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It is just so Super (Sentinel).


JimH

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One of the things that made the decision to build another Super easy was that we had a boiler lying around. We designed and built the boiler for the first one, then built a new one for the S Type and then built another three of them. However, for reasons that don't need to be gone into we didn't sell the last one and kept it back. Here is the the last one we built sitting in a support frame. A pressure vessel designed, constructed and documented to the Pressure Equipment Directive. This is not your usual try to claim that it is a repair effort and the design dossier is what might be called extensive.

 

The grates are at the bottom and you drop coal down the top. It is a water tube design which is a copy of Sentinel's own design. It is what is referred to as a spiral pattern firebox. See below.

 

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Here is a firebox that we made for the S Type prior to the tubes being welded into the firebox. The are sixty 1" OD tubes. This is double the number that Sentinel used. The problem of this design is that machining the tube holes is a little tricky because they pierce the firebox at a crazy angle.

 

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The pattern the tubes make is rather hypnotic. The reason for this layout is that it gives a high heating area but it lets you have a hole in the middle. This is very important because that is what the coal falls through.

 

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What we also had lying around was a new superheater which was meant to go with the boiler. The superheater sits inside the combustion space and heats the steam to above saturation temperature. Higher temperature = higher efficiency. Note 944 being ignored.

 

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So that is what we started with. A new boiler and a new superheater that were lying round doing nothing.

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Fab. Please keep it coming.

 

Do you do all machining yourself? There are some huge machines at the locomotive repairers. Just wondered - looks like you are very well equipped.

This is epic work, keep it coming please.

 

 

Sent from my SM-G930F using Tapatalk

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What a brilliant thread.

 

I think Sentinel Works is where Perkins (now Caterpillar) still are in Shrewsbury.

Sentinel were bought by RR(possibly also with the idea of entering the road transport market) and used to develop/build their high speed diesels. Presumably later flogged to Perkins.
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So where are we? By this point the list looked a bit like:

 

Boiler

Superheater

Chimney base

Injector

Most of the steering box

A steering wheel

Windscreen hinges

Ash pan

Tank filter boxes

Feed heater box and lid

A vague idea what we are up to

 

When we built the last one we started with an engine and then fretted about making axles and boilers and the rest of it. Now we were pretty happy that the rest of it could be built but the engine was going to be a problem. What Sentinel built was a fairly standard twin cylnder, double acting engine with poppet valves operated from camshafts (we'll come to them later). Where things got odd is that the Super has a twin chain drive. There is a sprocket on both ends of the crankshaft driving a chain to a sprocket on each rear wheel.

 

Errr, where are we going to put the differential?

 

After much head scratching they come up with one of the more mental ideas in vehicle design. We'll put it in the crankshaft. And in a stroke they made what would have been a difficult job of making an engine very much harder. So there was humming and hawing and then as is usually the case if you think about a problem for long enough someone solves it for you. The widow of John Keeley died and there was a big auction of all the stuff he had amassed over his life. One of the lots was the remains of a sorry looking Super engine minus lots of bits. Fortunately there was a crankcase and - most importantly - a crankshaft. The old man trooped down there with the intention of buying it come what may. A coupe of weeks later we had to do an 850 mile round trip in the LDV to pick it up. Here it is, upside down, on a pallet. The big bits that are missing are the cylinders, the camshafts, all of the valve gear and the water pump. Still, we stand a chance of getting a waggon number if we can identify it.

 

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Peering through the crankcase door you can glimpse the crankshaft. Pretty much everything you can see is buggered.

 

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Hosed down and on the workshop floor things look a bit better.

 

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So you take it to bits and have a look. This is the crankshaft stripped of all its shafts and gears.

 

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To give some idea of scale those are 3.5 tonne axlestands it is sitting on. Two people can just lift the bare crank. One of the avenues we explored was having a crankshaft made by LCR (who are an amazing company who can do some well impressive stuff) because it is way beyond our workshop capability. The estimate from LCR was that to manufacture what you are looking at there less the balance weights would be £14,000 plus yer dreaded, mate. When you saw what they were doing for the money we had no argument with the price. The problem was that it was £14K FFS. 

 

Just to jump forward a little so you can see what it is meant to look like this is the same crankshaft once we'd finished it. I'll fill in how it got to be like this but it should give an idea of how it works. The large lumps of metal on each end of the crank are the partially machined sprocket carriers. These spin freely on the crankshaft and are driven by shafts that pass the the hollow journals. It is unbelieveably heavy by this point. You see the massive main bearings? It needs them.

