3" Fowler Road Loco

Hi guys,

Your boiler should be certified for safe operation by a club inspector. Check with him if you can get a 110psi ticket.

You would be best off talking to whoever is going to test and certify the boiler to see what they want to see but most likely they will want to see the bare boiler. There may be a reason it was only tested for 80psi WP such as thinner material, less stays, rolled barrel instead of tube, etc

110psi should not be a problem for Ramsbottom valves, my 2" A7 has 100psi working pressure and uses them, the steel boilered 3" ones also use them but run higher pressures

J

i suggest you have a chat with John Ellis. he is an old friend and very helpful. if you havent got his phone number i can send it to you via a PM.

for a 110 psi certificate you need to have a club test to 220psi. personally i doubt whether a working pressure of 110 psi is required. but you ought to have a chat with John first.

cheers,

julian

Higher the better if you want to try and get the compounding to work

I can (however reluctantly) strip back the engine to get the bare boiler ready for inspection.

Is there a formula/formulae for working out a working pressure tolerance for boilers? If I could work out the tolerance then the boiler inspector could check this and suggest an safe working pressure within the tolerance?

I would think that at 110psi I would be struggling to achieve true compounding

Julian,

Am I right in thinking that John Ellis is or is related to the Bishop-Ellis label?

If I could get his number that would be great. Perhaps it was worked out that only 80psi was required? (I doubt this).

I'm not sure what drawing has been used to build the boiler but there are some distinct differences between my boiler and the boiler in the drawing, such as my boiler is copper and sil. solder construction, the drawing shows steel and welding; my boiler has a single blow down valve at center-bottom of the back head whereas the drawing shows two plug on the back head (one on each corner) and two mud lids in each corner of the throat plate with a large mud lid in the side of the boiler barrel.

In reality, the drawing for the boiler shows a great spec for the model, only addition I would make is remove the bottom tube and replace with a wash out plug in the smoke box tube plate.

My 4" A7 has a WP of 110psi and the typical Fowler ramsbottom's cope and perform brilliantly so I have no doubt why they shouldn't be able to be used on this boiler. Only doubt is coming from the note on the boiler cert.

Dan

Relevant pictures of the engine regarding above ^ :

Does anyone have a detailed drawing of the ramsbottom safety valve for the 3" Plastow Fowler R3 road loco or have the actual they wouldn't mind measuring?

The drawing I have states a couple of details but not enough by far that I could make it.

Thanks,

Dan

I would think carefully before increasing the pressure to 110psi. The 3" Fowler is a big engine and the strength of copper decreases as temperature rises. Don't forget on a traction engine your boiler is also your chassis. I would do some sums before you go much further. Your drawing also states "Steel Boiler Details"

Edited By AndyA on 23/12/2015 19:13:16

I should mention that on Friday I found a drawing amongst the build notes (couldn't see why it was there so presuming mistake) for the copper boiler for this engine. The drawing is exactly the same to the boiler apart from two things: no smoke box tubeplate washout (listed as optional on the copper boiler drawing) and the boiler doesn't have a mudlid in the side of the barrel which the drawing specifies, although note is made that a dummy mudlid may be soldered to the barrel.

Also on the same day (after discovering the drawing) I spoke to my boiler inspector who studied the drawing and confirmed that it would be fine for 110psi with ramsbottom safety valves, which has put my mind at rest on the boiler side of things.

Just in need of the safety valve details now.

Thanks,

Dan.

If thats a steel boiler drawing either the designer had absolutely zero experience of steel boilers or it is the worst design ever thought up! I cant see it in any detail but it has definately been designed with copper in mind. Just saying....

What I described in my last post was the comparison between the copper boiler on my engine and the drawing for the copper boiler for this design. You can see in a couple of posts above the drawing for the steel boiler which is in fact a very good design for a steel boiler. The design for the copper boiler, as far as I can see, is also very good. H R Plastow has thought through these designs well in my opinion.

That steel boiler drawing does seem to have an excess of stays, more like you would expect on a copper boiler with 1/8" stays, would be a lot of work welding all those and not a lot of wastage allowance. Its worth remembering that the plastow designs are quite dated now and don't take into account TIG welding. Out of interest on another forum there is a 3" Fowler ploughing engine being built with steel boiler only 4 stays per side and one in the backhead.

J

PS PM sent

My boiler inspector made the same comment regarding the number of stays. Understandably my boiler inspector mentioned that with that amount of stays there should be no issue with a 110psi working pressure. The number of stays is the same for both the steel and copper versions of the boiler. When you say plastow designs are dated, these drawings were revised in about 1974....

Replied to your PM Jason

Finally made a start on the engine, the short term plan is to get it through a steam test so I can take it to a local show at the end of May. I steamed the engine shortly after it arrived (December 2015) and I found that although it runs, the pump didn't seem to work, the injector didn't work and the hand pump was useless against the boiler pressure.

All of the pipe work is completely wrong for a Fowler so that is one of the things to be sorted out whilst getting the pump and injector to work. First I focussed on getting the pump to work; it hadn't had the bypass machines into it, instead it had an external quarter-turn valve in the pipe work to turn on/off the bypass. So I removed the clack body of the pump (where the bypass is supposed to be fitted) and set it up in the 4 jaw ready for facing and machining. The drawings for this engine are pretty poor in terms of detail and clarity (although they are double-dimensioned for 3" and 4" scale), so I had to do a small bit of design/guess work. For example, the gland nut is described as having a 9/16" Fine thread; I know I haven't got any 9/16" dies or taps so any near equivalent for this strange size was out of the question. Instead I used 1/2" x 20, still unusual but I had both tap and die and was close enough for my requirements.

Once I had turned and threaded the gland boss, I then had to bore a hole though it into the first clack chamber then into the wall between the first and second clack chamber. Before I could do this I had to design the valve spindle but this was a fairly straightforward task. After I had bored the hole, I then replaced the 4 jaw with the 3 jaw and turned the valve spindle until it fitted nicely into the pump where I then drilled the bypass hole through it. Next was to make the gland nut, also a fairly straight forward task. I filed a square onto the end of the valve spindle and fitted a handle which I made from 1/4" thick steel plate, which more or less completed the important part of the pump.

This afternoon I assembled the pump back in the engine and rebent the old pipe work to suit traditional Fowler looks; the holes need drilling in the footplate and the pipes dropping through. I also need to rebend the pipe from pump to clack valve which once done will mean I can steam up and give it a test!

Check out my 3" Fowler album to see progress pictures...

Cheers,

Dan.

Hi Dan

You have the making of a fine engine when I aquired my 3" Burrell I found the guy's over on Traction Talk (model engine section) very helpful and I would go as far as to suggest you may find even someone who own's one.

H