Finescale - of a sort?!

[Peter Insole]

On this fascinating subject there is quite a bit more that I could go rambling on about, but this morning I remembered that the purpose of this thread is more to do with the model build! I shall now therefore move hopefully closer to the point...

At the top of my priority list of previously unobtainable details was the steam brake valve - with particular emphasis on determining not only the precise design of the original fittings, but most importantly, what material each part was made of!

Here is the unfortunate "lash-up" job on "Wren" at the NRM:



This, along with several other reference shots, at least provide sufficient information to make up the main body, complete with slightly tricky to make backstops on wings! The thick brass lever handle is evidently an almost useless bodge of the lowest order though!

Below is another cropped image (usual copyright disclaimer) and previously the best I could find to show more of what it should be like - on a Horwich built loco anyway:



Finally, two pictures of the genuine article, or at least one that matches what can be discerned in available drawings, and appears more likely to have been originally supplied by Beyer Peacock...



The first thing to say about these last two images; please ignore the peculiar steam valve, handwheel and additional pipe fitted to the top of the manifold... these items are later additions; providing a separate supply for a small "Beccles" type pump, fitted to augment the single injector, and unique to BP's own "Dot"!

The other is that the steam brake valve body on this engine is very slightly different from both the specification, and the Horwich ones - with the backstops set further inboard - and ironically, (considering that I want a Horwich variant) marginally easier to model! Every other part matches the drawings, although clearly, some of the later examples (including "Mouse") had shorter and thicker handles on the levers!

I had hoped that in finally, and literally getting "hands on", I would be able to discover whether the lever and/or handles were manufactured in either steel or non-ferrous alloys... naturally assuming that it would be an easy matter to distinguish - and subsequently replicate on the model.



Pah! Like hell it is!

One of the curators suggested that the distinctively dull, grey (with an almost Mazac like appearance) material might be gunmetal?

I have always been under the impression that as they are subjected to pressure, all steam fittings are usually made in bronze or gunmetal anyway, but that common brass is a perfectly reasonable substitute to represent both when modelling a polished finish?

The really big question now is; what colour on earth were these levers when still in regular service?

Did they look generally brassy, bronzy or steely - and if none of those, what can I possibly use to make it?!

Pete.

 

[oldravendale]

Here is the unfortunate "lash-up" job on "Wren" at the NRM:

View attachment 220273

This, along with several other reference shots, at least provide sufficient information to make up the main body, complete with slightly tricky to make backstops on wings! The thick brass lever handle is evidently an almost useless bodge of the lowest order though!

To see and hear that is rather sad, Pete. The NRM should be able to do a bit better than a bodge. And if a lash up it should be stated as such or at least representative of what might have been there. Or maybe an appropriate notice was on display. I suspect from your comments that this wasn't the case.

With money tight there are other, probably more pro active repositories for our heritage.

Brian

 

[Yorkshire Dave]

With regard to the B&W photo crop - depending on what film stock and when the photo was taken of Midget (looks like 1932 according to the properties in the caption when you hover over the picture) I would say the main upright handle was painted red - remembering red appears as black on orthochromatic film which would have been prevelant at the time. Although Panchromatic film was available it was far more expensive.

The smaller handles I suspect would be is the worn polished finish of the metal alloy used.

Colour rendition on B&W is discussed in the thread here Black and White Colour Rendition

 

[Peter Insole]

Wow Dave, thanks for that keen observation! I had been pondering why that particular handle was so notably darker than it ought to be in the photo of Midget. That very plausible explanation never crossed my mind though!

I wonder if painting brake levers and handles red was an LMS feature based on standardised "Group" practice, or whether that was an earlier, constituent company (hopefully LYR) tradition carried over into the 1930's?

Pete.

 

[Tim Humphreys ex Mudhen]

I don't think we should be too harsh on the NRM. The loco could easily have been scrapped and at least they saved it. To expect them to restore it to original condition might be a expecting a bit too much. I'm sure locos of this type went through many changes in their working life.

Keep up the good work Pete,

Tim

 

[Overseer]

I would expect the brake handle to be steel (or iron), and that is what the photos seem to show. Probably painted ex works but the paint would chip/wear off with use. It would be hot so a cloth or gloves would be needed to hold the handle. The thicker handles might be wrapped in something insulating.

 

[Peter Insole]

I'm sorry Tim if my comments came across as being harsh... but they were perhaps a measure of my sadness, and even at times a degree of frustration!

