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GNR (Ireland) VS Class 4-4-0 - a Skritchbuild in 4mm

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Way back in the 1970s, I was given a photocopy of a drawing of a Great Northern (Ireland) VS Class and ever since then have had a desire to build one. The five VS locos were built by Beyer Peacock in 1948 - allegedly the last 4-4-0s to be built anywhere.

I still have that photocopy, but it's faded so much that you can barely now see the drawing. Fortunately I've since got a replacement of the same drawing courtesy Mick Rawlings of Ballyconnell Road fame. Even more recently, the Irish Railway Record Society has started to make available copies of the treasure trove of Dundalk Works drawings found in a large trunk in Inchicore. One of the sets available is for the VS and probably contains sufficent information to build a real loco, never mind a model. Needless to say, I bought a set.

So there's not really any excuse now not to build a VS .....

There are a number of possible starting points for such a model.

Colm Flanagan has produced a very passable likeness in 16.5 mm gauge using a Hornby Schools Class as a basis. I ruled this approach out as I work in 21 mm (5' 3") gauge and the additional work converting the 00 gauge workings to 21mm would probably end up being more than building from scratch.

Building entirely from scratch is certainly a possibility, and this was my original intention.

However, the VS class design was very much based on the earlier V Class Compounds of 1932 (of which No. 85 happily survives) There's an excellent etched kit for the Compounds available from Studio Scale Models.

I looked closely at one such kit and came to the conclusion that there were very many common components - although there are also significant differences.

To cut a long story short I took the plunge and ordered a V Class kit (the loco only, as the VS tender is completely different) from Des Sullivan at SSM.

This has now arrived and the etches are shown below. It will be a "Skritchbuild" as a significant number of components will come from the etched kit. The tender will be scratchbuilt, and items such as the valve gear, running plate and cylinders will also need to be scratchbuilt or sourced elsewhere from suitable components.

This will be a learning process for me, as there are many aspects that I am not yet sure how best to approach. Hopefully it will also provide pointers to anyone else comtemplating such a model- in the worst case, how not to do it!



Starting point: The V Class (GNR Compound) Etches from SSM

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Now that looks like fun!


......ordered a V Class kit (the loco only, as the VS tender is completely different) from Des Sullivan at SSM...... The tender will be scratchbuilt, and items such as the valve gear, running plate and cylinders will also need to be scratchbuilt or sourced elsewhere from suitable components......



Starting point: The V Class (GNR Compound) Etches from SSM

Interesting to see that, although you may have ordered a loco only, the etches clearly include parts for a tender....

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Now that looks like fun!



......the etches clearly include parts for a tender....


"Fun will be provided in the box with each kit....." :)

Yes, they do include some tender parts - some of these are the curved extensions which were fitted to the Compounds' (and some other) tenders to increase coal capacity. There is also a set of tender frames and beading for the top edge of the tender sides. Needless to say none of these parts will go to waste .....


So, on to the first steps in building the loco. - at which point I discover that my 4mm drawing of the loco is reproduced slightly underscale. I will need to scan it in and do a print to the correct size. The reason for doing this will become apparent shortly.


The first task is to solder up the coupling rods (I also did the connecting rods at the same time), followed by putting together the main frames.


The design of the kit makes assembling the rods very easy. Cut the rods out from the fret, but leave the tabs joining the two halves of each rod intact. Then just fold the halves together and the tabs ensure they align correctly.


I've run some solder along the top and bottom faces of the rods to fill in any gaps, then filed the whole thing smooth.



Rods after initial soldering up, & Mainframes



Rods after cleaning up the solder & polishing





It's a small first step. If things all go according to plan I may hopefully end up with something looking like this (although these superb models are to 7mm scale rather than 4mm)



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....my 4mm drawing of the loco is reproduced slightly underscale. I will need to scan it in and do a print to the correct size. The reason for doing this will become apparent shortly.


Can have effects on the working of the valve gear.


The etch artwork also show how design technique has come on since the "S" class chassis was designed in TMD days.

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On to assembling the frames, and I have pretty much followed the instructions for this part.

This is relatively unusual for me, but the reason is that the chassis is much more "designed" than (for example) the S Class - from the same stable - which Horsetan mentions above.

With the S (the kit dates from the 1980s, but is still a good kit today), the usual mainframes and spacers are provided but if you want to provide compensation or suspension you're pretty much left to your own devices. With the V, compensation is designed in to the kit (though you can leave the components out if you really want a rigid chassis).

