7mm On Heather's Workbench - Aintree Iron: an Austerity adventure

[Heather Kay]

Today, "Know Your Prototype" lesson number 327:



I was studying the images I have of 90643 (which is the loco I'm trying to represent in this model) when I noticed something below the front buffer beam I hadn't noticed before. On the driver's side, under the cab, there is what appears to be a valve of some kind. I reckon it's an automatic drain valve for the vacuum brake pipe. I didn't think the relevant part was in the kit, so I had been mulling over how to adapt a casting that looked right but was the wrong shape. Then I discovered the wrong shape was in fact right for the valve at the front buffer beam I had never noticed before.

Lo! I pull out the sprue with the valve on it, and find the brass fairies have been in and added the under-cab one!

Sometimes I wonder if I am cut out for this game!

 

[OzzyO]

Heather, I think we all miss such and such on a first build more so if we don't know the loco class that well.

 

[Heather Kay]

Boiler fittings going on. The boiler's pilot holes needed opening up for the castings. I've also made a stab at drilling the chimney base deeper. It was fun trying to get the top feed pipes to fit neatly.

I think that'll do for today.

 

[Heather Kay]

Having received the spare sandboxes from bonnie Scotland, I fitted the pair to the outside of the frames. I know the castings are not quite the right shape, but I've simply cleaned things up and turned them 90 degrees so the chamfered bottom of the hopper faces outwards. I think they'll pass.

I spent some time pondering the sand pipe brackets. I can't find really clear images, so I plan to fabricate something that looks right - even if it turns out to be wrong.

Having finished the main frame detailing, then, I painted the insides a dull red and put the frames into the airing cupboard to dry.

I turned to some more boiler detailing.



90643 seems to have a slight variation in handrail support layout. The kit boiler has seven holes, but I counted only six supports in the photos. A bit of study showed where the difference lay, two holes each side were filled, and a new one marked out and drilled. I also marked and drilled holes for the characteristic loop handrail fitted to these locos on the opening side of the smokebox later in their lives.



Here are the results of my efforts. I've posed the exhaust pipe here, but forgot to do the same when taking the other side! The cast handrail supports (can't really call them knobs, as they're not really knobby) sprues have some long ones and some short ones. The long ones are for the smokebox, compensating for the boiler cladding with the shorter ones. The wire was passed through, gentle tweaks to realign some of the supports so the handrail was straight, a couple of drops of solder paste and a quick touch with the iron to fix. The loop rail was the second attempt.



Here's the other side with the ejector pipe. From the photos of 90643 I could just make out some kind of bracket supports holding the ejector pipe, which I represented by a couple of turns of fuse wire twisted off at the rear and glued into holes in the boiler.

I was planning to pose the upper works on the frames, even without wheels fitted. For some reason, despite having had a few hours in the AADF, some of the paint was tacky. I also couldn't get the frames to slip into the running plate with the boiler bolted in place. I think I shall have to see if the boiler can be mounted after the frames have been fitted.

Anyway, despite what seems glacial progress a Dub-Dee is emerging from the detritus on the workbench.

 

[Heather Kay]

Today I am on a quest to work out the cab fittings.

Before that, a mystery object.



According to the list of parts this is a grease trap. Taking that as read, whereabouts might this object fit in the great scheme of things?

Most of the parts for the backhead have been identified, and located on the cab photo that Dave Bowden posted in the Gallery section on the preserved WD loco. Importantly, comparing with a photo taken by BR in the early days of the conversions from the MoS specification, I can see the steam heating control on the fireman's side - so that can safely be left off.

Interestingly, the backhead gauges are mounted on nice brackets. The castings I have are these:



Would I be correct in assuming these may be a "standard" mould of gauges? Photos show three gauges for the driver, seen here on the left. What would they represent, please? The fireman has a triangular bracket, but only the boiler pressure gauge, according to the photos. The preserved loco has been fitted with steam heating, and that would be the centre gauge in this cast cluster. What would be the left gauge?

Perhaps some of the gauges are for the wartime locos with air brake equipment?

I'm happy to grind away the unneeded gauges, but it's always nice to know what they are for.