 

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However, jump back to a close up on a couple of the diff gears. You can probably see that they are buggered.So the crank needed all new bushes (8 off), new drive shafts (2 off), new master gears (2 off) new diff pinions (2 off) and new diff gears (2 off). On top of that it needed to have the big end journals reground which we can't do so it had to go to the engine remanufacturers to be reground and that took a while for it to come back.

 

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So from this exercise we have a very long list of things that need to be made/found to turn this into a working engine. However, work carries on other things. The steering box, cover, top bearing housing  and crank are were all done so now it needed the shaft and nut made. This is a left handed, two start ACME thread at 1" pitch which is a bit of a tall order to machine. Its a good thing the old man has had a bit of practce making these now so that wasn't too bad (for me - it took him several days). You need to cut a square thread first then go in with an ACME form tool so you need to kep your wits about you. These days threads like this would be rolled (and beautiful they would be too) but this is an oddball one so you would need to spring for the cost of the dies which is a no no.

 

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Meh, not bad I suppose...

 

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And this is the start of the front axle. The bend in the middle is so it goes around the boiler. Originally these were forged but we don't have a massive hammer so the approach we have taken was to make a pattern and have them cast in steel. Then we simply* weld them together in the middle. This also solves the problem of machining the axle since the whiole axle won't fit in our boring machine.

 

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This is an extract from the parts book. Gives you a bit of an idea what the front axle beam is meant to look like.

 

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And some long lengths of channel were delivered. You will be a chassis one day soon.

 

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That will do for now. In the next thrilling installment some things are cast and other things are machined.

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Never ceases to amaze me who is on AS. Excellent thread. I assume your old tractor is the one a gentleman collector in Essex now has.

 

We have engines too but much slower and noisier !

 

I believe it is living Essex way. In the last photo I saw of it from a couple of years ago it was still in the paint job and lettering we put on it so it should be a pretty easy spot.

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I'm utterly fascinated, really looking forwards to updates.

Can i ask how you go about registering the finished wagon?  i'm assuming it can't be treated as a new vehicle and go the BIVA route?

Whats the crack between rebuilding an existing boiler and making a completely new one? Paperwork and testing?

I love it that someone could identify the bits you bought at auction (and the fact someone was mad enough to save them for all this time!) rather than them ending up as scrap

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Most of this project involves turning large chunks of metal into turnings. In period many bits would have been cast in steel. However, that involves pattern making which is fine if you are making hundreds. For one or two you start with a billet and a big lathe. Here is the start of the drive gear blanks.

 

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And here are some of the bits. The torque the engine can produce is frightening so these components are under some fairly scary loads. These are all made from EN24 which should hopefully be up to the job. What you can see here is an old drive shaft, two new drive shafts and two new diff pinions (the smaller ones with a lump at one end. The lump is the blank for the gear.

 

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And here is a mostly assembled steering box. You can probably guess which end the steering wheel goes on. Note the lightweight* construction. You can just about lift this on your own.

 

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More castings. This is the quadrant for the reversing lever and hand brake. The one at the back was a wrecked old one which was faked up with filler and wood. The one at the front is the aluminium casting taken from the pattern. They used aluminium because it was lightweight. This is like BMW bragging that the 5 Series has lightweight aluminium suspension and completely forgetting to tell you that each front seat weighs over a hundredweight.

 

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And these lump of cast steel are the spring hangers. At the front the springs are anchored at the front (the hangers nearest the camera) and at the rear end of the spring it sits on a slipper than run on a dovetailed plate. The rear springs sit on slippers at both ends and the axle is located by a stout radius rod. This allos you to move the rear axle to get the chain tension right. So there are two fixed hangers and six floating slippers. A pattern got made for both types.

 

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Detail of a floating slipper

 

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This is some of the bits of the engine. The thing that looks like a piston is called a cross head. The thing fixed to the cross head is the con rod. You will probably spot that the construction isn't exactly Cosworth. The other big lump of metal is the stuffing box. This carries the glands that keep the steam and oil where they are supposed to be. The rusty bar in two pieces is one of the piston rods. Yet more metal to be turned into swarf to make new ones.

 

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A delivery of metal. What is lying on this pallet is all the bar to make the shafts and gears for the differential. There is also the metal for the front axle hubs and the engine sprocket carriers. Once upon a time getting material like this was an absolute nightmare. Now were have forward thinking suppliers who will send you what you want in the spec you want and (really important this one) without you having to buy a full length of the stuff. We live in good times.