With a 4-4-0, having some way to transfer weight from the front of the loco to the driving wheels is a Good Thing.

Also, the bogie design restricts the movement of the bogie rear wheelset so that it should not foul the slidebars.

First task is to attach the ashpan sides to the frames. The ashpan will need to be slightly modified at some point, but more of this later. A nice feature is the provision of small "locating holes" in the parts - short lengths of phospor bronze wire are threaded through these holes to accurately locate the parts before they are soldered.


Next the frames are assembled. the location of spacers, etc. is precisely defined by means of tabs and slots. The assembly process is "self jigging" - two long 10BA bolts are provided which pass through etched holes in the frames and hold everything in alignment until it is soldered up.


As an additional measure I've put jig axles through the driving wheel bearings to ensure that the coupling rods match up with the wheel centres.

The brass wheel bearings aren't soldered in - they will be removed and (probably) replaced with hornblocks once the chassis is soldered together.

I've now reached the point where the first modifications need to be made to produce a VS class, rather than a V Class frrom the kit.




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......t the chassis is much more "designed" than (for example) the S Class - from the same stable - which Horsetan mentions above.

With the S (the kit dates from the 1980s, but is still a good kit today), the usual mainframes and spacers are provided but if you want to provide compensation or suspension you're pretty much left to your own devices.....



....and you're definitely on your own if you're trying to install working inside motion. I've had the very devil's job of it!

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What a superb loco 85 is.


It's great to see her back doing what she is best at again.


When she was first restored in the 1980's I was still living in Ireland and on the RPSI's footplate roster. Many happy memories!

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While there hasn't been a huge amount of obvious physical progress, I have spent considerable time looking at the drawings and working out what changes I need to make, and what bits I will need to manufacture as a result.

I've also given some thought as to additional parts I need to buy (wheels, motor, gearbox, etc.) and started to acquire some of them.

It's a bit like doing some huge 3-dimensional jigsaw puzzle. Except in this case there are a number of the key pieces missing...

I assembled the cylinders as they would be for the V-class.



I had initially hoped to be able to use these as is and add the piston valves above them, but comparison with the drawings and trial

fitting showed that the cylinders would be in the wrong place......



.......so nothing for it but to remove the relevant bits and make complete new cylinders. I' ve left the motion bracket in situ at the

moment but it will need to be repositioned at some point.


A photocopy was made of the 4mm scale drawing, and the relevant parts cut out then glued to some brass sheet (all very Blue Peter....).

This gave a template to cut around with the piercing saw. The sheet is actually two pieces soldered together, giving front and rear for

each cylinder with one cut.


One of the distinctive features of the VS is that the cylinders are sharply inclined laterally (presumably for reasons of clearance).



In a similar way, a new running plate has been made by gluing the relevant bit of the drawing to nickel silver sheet and

cutting out as appropiate.



The VS differs from the V in that the running plate "joggles" out around the cylinders and outside motion,

whereas on the V (left) it is straight.


The cylinder ends were drilled out to take some brass tube, representing the cylinder bores and valve chests.

These parts were then soldered together.


Finally, I received these in the post from Guilplates. I won't be fitting them for a little while yet though!



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Next step is to build up the crossheads & piston rods. Because I'm doing a VS rather tha a V, drop links need to be added to the crossheads as part of the Walchaerts gear. Fortunately, Markits replacement crossheads (for DJH Stanier pacifics, etc, etc.) come with a selection of drop links. I had a couple of frets with the ones I hadn't used when fitting the Markits crossheads to other locos. Some of these spares were fairly close to what I needed for the VS (moral - never throw anything away!)


Etched crosshead parts from the V Class kit, and drop links spare from the Markits "Double Slidebar Crosshead" etch.



The crossheads consist of a number of etched parts, but there's a fold up jig which holds everything in line until you've soldered it together.


Diagram from instructions copyright Studio Scale Models Reproduced with permission.


After this, you cut off the jig giving (hopefully!) a perfectly aligned crosshead.



The finished crossheads fitted to the slidebars



I found that I could use the cylinder wrappers from the V kit. They're actually upside down - the VS had a couple of small circular covers near the top of the cylinders. I'm not sure what these were for - possibly inspection ports used when setting the valves? But if you turn the V class wrappers upside down, the circular bosses for the cylinder draincocks give a good representation of the circular inspection covers. Of course this means I will need to make some alternative arrangement for the draincocks on the VS, but later.....


Cylinder wrappers added.



As expected, the motion bracket was foul of the slidebars in their new position.  Simply solved by removing the motion bracket, then soldering it on again slightly lower down.



