Project It is just so Super (Sentinel).

[Spiny Norman]

On 4/23/2019 at 8:00 PM, dozeydustman said:

This thread is full of the utmost win. First time I've come across it.

+1.
It's like reading about an old locomotive being restored and then seeing pictures of it driving down the high street.  Superb. ?

[somewhatfoolish]

Lovely stuff.

10 hours ago, JimH said:

 Its spritely acceleration and well pucker brakes make it a piece of piss to drive in heavy traffic and the steering makes it a doddle to thread your way through towns.

Pucker is what your arse does when your brakes aren't pukka. :D

[JimH]

Some exciting things arrived on Monday. Someone who wasn't me had to trail down to darkest Lincolnshire to pick up some patterns and castings for the last big bit that needs made - the rear axle.

Wee bits first - the pattern for the radius rod ends. The rear axle can float around to keep the tension on the chains right and it is held in place by a pair of rods which are fixed to the engine suspension plates.

And there are two rods with an end at each end so we need four rod ends.  And as if by magic using only sand and molten metal you make four of them.

Then the radius rods need something to mount on. A radius rod palm first in wood...

The black bit is to locate the core. (casting things can get very complicated and pattern makers have to think in ways that makes my head hurt)

Then wood becomes metal. You need two of these.

Next you need some brakes. These aren't too different to those found on the back of your shitter, just bigger. The pattern...

And then the real thing. The brake shoes are cast in one piece. This makes it much easier to machine the outside diameter. They get split in two after they've been machined.

And finally you need something for it all to sit on. The spring pad. Pattern making is bit of an art.

And a big lump of SG iron. There is a lot of machining to turn this little lot into an axle. The axle beam slips through the hollow round hole. The square box at the bottom is an oil reservoir to keep the brake shafts lubricated.

What we need then is a couple of hubs and we are nearly there.

[busmansholiday]

Ah, pattern making and foundries turning them into something useful. I've spent many an hour ( longer than I should have been there) watching skilled men do this. It really is a fascinating operation. 

I'm sure you know that SG iron produces phosphine gas when you machine it in a damp atmosphere. Another thing I've been involved in.

[JimH]

I did not know that. I've just read a paper on the subject of using water based coolants when machining SG iron. Fortunately the stuff we machine in SG is always done without coolant.

 

Every day's a school day, yeah?

[busmansholiday]

Phosphine, not to be confused with phosgene like one of our safety managers did when he was talking to our turners.

The latter is a toxic gas that was used in WW I, imagine the fun we had trying to calm down our employees and explaining that the safety manager was a .........

[LightBulbFun]

17 minutes ago, busmansholiday said:

Phosphine, not to be confused with phosgene

sounds like a deadly version of how people confuse Phosphor and Phosphorus 

granted some phosphors can be quite poisonous, see any fluorescent tube from about before 1947

Beryllium based phosphor compounds ftw!

(I keep my 3 examples in a strong PVC pipe out of harm's way, so theres little chance of something smashing them and everyone getting berylliosis that and they are very rare so I don't want anything to happen to them!)

 

 

[UltraWomble]

 

Mad Ruskie tries to convert Lada to run on compressed air / steam

[UltraWomble]

Cant help you with the make Im afraid - photo taken 1907

[Justin Case]

46 minutes ago, UltraWomble said:

Cant help you with the make Im afraid - photo taken 1907

This is a Leyland steam waggon which was made from 1904 to 1914. It could be either B class or H class. No, I'm not that much of an anorak but I do happen to have a copy of 'The Undertype Steam Road Waggon' on the bookshelves within easy reach 

[JimH]

It's been a while since the last update and a few things have gone on so we'd better have a catch up.

When we last saw them most of the castings for the rear axle had just been delivered. This meant that someone who doesn't have a proper job had to spend most of his time standing in front of the boring machine turning them into something useful. Here are the brake shoes ready for lining. They are cast as a pair then separated, however, we have left them as one piece for lining so once the lining is on them it is easier to pick up a diameter to machine the brake drum to. 

