JimH

There is a blower ring around the blast pipe. The reason for the fan was it might have made it easier to control it automatically rather than using steam. You need to remember that the boiler in the S sits behind you and viewing the fire is far from easy. What we were looking at was the poor sod who was fireman permanently facing backwards trying to juggle the burner.

Just a few quickie pics because most of the stuff that has been worked on lately isn't terribly exciting or photogenic... The superheater set up and ready for prepping and welding. Welding is more pressure-tight than Jubilee clips but more expensive and takes time to learn. For those interested in that sort of thing, you see the piece of pipe in the middle? That represents the position and size of the stoking chute so you'll appreciate that your view of the fire is limited. It is worth bearing in mind that the Sentinel design may be rubbish but it is still better than a lot of others. If you can find a coppy of The Undertype Steam Wagon by Kelly there are lots of pictures and diagrams of other designs which are complete shit. IIRC it was Clayton who designed one with a floor mounted chute that sat to the side of the boiler. You just tipped coal in and hoped. Moar superheater. Incidentally, we don't do this sort of welding. All our boilers are what you might call "well documented". None of that "Oh, it's a repair" business around here. Can you tell what it is yet? Whatever it is it took two bloody weekends to make it. That's right. It's a chunk of eigth plate with D beading rivetted to it. Sentinel called it "a door". The first rule of Door Club is that the more crude the design of the door the more of a nightmare it is to make them fit properly. There are countersunk set screws holding the D beading on at this point. These have been replaced with rivets so it all looks right. Get's a wee bit more Sentinelly. And this is rather exciting. There han't been a pair of these cast for a while now. It's the rear hubs. One flange carries the wheels and the other takes the brake drum/drive sprokets. The little one at the end takes the hub cap. Originally these had plain bushes which are a right pain so they will have roller bearings in them like the later ones did. Much better if you actually want to drive them on the road. Other things that have been going on include having the duck canvas stitched up for the roof, grinding away on getting the brakes somewhere near, designing/making the exhaust pipe, getting the levers finished and thinking about exactly how much copper pipe was needed.

Starting was not easy because we were using compressed air to provide atomisation and something to run the blower. We have a 114cfm compressor which was up to the job and that made it possible to get steam on the boiler and swap over to using steam for the blower and atomising. What we were finding that it was just so very delicate trying to balance draught and firing rate that it was never going to be a lot of fun on the road. We discussed ditching the engine exhaust draught and going for induced draught with the blower. We sketched out an arrangement using FD fan or ID fan which could be controlled more easily. In the end it just felt like it was always going to be a dead end so went over to the pressure atomising burner. As for not making enough steam with the pressure atomising burnerremember that this boiler is a vertical one so the burner head was at the bottom of the box pointing up at the tube nest. Even with a ball nozzle on the burner it was not possible to get the flame low enough. If the box had been a couple of feet longer we'd have been in business but unfortunately the road was in the way so that wasn't an option. The bottom line was that the boiler was designed in the later 19th century to run with a fire at the bottom of it and what we were trying was going to be tricky to make work. The Foden O Type had a pretty woeful boiler but it was mounted horizontally which gave much more room to get a burner in. We have a Foden drawing for the O Type converted to run with an LD burner which made quite a tempting project but we decided to build a new Super instead.

In the snow. Slithered into the back of the car in front while I was driving a ‘64 T3 Notchback.

Sounds fun. Some years back I had a short go in one of the AC continuation cars. It kinda confirmed what I had suspected that they weren’t the most sophisticated devices. They still look the mutt’s, however.

Back when I was about 12 it was this exact car in this exact photograph in, I suspect, this exact book. However, then you grow up and learn and realise that they were some of the worst cars ever built. Your tastes become more refined and you understand how things should be done. This is why about the only car I really want to own is one of these... Everything else is just transport.

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.

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.

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.

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

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.

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.

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.

Most of the issues with sitting the engine in the back or towards the back is that you lack weight over the front wheels. Which can lead to issues trying to stop or stay in a straight line on a windy motorway. I drove a T3 Notachback for several years and you got used to second guessing what the wind was doing in an effort to stay bewteen the white lines. If I consult my genuine VW workshop manual for the VW1500 sitting on the shelf at my desk it confirms that the recommended tyre pressures are 24psi in the rear and 15psi for the fronts. That probably tells you everything you need to know. ETA: WTF goes on with my fingers that I can never, ever spell bewteen properly?

We don’t seem to be the dictionary definition of Petrolicious’ target market but I love this one. Not only does it feature the greatest rear engined car ever but also it has a brilliant last line. I love Alpines, me.