Finally, I have three of these:



I thought originally they may be to form part of the nest of pipes around the driver's side of the backhead. I now think I have been blessed with three copies where one is needed, and that is to form part of the thin pipe that runs along the boiler on the driver's side, kinks round the outside steam pipe, with a valve and tap, and then pokes into the front part of the smokebox.

I can't, for the life of me, work out what this feature may be or what its purpose may be. The best guess in this house is some form of steam lance fitting for clearing out the smokebox during disposal, but why have the tap fitting apparently inside the smokebox itself?

I await education and enlightenment!

 

[Dog Star]

Before that, a mystery object.

View attachment 41352

According to the list of parts this is a grease trap. Taking that as read, whereabouts might this object fit in the great scheme of things?

Between the exhaust steam passages of the cylinders and the exhaust steam injector... at the lowest point between the two and often bolted to a frame stretcher.

 

[Heather Kay]

Thanks Graham.

One wonders if it would be noticed if left off...

 

[Dog Star]

One wonders if it would be noticed if left off...

The exhaust steam pipe from cylinder to injector is likely to be of a large diameter, say 6" or so... so if you can see such a pipe, between or below frames, in photographs then you have an answer.

What might be worth asking is "where is the exhaust steam injector located?". If you can see the injector, possibly behind footsteps, then the exhaust steam pipe is going to be visible where the pipe connects to the injector.

 

[OzzyO]

Heather, the drivers gauges with the two inlets would be brake gauges (known as duplex gauges). I think that in B.R. days the WDs would have only had two gauges, vacuum on the drivers side and a pressure gauge on the fireman's side.

The six casting look like steam sanding pipes to me. The short end of the casting to the wheels with a small pipe (about 0.5mm) running into the union on the main pipe, then the long part of the casting running of course to the sand box.



The grease trap as Graham says is at a low point between the cylinders and the exhaust steam injector. You can just make it out to the right of Burt in this photo.


Sorry these photos are not of a WD but are used only to illustrate the above points.

OzzyO.

 

[Heather Kay]

It's awfully dark and murky down there.

I've peered at the sectional drawings, and numerous images, and I can't see anything below the cylinders or anything that matches the casting. I'm not sure where the steam pipe would run.

Considering there is nothing on the model to represent the pony truck bolster or bearing surfaces in the frames, I think I'll leave the trap out unless I get a clue about it at some point.

 

[Heather Kay]

The six casting look like steam sanding pipes to me. The short end of the casting to the wheels with a small pipe (about 0.5mm) running into the union on the main pipe, then the long part of the casting running of course to the sand box.

An interesting hypothesis, but I'm not convinced.



The castings show three distinct hexagonal nuts or unions. I can't see anything similar on the drawing or photos.

Thanks for the info on the grease trap. Again, I can't locate it on the drawings I have, but they are sectional ones published in one of the trade journals back in the day. A "proper" GA might be more help. I am leaning towards leaving it off the model, with no clear information about where or how it might be fitted on the prototype. It's not something glaringly obvious, like screwed to the boiler top or hanging off the front buffer beam!

 

[OzzyO]

Hello Heather,
well Graham and myself are talking out of our bums, as WDs don't have an exhaust steam injector they have two live steam injectors so they don't have a grease separator. The principal is true though.
The cab gauges, three of them are labelled in the drawing below, on the fireman's side he had two gauges boiler pressure and steam heat. Yes that threw me the WDs were first steam heat fitted.



OzzyO.

 

[Heather Kay]

Yes, I understand a batch was fitted for steam heating, but in general BR service this was removed. The preserved loco on the KWVR was repatriated from Sweden, and has been converted back to more or less WD BR spec, but retains some features that weren't standard. For example, I've just learned the cab side windows were not glazed, yet they remain glazed on the preserved loco as it had been fitted with an enclosed cab in Swedish service.

I spotted the labelled gauges on the drawing just now. I really ought to look harder!

Cheers Paul and Graham, for the information and education. The grease trap will go in the Bits Box.

 

[OzzyO]

Hello Heather,
sorry mate I'm not convinced about the castings being the pipes at the front end, if I'm looking at the correct pipes in these photos.


