THE CAB & BOILER BITS

I decided to finish off the bodywork before starting all the boiler bits. I could then clear away all the mess associated with the work. Some bits were quite tedious to make, like the angle which fitted over the boiler to finish off the joint between the cab and the cleading. There is no way of bending 3mm thick angle round a tight curve, so I had to fabricate it and weld the bits together. The welding was on the inside out of sight, ground smooth and any holes on the visible side filled with plastic padding. Everything riveted with copper 1/8 rivets.
The angle I used here was the drawn kind which has a better finish and a neat right angle on the inside edge. However, I have used the rolled angle for the cab uprights and inside the cab. This has the advantages of being much cheaper and the inside right angle is a neat curve which is much better when it comes to painting.
When it came to bending the angle for the curve of the roof, I cut numerous sawcuts which I understand are called kerfs, and as the angle is bent to the roof curve so the slots close up and are hidden with the ubiquitous plastic padding! I could have welded them and ground flat, but the roof bolted to it was quite strong enough. They are just visible in the photo. I welded a square to the bottom of the rear upright with a hole in and bolted this to the footplate. The whole assembly is rigid and strong; it also comes to pieces easily and quickly. Another tedious job was making the moulding round the cab sides. The straight was easy enough but the curves had to be cut from sheet. They are riveted and soft soldered in place.
When it came to the roof, I still had some 2mm galvanized steel sheet left, the only problem being how to bend it! It was too wide to roll and in the end I used a couple of sash clamps which I gradually over-tightened until it took on something of a curve. The bolts pulled it down to its final position and of course the tension helps the rigidity.
The only thing I haven't done is the window rings and at the moment I haven't the material. One thing I have decided I don't like and that is the massive brake column. It is going to get in the way. The original has a bar across the back of the cab and joined to the column; this I'm going to leave out. The bar most certainly will get in the way when it comes to coaling.
I'm going to have to take some time out as I need to build a new trailer. Perhaps I sold my other one too soon because the driving season is underway and I can't get my other engine to the track.

And so to the first of the boiler bits.

14 April 2004

AN APPEAL

I'm appealing to anybody who lives outside the UK for some information on boiler testing. The reason is that I would like to write an article for our club mag as I'm not very keen on having my boiler put through the 1-1/2 times boiler pressure test each year. This only applies to steel boilers; copper ones are every two years. As everybody is blaming Brussels for the new stringent regulations on construction, I am especially interested in European countries. Any information on boiler rules in your country would also be of interest.
Please Email me if you have any knowledge on the subject.
Many thanks in advance.

I'm a bit late updating the site this time. Of course it took me a great deal longer to make the trailer than I thought! Still, I'm back on the boiler bits. I thought I'd start with the most complicated one first: the sight glass. As I began the first part at the top I had to make a banjo connection so that the glass could be aligned properly with the bottom part.
No problem. But as I made the rest I began to realize that the firehole door was going to cause problems, especially with the bottom part. I made all the relevant parts from phosphor bronze which is not my favourite material. I think maybe it was a mistake to make two sight gauges the second being really just for appearances. This is because making the right hand side restricts the amount the door opens and could be a problem. Also, there is a lot of work in making each one.

The blowdown valve looks a bit odd as it has to be on the end of a long extension so as to give clearance for the door. Making 6 taps adds to the problems. Mine are on a 5 degree taper. The tap part is made from free cutting stainless and the handle is silver soldered in place afterwards. The photo shows the simple holding device to drill the hole in the end of the tap ready for the handle. The pressure of the drill is sufficient to hold the taper tap in the tapered hole. The second picture shows what happened when I drilled the final hole in the tap. This was done in situ. The hole in the unit is 5mm and the hole in the tap is 4.5 - it ran off. All because I forgot to start the hole with the 5mm drill to give it a centre before using the smaller drill. Silly error. After this I chose a smaller size as well which probably makes little difference, although a smaller hole is less susceptible to surging.

Making the handle is quite simple being turned from some old hex brass of a size I'm unlikely to use again. To get the bend without fracturing the brass, I heated it to red heat and put the end in the vice and bent to shape.
I've laid out most of the pieces I've made. The springs and 'O' rings are missing. The bronze looks nice when polished but after it's been hot it goes dull very quickly and it's not worth polishing every time. So for a change, I decided I'd paint the units with only brass bits on show. This last picture is posed so that I can check clearances. I only had one glass too. It is obvious that I'll have to have a re-think on the firehole door. Either longer handles for the regulator and door or a complete new system. If I'd thought about it sooner, I could have made a drop down door.

Later on I'll make the protecting box which goes round each sight glass and has the diagonal stripes behind to show water level, although I understand the water in a steel boiler has an additive to prevent rusting which colours the water to some extent.

11 May 2004

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