too easy to simply accept that this is what was spannered into the hole in 66 and not think any further. We had such a tussle with the museologists and lottery fools about how to handle history but at the time it never occurred to anyone that this legacy engine is, in its own way, another piece of our past that was slowly slipping into obscurity. As it happens the Bristol Orpheus is another mini-masterpiece of British engineering. It’s a small, compact turbojet from a time when turbojets were still something of a novelty and it boasted a number of innovative design features and an excellent power to weight ratio for its day. The turbine bearing, for example, uses a total-loss lubrication system whereby an air bleed from the 5th stage compressor combines with a metered oil supply to blow an oil mist onto the centre of the bearing from where it’s centrifuged into the jetpipe and simply burned off.

Bristol Siddeley sold it a little better than this when describing it as a ‘non-scavenged’ lube system that reduces the amount of plumbing and obviates the need for an oil cooler.

So long as your oil duration exceeds your fuel duration, it’s a neat way of lubing the back bearing and the little Orph’ was full of clever tricks like this so we thought rather than just spooning a nice clean one into K7 and happily showing off our new engine it would be more appropriate to rebuild an old one and teach you all a bit about how it works. (And ourselves too)

Our decision has inspired a fascinating journey all the way to the early fifties and back again and given us the pleasure of meeting some fascinating people.

I recently met with some of the engineers from the company that’s overhauling K7’s engine-driven fuel pump where we examined a set of springs from behind the pump pistons. Basically the Orph’ has seven combustion cans and the pump has seven small pistons to shove fuel their way with a spring behind each one. As may be imagined these springs do a lot of work and due to the pump design should one break the bits drop between the spinning pump rotor and a machined port-opening that immediately slices and dices the broken spring into thousands of tiny pieces then pumps them right through the engine. We don’t want that to happen.

For this reason the springs are a critical item and are usually replaced at overhaul but because K7’s pump dates back to 1959 it wasn’t certain that replacement springs were available. I couldn’t imagine what all the fuss was about because they certainly didn’t look like much, just springs really. Having speculated inwardly I then gave voice to my thoughts. It wasn’t a clever thing to do.

“Don’t know what you’re talking about, do you…” said one of the engineers with a twinkle in his eye.

All I could do was grin and agree.

I soon found out that before the springs are ever made into springs the raw wire has residual stresses set up in it by shot peening (the firing of tiny balls at the surface to cover it in a tensioned skin of microscopic dents) before being springified… That way the material can be stressed beyond what it’s theoretically capable of doing and become a very clever spring indeed. I moved on swiftly.

On another occasion we were discussing the elastomers in the fuel control system – rubber impregnated cloth diaphragms, mostly, that control servo-pistons and assorted rocker arms – and how they would definitely need replacing. Brand new and packaged they have only a relatively short shelf-life. Even properly inhibited inside a complete pump they don’t last more than a few years so a set of 1959 examples definitely wasn’t languishing in the stores and even if it was we’d not dare use it so we (or rather our sponsors) were faced with re-manufacturing the parts to a specification that hadn’t seen the light of day in half a century.

With ever an eye for K7’s originality, not to mention the scale of the favour I was about to ask, I suggested we re-use the originals because they looked and felt good as new and there’d be no real harm done if our engine ground to a halt halfway down the course.

I got that, ‘you don’t know what you’re talking about’ look again and they were right again. The problem here would not be the engine simply giving up and spooling down – what would happen is that should the pressure used to govern fuel flow start weeping through a pinprick in a diaphragm the engine wouldn’t stop at all, it would run away with itself, pouring ever greater quantities of kerosene into the fire until it howled itself to destruction in an explosion of hot shrapnel. We didn’t fancy that either.

There’s no denying that these pumps are robust little things and even in the broken spring scenario I was told the machine would ‘keep on trucking’ – for a while anyway. The modern version with carbon slippers on the piston ends and a host of incorporated cutting-edge materials can do an astonishing 22,000 hours on the wing between overhauls but having been warned of the dangers it would be grossly irresponsible to plough on regardless without thoroughly addressing all the safety issues. The elastomers are being re-manufactured…

We’re extremely fortunate with the engine controls but not so with the start system, which is both completely bespoke and was manufactured by Lucas Rotax, a company that’s long gone. There’s no spares or engineering support so we’re completely on our own in understanding and rebuilding all the twiddly bits that make it work but at least the start bottles are straightforward.

