Site Tools


gazettearchive:gazettevol19:scratch-l_yr-brake_vans

Scratch building L&YR 6 wheel brake vans

Jim Snowdon
Sourcr: Gazette Volume 19 No. 11 May 2016

Among our club’s O gauge group there are several of us, myself included, who have a penchant for the unusual when it comes to rolling stock. It was from this, inspired by the photograph of one in one of the late Geoff Gamble’s books, that the idea for a Lancashire and Yorkshire Railway 6-wheel goods brake was born.
The two vans side by side (or is it end to end), illustrating that the differences are hardly noticeable and that what is under the floor is beyond sight. Pity about the telegraph pole, though.

First, a word about the prototype. The Lancashire and Yorkshire Railway was conservative to say the least with its designs of goods brake vans, there being only three in the whole of its history. The original design, which set the style for the rest of the railway’s life, was a simple 10ton, fully enclosed 4-wheel van, characterised by having neither verandas nor lookouts, and clad in iron plates fixed over a timber frame. As a consequence of their metal bodies, they became popularly known, for whatever reasons at the time, as ‘Tin Tabernacles,’ or more usually just ‘Tin Tabs.’

As train weights grew, so did the need for heavier brake vans to control them, resulting in the appearance in 1900 of a 20 ton 4-wheel design. This retained the same iron and timber body construction, but introduced verandas at each end. The 6-wheel version that appeared subsequently was the 20 ton van design using existing lower capacity wheelsets that had become available as smaller wagons were scrapped. Externally the vans changed very little, save for the addition of the third axle and minor variations in the layout of the verandas, principally the position of the door into the van itself and the substitution of doors for the lifting bars previously provided at the entrances to the verandas. As befits vans which survived through to the period we are modelling, which is the early 1950s, the two vans that form the subject of this article are the later type, one having the modified suspension fitted to the final batch.

There is already a kit available for these vans, in the shape of the ex-Shedmaster example now sold by Laurie Griffin, https://www.lgminiatures.co.uk hence it is a fair question to ask ‘why scratchbuild?’ The answer is partly that I have never considered etched brass entirely capable of replicating the weight of the timber members used in the framing of, in this case, the veranda ends of the body, and partly that by scratchbuilding, I could retain full control of the dimensions. Nonetheless, the fact that Laurie does produce the kit was useful in providing a source for such fittings as the axleguards and springs and the brake shoes. The decision to build two vans came about from the realisation that the second only takes half the effort of the first and, as originally conceived, would have gone for sale via eBay.

Building a brake van is rather more complex than a simple box van, essentially due to the open nature of the verandas and the presence of the glazing in the inner ends of the van body. Initial construction was based around making and fitting the two body sides to the floor, ignoring the verandas for the time being. This way, the two sides are simple components – plain rectangles with just the opening for the guard’s droplight. Squareness was ensured by providing two half-height internal partitions, set about 10mm inside the ends of the body, as the actual van end was fabricated from many pieces, none of which were continuous across the full width of the body. As it turned out, these inner partitions came in useful later, providing the basis for a locker to contain the lead ballast weights.

The first step in erecting the body. The steel rule underneath the floor panel is not there by accident but allows the bottom edge of the sides to be set down below the floor. Later on in the build, that compensates for the way that Evergreen strip comes in imperial sizes - handy for 1:48 modelling but not 7mm/ft.

The basic body shell. Because these vans were timber framed, the end will be assembled from a series of panels, hence the yawning gap. At this stage, only the inner parts of the body corner pillars are fitted.

The ends themselves, which consist of a half-height glazed screen and the inward opening door set to one side, were built up piece by piece from Evergreen styrene strip. Although fiddly, this allows the visual texture of the construction, formed by the inset of the door and the beading around the windows, to be reproduced. It is not a process that can be rushed and is very much a case of cut and fit a part, then leave the model overnight for the joints to harden fully before fitting the next part. It is also a task where the Chopper, made by North West Short Lines in the USA, comes into its own as a means of both cutting the strip square and repeatedly to the same lengths. The order of construction is to fit the inner sections of the two corner posts first, as these provide the support for the arched top section of the body end. Each brake van needs two of these, as well as the two matching curved ribs that support the roof at the outer end of the veranda. These were all marked out on a piece of 0.060in styrene sheet and cut at the same sitting, the curved cuts being made using a piercing saw.

