Project It is just so Super (Sentinel).

[somewhatfoolish]

I want one now, although I think I would need a (much) bigger mill and a horizontal borer is not something I'm likely to use much.

[mk2_craig]

That auction... The estate did well out of all that random old rammle didn't it!! Fair play to the guy for stashing the stuff away. If that's the sum total of what went under the hammer I wonder what else went in the skip.

 

I am fascinated by this build - will be watching with much interest.

[quicksilver]

How have I missed this thread before? You guys built a steam waggon virtually from scratch?! That's some serious engineering and I take all my hats off to you.

 

And I can just imagine what old Mr Keeley was like, hoarding old tat like one of those places you'd see on Salvage Hunters but without Drew Pritchard upcycling stuff and selling it for eleventy million pounds.

[Tadhg Tiogar]

....And I can just imagine what old Mr Keeley was like, hoarding old tat ....

 

[kirton]

There's obviously a good number who are enjoying this engineering saga;  can I recommend for further entertainment and wondering at the ability of others the pre WW2 vehicles section of the Historic Military Vehicles forum and the Gosling family's rebuild of a Dennis, a Thorneycroft, and now starting on a Peerless

[Saabnut]

I *think* this is my favourite thread of all time! About 8 years ago I seriously considered buying a Steam Car, and a Stanley was at the top of the list. After a great deal of help from the Steam Car owners club, I reluctantly realised I did not have the engineering skills to maintain one myself, and living in the back end of beyond, using third parties was not practical, so I bought my Cobra instead.

 

I still would love a steamer to play with, but it will not happen now. Building one from scratch is possibly the craziest thing you could take on, and I doff my cap to you. Bravo.

[JimH]

Let's start this catch up with a bit of history. Right back at the start I mentioned the Standard. The Standard was a simple device and a tough wee bugger. A typically overloaded Standard, yesterday.

 

 

Brown Bailey ran their Standards, massively (and I mean massively) overloaded into the 1960s. If you know the Glasgow Transport Museum you'll know one of Brown Bailey's Standards.

 

It may look crude to our eyes but in comparison with what went before it was pretty bloody awesome. One day people will look at our Scanias and laugh in the same way. Anyway, the Standard was so brilliant that they sold thousands of them and Sentinel made a lot of money. By the 1920s sales were tailing off and money was getting tight which is why the new improved Super was developed. However, it was clear by then that despite their best efforts steam was not going to be viable as road haulage for very much longer so they needed to diversify. One of the things they went into was railway engines. In order to minimise risks they didn't leap headlong into building proper locos but instead chose to use as many bits from the waggons as possible. This restricted what they could build to shunters and, slightly later, rail cars. This is the quite late Sentinel Shunter that lives in the NRM

 

 

The Super engine sits vertically at the front and drive through a chain. The boiler (much bigger than the waggons in this case) is in the cab. There is a bigger version of this one in preservation that uses two Super engines. Sentinel shunters were actually quite successful and were built into the late 1950s. If you rake round most railway preservation places you'll almost certainly find one rotting into the weeds.

 

What is the point of all this wittering about railway engines? Well, the engines were the same as the waggons with one or two key differences namely they had a solid forged crankshaft and a differently shaped crankcase. They also ran pressure fed lubrication to mains and big ends. Why this development didn't make it onto the waggons is lost on me. They also had a slightly different (but significantly better) manifold arrangements but it is just too boring to go into that here. The upshot is that if you need a few bits for an engine then one of the first places to start is your friendly neighbourhood railway preservation yard. And we had one of those just down the road and it had not only a few shunters but also a very large pile of brand new spares. This would be just what we needed. In the end we came away with what we needed in exchange for a not exactly trivial sum of money. What will become clear over the next couple of photos is that we didn't have a great deal of choice.

 

Probably the most important missing pieces were the camshafts. Not satisfied with talk of railway things let's have a bit of talk about the mechanics of steam engines - apologies to anyone who is being taught to suck eggs. The reciprocating steam engine has many benefits but it also has some limitations.  One of those limitations is addressed by giving it variable valve timing. On a piston valve or slide valve engine this is a pretty simple task which involves some sort of linkage - and there are lots of different types of linkage - controlled by the operator. What you are doing is controlling for how much of the piston's stroke you admit steam. To produce lots of torque you need a lot of steam so to start, for example, you will run at 90% cut off. That is admit steam for almost all of the stroke. As speed builds you need to admit steam for less and less of the stroke. The shortest cut off may be as little as 20%. The other thing is that you often need to run a steam engine in reverse so altering the valve timing allows you to do that to. All very easy to understand and handy.

