MikeOxon

Thank you, Annie - you have seen your copy in NZ before mine's arrived here!. I've even got around to painting my model although there are still pipes and handrails to add.

The steel protection bars around the huts look surprisingly like modern crash barriers!

I agree. I like the line of huts with one marked 'GWR Foreman's Office'. I have a similar hut in the yard at North Leigh, so may label it in the same way! I wonder what the two guys by the gate are saying? "Right, Bert, you watch that office, while I look if there's owt worth nicking from these wagons"

It reminds me very much of creating aircraft files in the MS Flight Simulator. One problem there was that settings in one part of the fie could over-ride settings in another part. I spent fruitless hours trying to change a parameter only to find it was subordinate to another setting!!! Mike

Really good modelling - the 'Greyhound' looks splendid and Archibald Plummer is one of the most convincing model figures that I have seen. I really enjoy these Victorian scenes. I've fought for ages trying to compose header pictures - how it's cropped varies with the screen used to view the site. Nowadays, I prefer using a phone rather than a camera for model photos. Mike

Beautifully executed and photographed - it is a splendid trigger for the imagination - I can hear those carts rumbling along the roadway! Thank you for the idea about magnetic fencing usually, feature like this are a real pain when cleaning a layout. You make it look very simple but each of those trees is a work of art in its own right. The whole demonstrates that "small is beautiful" Mike

Thank you for commenting, @Annie. I am very sceptical about the Twining drawing, which was produced around 1940. I suspect he may have been influenced by the bogies on the Lehigh valley 4-2-4T. which was still extant at that time: The valve gear, as shown in the re-built version of No.9, will not fit between a 7' leading bogie and the driving wheels. It seems unlikely that they would have gone to the trouble of altering the arrangement during the rebuild, especially as it was re-built again, a little later, to match the layout of the 'Queen' class. This article referred to by @Miss Prismin the Imaginary Locomotives thread, is incorrect in stating that this engine used Joy's valve gear. As the 'Engineer' article referred to above clearly states, it was Stephenson gear. Joy did visit Swindon and saw this engine being built and there was a plan to use Joy's gear on the second, never built, version. The whole thing was an experiment by Dean to try and find a way of accommodating the valve gear when using larger cylinders. Eventually, he adopted Stroudley's arrangement, with the valves located below the cylinders. The real solution, of course, was to use outside cylinders, as Churchward realised. Mike

Your photos also jogged my own memory. I started a thread on GWR Absorbed Engines back in 2014. This engine, plus several other oddities, was mentioned, with some discussion of the outside valve gear, in the various posts. Mike

Nice drawing. Is it yours? The numbers are maker's numbers. Later re-numbered to 215-20 when with GWR According to Ahrons, one of these engines could still be seen "lying in a heap of scrap behind Swindon Works in 1886".

... and that's what I would call a 'recent' engine! It's not just small-scale modellers that go astray. There are some substantial differences between the Firefly replica at Didcot and photographs of the original Firefly. I know compromises have to be made if a working engine is to meet modern standards but the firebox cladding on the replica is almost wholly cosmetic, with the true firebox hidden inside. Yet the replica has a 'Haycock' style firebox where original photos show the 'Gothic' type, with arched sides. Why?

At least it doesn't mix systems of measurement units. A pity that the metric world never created something similar

Nothing beats a good photo ... when you have one! Those of us attempting to model the earlier part of the 19th century very rarely have that opportunity! In addition, many of the drawings we have were created long after the event, so are often extrapolations from limited information. In such cases, it is necessary to find as many independent sources of information as one can and after that it's down to personal judgements.

i suppose the difference is that I aim to create the main box and cylindrical shapes by extruding directly from drawings. It's not too difficult to make scaling adjustments in the computer, to compensate for errors in the drawings. The major difficulties arise when the drawings are incorrect in the placement or dimensions of specific features. in the end it's a personal matter how far we wish to take things but no-one wants to make things incorrectly, if better information is out there somewhere.

'Oiling round' was a standard feature of 19th century operations and, for example, was mentioned as a contributory factor in the BoT report on the 1913 accident at Ais Gill on the Settle & Carlisle line. By then, the procedure was probably unnecessary but continued as a routine practice'. Broad Gauge (BG) engines had the advantage of greater foot[plate width and (except for convertibles) many had an outside hand rail. I often think that a BG footplate is more like the deck of a ship, with its rail around the edge.

On the subject of inaccurate drawings, I found that the drawings I have of Firefly do not include the mini-splashers over the carrying wheels, although they can be seen in photographs. I only realised after I built my model and found that true scale wheels would not fit. I've now re-designed the footplate to include these splashers:

I agree with all the points you make, Duncan. I always check horizontal and vertical dimensions separately and make any necessary adjustments. The 'calibrate' function in 'Fusion 360' is very useful. I'm more concerned about actual drawing errors, where details are wrongly placed or wrongly sized, and so on. There's a lot we shall never know about these old engines but I don't like to perpetrate errors, if I find them.

Thank you Mikkel - making the model has changed my mind about these engines and I now think they are rather handsome. I'm still simply enjoying exploring what I can do with 3D modelling. I haven't given any thought to actually running any of these models and they may well remain as 'display' items. All the photos were taken without any significant cleaning up of the prints, apart from removing obvious loose strands and the like. I think the wheels would need proper metal rims to make working models.

