Cosmetic finishing touches

[Andrew C]

I bought a part built Brit from Station Road Steam back in May. They thought it was complete but weren't 100% sure. Turns out it was missing safety valves, Regulator and a few cosmetic bits.

So a few of days in the workshop and I had a new pair of safety valves and a regulator etc. I was in Blackgates and picked up a copy of the safety valve drawing forgot to ask about the regulator. Turns out the safety valves and regulator were on the same drawing

And so to the cosmetic stuff and the question. Do any of you have the dimensions of the whistle and its valve that should be fitted to the side smokebox on the Brit? I'm loathed to get the drawing posted from Blackgates as I have every thing else.

[Deleted]

What size Brit? I have the drawings for the 3 1/2"
JB
EDIT: Research suggests it's a 5" Winson code 4902 so I can't help!
JB

[Andrew C]

Yes your research is quite correct. It is the 5" version and 4902 is the one!

Thanks any way JB I'm sure someone will.

I had heard that the Winson/Modelworks engines had quality problems but had not realised it included things like the pipework! I did an initial hydraulic test back in September and one of the pipes from the manifold to the Injector valves did garden sprinkler impressions! On close inspection the silver soildered joint on one end was only half way round, So I checked the other pipes, and what do you know 5 others (Including both injector boiler feed) were the same.

I have the access to the facilities to correct this but that's not the point

[mutley]

Don't forget to correct the tender then by removing the front handrail extension pieces otherwise you will have clearance problems.

Andy

[Andrew C]

One of the first bits to depart into the scrap bucket

[Jim]

I'm building a 5"g Britannia, "Boadicea". Not sure if you're looking for a working whistle or not but I decided to make a dummy whistle for the smoke box side with a three chime working whistle between the frames under the smoke box. If you're interested I could PM the sketch/drawings to you. The photo shows the dummy whistle.

Jim

[Andrew C]

Hi Jim

That exactly what I intended to do, put a dummy on the smokebox and the real one elsewhere. I had thought under the running board just above the cylinder. It had not occurred to me to put it under the smokebox. Is the real chime three separate ones piped together or a single with three chambers?

Any details you have of either I would be most grateful.

Regards,

Andrew

[Jim]

Hi Craig,
I got a three chime whistle and valve, (seperate pipes) designed for 5"g from Polly Models other suppliers have them too. Given the space available I think if I was doing it again I'd go for the larger 7.25" whistle to get the bigger sound. I've tried my whistle on air and it certainly sounds good and would be a lot better on steam.
I'll send what details I have on the dummy which I made up out of odd bits and bobs.

Jim

[Andrew C]

Hi Jim yes please. I had intended to make three separate whistles and plumb them together. When you fit yours don't forget to make sure the openings are facing down and the closed end is raised above the inlet. This means any condensation will run out and the notes will allways be clear. So embarassing when it gurgles and spits and no sound comes out!

Andrew

[Jim]

Hi Andrew,
Sent pms with details such as they are. I had intended to make sure the whistle could drain condensate. As an ex cornet palyer in a brass band I've had my fair share of gurgles from the deep.

cheers
Jim

[Andrew C]

Ok thanks. I'll have a look when I get home.

[Andrew C]

Isn't technology great? Not only do I get an answer to the whistle question from halfway round the world (thanks Jim) but I can ask the next one sat on a train going home

So to the question. Do I clad and lag the backhead or just paint it? I'm really not sure. If I clad it how on earth do I work out the shape?

[Andrew C]

Well I think I might have answered the Backhead To clad or not to clad question myself as I have just noticed JB's post Brit Progress: Boiler Cladding. I just need to workout how the shape goes.