Annoyingly the first quote for lining them came back as just shy of £800 which seems a bit strong to us so we'll just get some linings and rivet them on as per the original design ourselves.

Then there was a big pile of SG iron that was to get turned into a rear axle. Sadly we are not good at taking pictures so there is quite a jump. This is the spring pad on the near side bolted onto the spring with the radius rod in place. The thing was we didn't have a measurement for the axle beam itself and with so many dimensions that you are trying to meet you have to start somewhere. Now the spring pads are in place we can get a width for the axle beam. The piece of channel and two studs is temporary. The proper thing is a piece of 1" plate with four studs. The radius rods are adjustable and allow the chains to be tensioned. The hole at the bottom takes the brake actuating shaft and you can see the hole at the top that takes the pivot pin for the brake shoes.

A spring slipper that allows the whole rear axle to be moved front to back. You start to spot where there were a few quick wins to help improve payload.

And a closer view of the off side. The funny block at the bottom with the cover bolted to it is an oil bath to keep the brake shaft lubricated. Why they did this is completely lost on me because it causes nothing but trouble - mostly to do with depositing oil on the brake drum. The eagle eyed may be able to spot that we have machined it to take proper modern oil seals and they will get lubricated with grease like what they should have done at the start.

At the other end of the radius rod there is a palm which bolts to the engine suspension plate. The exciting thing is that all of this lined up absolutely bang on first time.

Now what is needed is the big bit of bar that joins the two spring pads together. As you can see this is a very big bit of bar indeed. This is where having a big lathe is very handy.

What else? The brakes are getting there slowly. This is the brake cylinder mounting all tidied up and bolted in place. The spindle isn't supposed to poke out the back of it but it is because the piston hasn't been made for it yet.

The front cover for the cylinder took an age to make for some reason. Anyway, it's done now.

And some more links getting made for the brake system. In this case yet another yoke for the hand brake rod and crank for the handbrake actuating shaft (part way there which is why it is covered in welding spatter.

The water pump valve block got finished and here it is sitting in its rightful place. This allows you to either direct water to the boiler or spill it back to the tank. The bulb at the top is supposed to smooth out the flow a bit. Hmmmmm. Properly fiddly casting this one and a right pain to machine. The funny Y shaped fork at the bottom takes the lever which operates the by-pass valve.

And as an aside here is the S with its tipping body propped up while it gets the new tappets made and fitted to the inlet valves. They've all come back from the heat treatment place so they are ready to go on and set up. Tipping bodies are a complete and utter pain in the arse and I am never having anything to do with them ever again. Note all of the asbestos string. Pretty, eh?

Back to the Super. One of the jobs I'd been putting off was trying to do something with the cab roof. Namely trying to bend the bloody ash beams to shape. I did some reading on this and watched some YewToob videos on the subject which were mostly to do with furniture making but it was better than nowt. Right, off we go. First measure things and work out what radius you want to bend it to. Now take a large sheet of boiler plate and mark out the radius on that. Cut 18 bits of 2" angle then weld them to the plate to form a jib to which the hot wood can be clamped - I've got no pictures of any of this by the way. Now we need something to steam the wood. Reading suggested we needed a bit of 4" drain pipe and a wall paper stripper. What we ended up with was a 4" drain pipe and a crappy domestic steam cleaner which would run for the three hours or so that the wood needed to steamfor. So, bung the wood in, set it going and three hours later whip it out and clamp it to the jig. Leave it to dry for three days as recommended and hey presto!

Oh bollocks.

I'd set the jig up the for the radius we wanted. The idea that the woood would spring back slightly didn't cross my worried mind. Fortunately I'd tried to bend the tight radius first which meant that the tight radius was now very close to the other beam we needed.