 

However, the Super engine, like most undertype steam waggons from most manufacturers (Yorkshire being a notable exception), uses poppet valves (the same kind of thing as what your car uses) operated by a camshaft. If you have a camshaft how do you engineer variable valve timing? These days there are many ways of doing it and through the years various engineers have come up with all sorts of elegant solutions.

 

What we are talking about here is not elegant at all. The solution is that you have multiple lobes on each camshaft then as you want to change the cut off or go backwards you drag the camshafts from one lobe to another. Hmmmm. To illustrate here is the first prize from the trolley dash. It is a brand new, still in its waxed paper exhaust camshaft. My little beady eyes lit up when I saw this.

 

 

You have an inlet and an exhaust camshaft. Twin cam, four valves per cylinder and VTEC. There is nothing new under the sun. Each valve has four lobes. Two forward cut offs, a drain position (all valves held open) and a reverse. Because shunters tend to go forward as much as they go backwards the shunter camshafts have two forward, a drain and two reverse. Later DG and S Types waggons got three forward cut offs. Each one of the bumps you see is a lobe of a different grind. The long slot at the end take the drive dogs from the cam gears. It is long because the camshaft needs to slide within its drive gear.

 

This is a close up of some lobes. You may be able to make out the two forward - drain - two reverse lobes for each valve. Making these would have been tricky so it was a huge step forward to get them.

 

 

This is someone else's photo of the inside of their Sentinel shunter crankcase. It gives a pretty good idea of how things work. The engine sat upright in the shunters so they added a little tray underneath the camshafts so they always ran in oil. The things poking down are the tappets.

 

 

Enough about valves what else did we get? These are the inlet manifolds linked by the steam inlet pipe. These were overhauled spares which were nice because everything was there. Even though the valves were new they won't be used because the steel used by Sentinel was absolutely hopeless and valve seat life was close to non-existent. New ones in the right steel will be used (you'll like them when we get to them).

 

 

A pair of exhaust manifolds. You might see that one has been dropped at some point and bent the valve stem. Hardly a disaster but it broke the valve guide too. A little bit of remedial work required.

 

 

Valve adjusters. These screw onto the end of the valves and allow the clearances to be adjusted.

 

 

A pair of new pistons. Very nice. The log shaped thing is the exhaust manifold link pipe.

 

 

And lastly for the store shed was a pile of new piston rings.

 

 

There are still a few key components missing so we had to venture into the undergrowth to find the sorry remains of the two used, incomplete and mostly buggered spare engines to get the rest.

Our luck was in and one of the engines had one of its cylinders still on. This is well and truly knackered but it can be used as the basis for a pattern so that is good enough. That is the old piston next to it. We had to cut through the piston rod to get the cylinder off.

 

 

A pile of tappets. Hopefully from this pile there will be eight that can be pressed into service.

 

 

Camshaft gear train. The big one is the idler that is driven by the crankshaft and the smaller pair are the camshaft drive gears. They sit on bronze carriers which allow the camshaft to slide relative to the gear. The big bronze eccentric on the large idler gear is what drive the water pump.

 

 

This is what Honda copied to make their VTEC engines. There are forks inside this cast iron housing which engage with the camshafts. This allows the driver to move the camshafts to the desired position. You don't need to know too much about steam engines to know that using poppet valves is a really, really stupid thing to do. Suffice to say when Abner Doble designed his cutting edge steam cars and lorries he did not use poppet valves.

 

 

And the last piece of the jigsaw. A cylinder head. Only one sadly so we'll need to make another. The big bronze valve is a relief valve. If you get it wrong and overfill the boiler water can get carried over into the engine. This is called priming and it can also happen under other conditions. Priming is very bad news for a steam engine and usually results in people looking very sad and/or gulty and wondering just how all this broken thing can be made better. However, a decent relief valve at either end can save the situation. Waggons didn't have RVs but locos did. We'll keep the RVs on this one.

 

 

That will do for this time. In the next installment we go back to making patterns, a new lathe appears and some things start to look finished.

