Sunday, 7 July 2019

July 2019 meeting

Our July meeting took place a week earlier than usual. Andy, Jim, Alisdair and Alistair met at Graham's house in Edinburgh. One subject of discussion was last weekend's Perth exhibition put on by the Scottish Model Engineering Trust, where the FCAG (pictured, Jim and Nigel) manned the 2mmSA's Further North roadshow.

Thanks to the Perth club for inviting us. We enjoyed the show which had a subtly different flavour this year, with a diverse range of prototypes and scales and a consistent standard of layouts.

But back to our July meeting. The Short Talk was by Jim, expounding on how to file up turnout switches and crossings with jigs. Or at least, that was his original intention, but he ended up talking us through the whole Watt Way of turnout construction.

Jim has written up his methods extensively in the 2mmSA magazine, and the Association's Track book (available to non-members for online purchase here) is another valuable reference. I won't give more than a summary here. It's well worth reading (or re-reading) Jim's articles mentioned below. (The magazine archive is available to Association members on a USB stick as part P-109 from Shop 1).

Jim models late-1890s Caledonian Railway practice, so bullhead rail, interlaced timbering and loose-heeled switches are the order of the day. His article in the August 2012 magazine covered the construction process. He lays out the turnout on a Templot plan, starting with the four interlaced sleepers in each road of the crossing which carry the crossing itself and the check rails. The tip of the crossing's point rail must sit on a main road timber so this is positioned first, then the others added. Next, the two close-spaced timbers which anchor the switches (at the opposite end of the closure rails from the crossing) are positioned. Then interlaced timbers are laid by eye between these two, starting with a sleeper on the main road and proceeding towards the crossing. (Templot can produce a template showing these by shoving timbers, but this lengthy process is not really necessary in 2mm scale).

The switch rails are aligned with the closure rails with little fishplates made from copper shim, bent into a "U" formed in a jig (slot sawed in a piece of brass strip of rail thickness). The fishplate must be no longer than the space between two sleepers. It is threaded onto the switch rail and squeezed gently into the rail web using tweezers, then slid along so it projects half-way off the rail end and soldered. The fishplate can then be slipped onto the closure rail, but is not soldered: it is prevented from falling out by the tiebar mechanism which holds the switch rails in place vertically and horizontally.

Jim's tiebar design was written up in the December 2008 magazine. The tiebar is formed in two parts from wire bent up in a small jig made from a sandwich of three brass plates, one with sawcuts of precise widths and depths to receive the wire at various stages of bending, the other two on either side to stop the wire moving from a vertical plane. Very easy to make with hand tools and very effective. We were shown the jig and the wires.


Once installed the tiebar looks very neat, and the arrangements under the baseboard are equally straightforward. In his demonstration model shown here Jim deliberately left the through-baseboard pivot exposed so it can be seen, but on a layout this would be hidden by a ballasted slip of paper with a slit for the wires, which then look very much like a prototype tiebar.

Jim also described his memory wire point actuators, which have the advantage of silent operation compared to solenoids or servos. The February 2013 magazine gives further details. 

Switch rails and crossing point and splice rails are filed up from bullhead rail using a Geoff Jones hinge jig. Jim described how he made the 0.030" brass profile plates in the August 2012 magazine. The hinge is steel. He showed us the jig.

Jim's original ballast recipe was 1:1:3 Cascamite:Plaster-of-Paris:fine sand, with poster paint added for colouring. There was some doubt whether Cascamite (a powdered-resin wood glue) is still available, but a quick check on trhe Internet shows several sources online. More recently Jim has used crushed cat litter. If this is done carefully, the cat can be straightened out and re-used.

At that point we paused for a feed. Bacon rolls, cake, tea and coffee were consumed, then it was back to work. Andy was fiddling with wagons on his test track while Jim progressed with the second footbridge for the Grampian area group's Dunallander layout - he received the bridge columns at the Perth show from Roy Bremner, fresh from his lathe. Turning the thin columns required a bit of experimentation but ultimately Roy got the knack of it.

Alisdair was working on adjusting the Electra couplings on his stock for consistent operation, so had brought along his portable test-track/cameo Aye for that purpose. The two parts bolt together for transit:
then are separated: 

and joined using flight-case over-centre catches. Very neat.