They’re spherical pressure vessels; one fitted either side of the inlet trunk on a steel frame. We always had high hopes of resurrecting them because the system remained pressurized during the boat’s long sojourn on the lakebed and when compressed air started hissing out after we’d cracked a fitting we all ran like hell. The reality seems to be a little different in that the right-hand bottle stayed dry because the main air valve and pressure regulating valve remained firmly shut providing a double barrier to water ingress but the other had a much simpler arrangement at its neck and ended up partially flooded.

Following much deliberation we decided to tackle the easy one and soon had it cleaned so we could inspect it inside and out. The dilemma we faced was that in order to get it through a hydrostatic test we’d have to shot-blast it losing in the process all the original paint and inspection stickers. If there was no chance of it surviving the test we’d have been better conserving it as a museum piece and finding another way to start the engine.

First we had the colour properly matched and a tin of paint mixed then all the stickers were meticulously measured, photographed and their position on the bottle recorded before the bottle went to the blasting dept…

Looks like the surface of some distant planet, doesn’t it… The blasting was intended to reveal any surface pitting. This doesn’t occur on the inside because it was dry but out here it swilled about in an electrolyte amongst a cocktail of other metals and suffered its share of dissimilar metal woes. Having consulted with several experts we were signed off to dress these pits with a die-grinder then build up the wall of the bottle by welding with the appropriate filler rods. It worked like a dream.

Next, give the repairs a good polish…

The neck had pitted too so that was carefully rebuilt and the wire-locking holes re-drilled.

Perfection… but would it take a test? Detailed boroscopic examination of the interior showed it to be in excellent condition but the proof would be in pumping it full of water. That’s how it’s done… were the bottle to fail when full of compressed air it would be like a bomb going off so the bottle is pumped up with high-pressure water instead, which is incompressible so far as the scope of the test is concerned, so if the bottle failed we’d get soaked and disappointed but no more.

The bottle was plumbed into the test rig and calm as could be the man opened the valve and a small Haskell pump relentlessly bumped up the pressure until it was stopped at 3200psi.

Each bottle holds approximately 17 litres of air at 220 Bar or 1052 cubic inches at 3200psi. The start system uses a pound of air a second and the start sequence takes six seconds so the pair of them together were good for twelve starts but to achieve a working pressure of 3200psi we’d have needed to test the bottle to 4600psi (that’s the test pressure stated on the label though these days the test pressure would be nearer 4800psi).

What we decided to do was test to the last working pressure – that which Donald used in 66/67 – then impose a new max working pressure of 2000psi. Assuming we can achieve similar performance with the other bottle we’ll have a much lower stressed setup that’s still good for at least a half dozen healthy starts. Let’s see what happens with the other bottle, eh – not to mention all the valves and twiddly bits we’re rebuilding to go with it.

Speaking of rebuilding – we’ve been getting all adventurous with the cockpit opening again. The past few years have been a huge learning curve with us first wondering who we might get along to make the complex shapes needed to rebuild the pointy end of our boat and then, on discovering that not many people actually know how to do this and even fewer on a volunteer basis, we chose to have a go ourselves and built this.

It wasn’t actually too difficult to fabricate from new, 1.5mm sheet alloy and it looked great but a certain piece dragged from the lakebed wouldn’t lie down and die quietly. It just looked too good to ignore.

That blue bit popped off and sank in the crash in remarkable condition and we often wondered whether it might graft back in as an original piece of outer bodywork.

Sure enough…

It worked a treat and we were all smugly pleased with the result but that’s where the matter rested because shortly afterwards we tore the boat down again to have the frame painted and the cockpit opening went into storage.

Fast forward a couple of years and the time came to have another look. But by now we’d got better at our night and weekend tin-bashery and thought another piece or two might save.

Like this, for example.

OK – so it was a little ‘crumply-dumply’ as my four-year-old would say but we’re not scared of things like that any more and a few strategic whacks with a hammer had it looking marginally better.

Now it only takes a small amount of imagination to see the curved cockpit opening at the bottom. One of our sponsors came to visit last week and having looked about awhile said, “Who could ever have imagined that all that scrap you pulled out of the lake could be turned into this?”

What could I say?

Some more tin-bashing and we had another piece ready to be grafted back in.

What we did in this case was to pin original over new then slowly cut away the new material and shape in the edges for welding until a big chunk of it eventually fell away effectively replaced by old tin.

The final piece in the jigsaw was the end of our panel.

Crumply-dumply to begin with but then…