[JimH]

I seriously considered buying a Steam Car, and a Stanley was at the top of the list. After a great deal of help from the Steam Car owners club, I reluctantly realised I did not have the engineering skills to maintain one myself, and living in the back end of beyond, using third parties was not practical, so I bought my Cobra instead.

One of AC's lash ups sounds a lot more fun than one of Stanley's lash ups.

 

Fragile is probably the word that leaps to mind when thinking of steam cars.

[Supernaut]

I just wanted an excuse to post this, with the talk of steam cars.

 

[Datsuncog]

I know absolutely diddly-squat about steam vehicles - but I know I'm loving this.

 

Top threadage, sir, this is utterly fascinating stuff... can't wait to see how it progresses.

[Tadhg Tiogar]

....This is someone else's photo of the inside of their Sentinel shunter crankcase. It gives a pretty good idea of how things work. The engine sat upright in the shunters so they added a little tray underneath the camshafts so they always ran in oil. The things poking down are the tappets.

 

 

.....

 

That reminds me of Oliver Bulleid's (in)famous "oil bath" which was part of his chain-driven valve gear system, built into his Merchant Navy and Light Pacifics. Apparently there was a bit of a problem with leaks....

[JimH]

It's funny how certain utterly vital developments we now take for granted completely pass us by. It's also interesting how recent some of these developments are. Need to keep oil from leaking past a rotating or sliding shaft? How about this cost pennies, live forever lip seal? Pop one of those in and Bob's yer uncle.

 

Not back then we couldn't. They farted around with felt and leather and cotton and lead and asbestos and all sorts of things in an effort to make seals but they still poured oil everywhere.

[MarvinsMom]

we used to see this magnificent beastie in Whitby regularly up until a couple of years ago, when the owner decided to sell up after having no end of problems with the cuntcil, who were, are and always will be a bunch of dicks.....

 

 

shame cos i used to love seeing her running around town. and with a suprising turn of speed too. For those who know Whitby this is on the climb up Kyber Pass onto West Cliff.

 

Nice to see the big Sentinal at the NRM, she was built new for Teesside Bridge, in Middlesbrough, so i've alway had a soft spot for her, as she is from a "local" if sadly long defunct, firm.

 

i shall look forward to reading more of your exploits. it goes to show, what can be achived with the right skills and some patients.

[Sir Snipes]

Wow, I never expected to be reading about vvt in a thread about steam engines!

[lisbon_road]

I'll never mention parts being hard to find again..

 

Keep it coming, big thanks.

[DodgeRover]

Were you not tempted to make improvements as you went along to show what could have been if the technology had been available?

[mat_the_cat]

I never thought I'd be interested reading about a steam lorry, but it's absolutely fascinating.

 

in the LDV

 

/\ And the icing on the cake!

[Zelandeth]

Wondered how long it would be before someone mentioned the Doble vehicles...Really hope to get a look at one in person one day, while fiendishly complicated, there really can't have been anything that could touch them in terms of performance or refinement back in their day.

[JimH]

Oh joy. Another update. You see that thing that looks a bit like a cylinder all covered in old cladding and asbestos? No hope for that but it will live again as a pattern. A bit of a cheat I am afraid but we only need to make two of them. The foundry hated us for this.

 

 

And slightly less cheating, this is the pattern for the water pump con rods. Water pumps in steamers are expected to do a bit more work than in your Acclaim so they are a bit more butch.

 

 

One of the things we were struggling with was that there was a bit of a hole in the lathe capability. The shafts for the diff were all made in EN24 which seems to need fairly high cutting speeds. The Swift couldn't spin that fast and the Colchester Student wasn't big enough. The problem is that people are only just discovering that the amazing Bristol Churchill Imperial lathe buit in Qingdao for three and six wasn't quite the amazing bargain they thought it was so half way decent lathes are getting expensive again. Most dealers want £5-7K for a Colchester Triumph these days depening on spec. We managed to fine this one for a fraction of that. Mainly because it had very little kit with it and there had been a rather shoddy repair to the clutch and input shaft.

 

 

This is it in the process of being taken to bits. Once it is done we will be able to spin things quite fast. I'm not a massive fan of Colchester lathes but go and take a look at what a Dean Smith and Grace or Lang will set you back and you'll see why we'll just have to live with it. In the end it needed only a set of guide rollers for the clutch bought for it. We were able to make everything else. This was good because Colchester spares are terrifyingly expensive. A tiny padded envelope arrives with three tiny rollers in it. Doesn't seem a very fair swap for the four hundred notes you handed over for them.