 

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Pattern making was now in full swing. If you look up the page to the extract from the parts book for the front axle you will see the axle beam and two other lumps which are the swivels. These take the stub axles and allow them to be swung. The "pins" top and bottom is what they rotate on and the big funny shaped lumps take the bolts to fix the steering arms too. This design was another of Sentinel's "improvements". They also patented it so no one could copy it. I think this was Sentinel's idea of a joke.

 

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Yet more castings. One big end was missing and the other was unsurprisingly shot. We took the old one and carefully built it up with filler to make a pattern. These are the bronze castings made from that pattern. The thing that looks like a scoop is a scoop for scooping up oil in a desperate attempt to keep the bearing surfaces oiled. This is what passed for engineering back then.

 

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Enough of the castings already. I told you it would be a castings day. These are the C brackets for the front axle. These bolt to the axle beam and carry the lower bearing for the swivel above. You have probably worked out by now that there is a fairly mammoth machining effort looming.

 

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Last bit of the axle jigsaw puzzle are the steering arms. These were drop forged originally but we'll have to start with steel castings. It will start to become apparent how this pile of raw castings join together to make a finished axle.

 

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This is where we came in. The finished diff gear blanks. We can handle most stuff in our own workshop but gear hobbing is not one of the things we are set up for. The six blanks were taken to Leek Gears who are in Leek and machine gears. On top of that they are smashing, helpful people and I recommend them for all your gear cutting requirements.

 

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That's enough tedium for one post. Next time we win* a trolley dash at the local railway preservation place and come away with most of the bits we need for the engine. Or at least bits we can use to make non-knackered bits.

 

 

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Can i ask how you go about registering the finished wagon?  i'm assuming it can't be treated as a new vehicle and go the BIVA route?

Whats the crack between rebuilding an existing boiler and making a completely new one? Paperwork and testing?

I love it that someone could identify the bits you bought at auction (and the fact someone was mad enough to save them for all this time!) rather than them ending up as scrap

 

It looks like we have a number for the engine. We know which scrap dealer the engine came from before it ended up in Mr Keeley's yard and people have a good idea what went through that dealer's yard so we are pretty sure it is the engine from waggon 6982 which is a later waggon dating from 1927. It was first owned by Kelvin Transport in Alexandria (the one near Glasgow rather than the Egyptian one) so it has come back quite close to home. Hopefully we can get enough together to get an age related plate. We don't get that bent out of shape about original numbers. There is a reason for this but I won't go on about it.

 

Repairing/manufacturing is about the standards that are applied. If it is a "repair" then the standard that is applied is one that relates to the original design. This in itself can cause problems because getting hold of superceded BS documents  can be tricky. If it is manufactured then you apply the standards of the day. Personally speaking if I am sitting next to a large pressure vessel at 255psi then I'd like the very highest standards applied please. This place is fairly open so I won't vent my spleen on the subject of bodging 100 year old boilers back together on a wing and a prayer. It wouldn't be very interesting, either.

 

Our boilers are built to BS5750, certified by Lloyds and carry a CE mark which is what any pressure vessel needs to carry if you want to sell it commercially. We are engineers with a petro-chems background so documenting/manufacturing pressure vessels is something of which we have a little knowledge. Suffice to say a properly designed, manufactured and documented pressure vessel should have no problem getting insurance in future. I am not sure this is going to remain the case for all pressure vessels.

 

Finally, most of what John Keeley bought ended up as scrap in sheds and hedgerows. There were two sales - one of his motorbike collection which got a bit of coverage and one of everything else. The catalogue of his "collection" is still online.It gives the impression of a man who just bought anything.

 

https://www.i-bidder.com/en-gb/auction-catalogues/cheffinsov/catalogue-id-cheffi1-10039

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Fascinating reading, and thanks for sharing. I shudder to think of the cost if you totted up your labour, if you were building the Super for a customer. The fact you’re actually doing it anyway is fantastic.

I’ve got a ‘63 Raleigh Superbe cycle sat in the garage. I reckon yours needs a name swap with mine - I’d rate yours as superb, not super!

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Costs in terms of actually outlay are not horrific. You certainly couldn't buy much of a new car with it these days. However, on the few occasions that external machine shop assistance is needed (gear cutting and large diameter spherical turning are the only things so far) you become very aware of what workshop time should be costing and what it would cost to build something like this if you didn't have a semi-decent workshop of your own.

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..... most of what John Keeley bought ended up as scrap in sheds and hedgerows. There were two sales - one of his motorbike collection which got a bit of coverage and one of everything else. The catalogue of his "collection" is still online.It gives the impression of a man who just bought anything.

 

https://www.i-bidder.com/en-gb/auction-catalogues/cheffinsov/catalogue-id-cheffi1-10039

 

I think that's called "hoarding".

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