Right, grind all the angle brackets off and re-set them on a guess as to how much the wood was going to spring back. Repeat the exercise only using a piece of aluminium pipe because uPVC pipe can't really take the temperature for that long.

Oh bollocks.

Too far. Reset the jig again and try again.

Oh bollocks.

Too far the other way. It was at this point it occured that ash may be good for steam bending but I doubt that it was going to take too many cookings before I wrecked something. It also occured that the chances of hitting the exact radius needed was somewhere close to zero. It was at this point we decided to stick at 19 and make a firring piece to get the radius spot on that way. I took a strip of tulipwood and glued it with Cascamite to the top of the beam. Then after planing and sanding it it ends up with a join that once it is painted you would never know it was there. Now the radius can be marked out by measurement and after buying a cheapy bench sander here...

It was possible to sand the firring piece to the correct radius. Here's the front one in place

And the rear one. The beams were supposed to be held in place with finger joints but because the "ash" bend is metal in our case I have bolted the beams in from the ends using barrel nuts so you can't see very much at all. Note the roof planks sitting in just the right place. All of this wood is painted in a sandy beige colour so the mis-match in the types of wood shouldn't be too obvious. The only real cost is reducing headroom in the rear a little.

So after only a couple of weekends it is ready to put the roof planks on. Once the planks are on it will be covered in duck canvas to help keep the rain out.

I think we'll be doing the curved beams for the body as glu-lam rather than hot formed - unless someone tells me how you bend these things properly to the right radius. I really don't fancy trying to hot form eight of these things to the same radius.

 

[nomiST]

Awesome.

[JimH]

Time for another update. So the roof beams are in so it's now time for it to get a roof. This is meant to be done in "deal matchboard" according to the drawing which my Big Boy's Book of Wood tells me is T&G made out of any old shit you can lay your hands on. For good or ill we decided to use the same tulipwood that we did the sides in.

It is screwed into the ash beams, the oak beam at the rear and then bolted with stainless self tappers to the metal "ash" bend. Hopefully this should all stay where it is meant to be. I was quite pleased with how this has turned out...

The coach bolts haven't been cut down yet but everything looks pretty neat and tidy to me. For a woodworking basketcase I think things are looking pretty tidy. I'd certainly be in with a shout of a pass in CSE woodwork.

And it came down neatly at the front too.

The upright is yet to be finished (and obviously the windscreens haven't even been started) but this is the view you get from the driving seat

It looks a lot more like a lorry now the roof is on.

One day son, all this will be painted a sort of sandy beige colour.

Then things get stressful. You probably see that there is no way for the smoke to get out so it needs a hole cut in it for the chimney to pass through. This is stressful because you only have one go at it and if the hole is in the wrong place then it's not going to look very good at all.It took most of a Sunday to make the flame guard (under certain conditions flames leap out of the stocking chute so the roof needs a bit of protection (as do your eyebrows if you aren't quick). The flame guard looks a little odd because it needs cropped off on the same line as the windscreens sit - it will look right when they are in. The screws are too long because this is the first fit. There is a plate at the top as well so the wood is sandwiched bewteen two bits of steel.

And a roll of duck canvas arrived. This will go up to the people with big sewing machines to stitch it into one piece to go on top of the roof to keep the rain out.

I was planning on gluing this down to the wood. Anyone know if that is a good idea or a very silly thing to do?

The last bits of trim went on the back of the cab so it is nearly ready to make a start on the body. The final bit once the canvas is on is to refit the D beading that hides the edge of the canvas. I've now started working out the materials list for the van body which is a very long list and I don't think things are going to be very cheap. The one big decision which is coming up is what colour is it going to be. The back of the cab will need to be painted before the body goes on because it is almost completely obscured by the front wall of the box body.

 

What else? Here are the brake shoes machined and sitting roughly in the right place. They aren't split yet because we haven't got round to it. You should start to get an idea of how things are laid out on the rear axle.

