magmouse

Thanks @Craigw and @Miss Prism. So people can cross references with @Craigw's comments, the wagon numbers are as follows: Atkins et al, A History of GWR Goods Wagons, p46 - 75707 Russell, GWR Wagons Appendix, p.14 - 12325 Russell, GWR Wagons Appendix, p.20 - 76267. Mapping the wagons in the photos to lot numbers is helpful - do you have dates for those lots? It's curious that early O4's were built without door springs, since earlier 4-plank wagons had these - unless all door strings were retro-fitted after the 5-plank O4 design was introduced? None of this quite gets us to a date for the shift from short to long springs... Similarly, thanks @Miss Prism for the response re the introduction of reversible brake shoes. Again, possibly a wild goose chase, but it would be useful to track down their earliest appearance in photos we can confidently date. For my narrow purposes, it would also be very helpful to either confirm or deny the stated date for the picture of 76267 in the Appendix. Nick.

I currently have a Slaters (ex. CooperCraft) GWR 5-plank wagon, diagram O4, on my workbench. I am trying to decide what I am going to do about livery and door stops. Regarding door stops, Atkins et al, in A History of GWR Goods Wagons, claim the O4 diagram was the first merchandise open with low hanging door stops (as opposed to the short ones that barely go below the solebar). They say this on p.46 of the first combined edition, in a caption to a photograph which illustrates their point. However, in Russell's GWR Wagons Appendix on p.14 there is a five plank with short door stops, contradicting Atkins et al. or at least indicating the long doorstops were not used universally after they were initially introduced. The wagon in this photo looks pretty new, but there is confusion over the dates in the caption, which claims the wagon is an O5 from 1888 (but that would be a four plank, and this is five). It also says the photo is 1909, but the date on the sheet on the wagon is November 1900, and the sheet looks brand new. The plot thickens, as on page 20, fig 30 shows a diagram O4, with long door stops, but there appear to be marks on the plank work of the door suggesting it previously had short stops with associated banger plates. Between them, these two photos indicate that perhaps at least some O4s had short door stops to begin with, but these were later changed to long ones. The photo on page 20 is dated 1907, but given the flakiness over dating in the caption on p14, I am not too confident about this. A further bit of evidence is the wagon on page 20 has reversible brake shoes, which according to Jim Champ (http://www.gwr.org.uk/nowagonbrakes.html) don't come in until 1911. If Jim is correct, this photo must be after 1911. In terms of livery, I subscribe to the 1904 theory for the introduction of grey livery. Assuming this is correct, most or all diagram O4 wagons would have been initially in red livery (built 1902-04). The page 20 picture, then, if the caption date of 1907 is correct, shows a wagon repainted no more than 5 years after being built, with modified door stops and preternaturally early reversible brake shoes. I am modelling c.1908, so the questions for me are - when do long door stops come in? Is it feasible a wagon was repainted so soon after being built - perhaps at the same time other work was undertaken (repairs?)? More generally, should I stop believing in the 1904 date for the change from red to grey?? Should I stop believing Jim Russell's caption dates???? Penetrating insights gratefully received... Nick. PS - and here is a picture of it on the workbench, awaiting decisions on the above questions. I am modelling it with the sheet bar up and a sheet over it - hence the reinforcing of the sheet bar, and not worrying about interior detail or the top half of the body. The kit brakegear has been replaced with more accurate and refined WEP etched brass components.

Yes, a forging makes sense. And agreed re your stricter application of the term J-hanger - but then you need a term for the other thing that does a similar job but isn't a J-shape. The true J-hanger also adds secondary suspension through the compressible rubber discs - helping to compensate for the way the vertical connection means vertical movement of the spring ends is transmitted directly to the vehicle chassis. An advantage of the link system is it can take up some of the vertical movement without passing it on to the chassis. Can't help you with a name for the wooden block the wrought iron strip is attached to in your post that started this discussion. And we now have the not-a-j-hanger to find a name for, too, so terminologically we seem to be going backwards... Nick.