The ends are now taking shape, with the lower planking fitted as a panel, followed by the top roof former, then the door pillar fitted in between the two. \\

A useful trick in doing this is to pull the saw back from the cutting face on the up stroke, when it is not cutting, as this markedly reduces the build-up of swarf on top of the cutting line and makes it much easier to guide the saw. The more accurate the cut, the less there is to trim off with a file afterwards. It also pays to let the blade cut in its own time, without forcing, and any blade which has a tendency to drift should be thrown away. Trying to counter such drift is possible, but simply adds to the concentration required and the risk of cutting into the work. It is tempting to cut these parts to the required length, but the dimensional tolerances that inevitably creep in during construction mean that it is better to cut them slightly over length and trim them back to fit individually.

Constructing the three-pane window does require a lot of patience and many small parts of plastic strip, but is actually easier than it seems. The key is to work steadily from one side to the other, and not to rush. Patience is very much a virtue when fabricating detailed parts in styrene.

Building the ends. Because the veranda doors are set back into the framing, the ends of the van are very three-dimensional and have to be built up much like the prototype, with the corner pillars, roof stick and cant rail extensions all added, bit by bit, from Evergreen section.

Last step before fitting the roof is to paint the inside of both the van and the verandas. The insides of goods brake vans were dingy at the best of times, so that on the model most of the effect of the glazing is to provide see through at the right angles. The inside of the van is always going to be in the dark so there is little point in fitting detail and the interior is simply painted black to kill the effect of the white styrene.

With the roof arch in place, the inner door post is fitted between it and the floor. This is the first of many parts that has to be fitted snugly into place and the skill lies in getting them just the right length to be a dead fit, not loose and, if anything, just a tad on the tight side. Within limits, the softening that occurs when the solvent is applied will accommodate the slightly tight fit. Achieving such a fit is a matter of delicate use of a needle file. If you think it needs two passes of the file, give it one – it is much easier to remove material than it is to add it, and if you overdo it, mutter darkly and start again.

columns

From here on the two vans, which have been identical thus far, start to differ. This one (van 1) will be built to run on cast L&Y pattern axleguards. When fitting cast components such as these to a plastic underframe I like to ensure that they are well supported, in this case by being sandwiched between the back of the solebar and an inner longitude. That not only keeps them upright whilst the epoxy cures but also allows the adhesive to be applied to both sides.

It is often handy to cut one or two extra pieces, on the basis that if you have deliberately made spares, Murphy’s Law will determine that you will not need them. Another tip is to turn the job round between passes so that any tendency to file offsquare cancels itself out.

Back to the window, and the technique is to measure the opening (not the drawing) accurately for actual width and height. A dial or Vernier calliper helps no end for this, not specifically for the accuracy, as none of us can mark out to better than 0.25mm on a good day, but for the ease of access. With the dimensions established, the Chopper can be put to serious use cutting the strip required for the window pillars and the beading for the glass. The pillars are cut from 40 × 0.060in strip and the beading is cut from 20 × 0.040in, thus giving the right degree of depth to the finished article.

columns

The body structurally complete, with a roof pinched from a Parkside GWR brake van. This happened to be the right profile and saved having to make a former to heat form the styrene sheet that would otherwise have been required. Parkside are quite happy to supply individual moulding sprues for a modest sum.

For reasons that will become obvious in a moment, the verticals are cut to fit the full depth of the opening and the horizontals are cut to fit between them, although those for the third pane should be cut a little oversize (Murphy’s Law again).