And here are the brake linings that arrived recently. These are secured to the shoes with copper rivets which are in the bag. Just like they used to be on cars once upon a time.

And here's the piston for the brake cylinder. There are no grooves machined in it yet for the rings because the rings haven't been made yet.

And the last bit of brakes that arrived were a couple of lengths of gauge plate to make the sliders for the balance bar. It will be obvious what they do when they've been bolted in.

Here is a superheater. Without wishing to teach anyone to suck eggs this takes saturated steam from the boiler and passes it through a pair of coils which sit in the combustion space of the boiler. This increases the temperature of the steam and improves efficiency. Back in the day they were often trouble because the temperatures they ran at were a little on the high side for the steels we had back then. However, this is made from chrome moly tube which will live forever on this duty. Steam temperature at the outlet is about 550F.

It is sitting on a jig because it is much easier to set it up on the floor rather than in the cab. On the left is the boiler outlet, the block on the right is part of the throttle valve and the tube in the middle is where the stoking chute would be.

Steam leaves the boiler from this elbow...

Runs through the coils (there are a pair in tandem to increase heating area) and then exit the superheater to the throttle valve here...

We'd made this coil for a S boiler which has a slightly different layout so the throttle valve tails need to be re-made. Once the bends are right they are TIGed up and everything should just slot neatly into place in the boiler. Huzzah!

The list of things to do keeps getting longer. Tune in next week. Same bat time, same bat channel.

 

 

 

 

 

 

[320touring]

Top update as per - will be back next week for more!

 

Keep up the good work!

[Saabnut]

I always get a little bit excited when I see there has been an update on my favourite thread. I wish I was capable of this type of craftmanship, but I am not so will just have to admire someone elses efforts. Thank you.

[83C]

Fantastic thread. 

I’m interested in how you fire a Sentinel - is it just a case of drop the coal in the top and hope it covers the grate, or is there some finesse to avoid holes in the fire?

[JimH]

You sort of gauge the depth of the fire by the distance between the top of the fire and the stoking chute. The fire runs about six - eight inches thick and apart from a small patch in the middle you can’t see any of it so it just comes down to a bit of practice sort of guessing how often to tip more in. It is far from a precise art.

[Jenson Velcro]

I love this thread and the wide range of old school skills being used. I always look forward to the next instalment.

[83C]

56 minutes ago, JimH said:

You sort of gauge the depth of the fire by the distance between the top of the fire and the stoking chute. The fire runs about six - eight inches thick and apart from a small patch in the middle you can’t see any of it so it just comes down to a bit of practice sort of guessing how often to tip more in. It is far from a precise art.

Ah I see. If you can see the grate = stick more in!

[JimH]

If you can see the grate then you have problems because it is waaaaaay too thin. For the amount of steam you are hoping to pull off the boiler the grates are a smidgin over three square feet so you are working the fire pretty hard so you have to keep it quite deep.

When we ran the last one a lot you just got the feel for how ofen you tipped some fuel in. It's not very often - a good Super should be doing about 25miles to the cwt while the super efficient S is managing low to mid 30s to the cwt. If you equate that in cost terms to diesel it is doing about 14 to the gallon which seems not bad to me.

[JimH]

Incidentally, anyone have any thoughts on what this colour might be.

 

[83C]

37 minutes ago, JimH said:

If you can see the grate then you have problems because it is waaaaaay too thin. For the amount of steam you are hoping to pull off the boiler the grates are a smidgin over three square feet so you are working the fire pretty hard so you have to keep it quite deep.

When we ran the last one a lot you just got the feel for how ofen you tipped some fuel in. It's not very often - a good Super should be doing about 25miles to the cwt while the super efficient S is managing low to mid 30s to the cwt. If you equate that in cost terms to diesel it is doing about 14 to the gallon which seems not bad to me.

Seems pretty reasonable. How controllable is the boiler in terms of adjusting steam production to suit the situation? I'm used to firing railway steam locos and it seems to me there are two things that I rely on that simply aren't there for a Sentinel - the ability to judge the fire by the colour at the chimney and the relative predictability of the railway as opposed to traffic, roadworks etc on the roads.