This discussion has made me curious about the design of underframe mechanics in relation to available materials and manufacturing techniques. Most of the metal parts of a wooden wagon underframe can be made from flat material - axleguards, washer plates, and so on. Cast components such as axle boxes and buffer housings have either low forces acting on them or are in compression - suitable for cast iron. The J-hanger shown above has significant tension and bending forces, which are not good for cast iron, hence my suggestion it would need to be steel. Steel become cheap and readily available following the invention of the Bessemer process in the mid 1850s, with production ramping up (and so prices coming down) over - what? - the following couple of decades? Just trying to think this through in relation to the shift of manufacturing away from the individual, hand-made, production of metal components by blacksmithing techniques towards more mechanised and standardised manufacture. As we know, railway companies stuck with some manufacturing methods long after arguable better ones came along (think wooden underframes still being made well into the 20th century, long after steel construction was possible). Presumably this is driven by cost, and by being able to be maintained in the field with relatively simple and available skills. Does this narrative fit with the timing of the adoption of materials and techniques for wagon construction, or am I barking up an attractive but entirely incorrect tree? Nick.

Nor me!

@Compound2632 - thanks for sharing the drawing of the other end of the spring. So, a similar arrangement, but instead of the horizontal forces from the two springs being balanced against each other, the horizontal force is taken by the headstock via the L-shaped end of the wrought iron strip. Then there's the hybrid design, with J-hangers on the outer end, reliant on a probably more expensive cast item. Possibly requiring steel, rather than iron? Nick.

I think the shaped wooden part is integral to the design - without it, the wrought iron strip would just bend until the top of the spring link hit the underside of the solebar. Nick.

A speculative answer: the swing links each carry a share of the weight of the van, downwards, at one end, and of course the reaction force, upwards, at the other. They are therefore in tension. However, because they aren't vertical, there is also a significant horizontal force - actually larger than the vertical. With the arrangement shown, this substantial horizontal force is carried by the wrought iron strip more or less along its length. Also, the horizontal force from the spring of the other axle is pulling in the opposite direction, and will be roughly the same, so these two forces balance each other in the wrought iron strip, rather than being transmitted to the wooden solebar via the bolts. Overall, it makes good use of the materials' properties to create a strong structure, in a way a blacksmith could readily make (much easier than the j-hanger design - are these cast?). I'd be interested too see the part of the drawing showing the other end of the spring, but for some reason the search engine at the Midland Study Centre won't reveal it's treasures... Could you post it or give a direct link? Nick.

This is going to be really useful when I (eventually!) build my planned layout, which I want to give full lighting of buildings, etc. Thanks for providing so much clear detail. Nick.

The flame cut edge looks great - very impressive. I agree using P4 wheels will make a big difference too. Perhaps also replace the tie bars between the axle guards with brass or nickel silver strip, for added delicacy? Nick.

For fine, hairless thread, I would suggest looking at the stuff ship modellers use for rigging - available in a variety of thicknesses. There are a few online stores that sell this, but I often use https://www.cornwallmodelboats.co.uk. Search for ‘rigging thread’ - they have sizes down to 0.2mm. If you want to represent steel rope, you might be able to stain it a dark grey/black.

I love your concrete textures in that last photo - cracked, battered, stained and patched. Even the magnet feels like a bit of leftover inset metalwork for some long-forgotten purpose, but the edges still polished by the vehicles driving over it. All very evocative.

@Crimson Rambler - thanks for this. As you say, not much rust, but this photo usefully shows exactly how the rule ‘black below the solebar’ was applied, which I had been struggling to make out in other photos. There is a black/grey boundary on the vee hanger and the brake lever guard, while the brake lever itself is all black. Happily, this is what I did on my model! Nick.

No - just what you can see from normal viewing angles. I was prompted to model the release mechanism after some discussion of it earlier in this thread, and made it using some bits of plasticard and wire - all quite fiddly. A short while after, I realised there is a nice etched version on the David J Parkins under frame detailing etch I have in stock...

Thanks - and yes, I take your point about rust. The photos of the period are very hard to interpret in that regard - certainly some wagons got into both a dirty and rather battered state. The trouble is, I like what it does for the overall colour palette and to help make the detail pop. So my inner poet and my inner historian are constantly arm-wrestling for control of the weathering powders...

I've been lurking on RMweb and this thread for some time now, so I feel it's time to 'break cover' and post. The contributions of members across the forum, and in this thread especially, have been very useful and indeed inspirational to me. So by way of a 'thank you', and to demonstrate that information shared here is not wasted, I thought it would appropriate here to share some pictures of my recently completed Slaters D299 in 7mm scale: Although my plans are for a 1908 GWR layout set in a fictional port on the Dorset coast, the D299 has an important role in the wagon roster, bringing beer from Burton on Trent to the thirsty inhabitants of Netherport: And a close-up of the contents (made using the Slaters barrels, and a lot of inspiration from @Tricky: Best wishes - Nick.