Mol_PMB

Very nice indeed! Superb rolling stock and layout atmosphere.

Many thanks! Looks like there's plenty of neat designs there, I'll have to see whether any are suitable for my needs or if I can just use some of the ideas. I've had a look at using one of High Level's more standard gearboxes, the RoadRunner, which is only 8.6mm wide. The final drive gear is 23 tooth, and it would be possible to create a geartrain directly from that to the second axle either with five gears 23-12-12-12-23 (purple). High Level don't offer gears bigger than 23 tooth, but other suppliers do. Replacing the three small ones with a 27 tooth in a straight line (red) would mesh fine, but the ground clearance would be zero with the 27-tooth gear, not ideal for a loco with suspension. Another option would be a 28 tooth gear mounted slightly higher (green) though the motor might have to be tipped further forward to suit. With this type of arrangement, I'd need to provide some form of non-rigid torque reaction for the motor that didn't mess with the suspension too much. Why is it so hard? I thought having no rods would make it easier than a D class... Maybe I should revert to the previous arrangement, make the leading axle rigid and just put the CSB on the other two axles.

The thin ones! And there's still not enough room in OO. 21mm is OK, but I want to design this to work for both gauges. Thanks for confirming. I'm not a fan of rigid chassis either! For a 6-wheel loco I need a more complex arrangement of compensation or springing, which is why the hornblocks and CSB method appeal. But I think that works best if all wheels are sprung.

Many thanks - I feared that would be the case. It definitely doesn’t fit for 00 gauge! I’ll have to find an alternative solution if this is to be buildable for OO with hornblocks. Maybe a rigid chassis would be sufficient for OO?

Thanks for the tip re NWSL. I have successfully used their products in the past, though I got the impression that their range isn't as big as it once was. Certainly last time I looked to re-order parts I'd had from them in the past, it seems they are no longer stocked. Anyway, here's a sketch I've worked up this evening. The wheels and 2mm axles are shown in black, the functional frame in dark grey and the cosmetic frame behind in grey: The idea is to use a QuaDriver 20mm wheelbase to power the two closely-spaced axles, with the 'tower' at the left-hand end wheelset and the arm connected to the middle wheelset. I can't find any actual dimensions for this unit, but from @Tullygrainey's photo (reproduced below) it looks like it should be fine. Then I'll have to create a custom equivalent of a Drivestretcher with five 20-tooth gears to connect to the third axle (sketched in blue above, I know they're not proper gear shapes but it's the PCD that matters and 4x8=32 so that works. Having done a lot of searching online I think I've found the key dimensions of the hornblocks, datum holes and CSB pivot heights. I've had to refer to several different websites and documents because I haven't yet found any one source that provides a complete dataset. I think the following are correct: Hornblock slot in frames is 5mm wide. Top of hornblock slot is 4mm above axle centreline. CSB pivot points are 3mm, 4mm or 5mm above the axle centreline. I've used 5mm in the sketch above. Small datum hole above hornblock slot is 5.2mm above the axle centreline (this is an estimate, but it's more than 5mm as on the images of the CSB jig it's fractionally above the 5mm row) I've then used one of the online CSB spreadsheets to work out where the pivot points ought to be if the wheels are to be equally loaded. A=18, B=11, C=24, D=16. Hopefully I've got this right - @Horsetan does this look plausible? I still need to work out the width between the frames. Again it's hard to find published dimensions for the width of the QuadDriver gearbox, but it looks like it might be a tight fit between the the thinner 'spacesaver' hornblocks for OO gauge. I fear it might not fit at all. The thinner hornblocks are nominally 2.2mm wide, so with OO back-to-back being 14.5mm that leaves only 10.1mm for the gearbox as well as any clearance needed. The gearbox looks wider than 10mm! @Tullygrainey, is yours accessible to measure the width of the QuadDriver gearbox? For once, 21mm gauge is easier in this case, but I need to make my solution work for both gauges. This is becoming a headache!

The West Clare had 4 so surely you ‘need’ just the one more?

The early applications of black and tan (1962/3) were done before the CIE 'roundel' was introduced at the end of 1963, so they didn't have the roundel applied. Examples include B141s as delivered, and the relatively small number of Crossley-engined A and C class locos painted in black and tan. Later repaints (and the newly-delivered 181 class) in the mid and late 1960s had the roundel with the black and tan livery, but on the AR / B101 / B201 class locos the tan band was usually not as deep. The deep tan band and CIE roundel shown on A39R above is prototypically correct for this loco, but it was a rare combination. Considering the AEC railcars in black and tan, some of them carried the roundel and unusually it was on the tan (orange) band, not on the black. The roundel colours were therefore changed so it would show up. The 'broken wheel' was black with a fine white edging, while the CIE remained white. No AEC railcars carried 'Supertrain' which as far as I am aware was only applied to air-conditioned coaches (Mk2 and Mk3) and locomotives.

