7mm On Heather's Workbench - the answer to life, the universe and…

One of those satisfying creatures, a returning client, asked me if I'd care to take on a project he'd started but felt unable to complete. Of course, I agreed. After a spot of negotiation, I was entrusted with a large box containing an almost complete Churchward 4200 class 2-8-0T, hailing from the JLTRT stable, out of Mitchell Designs.

So, a "finish it for me" commission. How much do I have to finish, exactly?



Well, to be fair, not a great deal - on the surface. The major etched parts are assembled, the chassis is rolling, so all I have to do is fit the motor, wire it up, add all the detail parts, paint and deliver. Oh, I will acquire a crew, but otherwise all I need is in the box. We even have the number plates for 4250, shed plates for 87B, and a ready source of spare parts from sunny Irvine. The super detail kit seems to have been added to the mix.

With help from the Hampshire GWR Reference Library, I now have more information about the class. It has also been noted that the K&ESR has 4253 as a kit of parts which willing volunteers are assembling as I type. My guess is the client has the same two volumes of Russell's pictorial history and chose the loco number because two photos of it in final condition appear there!

The plan is to construct the loco to suit the latest phase of the real thing, in other words in BR late 1950s. Plain black livery, final totem, the client will probably fit DCC gubbins, so I shall make allowances.

The superstructure is pretty well complete. I have cleaned up flux residue and some dodgy soldering, given the whole thing a going over with brass and fibreglass brushes, and given it a scrub with Viakal. The chimney and safety valve bonnet have been posed for the photo, but I've cleaned them up. I'm tempted to crack on and fit the final details to the bodywork, but I really should get the chassis rolling.

The chassis frames are assembled. The leading coupled wheels are beam compensated, the third axle is rigid, and the trailing one is sprung. The coupling and connecting rods are milled, probably from a well-known source. The cylinder block has been partly assembled, and the pony truck is almost ready to fit.

I decided it was worth spending time getting to know the remaining parts in order to complete the chassis. With the help of the instructions, I managed to identify most things, and I've separated cab and body castings into a fresh plastic bag, leaving all the underframe components. Attention turned to the cylinders.

Originally, the kit was designed for a lot of the detail to be etched, and the instructions (and frets) still follow this construction method. Various parts are replaced with castings, such as the slide bars, motion brackets, cylinder fronts and so on. So begins the game of identify the part!



The photo shows the cylinder fronts, cylinder release valves (52) and the cylinder drain cocks (53). The small castings to the left of the cocks, though, are unidentified.



This is the sprue from the casting parts list. I've circled the small parts, unidentified. They look like bolts. As yet, I can't find out what they might be for. Meanwhile, parts 76 Piston Extension remain elusive. I've been through the parts several times, and haven't found a pair of anything that remotely resembles the drawing.



Part 76 seems to fit dead centre in the cylinder front. If the small cast parts are the right ones, perhaps I don't need them as the cylinder front castings have a hexagonal bolt head already in place. Guess what I shall be doing this morning!

The plan is to try and get the frames powered up, then work out a way to fit the milled connecting rod into the cast crosshead. I think I'm going to enjoy this.

Hi Heather,
I think they are (internal spring?) for P/N 52, stuff in the hole & put 52 on top
Andy

demu1037 said:

Hi Heather,
I think they are (internal spring?) for P/N 52, stuff in the hole & put 52 on top
Andy

Click to expand...

That makes perfect sense. Obvious when you think about it.

Just be patient Heather, there will be a knowledgable GWR whizz passing anytime soon with all the right answers.
This is Western Thunder after all.

EDIT.
There you are even as I typed this it happened.

Heather Kay said:

That makes perfect sense. Obvious when you think about it.

Click to expand...

see picture,

Heather Kay said:

I decided it was worth spending time getting to know the remaining parts in order to complete the chassis. ... The photo shows the cylinder fronts, cylinder release valves (52) and the cylinder drain cocks (53). The small castings to the left of the cocks, though, are unidentified.

Click to expand...

And so the fun continues...

Part 52 is the outer body of the relief valve and the un-numbered part represents the valve and spring that sits within the outer body. Fit one into the other and use the hole (in the cylinder cover) which is off-centre and below the cylinder centre line.

Part 53 is the later style of water drain cock with a mushroom valve that is pushed to open (spring return) - the earlier style is a plug cock, screwed into the bottom of the cylinder block and the "plug" rotates" to open. The later style as supplied is the more probable type for a BR-era engine... just check photos of the period as some of the plug cock style did survive into BR days (I think that the early style was replaced only when cylinders were swapped).