 

Various manifolds cleaned up and waiting for their new valves. Also in that pile are some crankcase breathers a pair of cam gear covers and a pair of gland followers for the water pump.

 

 

This is what came back from the foundry. Some vaguely cylinder shaped lumps of cast iron. These will need a lot of machining to turn them into something that actually works. Lots of things that if we were doing it properly would be cored so things like ports would already be there. However, we will have to rely on man hours to machine them instead. You see that mutant lump of cast iron sitting next to a cylinder? That is one of the three balance weights from the crankshaft. Lump of brass lower right is another project. I'll show you that later.

 

 

Some more bits back from the foundry. New cylinder heads and a water pump con rod. Also visible are a pair of finished drive shafts and a piston.

 

 

 

Eventually the crankshaft came back from the grinders. We can do a lot of things but crank grinding is not one of them. Now the work of rebuilding it can begin. You see the bronze bushes? They are all buggered and need replaced. Note the finished quality of the crankshaft forging. This is why I get annoyed when people tell me, "They don't build them like they used to, eh?". No, we build them properly now.

 

 

 

Another important bit. A casting for the water pump. It also came with a ram but it is worn and too small so we'll need a new one of them. This Super is being built with a high volume water pump 'cos that will mean we can go faster for longer (go faster = need more steam = need more water).

 

 

Spot the difference? The bushes have gone. A trivial change but took a while to do. Bushes are usually made with an interference fit so you shrink them in liquid nitrogen or heat the thing into which they are fitting. Then when things return to the normal temperature everything stays put. However, getting them back out is a bit of a bugger. The usual approach is to pop the thing in the lathe/boring machine and machine them off center until the bush collapses. A bit tricky in this case so we opted to cut them very carefully by hand. See the yellow macine hacksaw blade on the floor? Took a while but we got there.

 

 

And this is some of what came out. The big ones are the main bearings. They were machined off centre. Now we jus need to make one of everything and it can all go back together.

 

 

Another bit. This is the foot valve for the steam brake. Steam brakes are awesome - beautiful controllable linear things that ooze feel.

 

 

Woo yay! Finished things. These came back from Leek Gears. Teeth are all flame harded. A very pleasing sight and no mistake.

 

 

 

You know how when you go to some seaside town there are horse and carriages clip clopping up and down the front? These days people seem to get all arsey about horse cack all over the place so there is usually some sort of turd catch tray at the back end of Dobbin. This is the same sort of idea. This is the ash pan. Catches the ashes as they fall through the grate. Actaully it was more about controlling draught on the fire rather than keeping the front at Skeg tidy.

 

 

There was now a lot of machining to do. Here is a nearlyfinished big end being fitted to the crank journal. You do an lot of work to make things fit. This is why fitters are called fitters. Lego man appears in the next few photos because someone somewhere else whined that there was no idea of scale. The sharp eyed will notice that the bolts are too short. This is because we are using the old bolts here. New ones are being made elsewhere in the workshop.

 

 

And this is the first dry fit of the crankcase and trunk guides. A lot of measuring needs to go on to get the cylinders right. Measure nine times, get someone else to measure another dozen times, give it one final check, then measure twice more for luck, cut once. There are a lot of things need to be in the right place. Front axle C bracket just sitting there for some reason.

 

 

The other big end being machined.

 

 

A nice oh it might be finished one day bit. A pair of reproduction waggon plates. Lists all of the patents the waggon was built under. An act of supreme corporate arrogance because no one was going to copy them. Ever. Sentinel would have been better off trying to patent a Gardner LW engine.

 

 

Bottle for the water pump. This smooths out the flow. A bit. Promise.

 

 

And finally the spring slippers being machined in the shaper. Shapers are very under rated machines. You can do a lot with them.

 

 

Looking forward in the photostream next time things start to look even more finished and the crankshaft ends up looking like it did in that photo I put up earlier.

 

 

[JimH]

Wondered how long it would be before someone mentioned the Doble vehicles...Really hope to get a look at one in person one day, while fiendishly complicated, there really can't have been anything that could touch them in terms of performance or refinement back in their day.

 

Sentinel engaged Doble as a consultant in a last ditch effort to do something with steam road haulage. He designed some interesting engines and boilers but as with his cars he was banging his head against the stone aged control systems and metals that were not up to the temperatures and pressures he needed. These days it would be very much easier were it not for the fact that the IC engine would still be about eight trillion times better.

