Horsetan

Non-standard designs, and possibly some way ahead of contemporary British engines. And yet, in the years to come, British designers did adopt some American practices, such as tapered boilers. By 1926, British locomotive design standardisation was arguably being left behind again, this time by the German "Einheitslok" design principles.

David Barham also showed us three Cavan & Leitrim open wagons that he'd been asked to print for OOn3. He said that current technology allowed him to print all three wagons in about one hour. Will be available as a Brassmasters kit in due course, probably next year.

....if somewhat inaccessible now. Wasn't there another one of the same design in Portadown?

The Schenectady Mogul - or something very similar- in the photo may also have found their way to Norway. There is a drawing for them, for engines numbered 22 to 24, in the aforementioned archive.

I seem to recall that the Barry Railway had some very American-looking 0-8-2Ts at one stage. Update: ah, no, it was an 0-6-2T. Class K, apparently. Photo of one here: It was the Port Talbot Railway that had the American-built 0-8-2Ts: Sample photo here

In the case of Templot and PlugTrack, the software and files themselves are free of charge, with the only cost being that to get the things printed by a print specialist.

At last night's monthly meeting of the North London Group of P4 modellers, we had a lecture demonstration put on by visiting lecturer David Barham, who explained the state of CAD and 3D printing today. He displayed samples of his work, including an ex-Great Eastern Railway J17 0-6-0 kit he is developing for Brassmasters - it looked that good, I signed up for one. Also of interest was a sample of 3D-printed trackwork known as PlugTrack - this is a system of 3D sleepers and chairs that simply plug into rectangular holes in the sleepers. The system is derived from Martyn Wynne's famous Templot software. I thought it offered potential for Irish 21mm gauge track building. Frighteningly good stuff.

They look similar to some of the engines built for railways in South Wales. The other 290+ drawings in that archive are fascinating.

Similar things used to happen with Bachmann and Bachmann-Liliput models.

I've discovered that Alan Gibson Workshop produces electrically conductive coach wheels, plus bushes for 1.5mm axles (hopefully the bushes are 2mm o/d, which means they can be pressed straight into the wheels).

The batteries would have to be programmed to run out just short of the destination

Presumably this would include wholesale demolition of all properties and structures that were built on the original formations.....

All good here, thanks, and the grey cells are already working out the least painful way of installing new wheels for 21mm gauge.

I think we might have a partial solution in the form of this brass tube - conventional P4 coach disc wheels could be mounted on this, and the 1.5mm pinpoint axle (if IRM have spares of part no.84 available) would telescope inside it.... Alternative insulated centre tubes cut to the wider gauge could then finish off the converted set.

When all's said and done, it all helps to make you think a bit harder and develop your own methods to get round the problem. That's modelling. Having said that, when Dapol brought out their Class 52 Western diesel-hydraulic, the bogies worked on the same split axle / stub axle principle. To convert it to P4, Ultrascale produced a limited batch of P4 wheels with the stub axles already fitted, and the wheels themselves were non-insulated. They weren't cheap, at 60 quid for 12 specially-produced disc wheels, but they worked. Thereafter the model performed the same way that Dapol designed it to. I'm not sure Ultrascale would do the same again for a limited number of 21mm gauge coach conversions - I can see it would be an expensive exercise.

They won't work on 21mm gauge without cutting and splicing-in new inserts to take up the wider spacing. However, that's relatively minor compared to what will be required to install new wheels (and axles). The Murphy Models Mk2s are much more straightforward in that respect, but will themselves need to have the bogie frames widened to match the IRM overall width.

The parts diagrams are spectacular.... ....and so are the full-width bogies.... One thing I note is that the conversion to 21mm gauge (P4 profile wheels) may not be completely straightforward, as the IRM bogie wheels work on a split-axle principle, with the wheels being an interference fit on 1.5mm dia stub axles which then plug in either side of the insulated centre tube. Conventional P4 wheels are generally mounted on 2mm dia axles and if these were swapped straight in, then the lighting function will be lost as the P4 wheels tend to be plastic-centred. Somewhere in the bombsite that is my worktop, I have a pack of the old Exactoscale P4 coach wheels which - unlike the conventional type - were designed to mount on their own 1mm dia axles. This is going to require a bit of lateral thinking....

Update: it looks like they did, so that's a relief. Next job is to convert everything to 21mm gauge.

Alan's Irish 21mm output is sublime

The wheels and some of the motion were salvaged from no.54, I think. I don't think the RPSI managed to save a spare boiler, otherwise they wouldn't be building an all new boiler and firebox now. Interesting to note that the driving wheel pattern is the same one used on the LMS Black Five.

Presumably the more expensive ones are the ones with the fewest flaws!

RPSI have quietly made considerable strides over the last decade in building an all-new one.

Here's one way of doing it My understanding is that the bogie frame itself should directly support the main chassis frames and be permitted to slide from side-to-side, and not permitted any vertical movement. Only the bogie axles themselves should be allowed to go up and down. Chris Pendlenton explains his bogie principles here - he's one of the few who understands how a model bogie should work, and how you get there.

Branchlines does a fret for the central buffer, chopper-type couplings.

I haven't had time this week to open the wreck of the parcel, but will get round to it on Saturday. It's currently sitting there, looking like the elephant in the room.