Accuracy of Drawings In an earlier post, I wrote: “I used the same method that I described in my previous post to extrude the saddle tank from a drawing – this time a pencil sketch by F.J.Roche, reproduced in the ‘Broadsheet’ article. This drawing was useful for the front elevation but I feel the drawing in Mike Sharman’s compilation by the Oakwood Press is more dependable for the side elevation.” Some recent correspondence within the Broad Gauge Society (BGS) e-group suggested that the drawings in the Mike Sharman compilation may not in fact be that accurate, I quote: “The Sharman's book drawings were transcribed from originals published in the Loco Magazine. The one in question here* was published in 1903. The transcribers varied greatly. The originals are believed to be accurate but ... this particular transcription was one of the least accurate.” * This quote refers to a drawing of a Dean 2-4-0 convertible of the 3501 class, not my engine, but it sowed seeds of doubt in my mind. On looking more closely, I noticed for example, that the spokes of the bogie wheels on ‘Aurora’ were not placed accurately on the drawing, which showed up clearly when I designed my own wheel, using ‘Fusion 360’s Pattern command to produce nine equally spaced spokes. 3D-printed wheel laid over Drawing It’s a small point but a warning not to believe the correctness of all the details on the drawing. I have now measured the wheel base and other key dimensions on my 3D-printed model and have been relieved to find that they are all accurate. I shall pay more attention to the accuracy of any drawings I use as a basis for extruding models in the future. Front Elevation Looking through my own small collection of drawings, I found three showing the front elevation of one of these 4-4-0ST engines. Two of these, by F.J.Roche and by Ian Beattie are said to be of ‘Lance’ (both drawings are from the BGS magazine ‘Broadsheet’ no.17), whereas the one by Alan Prior (in his book ‘19th Century Railway Drawings') is of ‘Corsair’. Putting these three alongside one another shows that there are many significant differences between them: Front elevation drawings compared Faced with discrepancies such as these, I turned to photographs and, in particular, the one of ‘Aurora’ that I showed in an earlier post The tank seen in this photo appears to have the more rounded profile shown in the Roche drawing above, although the sand pipes are not so arched. Of course, those early engines often showed a iot of individual variation, so the dictum to work from photographs as far as possible is very sound but can be difficult to apply, when photos were so far and few between. Following ‘rules’ may not be best Another interesting point appeared when I started to create the trial prints of the wheels that I designed for my model of ‘Aurora’ I made the initial prints by laying the inside of the wheel flat on my printer bed. This meant that the widest part of the wheel, with the flange, lay on the bed so that there were no overhangs as the printing progressed, which is the ‘preferred’ method. In practice, the flanges came out thinner than expected and were damaged when I removed them from the printer. This may be a result of using a printer with an unheated bed but it was another case where disobeying the rule book yielded a better result! My later prints were made with the outer face of the wheel on the bed, so that the flanges actually overhung the main part of the wheel, as it printed. Nevertheless, the flanges printed cleanly and, by printing in this orientation, I could include sleeves extending from the backs of the wheels, to guide the pin-point axles and ensure the correct back-to-back measurement between the wheels. 3D-printed wheel-sets with integral axle sleeves Each sleeve contains a clearance hole for the 2mm axle, while the wheel itself is an interference fit onto the axle. I assembled each wheel-set by dropping a pin-point axle into the sleeve and then tapping it gently home into the wheel with a light hammer, as shown below. Once one wheel had been attached, I turned the part over and tapped the axle into the other wheel, until the two spacing sleeves meet at the centre line. Assembling a wheel-set Once I had produced a set of wheels, I could place them under my model, so that it began to look like a real engine! It has a purposeful look, well matched to its task of hauling important passenger trains over the South Devon banks. The famous Gooch singles may have stolen the limelight but it was these tank engines that maintained services across the more difficult routes of the South Western peninsular – they must be lauded for that capability ‘Aurora’ on her Wheels A few years ago, I could not have contemplated making a model like this and I am pleased that, during its design and construction, I have gained an appreciation of the prototype’s remarkable qualities. No longer shall I call it an ‘ugly duckling’ As usual, there’s a lot of finishing still to be done. One day, I must get together my collection of unfinished Broad Gauge locomotives and have a session of handrail fixing,-plus all those additional fittings and polished brass-work that make make them into beautiful swans. Mike

Memo to yourself - design layout so that station is on straight track

An interesting comment at the end of Bernard Holland's article: "...with the solitary exception of Hem Heath whose first shaft was not sunk until the late 1920s and whose reserves are reputedly good for another 600 years." How perceptions have changed!

So much modern software suffers from being modified by people who are more concerned with 'eye candy' than the underlying operating principles.

There’s lace making on the island of Burano if that helps

As mentioned in my previous post, Dean initially devised a centreless bogie for his experimental 4-4-0T No.1. I have picked out the frame in blue, as in my drawing of the carriage bogie above, on the drawing by E.W.Twining. This engine apparently failed to stay on the track and was soon converted to a 2-4-0T. Mike

Thank you, Simon, that's a much better way of describing things! The bogie, of course is supported by the wheels. Dean had earlier experimented with a bogie where, instead of using a cross beam, he ran it longitudinally outside the bogie. That just tended to bend under sideways pressure, leading to de-railments.

The Dean centreless bogie was a weird and wonderful thing! I find it hard to 'translate' from engineering drawings to a three-dimensional structure, so I tried colouring the various parts on side and end elevations, then cutting and pasting in Photoshop to create a crude perspective sketch: This shows how the bogie frame (red) is supported from below on rods (green) that pass up through the cross beam (blue) and are clamped between sprung cups (green) below the beam. It's important to distinguish between these cups and the ones (grey) that support the ends of the leaf springs on the sides of the bogie. It's clear that this arrangement does not allow for much lateral movement of the bogie and would not adapt to most model railway curves. Mike