After much tweaking of couplings and noting down of wagon numbers "Not to Go" with defects, Alisdair pronounced himself satisfied. The loco assigned to the coupling test duty was his Caley "Jumbo", 57232:

Graham contemplated his LNER fish van chassis collection, which has been growing at the rate of three or four chassis a month. At some point, buffers, wheels, couplings and paint will be required. And the bodies (Foxhunter kits) of course!

The August meeting will probably be in the West, with details to be sent out by Alisdair as usual once venue and date are confirmed.

Saturday, 15 June 2019

June 2019 meeting

Jim, Alistair, Stephen, Andy, Gordon, Simon and Graham met at Alisdair's house in sunny Scotstoun for this month's meeting. The Short Talk was by Alisdair himself, on a subject close to his heart as a retired civil engineer: Bridges, and typical features to include when modelling them. He recommended "Bridges for Modellers", L.V. Wood, as a good reference (originally by OPC, reprinted more recently in paperback: check out the usual Internet sites to find a copy).

The talk was illustrated with photos of railway bridges in the Glasgow area. We were shown how iron and steel girder bridges often have a "hog-backed" shape seen from the side, rising from each end to the middle, with characteristic vertical stiffeners to the side of each flanged girder. Among other functions, these stop the girder failing by buckling downwards or outwards. The stiffeners are often wider at the top, and their spacing varies: a long span will have closer stiffeners. Under the bridge, cross-beams in line with the stiffeners prevent shear forces tearing the bridge apart, and in older bridges are often revealed by rivet patterns on the side girders. Steel troughs between the cross-beams allow the track to be ballasted across the bridge; the troughs are often lighter weight when a load such as platforms rather than track is carried. There will be pilasters at the end of the bridge, which provide a structural function on arches but also a practical and aesthetic function on other bridge designs.

We were shown a variety of photos of skew bridges and Alisdair explained the various additional forces these introduce, often in counter-intuitive directions, and the design features required in consequence. We saw examples of bridges replaced during their working lives and the difference this can make to the abutments, for example ashlar masonry being replaced by brick or concrete; and how concrete retaining walls are often given horizontal courses to conceal the cracking which occurs normally - the concrete cracks unobtrusively at the course rather than in full view.

Detailed photos were produced of bridge beams resting on padstones at each abutment: stone padstones on older bridges, concrete in modern. Arch bridges were explained as being basically of circular, elliptical or segmented shapes, with the segmented type in particular requiring substantial amounts of rubble behind the abutments to stop the ends of the arch kicking out. Circular arches are much less demanding. The arches also rest on padstones, with skewbacks (I think) to spread the load outwards. Seen from below, the arch stones typically fit very tightly together, since if they are loose they will move and rub when loaded, and soon fail.

Other stresses try to tear the arch apart sideways, and if this starts cracks, patresses (steel plates) are often applied to each side of the arch connected by rods passing right through the structure to resist these forces. There was much more explanation and many illustrative photographs showing how the various design features were expressed by engineers in the distant and more recent past. The speaker's expert knowledge of these features did not stop the audience from contributing their own views, but Alisdair showed commendable restraint and so we were all satisfied. A most interesting talk which hopefully will lead to more accurate bridges on our layouts. We had no idea Alisdair's professional life had been dominated thus by stress, but it does explain some of his own more unusual design features which have puzzled us in the past.

Simon had some interesting boat kits in card and paper for a Clyde puffer and a small fishing boat from ScaleScenes. These look to be nicely designed as waterline or full-hull versions with excellent instructions. Simon also had questions for us regarding point construction with the Laurie Adams chairplates, which he finds either too tight or too lose to grip the rail. Discussion ensued without conclusions: advice will be sought from the designer.

Jim had his latest footbridge etches for Dunallander for our inspection, and very nice they looked too. He's awaiting arrival of the turned support pillars.

The stair treads are folded up from a single piece of etch, but Jim soldered a flattened fine wire on each one to provide a lip to the steps: the slight relief catches the eye and improves the appearance considerably. The T-section girders of the side supports and hooped entrance arch are surprisingly strong, in spite of being from 10-thou material for the stem of the "T" and 5 thou for the top. The design and build is documented in Jim's RMWeb thread here.

Jim also had his venerable 498 class Caley dock tank for inspection so we could see the recently-fitted pickup skates in action. The photos deliberately use a light background for illustration: in practice on the layout they are not visible.

If you look closely you can also see the coil springs in the Alex Jackson couplings.

Jim found it was necessary to shape the support wires for the phosphor-bronze skates carefully, so they do not catch on point crossings.