Edit: Was oil firing ever tried? Given the shape of the combustion area a Laidlaw-Drew swirl-type burner would seem to be an ideal fitment. 

[JimH]

Long story. Oil firing was tried a few times in period but was always abandoned because it was just trouble - I suspect you also ran up against the problem was that coal was dirt cheap and oil wasn't. However, when we rebuilt the S we decided that oil firing was the way to go.

Experiment 1. A Laidlaw-Drew burner

We copied this burner from the ones they use at Ffffestiniog. It sat at the bottom of the boiler in a refactory lined support which took the place of the grates. We then took a steam feed from the boiler through a control valve and fuel through a fancy pants needle valve which was supposed to give us decent fine control over fuel flow. To start it we had compressed air. This was OK in the workshop because we have a 115cfm compressor which was more than butch enough. We would fret about want to do away from home later on. There was a propane pilot light  to keep things lit.

Results: Absolutely fucking useless. the main problems were that it would light and burn but trying to balance the burner was nigh on impossible even at a stand still. Had we been bouncing along the road it just wasn't going to happen. The other problem we could foresee was that on the road steam is on and off almost all the time so the draught you were having to deal with was constantly changing. We hummed and hawwed about steam bleeds up the chimney to keep draw on it when the throttle was closed but it became very obvious, very quickly that this project was going nowhere.

I think they could make the LD burners work at BF because they knew what was coming up so they could adjust the burner accordingly. There were no surprises so you got good at knowing how to control it. The other thing was that on a given bit of track the conditions were constant for a reasonable period of time. We are climbing this hill for some minutes so set the burners and off we go. You don't really have that luxury on the road.

If you know anyone who might like a very nicely made LD burner we have one here.

Experiment 2: The pressure atomising burner

The big problem with the Sentinels is that the boiler sits vertically quite close to the ground so there isn't much room to fit anything. So what we did was:

1. Got a 330KW 2 stage Riello burner and removed the burner head and igniters. This was mounted in a stainless steel plate which took the place of the grates pointing upwards at the tubes. The ashpan was cut to cover the burner head to keep things looking kosher.

2. The fan/pump (which is pretty big) was mounted in the tipper body and then the oil/air was piped/ducted to the burner head under the boiler. This was achieved in a pretty discrete way and it was pretty damn hard to spot what we had done even though it was a 4" duct running to the burner head. The oil tank say in the tipper body too.

3. Get two very large 12V batteries (ex mobile traffic light ones) then run them through an inverter to give us the 240V to run the burner. 

4. Now things get technical. With a pressure transducer on the boiler it was possible to run the signal through a Siemens Logo PLC which would control the burner. This allowed us to get quite sophisticated on the problems ass as it let us run mulitiple programmes. For example start up cycle would run the burner for a few minutes the shut down for a few minutes so it heated everything up nice and gently. There were then settings for running, banking down and testing the R/V. In the run setting it was able to set the behaviour of the burner depending on whether pressure was falling or rising and how quickly it was doing it. If the pressure dropped quickly it would bang the second stage of the burner on. If it was dropping slowly it would only put the first stage on. It were reet clever even though I say so myself. Having a BiL who designs industrial control systems for a living helps somewhat.

5. We then separated the engine from the boiler completely. There was no need for draught so the blast pipe went and it just exhausted up the back of the cab next to the R/V vent pipe. This meant we weren't dropping any water or steam oil onto the burner head.

6. After some messing around with the programming we were now ready to test it on the road.

Results: Disappointing.