The cylinder assembly fitted to the frames, It is not quite complete (front cylinder covers and various other parts to be added), but the first signs of it being a VS are now evident.




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This looks fantastic. What are you doing for suspension?


Thank You. It's a bit scary at the moment because if it all goes horribly wrong I will have ruined a rather good kit. I am now well past the point of no return, though - said point being where I could still say "actually I have changed my mind an am just going to build it as a V Class".  I spent tonight soldering up the new running plate, more of which shortly.


I have not decided what suspension to fit. I've been looking at some Exactoscale hornblocks, but there are alternatives such as MJT and Kean Maygib of which I have some somewhere.


In the short term I will keep the chassis rigid and will fit some temporary wheels which will allow me to assemble the rods & motion and get all that working.


Assuming it all goes together OK, I will then fit the hornblocks and the proper wheels. At least that's the theory .....




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You might want to try High Level hornblocks. Very easy to assemble and fit.


At least you're not trying inside motion on this one. I'm still struggling with the setup for the "S" class, and it's giving me a headache.


Bejabbers, there's enough motion on the outside to worry about!! :mosking:


Though actually I do have the drawings of the inside motion in detail.

I'm hoping though that the large boiler close to the frames will hide any such absence.


Sorry to hear that your S Class is causing a struggle.


I've pretty much completed mine now. I can recommend the Brassmasters 4F inside motion for the S Class in that it fits in very nicely. However I can reveal that during  some of the more fiddly bits of constructing this motion I was tempted to retreat and apply a cold wet towel to the head.......


I'll take a few pictures of the S Class and post in another thread (probably in the "Irish Railways" section).


I'll also look into High Level hornblocks - I believe they are good.



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... I can recommend the Brassmasters 4F inside motion for the S Class in that it fits in very nicely. ....

I might end up salvaging a few bits from that fret. So far I have inside cranks and eccentrics from Martin Finney, plus a few parts from the inside motion fret for a Drummond T9.

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  • 2 weeks later...

Work has been continuing on the VS, although it's been a tad frustrating as lots of hours have been put in but there haven't been leaps and bounds towards something resembling a loco appearing. This is mainly because I have veered off into the realms of scratchbuilding (due to the differences between the loco I am constructing and the one the kit represents).  I can say that this definitely slows things down a lot! Nevertheless, much progress actually has been made, and I'm hopeful that with some of the major modifications now done, things will speed up a bit.

The illustration below was included with the instructions for the V Class kit (not sure if it still is) and shows the main differences between the V & VS classes.
Copyright Studio Scale Models. Reproduced with permission.

The bogie frame is assembled.


The next task is to form the running plate. The new composite running plate consisting of the V Class running plate from the kit with the new VS Class running plate (replete with "joggles") soldered on top is seen here on the frames. The cab sides have been attached temporarily, mainly to form the drop of the running plate at the rear.


The distinctive front end and buffer beam folded up and added.


One of the differences between V and VS is that the running plate valances are thinner on the latter (3 inches as opposed to 5 inches deep). I thought about trying to adapt the valances from the kit by filing them down, but in the end decided to make entirely new ones using 1 mm nickel silver strip, and parts cut out of nickel silver sheet.

Here are the strips for the valances (with the rivets holding on the front steps embossed) also the front and rear drops which had to be cut from sheet with a piercing saw.


Front drops added.


And the rear ones. They look a bit rough at the moment, but will be cleaned up with a fine file now they are in situ.


Then the centre section was bent to shape and soldered in place. The valance from the V class is shown below for comparison.


Both sides now soldered in place but lots of cleaning up still to do!
Note the cental area in the running plate which has been left in place to give it strength while assembling, but which will be removed to clear wheels, gearbox, etc.


I had intended to remove the cab sides again but found that this would now be difficult with the valances soldered in place. Fortunately I could leave them were they were and still form the curves at the top.




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  • 4 weeks later...

Thanks for your comments, Mike.

I have been away for a period, so I am just getting back into the build. The current phase is to complete the basics of the loco body including many of the modifications needed to change from a V to a VS. Once that is done I can start looking at the mechanical bits. There's also the small matter of a complete tender ...

The curve at the top of the cab sides was too angular for my liking, so further fiddling around using brass rods as rollers ensued until it had a more rounded appearance.


A small but noticeable difference between the two classes is the difference in shape of the front cab windows.

The oblong shape of the V was moified to the slightly taller, pointy shape of the VS.


