Leaderboard

In our back garden when I was a boy, we had an old signal box. I don't know where it came from - we certainly didn't have a (full size) railway to go with it. My grandfather (always known as GP) lived in the cottage next door and used the signal box as a workshop; I spent a good deal of time there, avoiding homework and learning how to make stuff. On my workbench is a steel try square which is in daily use just as it has been for some four generations: it was in the signal box when I was a boy and it's stamped with GP's father's initials - my great grandfather. He was a railway carriage joiner in a south London workshop - his brother was a railway signalman, somewhere adjacent to New Cross. So with such appropriate credentials, I set out to make some signals for Swan Hill. This picture shows the first signals made for Swan Hill: it's pretty much the same picture that I posted at Christmas 2020 but then, they didn't actually work. Now they do. Great excitement and if I could master how to do it, I'd post a video. Not content with having them just go 'On' and 'Off', they needed to be doing a bit more than that and so work began on "the brain". All the wiring on the layout is led back to a junction box which, in its primitive state, allowed the track and point servos to be tested and checked. Now there are also a bunch of relays which interlock the signals with the points so that, for instance, when the points are correctly set for the route, the 'Up' starter is enabled and when the Up starter is set 'Off' the train can be sent up the line but only in the 'Up' direction as there are diodes preventing reversal - which foxes my grandsons. As and when signals are installed, the primitive circuits can be adapted and further relay logic interposed from the comfort of a deck chair in front of the layout. I started with a signal ladder... The stiles are drilled 0.5mm using a jig-with-bent-pin to determine the hole locations. Assembly on a (scalded) jig made up from nails and a straight edge. One side is soldered up first and then the ladder turned round in the jig, the stile pulled straight and the other side soldered. The completed ladder (lousy photo). The next pictures are actually another bracket signal which is not yet installed but show the same methods as the bracket signal above. All the n/s strip is cut on a small table saw (Proxxon) having been cyano'd to 4mm mdf. Making the bracket - flat n/s strip curved in a jig (shown in an earlier post) and set against some nails on a knocking up board - jig too posh a name for that. The other part of the angle is set on and soldered in. The rest of the bracket is made up from strip, set out on the drawing using s/s pins to hold things in place. Next, landing planking - the GWR insisted they run fore and aft rather than side to side. Then guardrailing. The stanchions are 1mm diam n/s turned down each end to 0.7mm and set in drilled holes in the planking at the base and soldered into notches filed into the lightly flattened gaurdrail at the top; The shoulder produced by turning at top and base controls the height which otherwise, in my hands, would be a wobbly muddle - or more of a muddle anyway. The completed home signals which are yet to be installed on the layout... The finials are ModelU - very nice they are too. I've made up fork end connectors for the rodding and the cranks are all hand cut and filed to shape. The posts and dolls are hardwood - American walnut (see living room coffee table) and the signals arms and spectacles are from Scale Signal Supply. The spectacle glazing is bubble type packaging cut to shape and painted with glass paint. The two 'Up' starters and backing 'Up' 'Down' line signal and the Siding to Up line starter. I'll post something about the lamps and lighting in a day or so: lamps are all working and show up as pin point back lights in the picture above. I've also fitted working lighting to the buffer stops - red, but fairly impossible to see here.