And indeed the "beetle-crusher" did seem to run better.

Alisdair had his erstwhile test plank on display, which has now blossomed into "Aye", a mini-layout based on an imaginary Highland Railway station. (There is bound to be some horrible pun involving the title, so far not revealed to us, and for all I know the spelling is less obvious, in the same way that the village of Avoch - from the Scots gaelic Abhach, "mouth of the stream" - on the Black Isle is pronounced "Och"). The station building, based on Grandtully, was featured in last month's blog.

A detail of how the boards are joined using flight-case over-centre clips:

and the spring-loaded sector plate stop:

and a view from underneath:

A fault-finding session ensued: a slight kink in the track, hard to spot without assembling the full layout, was the cause of persistent derailments of longer-wheelbase locos. A faulty DPDT switch was also replaced. We will no doubt return to "Aye" in future blogs.

The big news at piece-time was the replacement of bacon, with its attendant smell and mess, by roast ham with cream cheese and tomato in the rolls. Domestic harmony was thus assured and it has to be said that the rolls were fully better than the previous version. A wide variety of fresh baking was also provided. The East Coast elements of the FCAG will have to look to their culinary laurels. This is, of course, all a distraction from serious modelling, but we are easily led astray.

Some discipline was eventually restored and a peaceful scene ensued in the afternoon sunlight: Jim working on preparing the etches (of his own device) for his new loco, which will be a Caley 323 class "Jubilee Tank"; Stephen soldering up the axleboxes he'd spent his dinner money on at Tutbury; Alistair adding a loco servicing road to his Edinburgh layout pipe-dream; Andy browsing the latest magazines; Graham soldering up yet another 2mmSA LNE fishvan chassis; and Alisdair brewing coffee and tea. His flowery pinny is on order.

And so the afternoon drew to a close. Our next meeting is proposed to be in Edinburgh, exceptionally on the first Saturday of the month, July 6th.

Saturday, 8 June 2019

June 2019: 2mmSA Expo, Tutbury

Three FCAG members - Stephen, Alisdair and Graham - made the trip south to Tutbury in the English Midlands to sample the delights of the 2mmSA Expo. The trip was well worthwhile and there was plenty inspiration on display. Here are a few random snaps.

Bryn Davies' Colwyn Bay Goods: a Clayton seems to have escaped to Wales ... but to be fair most of the shunting was with more conventional motive power.

Angus Higgins' Glencruitten. I haven't captured the colours very well - the contrast of the sky, grass, and camouflaged hangar is striking, and very satisfying.

Ian Smeeton's Paisley St. James: a web of steel (or rather, nickel-silver)

The Kent and Essex Area Group's Lighterman's Yard, impressive as always.

Pete Matcham's Kyle of Lochalsh: I think this is the first time I've seen it "in the flesh". I managed to catch it when there were no trains, just as the prototype usually appears:

and his new concept display for Meeth:

I forgot to capture the other concept display for Loch Awe. Everything executed with great style and precision.

Anthony Yeates' Corrieshalloch, which gets better every time I see it. A Peter Drummond Banking Tank (oops - I missed a photo), and a variety of coaching stock including a Jones coupé-ended coach and an HR brake van, all from Anthony's own etches, were on display.

Steve Nichols' Parkend. A lovely layout which also ran beautifully.

There were demos a-plenty: Andy Carlson's Arduino-controlled shunting tractor and concept for Hayle North Quay:

Keith Armes' track-building: Keith was also showing a small layout:

David Eveleigh's coach-painting:

Nick Mitchell's stay-alive DCC:

Edward Sissling's wheel-turning:

and trade support from Nick Tilston's N Brass

and Allen Doherty's Worsley Works. Allen showed me how to use inexpensive garden secateurs - Kent and Stowe 6mm pruning shears, available on eBay for less than £10 - as metal shears to cut sheet brass to precise size without distortion. The trick is to cut only with the part of the shears from the pivot to half-way along the blades, then move the blades for the next cut, rather than cutting right to the end of the blades; and to take a rough cut wide of your scribed guide line which will leave a twisted edge before trimming to the guide line with a final exact cut by shearing off a thin strip; all the curl goes into the thin waste part leaving an undistorted model part. Easy when you know how! Thanks Allen.

A very nice day out, just the thing to take the mind off the weather! Thanks very much to organiser John Aldrick, to all the exhibitors, demonstrators and traders, and to the 2mm shopkeepers who lightened all our wallets with their usual aplomb.