 

I saw the Doble steamer in the museum at Donnington. However, when I was there it was sitting next to the Bugatti Royale so the Doble looked a bit crap and teeny weeny.

[Mally]

And I thought all you needed was a bit of plywood for the cab!

[JimH]

In the last episode the gears had returned fron Leek Gears and the bushes had been removed fro the crankshaft. Large chunks of bronze were then reduced to swarf to make new bushes. This pile here represents everything needed to make the differential for a Super. Ignore the black things. They are plastic supports for the drive shafts while things are being fitted up. Last episode I went on about shinking bushes in. This is a right old pain to do because it's helpful to have a supply of liquid nitrogen which is tricky or you need to heat things that you aren't entirely happy with heating. On top of that once you have fitted the bush you need to finish bore it.

 

However, on its white charger Modern Progress appears over the horizon in the shape of engineering adhesives. Now you fit the bush to the shaft and leave it slightly under sized so it slips into the housing. Then once you are happy with how everything fits you pop on some posh glue and wait for it to set. Brilliant. However, the world of engineering adhesives is a bit complicated and you need to know which ones to use and where. Spec sheets start to get quite long and weary. Still brilliant, though. 

 

 

An almost complete water pump set up. Idler gear complete with eccentric, machined con rod, new pump ram (not yet machined to length) and bottle. There is a very important and complicated bit missing but we were still trying to talk to someone in Aus about one they were having cast. The pump ram has been made as big as we can get it into the body. This means we can get more water into the boiler.

 

 

About this point the milling machine broke. I believe that before we got it the thing had sat outside for a short time. I seems that water got into the quill bearing and it gave up the ghost. These are fiddly little buggers to work on but here it is returned to full health.

 

 

Close up of a tappet once it came out of the bead blaster. This one is one of the better ones. Not pretty. A little care and attention should return them to if not factory fresh at least a decent impression of it.

 

 

And the same tappets and lock plates fitted to the crank case. These are polished at the moment but they should be chemically blackened so they look right. Just another four to do.

 

 

And if we zoom out we can see that the crankshaft has been trial fitted. This point of all this was we needed to measure the positions of the push rods so the manifolds were fitted to the cylinders in the right place. We also needed to get the piston rods the right length.

 

 

And here's a cylinder being machined. Our boring machine isn't bad but it doesn't have a live spindle which makes it a bit of a faff at times. If anyone has one with a live spindle looking for a new home for not much let me know and I'll be there tonight to pick it up. Note writing all over it so no one gets confused about which end is which.

 

 

Bored and faced. Just the sticky problem of the ports to go. And a few other things.

 

 

We did a job for a now defuct paper maker. Well, they were already defunct which was why we were doing the job. Because we were on site at the time we were allowed to have a trolley dash in what was left of their metals store. In the end we probably got a ton and a half of flat, round and hex bar as well as handy bits of pipe. Here is some of it carefully stored under the Goddess.

 

 

Non-ferrous cuttings bin. Turning down flanged bushes from cored bar causes a lot of these. We weigh them in occassionally in a pathetic attempt to make it look like we are saving money.

 

 

And this is the pile of steel and cast iron turnings generated over a weekend.

 

 

The final part of the diff jigsaw is the sprocket carriers. These hubs have the drive sprockets bolted to them. Take piece of stock bar and machine it until you have (i) one of these and (ii) a pile like the one above. Note shiny tappets.

 

 

The pile gets bigger and a lot less depressing.

 

 

Con rods with new big ends and little ends. New bolts for the big ends not yet made.

 

 

My old man does a lot of this. He likes writing lists so he can score things off. I tend to be a bit more slap dash in my approach to planning projects. There are a lot of white boards in the workshops.

 

 

Yet another long LDV drive to pick up some new (to us anyway) bending rolls. The poor LDV gets used a lot. Note yet another whiteboard in background.

 

 

And *drum roll* the finished differential fitted to the crankshaft. Important piece of progress this. If you understand that the sprocket carriers spin freely on the crankshaft you should be able to get how it works. One of the downsides of this design is that you can't lock it which was a lot handier then than it is now. The other disadvantage is that it is massively heavy and expected to spin at about 1400 RPM max.