It’s been quite a long time since my last posting, or at least it feels that way. I have reached a small milestone with the completion of what I will call phase 1 of the layout comprising most of one side of the loft, which is the top part of the track plan as I laid it out. If some of the track looks slightly out of line in the pictures, it is because alignment is only maintained by the droppers on each rail through the holes drilled in the baseboard. Where appropriate the tracks hold their gauge properly although in this case we are talking setrack gauge as I reuse track from the previous layout. Track will be pinned where necessary to keep sections straight. The track needs to be tested and some may be slightly concerned about how much is laid without much testing. In the distance the 56XX has been running but as the track is not fixed, I havn’t moved the control pins of the point motors (MTB MP1’s ) into their final positions, meaning stock can’t run over them at the moment. Before I get to that I have to connect all the droppers to their busses and wire up the point motors. I had a few problems with my chosen setup, using Digikeijs DR4018’s. I didn’t realise how careful I was going to have to be wiring them, as it seems to be easy to blow individual outputs if only a hair gets across the terminals, so each unit I have bought so far has only 7 functional outputs now instead of 8. Still I have devised a protocol for wiring them and with about 70 to install altogether I will get plenty of practice. The other side of track testing is not just to ensure power continuity but to see what track elements cause problems for the rolling stock, and in this part of the layout, there are bound to be a few as I have installed a very challenging station throat. I am sure the 56XX will sail through everything towing a few carriages, but my so far only DCC converted loco is a Modified Hall with a very light pony truck. Whether that will go round the switch corners is open to question. I’m going to start testing with the PM’s controlled by DCC through the accessory bus and DC power through the track bus which is entirely separate. The nearest part of the layout will be a 4-road terminus station. There is parallel access so inprinciple trains will eb able to leave and arrive at the same time. There are two loco storage roads that can only be accessed from two platforms. The track runnign diagonally across the layout in front of the station complex, as seen in the last photo, is a loop line, which will allow locos to reverse out of the station and run round the loop back to the station facing the opposite way, this will be a mainly steam age operation obviously. The station tracks are fairly long and while I havnt done precise calculations yet, should allow 5-6 coach trains depending on stock. That depends where the outgoing loco will finish bearing in mind there is a steam loco up at the buffers. It will get interesting at some point.

Being somewhat of a back-water in railway history, the Witney branch via North Leigh became home to many unusual vehicles, rarely seen elsewhere. I have already shown the standard-gauge Tilt Wagon ('Hat Box') but a particular claim to fame for this line was that it became the 'stamping ground' for William Dean's experimental 4-2-4 express tank engine, shown below entering North Leigh station. William Dean's experimental 4-2-4T No.9 at North Leigh My first encounter with this locomotive was many years ago, through the pages of John Gibson's “GW Locomotive Design - A Critical Appreciation”, which portrayed it as such an embarrassing failure that all traces of it had to be expunged from the record, with an order going out that 'this thing never existed'. If that were true, Dean would hardly have provided an article for 'The Engineer, Sept.24th 1886', with a detailed drawing of the unusual outside Stephenson valve gear. Dean explained that this arrangement was intended to get rid of the excessive cramping up of the valve gear, necessary when large cylinders have the valve chests placed between them. Outside Valve Gear on Re-built GWR No.9 (from 'The Engineer') In fact, Dean had arrived in office knowing that the Broad Gauge was nearing its end and a new type of locomotive would soon be needed, to replace the Gooch singles. Amongst the ideas to be tested was the possibility of using express tank engines, as designed successfully by Pearson, for the Bristol & Exeter railway. E L Ahrons, who arrived at Swindon in 1885, described the original configuration of the engine as having a 30' overall wheelbase, including two carrying bogies of wheelbases 7' 3" and 5' 6" respectively. He also stated that the length of the platform was 36' 5-5/8". Very much later (around 1940), E W Twining produced an outline drawing, purporting to show the layout of the tank engine. A comparison of his sketch with the detailed drawing of the valve gear in 'The Engineer' reveals that it is simply not possible to fit this gear between the front bogie and the driving wheel, if the longer bogie is placed at the front! In my opinion, Twining's chassis seems to bear a very considerable resemblance to the Lehigh Valley inspection saloon, still in existence at that time, even down to the bicycle-style 'mudguards' over the front bogie wheels. My own solution places the shorter bogie at the front and, with this configuration, a well-balanced design results. The front bogie fits neatly under the smokebox, leaving room for the outside valve gear, while the rear 7' 3" bogie fits immediately behind the firebox, within the overall 30' wheelbase. Apart from the reversed bogies, the dimensions conform to Ahrons' description. The construction of my model followed similar lines to those I have described previously, when I built my 'Queen'-class engine. I built the engine in two parts: a rectangular chassis, carrying the driving wheels plus two bogies, and a box structure for the upper body. The boiler is represented by a