Friday, 7 September 2007

Southon Yard - Shoebox Layout

Southon Yard is the motive power depot of one of the Welsh narrow-gauge lines. The yard features a 25-foot turntable, a two-road engine shed, and a workshop for maintaining the line’s engines and rolling stock. Locos enter and leave the yard via the line behind the engine shed, they are turned if required, coaled and watered. You may also see shunting of coal wagons and supplies to the works. The turntable may seem unusual on a line such as this, but the Ffestiniog and the Lynton and Barnstable lines had similar ones, as did tramways such as the Glyn Valley, as the locos usually ran cab-first on tramways. In fact, this line has some tram engines so it may have been originally built as a tramway.

The layout was designed and built to fit into a shoebox for a competition at EXPO-NG in 2004, although I do have large feet which helped! The lighting and back-scene remove for this, as was allowed in the competition rules. It was also designed to be a setting for displaying my growing collection of 009 locos, and can be placed on a shelf. The design and construction of the layout had to be carefully thought out because it is so small. The turntable is motorised through a set of gears and shafts, the motor is in the workshop!

It was great fun to build this layout for the competition, even though it was designed and built within a tight 5-month timescale! I managed to use some buildings from a previousl layout that was never completed, but even so there was a surprising ammount of work for such a small layout. The icing on the cake was that I won the competition!

More pictures can be found at:
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herculessmiley said...

We are delighted to discover your blog. My son saw Southon Yard in Railway Modeller and now he is designing his own OO9 layout (with a bit of input from me!). He is stuck on how to create a small turntable like yours - please can you advise?

Michael Campbell said...

Yes it was quite tricky! The easiest option would be to modify an N-Gauge commercial one such as the PECO one, but that would be larger. I scratchbuilt mine.

Cut a hole to the diameter in the board and put another board over the bottom - I used 6mm MDF so the "well" is about 18 inches deep to scale. I lined the sides with Slaters stone sheet and plasticard capstones. Drill a hole dead central and glue two semi-circles of rail like this () - one is wired to one rail of the feed track, the other to the other.

I got a pack of gears and shafts from Squires (Bognor) and used an old motor from a toy. A large gear is glued under the baseboard with the hole opened slightly to make a bearing (perpendicular to the board). Then a shaft is passed through with a large gear at the bottom, and a gear cut back to a square on top, onto which the table is built. These should be a tight fit and superglue if required (I roughened up the shaft first).

The motor has a worm on it which drives a shaft, which has a worm driving the large gear under the board. I supported the shaft in plastic angle with holes in, glued to the board with bostik and adjusted while wet. I simply switch the track controller over to the motor and line it up by eye (takes practice!)

I built the table from plasticard around the cut-back gear on the shaft. The ends run on small brass pulley wheels (also from Squires) on the rails. There is a brass "wiper" at each end, one rail is connected to one, one to the other. Thus as the table rotates the pickups swap ends and the polarity is reversed, so the train always runs the right way!

It's a bit heath-robinson but it works, only slight problem is that the pickup wipers lift the table slightly causing a slight step in the rails.

Good luck with yours! Let us know how you get on.


Anonymous said...

Thank you for your advice. We have taken the easier route of a PECO turntable. We are novices!

Our next problem is working out how to get power to the lines which run from our turntable. From your photo it appears there is no electrical connection between the turntable rails and the rails it lines up with. Does this mean lots of parallel connections are needed underneath the baseboard?

Michael Campbell said...

Aah, now the solution to that is simple when you know how! It's easier to explain with a sketch but I'll see what I can do ...

The turntable (like all prototype turntables) rests on a circular rail around the outside of the pit. I made mine from PECO rail, but in two semi-circular parts. Each half is wired to a different rail of the adjacent track.

The turntable deck rails (i.e. the track) each have a wire down to a brass "wiper" as mentioned above, at opposite ends of the turntable. As each of these is therefore on different halves of the circular rail, each rail of the turntable track has different polarity - so the same track current as the adjacent track.

The great things about this are that:
1) No wires to the table deck to get twisted or break
2) When the table is rotated half-way the brass wipers swap which half of the circular rail they make contact with - so reversing the polarity to the deck. This means you don't need to switch the wires to the turntable, the loco will always move the "correct" direction relative to the controller even after being turned!

I don't know if the PECO turntable would allow for this - I think the circular rail is plastic? Perhaps the instructions will help.

Good luck!

herculessmiley said...

Hmm...maybe we'd do better with a sketch! However, the PECO turntable has a pair of wipers and contact near the central pivot which we think does the same job as your rails. Are the turntable rails connected to get their power supply from one of the feeder tracks? For example in your layout diagram from the top left as shown? Are the contacts then wired to all the other ptoential lines from the turntable?

We've found a picture which shows the control box for your turntable power supplies (we think). This suggests the other lines are given power separately and switched on and off.

herculessmiley said...
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