All of these pipes in these photos have the pipe union at 90degs. As you say you only need one of these castings, so why would J.L.T.R.T. cast them as pairs? Whereas the castings have the union running in at about 30degs. that looks to me like it's to blow something, this would also have the effect of causing a partial vacuum behind the entry point. I can agree that the real thing does not have the three hexagons on it but some times the pattern makers don't always get it quite correct.
I would still go with the steam sanding gear.

OzzyO.

 

[mickoo]

I'm with Ozzy, the six fittings are almost certainly sanding pipes, or more importantly live steam sanding pipes, the sand bore will be about 1" dia, the live steam supply about 0.5". The live steam enters at about 45° and shoots out of the nozzle, the resulting vacuum on the back side helps draw down fresh sand.

The reason they do not match your GA, which is probably as built and more importantly built as a WD, is that your drawing shows gravity sanders, who's bore is significantly larger, say 2" (example) I suspect as built and for war torn duties, gravity sanders were fitted, however, in BR days, some/all ? may have been fitted with live steam sanders, you will need to check photos in BR service and see if there's a live steam feed of not, if not they remain as gravity. I don't have access to my material at the moment and Google throws no good close up shots, but I'll have a look tonight when I get home.

 

[Heather Kay]

With nothing better to go on, I'm inclined to agree with you. I shall work out if minor mods would work better.

Actually, now I think of it, I bet the union part is meant to be at the sandbox end. The locos did have steam sanders, and you can just make out a complex fitting to one of the outside sandboxes on one of Dave's photos. I've just chatted to Graham on the telephone about this, and we think that may explain the drawing more clearly.

Sanding pipes it is then!

 

[mickoo]

The contraption at the outside of the sandbox is probably the vacuum relief apparatus and blockage access port.





The steam pipe entry is nearly always as close to the exit point as possible to reduce blockages when the warm steam cools and makes the sand wet, much easier to blow out a few inches of wet sand than several feet of pipe work. The vacuum relief valve also works if the pipe does get blocked in that high pressure steam exits through this, rather than trying to blow all the sand out of the box through the lid!

The fact that the GA shows this value beneath the sandbox quite clearly means that it must be steam sanded and they simply have not added the live steam pipes, much like they will not show lubrication pipe runs, I suspect there will be a pipe size threashold under which items will not be drawn.

 

[Heather Kay]

Wow! Thanks M!

Back to the thinking for a bit. The idea of having to drill out the angled pipe to fit anothernbit of wire in place doesn't appeal. Studying the photos I have don't really show the steam pipe, unless it arrives inboard of the junction point and therefore is not visible under normal circumstances.

I'm increasingly coming round to the idea that I'll fabricate the mounting brackets, shove a length of wire through a short bit of tube to represent the bulge near the end of the pipe and cover it all with gunge! While it's a good thing to try to model what it should be like, sometimes it's simpler to model what you see.

I've tried fitting parts to the backhead. As usual, the sketch plan in the instructions identifies the parts but gives an unrealistic idea of the amount of available space. Add to that not all the locating holes have been cast, and I am getting more than a little narked with it. Something so simple, yet so hard.

Another excuse is an immoderate amount of pain from my right hip today. It's making sitting very uncomfortable, and making my mood swing to the very slightly miffed.

 

[Dog Star]

Paul is correct to admonish us for not thinking straight... why would a loco destined for the European theatre be given a piece of equipment that requires care in use and maintenance? Heather and I did consider that possibility that the casting might be a drain for steam heat, Heather thinks that some of the builds did have steam heat... do not ask me, to late for an Edwardian ferri-equi-nologist.

 

[mickoo]

Heather, just quickly as I'm out the door almost as soon as I got in, couple of rush crops from images on my hard drive

I've left them large size so you can see the details but the steam pipe is indeed fed into the back of the fitting and scoots up behind the frames, because it's on the back side I'd solder it parallel and then bend the pipe away at the appropriate point, a nice blob of solder will hold it in place.

The WD looks like it has a bulged fitting as opposed to your three nut one so to replicate that you could blob on some 5 min epoxy and just sand to shape once hardened.


You can just see the small pipe inside of the main sand pipe


A closer shot of the steam/sand fitting, the steam pipe is quite clear in this shot.

I'll have a look through my WD books later tonight and see if there's a more detailed shot somewhere if need be.