The underside of the other van, which will be fitted with a set of LMS pattern axleguards and springs that come on a handy moulding from several of Slaters BR wagons (X7060G). These are a close match to the arrangement used on the very last of the L&Y vans, the difference (apart from convenience) being the use of J-hangers and eyebolts for the springs, rather than the suspension links of the earlier L&Y designs. Being plastic, these axleguards bond better to the solebars without the need for the additional support required for the cast axleguards. What is also visible, just, is the way the solebars are built up from various sections of styrene strip to get the right depths. This is where the rebate provided by building the body on a steel rule comes into play as it allows for the imperial dimensions of the strip to be accommodated in a way that results in the solebars being the correct scale depth.

Assembly starts with fitting the first section of vertical beading to the corner post, followed by the horizontal beading for the top and bottom of the first pane. Positioning these is a matter of sticking them in slightly proud of the inside face of the body end, and then pushing the flat metal object such as a ruler or a square. Then go away and do something completely different for several hours – overnight will usually do – so that the joints can fully harden.

Van 1 with the cast axleguards in place, illustrating the way in which they are trapped between the inner and outer solebars. Although there is no suspension, the fact that the wheelbase is quite short means that it is able to cope quite well with good track.

Van 1 sitting on its own wheels for the first time, looking very plain without all the rivets and nuts that held everything together.

Installing the rest of the window frame is a matter of proceeding from out to in a bit at a time. Because the horizontal beading sections were cut to fit between the verticals, placing the next vertical is simply a matter of butting up to the ends of the horizontals.

Only the last pane will be a little tricky, as it is almost inevitable that it will turn out to be slightly wider than the others, so that the horizontal beading will need adjusting to fit the space, which is the reason for cutting them oversize in the first place.

So much for the main body, but what of the verandas? These consisted of a timber frame with the section between the waist and curb rails filled in with boards. To replicate the construction depth on the inside face, the end was made up from a section of 0.040in styrene card with the framing built up around it, assembly being carried out with the end face down on a flat non-stick surface. The cant rail, which in the full size runs along the length of the top edge of the body side, sits on top of the corner posts so these are cut to a length that will fit under them. In the model, these are made as extension pieces which will attach end-on to the body end and sit on top of the corner posts, and are cut 2-3mm over length, not forgetting to allow for the fact that they overhang the body ends in any case.

Assembling the ends requires some care, as there is initially nothing to support them. My technique is to attach them to the end of the floor plate and then, while holding them square and vertical, to attach the cant rail extensions to the body end and the top of the corner posts. The final step, once the joints had hardened, was to fit the roof arch between the cant rail extensions, hence the reason for not cutting it to final length earlier.


Despite having the side sheathed in steel plate, there were a lot of bolts holding these vans together. These are modelled using tiny squares cut from 0.010 x 0.020in Evergreen strip, each one applied with a needle and a spot of solvent. Not 100% accurate, as the bolts aren't sticking through the nuts, and the rivets on the solebars aren't round, but what matters most is the visual texture that they give the van body at all normal viewing distances.

From here on, finishing off the body is straightforward, basically adding the veranda doors, the roof and the end posts. For these two vans, the roof was made by cutting down the roof moulding from a Parkside GWR brake van, obtained directly from the manufacturer for the usual nominal £1 per sprue. The choice was determined by the fact that I did not have a piece of suitably sized metal tube over which to heat form a piece of styrene sheet. The outside of the joint between the framing and boarding is covered by a rounded beading on the prototype, replicated on the model by sections of 0.040in half-round Evergreen strip cut to fit, complete with mitred joints. It helps considerably that the buffers had not been fitted at this stage, as the body can be stood on end.

columns Van 1 used a set of cast brass brake shoes available from Laurie Griffin. As with the plastic ones, these were made up as pairs soldered onto a length of brass strip that was then epoxied onto the cross members that had been fitted earlier.

The visible part of the underframe is straightforward, although as the largest Evergreen channel section is ¼in. deep, a little cunning is required to replicate the 7mm depth that is required. One flange of the channel is cut off and the resulting L-section glued onto a piece of 80 × 0.040in strip to bring the section up to the required depth. The headstocks are made in the same way, although as the flanges face inwards, the section is filled in with a piece of strip where it will be hidden between the solebars, principally to provide a more solid anchorage for the buffers and couplings and to provide a solid stop for locating the ends of the solebars. The internals of the underframe call for rather more thought, not in trying to replicate the original (why model what you cannot see?), but in considering how to install the axleguards and brakes.