Fortunately, mine seems to have survived being thrown over a 6' high gate by the courier, and sitting in the rain for most of the day. A credit to Accurascale packaging (though it took a while to properly dry out the cardboard box). I've just given it a test run on 'Boysnope Bump' with a few trucks, and it sounds and runs very nicely. I'm impressed! I haven't done much with this layout for a year or so (and of course it's not finished, though probably more advanced than most of my layout attempts). One of those things about long lead-time pre-orders - this is the first of 3 locos I ordered in advance to actually turn up! When I get back to O gauge it will need some serious weathering to represent the Lancashire Tar Distillers 88DS!

Thanks David. I've used Delrin chain in 7mm scale too, but it doesn't seem to be widely used in 4mm scale and these locos have particularly small wheels which would require small sprockets and a fine chain. With any small shunter I think compensation or springing of some sort is very important - not just to minimise derailments but to improve pick up, exactly as you say. From an enquiry on RMweb I have the following answer relating to the High Level gearboxes (though this is from someone who uses them, rather than the manufacturer): Most gears are module 0.4 but the likes of the reduction gear in the 54:1 gear boxes are a mix. The 27/10 twin gear is mod 0.3 for the 27 tooth and Module 0.4 for the 10 tooth. The High Level 'Quaddriver' is a good call, it's available in 20mm wheelbase which would be right for the two closer wheelsets on the E401. Though to get the weight over the driven axles in that case would give a loco with very asymmetric weight distribution. I was thinking of using the same principle to power all 3 wheelsets, but it's a bit of a challenge to arrange that to work smoothly with compensation/springing as well. I'll keep working on the body artwork while I consider the chassis!

Ah great, many thanks, I’ll have a good read tomorrow!

Sorry, the existing etch can’t be built as a E421 - there are many very significant differences between the two classes. The E421s are 2 feet longer for a start! Cabs and bonnets are completely different in both styles and dimensions. The chassis could be common between both classes. I’m not ruling out doing an E421 as a follow-up, depending on how the E401 turns out. But I suspect IRM may have an E421 somewhere in their future plans which is partly what has steered me towards the E401. Please not that this is absolutely not a commercial venture but I would be happy to support interested fellow modellers. I’d still welcome some advice on the chassis though! How would you arrange the gearing? Cheers, Mol

Best tell them to take a few chainsaws then if there's a tree down across the line! Seriously, there have been some train drivers with life-changing injuries as a consequence of crashing into trees. Do Translink have a way to report this sort of thing?

I look forward to seeing your plans!

I'm hoping that I can get the body etch artwork finished within the next week or so, and then maybe in 2 weeks time I can show the prototype body being built. I'll do a separate thread for that. The chassis is still a challenge. I'm leaving as much space as possible to fit it in. I'll work something out eventually. It makes sense to do the chassis on a separate etch as it will need a thicker material and there will be variants needed for different track gauges. It would be interesting to know, among any forum members who would contemplate an etched E401 kit (this may well be a very small audience!) would you prefer rigid, compensated, sprung, CSB? And what gauge are you working in? Personally I'm working in 21mm gauge and most of my experience is with compensation rather than springing, but I'm open to new ideas especially if people can provide advice. And if you might possibly be interested in one of these, what period do you model? There were a lot of detail variations between the late 50s silver and the late 70s black eras, I've worked out most of these but which should I try and provide for? Cheers, Mol

Wonderful - many thanks! There are certainly some common features between that and what I can see on the E401 photos.

I've been doing some more work on the etch artwork including the cab, which is progressing nicely. I'm trying to make best use of fold-up subassemblies rather than a myriad of separate parts, whilst avoiding awkward fit problems. Does anyone here have any photos of E class cab interior? E401 preferred but I appreciate that's less likely, E421 pics from the preserved examples would be better than nothing. Although the windows are fairly small I'd like to make some attempt at representing the control desk. Best I have for cab interior views so far are these: https://www.flickr.com/photos/irishrailwayarchive/54255284989/ https://www.flickr.com/photos/irishrailwayarchive/53509328774/ Also, if anyone's got a particular loco or period they would be interested in modelling, please let me know. There were lots of minor variations between the locos and it would be impractical to provide for them all, but I can do some. Cheers, Mol