Of course I am grateful that the engine was retained by the British Transport Commission. It was during the period after "official" withdrawal, when it was moved from it's original shed, to be put "on display" in the main erecting shop at Horwich, and simultaneously used for apprentice training that some "attractive" parts went missing. The final "resoration", before transfer to Clapham was at least carried out by very professional painters, albeit in a completely inaccurate livery - although lets face it, that was almost a fashion in the early 1960's! The "bodges" that I have referred to were all carried out by other Horwich artisans at that same time.

After a few years, and including the move to York, the condition of the engine may have become "tired". It had received a repaint or re varnish in 1975, and since then another much more significant overhaul, (I don't know on what date) including an (evidently) failed attempt to return it to steam, (when a cracked cylinder was discovered) and only after that, even more parts have gone missing!

I still cannot help feeling that, while the time, effort and money were being spent on it while at the NRM, unfortunately, no one at any of those opportune moments seemed to be aware of previous errors, and unwittingly ended up compounding them!

Pete.

 

[AJC]

I don't think we should be too harsh on the NRM. The loco could easily have been scrapped and at least they saved it. To expect them to restore it to original condition might be a expecting a bit too much. I'm sure locos of this type went through many changes in their working life.

Keep up the good work Pete,

Tim

Especially given the size of their collections, varying curatorial practices over the last 60 or so years (I think this particular loco was at Clapham before York, right?), the vagaries of funding, and so on.

Adam

 

[Mike W]

On the subject of the NRM, I suspect this loco was last "restored" before the NRM existed and not a priority to re-do. Also there's the question of whether they know exactly what it did look like, and when? i.e. could they do a proper job even if they wanted to?

Maybe, eventually, Peter's observations and notes will provide the full answer and can be presented to them as evidence.

Mike
(still love this thread - followed it from the start and its awesome!)

 

[Peter Insole]

Thank you for taking the trouble to reply Overseer. That is indeed what I had expected to find too, and was perhaps rather surprised to discover that, despite what the photographs might suggest, the material is definitely not either iron or steel. The regulator and reverser are however, and when standing on that footplate, the comparison was easier to determine.

I was continuing to consider Dave's idea of the red colour effect, and when looking again at the B&W image in question, (of Midget) I get the impression that the handle was distinctly shorter, and a bit larger in circumference than any of the metal ones shown in either drawings or other pictures.

Was this particular engine fitted at this time with a little wooden handle perchance?

I did a search last night, and found a couple of examples of vacuum brake valves similarly equipped, and the colour photographs of both indicated that the very fine grained hardwood was of a distinctly reddish shade! I do get the strong impression that Midget might have been unique though!

It matters not the tiniest jot if I choose to take any liberties with my own model, but I would be so much happier feeling that the particular conundrum of identifying the original materials was cracked!

Pete.

 

[Peter Insole]

At long last, the grip of the 'orrible grots that I got from Wales is finally letting go - and for the last couple of days I have been able to spend some time down in the dark, and this dismally damp year, the doubly dank dungeon!

(The spiders seem to be even bigger and busier than ever before down there too!)

Once I had broken through some of the cobwebs, I fancied tackling first the brass (pretend bronzy) bits of the brake valve:



I was not sure if it was the best idea, but I decided to make a long 8mm round section to pass right through the main body of the valve, thus ensuring at least one of the spurs would stay perfectly aligned when soldering up.

Drilling another 8mm hole at right angles into the body was a bit hair raising, bearing in mind how little free metal would be left on either side:



I didn't want to go in too deep as well, fearing that I might accidentally break through the plain side with the drill point. In the end I bottled it while still a tad shallow though!

Spinning a cone on the end of a very short length of 8mm rod, and then narrowing down a section to 6mm for the thread got a bit too fiddly for comfort - and indeed, I got myself into terrible trouble with an M6 die!

I have absolutely no idea why I wanted to cut the thread before soldering the branch in? - it would have been so much easier if I had waited?!

Whatever, with such a small item to grip in the vice, I couldn't see enough metal, and the hand held die went seriously off line during the cut! The only way I could imagine to retrieve the job was by annealing the brass, running an M6 nut over the wonky thread, holding the nut in the vice jaws, and then pull the desperately short branch back in to line with a length of tube!

It put up a bit of a fight - and it took three goes with the "gas and dunk" until I was anywhere near happy!




Cutting, shaping and fitting the peculiarly winged quadrant plate over the shouldered top of the body will be the next, taxing task to come!