Andy's photo (@demu1037) shows little details that you shall be including... all of the cylinder drain cocks are identical on the prototype and that is what JLTRT supplies in the kit. All of the fittings are mounted below a flat bar which supports the outer ends of the operating rod / cranks (rod goes from side to side) - are the cranks in the kit? The front and rear fittings are retained by studs which pass through the flat bar and into the cylinder block. The centre fitting is mounted to a dropped section of the bar... and separated from the bar by a flange that has a screw thread on the upper surface. The purpose of the flange is to provide a connection for the pipe from the steam chest, the pipe runs down the outside of the back of the block and makes a 90 degree turn just above the flange.

We shall all be watching.

Locomodels said:

Just be patient Heather, there will be a knowledgable GWR whizz passing anytime soon with all the right answers.
This is Western Thunder after all.

EDIT.
There you are even as I typed this it happened.

Click to expand...

I think I need to go and lie down for a bit!

Dog Star said:

All of the fittings are mounted below a flat bar which supports the outer ends of the operating rod / cranks (rod goes from side to side) - are the cranks in the kit? The front and rear fittings are retained by studs which pass through the flat bar and into the cylinder block. The centre fitting is mounted to a dropped section of the bar... and separated from the bar by a flange that has a screw thread on the upper surface. The purpose of the flange is to provide a connection for the pipe from the steam chest, the pipe runs down the outside of the back of the block and makes a 90 degree turn just above the flange.

Click to expand...

Are the cranks in the kit? You can probably guess the answer to that. Likewise, no bar, and nothing to let the centre cock be positioned lower.

Thanks for all the help so far. I shall peruse the various sources and try to make an adequate impression of the cylinder fittings. Don't forget, I've had to make from scratch on the WD, so this ought to be a comparative doddle!

Heather

I know its a different class of loco but the front end should be the same http://www.7200trust.org.uk/gallery.aspx
I remeber this loco in bits when I was helping rebuild http://www.wightwick-hall-6989.com/
Ian G

Be wary of the preserved locos. One of my fleet is preserved (and named, yuk!) but has a different bunker than it had when photographed on the scrapline a couple of months after it was running up that hill in Wales.
Simon
(Form? Two DA 52XX and one JLTRT 72XX)

Oh, it quite agree, Simon. The thing is, as the superstructure is mostly complete, I'm not going to worry about absolute fidelity to the chosen loco. I will aim to make the model as accurate in the main details as possible.

The first job has been to take the cylinder wrappers off, as they had been attached the wrong way round. An easy mistake, as it's not at all clear from the instructions and only obvious looking at photos - when the cylinder draincocks are actually visible!



Oh my, look at all that lovely solder to clean up. I wonder if the 42/52/72 kits have the resin cylinder blocks yet…

The wrappers went back on without major swearing, which was nice. The cylinder release valves were fitted. I even managed to fit the cylinder fronts in place.

Today has been about slide bars, motion brackets and fettling with the frames. Let's just say, nothing much got done in that direction, so I decided it was time to consider the cylinder draincocks.

I was fossicking about in the box of bits when I had one of those increasingly rare lightbulb moments. I was under the impression there were no supplied parts to represent the draincock bases, brackets and operating mechanism. I was wrong. There are etched parts. I neglected to take a photo in the flat, but the etched parts matched with the holes in the cylinder wrappers. A little folding and the brackets are formed, and a final part is fitted to make the operating rod. A complete faff and pain in the what-have-you to form and fit, especially as the holes have to be enlarged to take the cast cocks.



I don't know if that's at all clear, but you get the idea. The centre cock has to be lower, and a small etched washer is provided that almost helps! To be fair, it's not quite like the shots of preserved locos. I have to rely on preservation because my stock of historical images, for some unaccountable reason, fails to cover such details.



Anyway, it's all better than nothing. I'm reasonably pleased with how it turned out.

The next thing is to make up the etched motion brackets. I would prefer to use the lovely cast ones, but they are about 2.5mm too big and don't meet the slide bars. I'll illustrate that in the next post.

Setting the centre drain cock that bit lower is noticeable, good on you.

regards, Graham

I hate to do this to you, but I have. Pictures of cylinders on 42XX and 72XX locos, that is. Underexposed and pretty cr***y they may be, but they are scanned and ready to post process. I'll post later this evening without any post processing apart from lifting the density a bit.

The good news, Heather, is that as far as it's possible to see they look the same as yours!

Brian

Hi Heather.