[Andrew C]

Having waded through the snow to get to the workshop (all 9ins of the stuff) . I thought it was about time to sort some bits on the Brit. It is always where to start with so much to do. As the PTFE bar had arrived new piston valve rings seemed a good start point. Boring out to be a push fit on the bobbin was the first task. Then machine the outer material to just slide into the valve body. Parted off the first one, when I tried to fit it to the bobbin it would no fit!?? On closer inspection the act of parting had put a large lip on the inner edge. Some gentle filing soon removed the problem. A quick trial and all seemed ok. Cut the second and refitted the bobbin. Process was repeated on the other side. While the valves were out I took the opportunity to file a couple of flats on the outer ends of the stems now a spanner will fit and help screw the shaft in. I just hope there is enough room when the ring expands under steam.

[Jim]

Hi Andrew

You're making great progress there with your piston valves.
Regarding expansion problems with PTFE valves Shawki Shlemon I think, has a post on this problem. From memory he suggested heating the valve to 120c in the oven and turning off the excess to get a nice fit. In operation the valves leak a little when cold but work perfectly once in steam.
I intend follow this method with my valves but if you're interested check Shawki's posts first just to be sure. I've been known to get things horribly wrong

Jim

[Andrew C]

Dosen't time fly when your having fun! I had not realised it's five months since I last asked anything of you all. Having a month off in OZ was fun though even though we arrived in Melbourne to a monsoon! and its Febuary! Sorry Jim went charging past your place on the Hume Highway at about 6 in the evening on our way to Sidney for a Flight home the next morning

I have spent the end part of March and all of April fighting the Firebox and Backhead cladding. It finally looks the correct shape. However and here is the reason for the post, I cant get the cab to sit down. When it is bolted to the drag beam the front edge of the cab is pointed skywards. If I lift the back edge by 5 mm all is level. So can any of you give me a dimension from the underside of the cab floor to rail level? either in full size or for the 5" model. I currently have 150 mm which is 5mm above the boltings attached to the drag beam. The next question is I suppose should it slope up be 5mm?

Help!!!

[Deleted]

Hi Andrew

The cab on my Modelworks Britannia also slopes up very slightly at the front, but doesn't look too bad - I decided against making a new higher plate around the drag beam which would have solved the problem. I think the root of the problem is that the front end of the firebox sits slightly too high on the rear stretcher, at least on the Modelworks version. I was very tempted to file some excess copper off the bottom of the throatplate, but of course one mustn't do that!

One point to note is that the bolts holding the rear frame extensions to the main frames do allow for a certain amount of adjustment to the rear end height. By holding the extensions up as far as possible while tightening the bolts, you may be able to gain a few mm. This also enabled me to get the rear end of the ashpan close up to the underside of the firebox without altering the supporting brackets.

Kind regards, John

[Andrew C]

Hi John Thanks for that. Having looked at the photos of your Brit again yes there is a slight slope, but mine is much worse. It was much worse than 5mm before I took the drastic step of cutting out the cork from the top of the firebox! I had some insulation earmarked for the Atlantic tank I am restoring so that has been pinched and used. It is much thinner and lookst a bit like cotton wool that is untill you try to set light to it! It just does not do anything It doesn's burn or even char good stuff!
Having now checked the heights It is obvious that I have to level it and therefore make a new cab support plate. Everything else is now correct,even the runningboards sit corectly and are level, there is a slight but even gap between the cab and the firebox top and it looks so much better.

Andrew

[Jim]

Sorry I've been a bit slow rechecking things.

Pity we missed you as you whizzed up the Hume Highway but you were obviously observing the 110kph speed limit as the police have radar guns behind every third or fourth bush on that road. They are a great government revenue raiser .... don't ask

Sadly we would have missed you too as we were enjoying the snow and bracing winds in Yorkshire visiting our daughter.

How's progress on your Britannia going?.

Jim

[Andrew C]

There has been little progress for the last couple of months. what with work, the wife having a major operation and working on the railway I have had little time. I have clad the backhead and started to put things back together.


The firehole doors catch on the cladding so I think a thin shim behind the top and bottom rails is called for. It will need a cut down under the door. also there is way too much slack in the gap to the front rails so the doors can move about all over the place and usually jam. I'll make up some thin washers to space the rail sections.

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