All the brass and copperwork is certainly beginning look a bit more busy above that backhead now?!

Pete.

 

[Peter Insole]

Did I say taxing task? Groan... just don't ask!



I have still got some final finishing and cleaning to do - especially getting rid of a few stubborn solder marks, but otherwise it will do!

Pete.

 

[Peter Insole]

I have been plodding on, although not particularly quietly when things have gone wrong!

Making my own cap nuts to match the prototype style should be almost routine for me now, but either I wasn't concentrating enough - or I have simply forgotten how it was done before.

Whichever, I did end up with rather too many bits of annoyingly wasted brass hex this time!



I also had a go at stamping OFF and ON atop the stops!

Oh dear; the letters are very small, and are located on fairly large, flat, circular ends, with fairly wide, tapered shanks on the dies. Trying to accurately locate and align each one before striking (no second chances possible of course) was an almost impossible blind flying exercise - especially with such a frighteningly narrow strip to land on too!

One O ended up terribly wonky, and my middle F almost fell off the edge in the process, but ho-hum - tis done now!

Next time I should try working out some sort of jig - maybe a line of appropriately spaced holes drilled into a bit of slender brass angle might do the trick?




Before tackling the tricky little lever and handle, I decided to start on the poisonous piping instead...




Annealing and bending that noxious stuff to fit kept me busy for quite a while... and although the finished job does look fairly pleasing, the after-effects were not quite so!

I'm not sure if was the intoxication, but I thought that as the result of working with copper was obviously making me feel so groggy, I might as well continue to get more done in one go?!

Even dafter perhaps, (?) I fancied it was about time to complete the (normally unseen) smokebox plumbing too:




I did try to match the curves as closely to the general arrangements as possible, but it was such a damned fiddle getting in and out of that box to repeatedly "offer up", that I finally felt compelled to surrender... and have to accept a couple of now permanent anomalies!

In compensation, leaving the old, re-cycled 9mm tube in post annealing, and thoroughly "burned" condition does look absolutely perfect to my eyes, but I am aware that I will have to be extra careful when working back and blending in the "weathering" to match it?!

In the meantime, making and fitting the base for the blast pipe flange will have to be done before any final coats of paint can be considered though!

Pete.

 

[Giles]

Stunning, Peter!
Regarding the stamping, it's at least as good as most of the small industrials I've driven - they were never cleanly stamped if I recall correctly - what you've got is really rather genuine (or better) in that respect!!!

Just wonderful

 

[Mike W]

I have never knowingly met Peter Insole but when somebody produces such a wonderful and eccentric model that has kept my attention for all this time, (post #675 and I've read every one several times) and then says of the latest superb piece of modelling that it is only "fairly pleasing", well, I like your style Peter!

Mike

 

[Peter Insole]

Thank you so much Giles and Mike for your great kindness - and to everyone else for all your "likes".

Lately, I have started worrying that this little tale has been rumbling on for such a long time that there is a risk of it becoming repetitive or boring.

You have all cheered me up no end!

Pete.

 

[Osgood]

Typical apprentice stamping, that

 

[3 LINK]

Hi Pete,
Was just enjoying a catch up on your progress and noticed the piping around the pressure gauge.. Is there a reason for adorning the piping around the gauge as this practice seems standard on a lot of steam locos in the past, and I have also noticed this piping around the AWS gear on GWR locos.

All the best,

Martyn.

 

[Dog Star]

I have also noticed this piping around the AWS gear on GWR locos.

From the passing of wisdom at Didcot when the old boys were still around... to allow for expansion of the pipe in such a manner as to minimise cracking from application of boiler pressure (225psi for main line GW locos) and repeated heat cycles.

 

[Peter Insole]

That is an interesting answer Dog Star, and it might well be the case in GWR AWS gear, but (please correct me if I am wrong) I was under the impression that "Bourdon" type pressure gauges do not work reliably enough by having live steam in the internal workings.

I was led to believe that the "loop" in the pipework is meant to act as both a condenser and gravitational reservoir for cooling steam - and it is the resulting water, (non compressible) being pushed by live steam in the pipe (the internal bore of which remains constant) back into the gauge that provides a much more consistent and accurate reading. High pressure loco gauges might not therefore be directly steam worked, but are more "hydraulic" in action.

It turns out that "Wren", previously at the NRM, still has a replacement, curly, "pig-tail" version of the supply pipe, (by studying recently available images) proving that it was fitted in the late 1950's, and that device could well function in the same way as the original!

Pete.