 

 

 

One of the problems with the documenting what we do it that we are utterly piss poor at stopping to take photos so the record is a bit stilted to say the least. I've just been working through what few photos I've uploaded to Flickr over the past couple of years. This comes back to bite us time after time because we spend a lot of time wondering out loud "what did we do with the last one?" but because it was twenty years ago you can't remember. You end up scratching around a few photos searching for clues about what you did. Stuff pings into your head at three in the morning too. The point is that the next photo I uploaded is this one.

 

 

Oh. That's a bit of a jump. Cylinders finished and honed. Manifolds fitted, clad and the whole damn thing put together. Do you not think we could have got it together to take a few photos in all that time? No, apparently. Anyway. Here's a nearly finished Super Sentinel engine. We are in the process of setting the timing.

 

Closer on the cylinders and valves. Nothing polished or painted. Inlet valves at the top, exhaust at the bottom.

 

 

Compare this shot with the one when it arrived.

 

 

 

And we'll leave it at that today. Now the engine is somewhere near finished we need to start doing bits it needs to be a lorry.

 

 

[scruff]

Outstanding..!!

 

 

How have I missed this thread before? You guys built a steam waggon virtually from scratch?! That's some serious engineering and I take all my hats off to you.

 

And I can just imagine what old Mr Keeley was like, hoarding old tat like one of those places you'd see on Salvage Hunters but without Drew Pritchard upcycling stuff and selling it for eleventy million pounds.

 

John Keeley was a lovely old boy, a hoarder perhaps but he was not afraid to use his engines (the ones that worked anyway) and he ran an excellent rally in the fields around his home at Knowl Hill.  I was 16 when he died but my grandad and some of his chums knew him well and I am friendly with his nephew and great niece. He was a very astute collector and although there was a lot of scrap that would never have 'gone again' he had a good eye. The motorcycles were sold separately a few weeks before the Cheffins sale and made a fortune...! 

[Tadhg Tiogar]

..... I'm not a massive fan of Colchester lathes but go and take a look at what a Dean Smith and Grace or Lang will set you back and you'll see why we'll just have to live with it. In the end it needed only a set of guide rollers for the clutch bought for it. We were able to make everything else. This was good because Colchester spares are terrifyingly expensive. A tiny padded envelope arrives with three tiny rollers in it. Doesn't seem a very fair swap for the four hundred notes you handed over for them......

 

Four hundred seems to be what a whole Unimat 3 costs for miniature engineering.

[JimH]

Nearly up to date now. The finished engine - except for the paint - all bolted up, timed and full of oil.

 

 

 

If you look at the stuffing box you will see that it looks rusty. This is because it's been running on steam. We ran a pipe over from the S4 to give this a run on steam. The good news was that everything worked just fine. Now we can move on.

 

You'll be a chassis one day, my son. A pair of chassis rails clamped back to back so everything can be marked out as a matched pair. This makes fitting things like engine mounting plates much easier.

 

 

The floor of the cab is made from 3/16" plate. Yeah, really. It is meant to be admiralty pattern (diamonds) which hasn't been available for quite some time. We were lucky enough to find some sheets of it in an old plant that was being demolished. Being greedy we got as much as we could in the hope we could stitch it together in a clever enough way that you wouldn't see the joins.

 

 

Springs are easy. Spec them, phone up some spring benders, pay them some money and they appear. These waggons had a six ton payload. To look at the springs the payload was ten times that.

 

 

We found a near full set of tin basher's stakes for a pretty reasonable price. Might need to learn a bit more about tin bashing yet.

 

 

Full set of spring hangers somewhere near finished. The floating ones slide on dovetailed plates which are bolted to the chassis. This is the sort of extravagance that people mistake for quality. Boiler bits lying on the floor beong to the S.

 

 

Chassis rails in place and this is what passed for an engine mount. Therese were pressed but that is a bit tricky now so the pressed ribs are faked up with D section beading. You will notice that we built the chassis around the engine so we can lift it up into place. The engine is ridiculously heavy.

 

 

 

They don't build them like this any more. *rolls eyes*. Big lumps of channel with big bits of angle rivetted in place. Put bolts in to begin with then you have to pretend to be the most manly thing ever invented. You have to pretend to be a riveter.

 

 

The start of the front hubs. Big bit of metal makes the hubs and a big disc makes the bit you bolt the wheel to. There is a lot of work to go into these yet. The big bits of steel next to them are the stub axles.