It is also from this point onwards that the two vans are different. One uses the axleguard and brake castings available from Laurie Griffin, whilst the other uses spare mouldings from the Slaters BR van kits, https://slatersplastikard.com partly as an economy measure.

The Laurie Griffin brake shoes mounted on brass strip, making up a unit to be epoxied into the underframe. This is considerably easier than trying to fit them individually as they can be set to gauge and then fitted as a unit which is held in place while the epoxy cures.

Van 2 with its LMS springs and brakes, illustrating how little is visible behind the wheels.

I have always been a little uneasy about mixing metal and plastic components, because although the epoxy resin adhesives are good, I have found their adhesion to styrene to be sometimes a little suspect. Hence, my adoption of a belt and braces approach. For the first van, I used an additional section of Evergreen strip to create a slot behind the solebar, so that the castings could be glued on both the front and back faces, as well as being fully supported. Getting them aligned squarely across the frame was a matter of careful marking out on the solebars to indicate where the spring hangers should lie.

Fitting the brake shoes and hangers, which are one piece brass castings, called for rather more cunning. Inevitably, the first task was to tweak out the distortions that had crept in during the casting process, a task that should not be necessary if the casters let the waxes cool properly first. Each of the castings is provided with only a relatively small mounting pad, which might have been fine when soldered to a brass chassis, but not for gluing to plastic.
After some thought, a hybrid strategy was evolved, with the individual castings soldered to a brass strip which was then glued to a styrene strip running across the chassis, set at a measured distance from the axle centreline in order to give the correct relationship between the brake blocks and the wheels.

The complete assembly under Van 1. Although I have fitted the brake beams, I have not gone so far as to model the linkage, because it is invisible behind the wheels once the model is on the track. (I am not a believer in modelling what can’t be seen.)

columns Van 2 has the Slaters axleguards and springs, which makes the underframe structure simpler. The brake shoes and hangers come from the same Slaters moulding as provided the axleguards, and are individually fitted to cross beams slotted in between the solebars.

The underside of Van 2 showing the footboards as fitted.

The width of the brass strip was determined from a trial and error measurement of the position of the casting relative to the van floor, so that the foot of the casting is lined up with the edge of the strip. With each pair of shoes attached to the strip, the assembly was substantial enough to be tried for fit and tweaked as necessary before being glued into place. Doing things the other way round, gluing the castings in place and then trying to adjust them would simply have resulted in breaking the glue joint.

The Slaters brake shoe assemblies before fitting.

As noted earlier, van number two was built using Slater's mouldings left over from previous BR wagon kits. Their moulding X7060G, which can be obtained separately, contains both the standard 3ft 6in. wagon spring and the longer 4ft 6in. J-hanger springs used by the LMS, and subsequently BR, on the clasp braked vehicles, as well as a set of brake shoes and hangers sufficient for one wheelset. Although the standard L&Y design used a link suspended spring, as per Laurie’s castings, the final batch of vans used an underframe with J-hanger springs that are sufficiently close to the later LMS design for the latter to be passable.

Using plastic, rather than metal, components has the advantage that there are no dissimilar materials to worry about. Since the axleguards can be stuck directly to the back of the solebars, the internal structure of the underframe is much simpler. The springs, which are separate mouldings, are used as they are except for trimming back the feet of the hanger brackets by about 2.5mm; the middle brackets abut each other and would, in the full size, have been a single unit.

The only slight hitch with the use of these components is in the axleboxes. Being for BR wagons, the moulding contains a pair of RCH split boxes, and a pair of the fabricated pattern open front boxes, neither of which is suitable as they stand. From photographs of late period L&Y vans, it appears that the axleboxes are very similar to the LMS open-fronted pattern, as provided by Parkside on their LMS brake van. Having obtained the requisite number of mouldings, it turned out that the axlebox mouldings themselves were not dimensionally compatible with the Slaters mouldings.