half round section soldered into position between the two side tanks. The steps in my construction are shown below: I have fitted an extended cab roof, similar to those used on other GWR tank engines in the same period, and a rear spectacle plate, appropriate for high-speed reverse running. Other features include cutaways in the tanks, to allow access to the motion, and tanks that extend a short distance in front of the smokebox, both as mentioned by Ahrons. The long (11' 6") boiler, in two rings, was designed to provide similar steaming capacity to the large-diameter boilers of the Gooch singles. My model wears the new livery, introduced in 1881, with Indian red frames and vermilion lining (though at that time the wheels were still green). With this presentation, I believe that the engine is worthy of the description given by David Joy, when he visited Swindon around 1882 "I saw all about a mighty 'single' tank engine ... I saw drawings and all, and she looked a beauty". My Interpretation of GWR 4-2-4T No.9 The real significance of this engine was that, while it showed that the 4-2-4 express tank engine concept was not appropriate for the standard gauge, it addressed an urgent need to re-visit valve-gear design for more powerful engines. The eventual outcome was, of course, the famous Dean Singles, with the same length of boiler and direct-driven valves, mounted below the cylinders. The family relationship can be seen in the following extremely rare photo of these two engines, side-by-side at North Leigh: Dean 'Single' alongside its 4-2-4T pre-decessor at North Leigh My model currently only has 'cosmetic' outside valve gear, cut from plasticard with my Silhouette cutter. It is powered by a Tenshodo WB28.7 SPUD, contained within the rear bogie, in the same way that my 4-2-2 uses a similar one in its front bogie. The model negotiates my small-radius curves with ease and does not share a tendency for de-railing, which apparently afflicted the prototype! Update: I have created a 3D computer model of this engine - see https://www.rmweb.co.uk/blogs/entry/26347-william-dean’s-express-tank-revisited/ Mike references: Great Western Locomotive Design, John C Gibson 1984 The British Steam Railway Locomotive 1825 - 1925, E L Ahrons, 1927 Swindon Steam, L A Summers, 2013

Building the Chassis This is an addendum to my previous post about building a Broad Gauge cattle wagon body. Although I built a chassis at that stage, I found the construction was too light and would not support wheel-sets adequately. I should have remembered that I had the same problem with the first design I did for a carriage chassis, so this post is an aide memoire to help me avoid the same mistakes again. My chassis is basically a rectangle to fit under the body, with axle-boxes and springs added in the appropriate places. Building the rectangular plate in ‘Fusion 360’ is straightforward but adding the axle-box details proved more tricky. My staring point was to make a 2D-drawing of one side of the chassis, showing the locations and sizes of the various components that make up the under-gear. For this, I used ‘Autosketch’ to produce the drawing shown below: Next, I produced the base rectangular plate in ‘Fusion 360’. I started by drawing a rectangle 66mm x 34mm and extruded this, using the push-pull tool, to make a plate 3mm thick. I drew additional rectangles on the surface of the plate and recessed these by 2mm (push-pull again) to form a basic chassis with sole bars around the edges and some internal support at the centre. Next, I imported the 'Autosketch' drawing (saved in DXF format) and extruded the various elements of the drawing to form the running-gear components along the side of the chassis. This was quite complex, since I first extruded inwards to make a firm attachment to the sole-bars and then outwards to form the outer faces of the axle-boxes and springs. These Steps are illustrated below: Step 1: the 3D chassis; Step 2: adding the side drawing Step 3: extruding over solebar; Step 4: extruding outside faces Once I had completed the axle-boxes along one side, I realised that the various parts all appeared as separate ‘bodies’, so I used the ‘Combine’ command on the ‘Modify’ menu to make the whole assembly into a single ‘body’. This is important because only a single ‘body’ can be exported to ‘Cura’ for 3D printing. The next stage proved tricky since I fell foul of one of Fusion 360’s quirks. My aim was to split the chassis lengthwise and then make a mirror image of the side with the axle-boxes and use it to complete the opposite side. My first step was to create an offset plane along the mid-line of the chassis, using the 'offset plane' command in the ‘Construct’ menu. I could then use the ‘split body’ command in the ‘Modify’ menu to create two ‘bodies’, one for each side of the chassis. When I tried to delete the unwanted side, however, I received error messages : If one is foolish enough to continue, then large parts of the model disappear! Clearly, this is not the right approach. Eventually, I succeeded after several attempts, during which I learned to understand the difference between ‘Delete’ and ‘Remove’, when applied to ‘bodies’. Everything worked fine, providing I used ‘Remove’ from the drop-down menu that appears when right-clicking on the relevant ‘body’. Another step on the learning curve I have summarised the steps needed to complete the model in the following diagram: In step 5, I set up an offset plane half-way across the chassis, then selected ‘split body’, to cut the chassis into two halves. In Step 6, I selected ‘Remove’ from the drop-down menu associated with this body. In Step 7, I used the ‘Move/Copy’ command to copy, rotate and move a copy of the original body (complete with axle-boxes) to lie alongside the original. It is important to check the rather insignificant box near the bottom of the menu to ensure that the original is copied and not simply moved! After aligning the two parts, I used