Here the cab front has been soldered in place. Some solder still needs to be cleaned up, and there's a lot of detail yet to be added.


The major parts of the smokebox, boiler & firebox laid out. The main differences here are that the VS has a longer smokebox than the V,

and that the front corners of the firebox are angular in the V, but rounded off in the VS.


A new base has been made and soldered in to the smokebox shell. This of course means I will not be able to use the

wrapper (left) provided in the kit, but at least I can use it as a pattern to make a slightly longer one.


The boiler (a flat sheet from the etch) is rolled to shape using the GW rollers, and the seam soldered.






The firebox seems daunting.  It must be formed to shape around the template (left). This template also happens to have all the nameplates

for the V Class locos etched in the centre of it. I won't need these for the VS, so if anyone wants a pair of nameplates for a Compound, drop me a line!



The instructions specified using 6mm dia. rods to roll the curves, and a nice smooth curve resulted.

Had this been a Midland engine that would have been job done ....



.... but the reverse curves at the bottom must also be formed. Again using the 6mm rods, and with the half etched ribbing

on the inside of the firebox making it easier to bend, the curves were formed without too much difficulty.


A trial fit of the firebox, boiler, and smokebox shell.



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  • 1 month later...

I haven't posted anything here for a while, but have been working away on this project, although progress is never as swift as I would like. I'm very aware that time is slipping away quickly so a major effort is needed to get this to the stage where I know that it basically works and can be completed in time.

Anyway, an update on progress:

The new smokebox wrapper was cut out from sheet, and has had the rivets embossed on it. The shorter wrapper for the V class (top) was useful as a pattern.

The wrapper is rolled ......


...... and carefully soldered to the smokebox shell.


The centre splasher sides are added to the running plate. Note that the central section has now been cut out, so the running plate is now quite delicate, and care must be taken not to bend or twist it. There is a small lip on the inner face of the face of the splasher ......


...... which is filed off to give maximum clearance for the wheels and motion.

Here the front frames have been added to the running plate and the smokebox trial fitted. These frames were made from nickel silver strip and embossed with rivets. The V class frames are a different shape, and have an overlapping joint in the middle. The splasher tops have also been added, adding back some strength to the assembly.


I'm glad I don't have to make this bit! I will cut off the apron plate from the bottom as it will be easier to add separately.

The axleboxes / hornguides ready for fitting to the frames. These are Alan Gibson items, but required a lot of work to get them working properly.

I also made a couple of modifications. I removed the lip (which locates in the slots in the frames) from the sides of the hornguides. This means that when located in the frames, the assembly can be adjusted slightly backwards or forwards. The reason for this will become clear. I also found that the short 14BA setscrews provided to attach the underkeeps could not be used, as they fouled against some of the cast detail when screwed in. So instead I screwed a 14BA brass bolt in as far as possible, soldered it in position, then cut off the head, leaving a 14BA stud. It was then possible to hold the underkeeps in position with two 14BA nuts.

The slots in the frames cut out in readiness. The spring detail (bottom) will be reused (attached to the underkeeps) at a later stage.

The axlebox assemblies are placed on jig axles. The springs will hold the assemblies tight against the frames in the next stage.

Here is the reason for removing the lips which would have locked the hornguides in a single position in the frame slots. Being able to adjust them slightly forwards or backwards in the frames allows an exact match to be made with the coupling rod centres. The coupling rods are placed over the ends of the axle jigs to allow this match to be made. Spend a lot of time lining things up, checking and rechecking. Then take a deep breath and solder the hornguides in place....


The wheelsets are trial fitted to the frames. I'm using Exactoscale wheels for the first time. These have the plus point that  they can be built to 21mm gauge just using the standard components as supplied.


The compensating beam which transfers weight from the bogie to the driving wheels has also been added. It's pretty much as per the instructions, but I've added a means of adjustment at the driving axle end as the screw at the front end of the beam will be between the cylinders and difficult to get at when the loco is assembled.

The front bogie completed, again using Exactoscale wheels.


The show so far, trial fitted together. I couldn't resist making the smoke deflectors, although it will be a while before I actually need them. They are not attached to the body, just set there, but hopefully it is now starting to look like a VS.





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  • 3 weeks later...

I like the idea of the stud fixing to the axlebox underkeeps very neat engineered solution compared to most commercial hornblocks.


It was kind of forced upon me as the method of fixing provided wouldn't have worked - one drawback might be if the nuts holding on the underkeeps start to work loose in traffic. Does anyone make 14BA spring washers?! :)

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