In the end, the model uses the Slaters BR fabricated axleboxes but with the front covers of the Parkside LMS axleboxes. Given the nearly miniscule size of an axlebox cover, these must rate as the most expensive part of the whole project in terms of their size – 50p for a plastic moulding little more than 4mm square. They fulfil the need though, and I still have three solebar mouldings with link suspended springs and various other bits that will probably find their way into another project in due course.

Van 1, now with footboards. The supports for these are another ‘pinch’ from the Parkside range, this time being from the LMS brake van. The attraction of these is that they are moulded in ABS, which not only attaches nicely to the styrene solebars with solvent but is resilient. The footboards are normally the widest thing on any brake van, and with the narrowness of the bodies on these L&Y vans, stick out a long way. Although various cast brass step board irons are available, they would have had to be attached using glue, creating the risk that they could easily become detached during normal handling.

As with the axleguards, so too with the brake shoes. They are fitted to the underframe in a very similar manner to the brass ones on van number one, in that pairs of shoes and hanger mouldings were attached to an L-shaped cross-member at the appropriate centres, and each assembly was then glued in place across the underframe. Being plastic, they can be spaced rather closer to the wheels without risk of an accidental short circuit. The brake blocks are not quite the right shape, being standard RCH pattern, but I will leave the reader to decide.

A characteristic feature of any goods brake van is the step boards, and the need to find some means of supporting them that will stand up to the rigours of handling. The initial plan was to use the cast brass brackets available from Laurie Griffin and which, one would presume, would fit the Shedmaster kit for these brake vans. Sadly, they did not, and although a swap was effected for some that looked more the part, that turned out to be a dead end as well.

The problem is that many of the available step board brackets are designed for carriages, which are a good bit wider over the body than goods brakes, and especially the L&Y ones, which are positively skinny. In the end, salvation was found in Parkside, in the form of the moulded plastic brackets used for the LMS brake van.

Each moulding contains two full length step irons as well as a single step bracket and three lamp irons and neatly solves several problems at one go. The only snag, inherent in any 6-wheel van, is the sheer quantity needed – each van takes eight mouldings, but the leftovers yield a goodly crop of lamp irons and instanter coupling links. The real benefit is that, being plastic, they are easy to attach securely and have enough resilience to stop the joints being strained by misjudged handling or storage. On an all-plastic vehicle, brass step irons might sound good but the joints to the plastic would be extremely susceptible to breakage.

Van 1 complete but awaiting lettering (hence the shiny patches for the transfers). This one is fitted with a through vacuum pipe and will finish up in BR Bauxite

The lamp irons were an unexpected bonus which saved having to fabricate them from sections of Evergreen strip; again, although brass castings are available, I have a preference for not mixing metal and plastic unless I have to, simply on account of the vulnerability of the joints. Cyanoacrylate glues may be good, but a lot depends upon the bond that can be achieved to the two materials. On the other hand, fabricating a lamp iron from Evergreen styrene strip requires four tiddly parts, much patience, a steady hand and several days waiting for the joints to harden.

The buffers and couplings are almost the last items to be fitted for the practical reason that without them, the van will stand on its end, which makes the detailing very much easier. Similarly with the step boards – once they are fitted, the van has to be propped up to avoid the weight being carried on them.

The final item of any significance, at least on the vacuum fitted examples, is the through pipe. Unlike most other vehicles, it is not hidden away below the underframe where it can be quietly forgotten, but carried in full view down one side in brackets attached to the outside of the step irons. At this point, the benefits of plastic step irons strike again, in that it is a practical proposition to fabricate the pipe from 1.5mm Evergreen rod which can be stuck directly to the irons and the bottom edge of the headstocks, to which it is clipped.

What of the results? Apart from letting the pictures speak for themselves, watching these two vans emerge from pieces of featureless white plastic has been a positive experience and there is that satisfaction of knowing that they were not just assembled, but created by my own hands.

Van 2 is finished in LMS bauxite. The layout on which they will run is set in the 1950s, so both could easily have existed side by side as it took years for goods stock to get repainted.

gazettearchive/gazettevol19/scratch-l_yr-brake_vans.txt · Last modified: 2021/11/15 19:02 by 127.0.0.1