the ‘Combine’ command to join all the parts into a single ‘body’, which, in Step 8, I could export to my 'Cura' 3-D printing software. One additional action was to mark and extrude rectangles behind each axle-box, to allow the wheels to protrude through the chassis floor. After all this, I could send the model to my 3D-printer to produce a chassis for my planned fleet of 9’ 9” wheelbase cattle wagons. Phew!!! Learning curves are strange things. I now do with aplomb, things which seemed almost impossible a few months ago but I can still come to a grinding halt when faced with how to remove an unwanted body. Similarly, the adhesion problems I had initially, when printing, seem to have disappeared. In fact, the adhesion has recently seemed too strong and I also noted that the filament was tending to form blobs at times. Reducing the print temperature from 200°C to 190°C appears to have solved both these difficulties. My second print head has, however, just failed. Since this is a special clip-in component, no longer readily available in UK, this may bring my time with the Geeetech E180 to a sudden halt, as I now have only one spare remaining. They do not seem to last very long! I can now show my first cattle wagon body standing on its wheels – Broad Gauge, of course Still a lot of work on fittings and painting. Mike EDIT: I made some minor adjustments to the 'push-pull' features on the axle-boxes / springs, which have made a significant improvement to their appearance - photos updated.

One layout scheme that has nagged me over the years has been that of a table-top modular system. That is, small scenic boards with simple track arrangements that can be plugged together in any configuration on a table top. I suppose it's just the next level up from set-track really. I've mentioned it before in an earlier post, but it didn't get much further at the time. However the idea has never completely gone away and the system of self-contained track modules that I'm currently using for Tweedale is a direct descendant, but for different reasons. Here the main purpose of the small modules is to allow easy construction on a workbench away from the layout itself. So far I have three of the boards wired up and working, but as yet without the scenery... Together they represent the line from Slaghill (background) to the Upper Tweedale exchange sidings (foreground), and provide enough scope for some simple shunting. Before adding more modules, I'll add scenery to these and experiment with different methods of lighting and presentation. 　 Now I hope you don't mind while I go off at a tangent for the rest of the post. As I had the boards lying around loose, I got to musing on the table-top system again, and wondered just how many workable combinations of these three modules I could make. As you can see, they consist basically of a small yard, a junction, and a loop. A quick calculation showed that in principle there were 72 possible ways they could be connected. However half of those were repeats (but rotated 180 degrees), while some others were unworkable as they would require additional headshunts. In the end I drew out the track plans on pieces of paper, shuffled them about, and whittled them down to 16 workable combinations... Furthermore there were also 8 workable configurations using just 2 out of the 3 modules... 　 For those who are into micro layouts and shunting puzzles, it seems to me this could form the basis for a small industrial shunting system, but with more operating flexibility than the usual micro. That is, once you get tired of the limitations of one configuration you could shuffle the modules for whole new operating experience. It must be said that some of the arrangements would be more satisfying to run than others. 　 Having got this far in my musing, the next obvious step was to consider taking such a system to an exhibition (which is unlikely but never say never). The first thing would be to pre-book a 6 foot table from the venue, then just take along a few modules, with some stock and a controller, and plonk them down in a random configuration on a dark cloth laid over the table. After a period of shunting I would then endeavour to amaze the onlookers, by taking it all apart and rearranging it into a new configuration (with a bit of showmanship and pizazz of course). Not only would it provide relief from the Small Layout Operating Boredom Syndrome, but it would also give the viewers a whole new perspective on the display. 　 Being set up on a table the viewpoint would be essentially birdseye, and I would make the most of this by giving the modules smoothly curved freeform edges, (bulging out to accomodate scenery), to give the overall display an eye-catching organic shape, as I've tried to depict in the diagrams above. To tidy it up I would also be inclined plug in rounded 'caps' with buffer stops to the truncated track ends. There would be no backscenes - the birdseye view combined with the dark tablecloth should be sufficient to frame the display. Scenically, I reckon a mine, quarry or other straggling single industry would work well. Another option might be an urban canyon, lining the tracks with factories and wharehouses, cropped at the module edges, but also with gaps between to provide interesting sight lines along the tracks for those with cameras or willing to stoop for an eye-level view. One thing that soon became obvious after playing around with these 2'6" modules, is that for the table-top system I'm describing they should ideally be shorter, say less than 2 feet. Actually the whole scheme would probably be better done in narrow gauge. Being more compact and with sharper curves, the display could then take on even weirder shapes. With enough modules it could become positively rococo. Now that certainly would have visual impact. 　 Anyway this has just been a digression into a flight of fancy. Make of it what you will. Next time I'll get back to the layout proper. 　 Cheers, Alan.