Many thanks for your thoughts and interest. At present I'm doing the E401, none of which survived. E401s were more numerous and have more choice of liveries; they were delivered in silver, but withdrawn in the late 1970s whereas some of the E421s survived into the early 1980s. I could probably develop an E421 afterwards if this works out well. There were significant differences between the classes in major dimensions and styling, though the wheelbase was the same so potentially a common chassis could be used. The E421s were better balanced. I think if IRM do an E class it's much more likely to be an E421, in fact I know they've had a good look round one of the E421s at Downpatrick. It's too early to think about pricing at present, or how many I might have made. I have my custom etches done by 4Dmodelshop, who provide excellent quality service and a quick turnround, and quantities as small as 1, but it costs more per etch than the firms which do mass production. I think my approach will be to make one etch to start with and build it myself, then I can do any debugging necessary for a small production run, and I'll also have a completed model for people to judge whether they would be interested. I haven't got my head round CSB, but thanks for the info on the hornguide standard and what slots I would need to provide. That will be very helpful when I get to doing the chassis artwork. I agree that the challenge of driving the wheelsets is how to do it without upsetting the compensation or springing. In the last 20+ years I have done most of my modelling in 7mm scale so I'm not familiar with the parts and methods typically used in 4mm scale. I've had a good look through the High Level Kits website and I'm more confused than it was before - it doesn't even say what gear module they use which is a fundamental dimension needed to design a gear train using their parts. All the examples given are steam locos with rods, where the gearbox only needs to drive one axle. If you understand CSB it sounds like you're way ahead of me on this! Could you help me with a rough sketch of how you would set it out and which components you might use? The wheelbase is 20+32mm, wheel diameter 12mm or 12.6mm. I don't think space in the bonnet is a limitation. My intention is that the functional chassis will be inside-framed, with the outside frames just cosmetic. Cheers, Mol

I've now also completed the footplate artwork, including bufferbeams and cosmetic frames. I've identified some suitable castings for the axleboxes and hornguides too. Next thing to do is to draw up the cab assembly. I'm still mulling over how to arrange the chassis. I think it needs some form of compensation, and probably a long row of gears and idlers to transmit the drive to all axles. There's no shortage of space in the bonnet and the motor could be positioned to drive onto any of the wheelsets, or indeed one of the intermediate gears. I expect the chassis will be made of thicker material so it won't be on this etch. That may also facilitate different gauge options. It may not be etched at all. Any thoughts?

If you missed out on IRM's cement bubbles and have since discovered that they never/rarely come up on eBay, then rest assured you don't need many for a realistic train. In fact your loco lash-up can be longer than the wagons they're hauling: A Waterford-Limerick empty cement passing Tipperary in 2007, by Colm O'Callaghan on Flickr.

On the subject of etch artwork, I've made a start on something Irish. Very much work in progress but there's probably enough here for someone to guess what it's going to be. It seems I use a different colour convention to John. On mine, black is full thickness, red is etch from the front, cyan is etch from the back, and white is etched right through. I haven't put tabs on yet. Hopefully something less likely to be produced by IRM as none of them exist any more. Initially for my own use but if it works out well I'll see if anyone else is interested. It's quite possible I'm making some bits rather fiddly for 4mm scale, as I'm more used to designing in 7mm scale. I'll find out in the test build. One thing I have learnt already is that the locos weren't all the same, so I'm trying to cater for some options. Close-up of part of it: Next I need to do the cab and the footplate, which should be relatively simple compared to what I've done so far. Then I must think more seriously about the chassis, compensation and gearing.

One more from Roger Joanes. Here's you're excuse to buy a Park Royal...

Several railtours went to Kingscourt in the freight-only period, some with steam (ex-GNR 132, RPSI 186) or diesel (059) haulage , and some with obscure railcars (SLNCR 'B', NIR 'RB3'). There was a black and tan Park Royal in the train hauled by 186, in 1970. Some photos from Jonathan Allen, Colm O'Callaghan and and Ernie on Flickr. There are very many more photos of Kingscourt on the IRRS Flickr archive which you can only view if you're an IRRS member: To answer your 'what if' question, then yes, 1990s would likely have been Park Royals and BR or Dutch van.

It's probably easier to acquire an E than a 400hp Maybach shunter!

This link seems to work: Mousa Models https://mousa-models.co.uk/product-category/4mm-scale/ Threads on RMWeb suggest that the owner has been ill recently, but at present there's no suggestion that the models have been withdrawn entirely. Hope that helps.

Many thanks John, that looks good. No rush, I've got plenty of projects on the go already, but I am definitely interested in some of these.