Try these for size. Not perfect as photos but as guides to the detail they seem to confirm what you've done.

The draincocks etc may not be complete as these photos were taken at Barry. First is 4247 on 9 November 1968, second is 7202 on the same date and third is 7202 on 18 November 1967.

Brian

Thanks Brian! I'm not a million miles off.

In an effort to make some progress with this build, I wanted to fit the cylinder block, get the motion brackets fitted and basically get the basic chassis powered.

Huh! It's never that easy.

First, the cylinders are missing the valve chest covers. Here's the real thing:



This image is borrowed from the 4253 Locomotive Company web site. You can see the valve chest covers quite plainly. Indeed, close inspection of period photos shows you can see them hidden in the murk under the raised part of the running plate.

Obviously, such things don't come in the box. I think I know why, too. The kit comes in different varieties, depending on which version of the 4200/5200/7200 you plan to build. With the square frame variety, the valve chests can be seen above the running plate, and indeed two brass castings are provided to replicate that. For the curved drop frame variety, there's nowt. Thoughts turned to wondering if other GWR kits from JLTRT have suitable parts.

While I pondered valve chests, I decided to work out fitting the cylinders and motion brackets.



From the same place as before, you can see the motion brackets and how they should fit snugly under the hanging bar. The kit has some nice chunky cast brackets, only they are too big.



Here you can see the cast bracket compared to the etched ones and the slide bars. What is going on is the kit was originally designed for the cylinder details, slide bars, crossheads and motion brackets to be formed from the etches, and these admittedly difficult fabrications have been replaced with castings. This is a Good Thing, provided the right parts are in the box. I must assume the motion brackets are from a different kit, but I have no way to prove this.

Oh well, I thought, might as well use the etched ones. They're a mite too small, and need to be opened up for the cast slide bars. Then there's the issue of the solid bracketry that holds the slide bars to the brackets - which is on the cast version. I put it all to one side and picked up another part while I worked out what to do.

The pony truck. Again, originally intended to be folded from the etch, my client had acquired the brass cast version. Very nice it is, too. Only there's no lifeguard detail. What I ended up doing was hacking the guards from the etch and soldering them on the casting.



While I was at it, I added the bracing stays or spacers. Then I thought about fitting the nice ATC casting…



Uh-huh. That's going to fit to the front of the truck frame, isn't it. It looks more like the casting is designed to fit to the back of a buffer plank. Not idea which way round it's supposed to be, and do you think I can find any images on the interwebs?

Before I hack the casting about, I thought it a suitable time to ask the question of the WT Hive Mind. There are other questions that have arisen from study of some photos that turned up. I haven't been able to ascertain the provenance of the pictures, so if I the copyright owner claims them I will happily take them down from this thread.



Here is a cropped copy of an image showing 4232 in its natural environment. Some details to note, useful for the engine pickers out there. First, the path taken by the front vacuum pipe - some way down from the buffer plank and then through the middle of the pony truck! Next, the dent along the cylinder wrapper. The footstep at the bottom of the smoke box front. Finally, is that really a whistle mounted to the front of the motion bracket extension? Obviously, it ought not to be a whistle, and it must be some kind of valve, but what is it exactly? I can say it only appears on the driver's side of the loco. This loco has the taller safety valve bonnet, whereas 4250 - the loco I am apparently building - has the shorter one.

All fascinating stuff.

Heather Kay said:

Finally, is that really a whistle mounted to the front of the motion bracket extension? Obviously, it ought not to be a whistle, and it must be some kind of valve, but what is it exactly?

Click to expand...

No, that is not really a whistle. The object mounted on the front of the motion plate is an oil pot... for the spindle of the vacuum pump. The pot has a nice cast iron body and cap (screw thread into top of body) and a armoured / flexible pipe diving into the deep and dark extremities of the frame.

Dog Star said:

No, that is not really a whistle. The object mounted on the front of the motion plate is an oil pot... for the spindle of the vacuum pump. The pot has a nice cast iron body and cap (screw thread into top of body) and a armoured / flexible pipe diving into the deep and dark extremities of the frame.

Click to expand...

Well, there you go. Thanks Graham!

I reckon my Bits Box will cough up a suitable whistle casting that will not look too far off.

Incidentally, you can see in the same photo the ATC shoe and bracket. It really does look like it's fixed to the back of the buffer plank. Anyway, off to stroll around the 4253 site again for inspiration.

I should admit to an error in my earlier post. While the K&ESR are rebuilding an actual 4200, the images I borrowed came from the ongoing refurbishment of a 7200 class at Quainton Road.