I find it hard to believe that more than six years have passed since I started to build a model of one of the early standard gauge engines, transferred to the GWR when they acquired the Oxford, Worcester, & Wolverhampton Railway (The Old Worse & Worse, as it was colloquially known) I have been reminding myself of what is in this, my older ‘Pre-Grouping’ blog, before I changed over to (became obsessed with) the Broad Gauge! My model of No.184, shown below, was the last model I built using traditional methods involving brass sheet. It also sat on the first ‘chassis’ I built – a simple pair of brass strips separated by ‘Markits’-type spacers. My model of No.184, photographed in 2014 Although the overall construction went quite well, I made a silly mistake with the underframe and ended up with outside frames that were too wide to allow free rotation of the outside cranks, while clearing my platforms! As a result, this pretty little model languished in my spares box for many years, although I did attempt a partial rebuild in 2017, when I also finally got around to building a Tender. Nevertheless, I still felt dissatisfied with the model and it all seemed a bit of a kludge. The boiler fittings never felt quite right, either, since I was reliant on the nearest matches I could find from the trade, being unable to construct my own components. No.184 with old 4-wheeers at North Leigh While reading through my old articles, I found I had written the following prophetic words in one of my replies to comments: “I'd like an affordable3D printer so I could keep everything in my own hands “ Well, a lot has changed since November 2014 and not only are there plenty of low-cost 3D-printers around but I have also got to grips with some of the problems involved in using CAD modelling tools! The first task was to sort out those outside frames! I was amazed to find how tough it was to dismantle those parts I had re-made in 2017. The lengths of Broad Gauge rail that I used to re-make the edges of the footplate un-soldered reasonably easily but the filler I had used in various places was as hard as rock and had to be ground out with a drum sanding-disk in my mini-drill, which produced clouds of white dust everywhere! Looking at those hand-cut outside frames, which I was very pleased with at the time, they look rather crude now, with barely a right-angle corner in sight! For rivets, I had used the brass rivet strips that used to come from ‘Mainly Trains’ but are now still available from ‘Wizard Models’. I built up a stock when ‘Mainly Trains’ closed and have used them for all sorts of things including a standard-gauge Tilt Wagon. I still had all my original drawings of No.184, so all I needed to do in order to make a new set of 3D printed frames was to import the appropriate drawing into ‘Fusion 360’ and trace over the lines, then extrude the new frames. Adding rivets is a breeze since @Timber pointed out the ‘pattern’ tool in ‘Fusion 360’. I simply create one rivet head and copy as many as I need along a chosen direction! I think the overall design took about an hour and then I could transfer the model file to the ‘Cura’ slicer software, to produce a file for my printer. 3D model over drawing ‘canvas’ in Fusion 360’ The complete set of frames took 33 minutes to print and now I had nice ‘square’ openings for the axles boxes, smooth lines of rivets, and correct spacing between the outer surfaces of the wheels and the inner sides of the outside cranks. My 3D-printed frames on the printer bed The funny thing is that at normal viewing distances, it really doesn’t look any different! (i’ve deliberately kept the image small to emphasis this point). It does, however, now have adequate clearances for the outside cranks. New outside frames in place below my original model Sometimes, I feel I want to re-make all my old models by means of the 3D printer but, when I look at them, they bring back many happy memories of the time I spent creating them in the ‘old ways’. It’s easy to be hyper-critical and see all the faults in the old constructions but, in practice, they look fine and they each have a ‘history’ attached to them. I shall resist the temptation to re-do everything and, instead, will concentrate on new and different prototypes, especially those which reveal something about railway history but are unlikely ever to be appear in the model marketplace. Mike