Ultimately the problem was that the boiler was not designed to be oil fired. It was simply not possible to get the burner head low enough to get the gas temperature at the tubes high enough to make sufficient steam. Superheater temperature was sky high but the tubes weren't getting enough heat to make enough steam. The other issue was that with the new Super starting to look like it was going to get finished the S's days here are numbered. Our view was that most people who were likely to buy it were going to be frighted off by the complexity of the system so since the boiler was coming out for its 10 year inspection the decision was taken to give up on the project and convert it back to run on coal.

The only way they were ever going to make oil firing work was to design the boiler to be oil fired in the first place. Of course, by that time we'd all realised that it was a shit load easier just to use the oil to run an IC engine which didn't need a ton of boiler. Or water.

Still, it was interesting to try it.

[JimH]

As usual we are really bad at taking pictures and I can't find anything of the LD burner stuff. Here's the pressure atomising burner head in its support

And this is it in situ

Look at the front mudflap and you'll see a slightly heavy matt black line. That is the air duct to the burner head. All the gubbins that was needed was pretty well hidden away.

And here is the stoking chute gone and replaced with a central flue. It is sitting under a highly polished aluminium cover. Incidentally, the water tanks on this waggon are for show. We run them empty to keep weight off the front wheels. The actual water tank sits in the tipper body over the rear axle.

And here is an early experimental run being overseen by No1 son. The reason for this picture is look behind my head. That is the control box with lots of lights and switches and a bloody PLC FFS. Normally it would be hidden behind a wooden panel so it looked like the coal bunker it was meant to be.

I'll keep looking if we have anything of the LD burner.

 

[JimH]

This is all I could find of the LD burner. This is the mounting with the air pipes sitting in a way to try to induce some swirl. This was recommended by the BF bods. The burner itself is not fitted in this photo.

And here is an early experimental set up of the pressure atomising burner which gives a good idea of how it was laid out. A couple of things to note here. The duct down to the burner head looks odd. This is because at this stage it is a bit of plastic pipe. We noticed that when we were testing it sometimes it just would not run right at all and would keep shutting down. It turned out that it only acted up when the workshop lights were turned on. The clear plastic pipe was letting enough light into the burner head to upset the flame eye. The problem was solved in the short term by wrapping the plastic pipe in a bin liner. Longer term the duct was made in stainless pipe which solved it altogether.

You can just make out the red of the pump and fan unit and a wee battery with a cheapy inverter next to it seeing if it is possible to run the fan independently of the workshop.

Note also a nearly new Megavan which despite being a few months old was in a dangerous condition when that photo was taken.

 

 

 

[83C]

Thanks for the detailed responses @JimH, I know a bit about the LD system having used it at the FR. In the Penrhyn Ladies especially the LD system (as modified by Boston Lodge) was by far and away the best way to make steam. On coal they handle 7 cars comfortably, on oil they were 8+ car engines. They were capable of making steam at a rate that comfortably exceeded the theoretical grate limit on coal. 

I’ll respond in detail probably tomorrow (I’m distracted by alcohol at the moment), but thanks again for the detailed response.

[PhilA]

11 hours ago, JimH said:

Incidentally, anyone have any thoughts on what this colour might be.

 

Dark Hunter Green?

[Zelandeth]

Please don't ever think you're boring us with these technical posts...more please!

Experiments like these with the oil firing are never failures.  While you may not have achieved the original goal you've learned a lot along the way and have simply found several ways that don't work.  I'll bet stuff you learned has been used elsewhere though.

[83C]

Been meaning to contribute a particular photo to this thread for a while. I pass this place regularly, being local to the area. Managed to grab a quick pic yesterday.

Sentinel Works, Shrewsbury. Now part of Radius Aerospace (formerly Doncasters, Perkins, Rolls-Royce diesels etc) still with the original gates, Sentinel and some signage.

[Dick Cheeseburger]

If Dibnah were still alive, I could see him being one of those punters who would be hanging around your workshop on a daily basis wanting to know intricate detail of your plans as you tried to get some work done.

Mind-blowing skills and attention to detail. My question - are you training up the next generation? Would be a shame to lose this intricate engineering knowhow.