 

 

 

Chain drives. Just like what you have on your bike but bigger. Supers used 1.75" pitch chain which is quite big. The sprockets can be bought off the shelf from Renolds but they are not cheap at all. Like buy a decent car not cheap. What we had been doing a fair bit of up to this point is using Jet Cut in Hillington who are terribly helpful water jet cutting people. Their kit is good enough to cut the sprockets from plate. This means we get all four sprockets for less than the cost of one off the shelf one. However, specing sprockets is tricky because there is a bit of variation in the standard. Since the work isn't exactly cheap we got them to make a template in plywood to test them before we got the proper ones made. Here is the wooden template being checked. Got it right in only three attempts. Note that the chain isn't light duty.

 

 

Front axle C bracket in the boring machine.

 

 

And some fairly finished swivels and steering arms. The short pins act as king pins and the hole down the middle takes the stub axle.

 

 

All our rivet snaps are too big for the chassis rivets and despite searching everywhere we could not find the right ones. We had to buy some fancy pants steel to make our own then sent them off for heat treatment. Note rivet gun.

 

 

Two halves of the front axle beam and C brackets machined and bolted up. Now we need to make a jig so we can hold it in the right place while we weld it together. Without boring the tits off you on the subject of geometry the change from solids to pneumatics cocked a lot of things up so we need to discretely introduce some angles to try to get things in about the right place.

 

 

Yet another pile of bronze to make the front axle bushes from.

 

 

Sprockets returned from Jet Cut.

 

 

The big ones will form part of the brake drum fabrication. Powerful stuff, a jet of water.

 

 

Progress slowed by other stuff. The S has been around for ten years which meant it was due a major boiler inspection. This involves removing the boiler from the chassis, removing the cladding and splitting the shell from the firebox. A right old faff and no mistake especially for a boiler that is eleven years old. This is it back together waiting for the insurance inspector to witness the hydraulic test. The big strap round it is just for lifting.

 

 

There is a fair amount of kit in the workshops which has been gathered over the past 30 years or so as things become available and there was space. Sometimes things turn up that you are not very likely to use but you are sure you will use them one day. This forge came out a training centre in 1993. We were convinced that one day it would come in handy and as if by magic a mere twenty five years later it's needed to heat the rivets for the chassis. Note Sprint not being polished.

 

 

Steering box trial fitted to chassis. Are you starting to get a feel for how crude these things are? Elegance was for other people.

 

 

The S minus its boiler. I was moaning the other day about dismantling cars just to get to the clutch. It is worth remembering that to get the boiler out of an S Type you first need to remove the roof. Plus ca change and all that.

 

 

And finally a last look at the chassis with some bits on it. You should start to get a feel for what goes where.

 

 

And that brings us up to dateish. The next jobs are rivet the chassis, make the front engine mount, get on with the front axle and make a start on the cab which is where I came in. More updates soon.

[LightBulbFun]

very interesting stuff

 

reminds me of the steam wagon featured on Britains greatest machines

 

 

(its about 10 mins in)

 

but im curious, whats the MOT procedure for a steam wagon/car? can you even get one MOTed if you wanted too? (I know there obviously MOT exempt LOL)

[JimH]

Steam powered vehicles are exempt MOT and the waggons are not HGV. The oddity is the rollers which have their own driving licence category. I can drive a 20 ton B6 road loco but not a 3 ton Wallis and Steevens Simplicity roller.

[scruff]

Again, excellent pics and words, brilliant progress.

What I know about Sentinels can be fitted on a stamp but I was interested to see you have a reflex water gauge in your S4 (your S4 I have never seen before so thanks for that). I am amazed more people don't! 

[406V6]

Fantastic stuff. I'm in awe of quality heavy engineering like this.

 

The thread title could do with an update - dropping in the works Sentinel and steam wagon - as it's easy to miss.

[JimH]

I was interested to see you have a reflex water gauge in your S4 (your S4 I have never seen before so thanks for that). I am amazed more people don't! 

I ain't getting in the cab of one of these things without a reflex water gauge. As Sir Robert Mark might have said, "I believe it is a major contribution to road safety".

 

The reason many people don't have a reflex glass is that if you replace the glass tube with a reflex one you end up with a very short sight glass which isn't very helpful. Because we made these boilers ourselves we took the opportunity to stretch the top and bottom gauge cocks as far apart as possible so we could get a nice long glass in.