In the early 1840s architects, engineers and managers were still grappling with the problems thrown up by a new technology that could pick up, transport and deliver hundreds of passengers at the same time. As a result early station track plans often look cumbersome with their long rows of wagon turntables, their separate platforms for arrivals and departures and their rows of carriage sidings crammed in between the platforms.
One early problem for the engineers was moving locomotives from one end of the train to the other at a terminus. Crossover points at the end of the line would have taken up valuable space in the small stations of the time. At some termini the problem was solved by uncoupling the locomotive at the entrance to the station and then rope-hauling the carriages into the platform before the loco ran in after them. At other stations a turntable, a section plate or a traverser was used to move locos (and sometimes coaches) between tracks inside the station so that they could run around their trains.
On a previous layout I built a satisfactory turntable on a CD disc with very basic electrics - simply a wire soldiered to each rail, with enough play to allow the turntable to be rotated through 180 degrees by one of my trusty coffee-stirrer rods. But a turntable would not fit onto my current layout (early locos plus their tenders are around five inches long in HO, and my baseboard is only four inches wide). So I decided to build a traverser instead.
The bed of the traverser was easily built from lottery cards: they are rigid and easy to work, but because a card is only 8 cms wide and I needed a traverser 12 cms long to take the Norris loco I used three overlapping layers to produce a sturdy, reasonably heavy bed 2.25 mms deep. I used four lengths of Peco Code 75 flat-bottomed rail for the runners supporting the traverser, and recycled some of the sleepers from the flexitrack as guides stuck beneath the traverser to keep it in place as it slides along the rails. As with my points, a long pin through the centre of the traverser connects with a coffee stirrer rod beneath the surface, allowing it to be slid between the two tracks by pulling and pushing the stirrer. The groove cut in the foamcore to allow the pin to move also acts as a stop when the traverser is in place at each end of its run. Lead tape (used by golfers to adjust the balance of their clubs, but also ideal for adding weight to rolling stock) provides extra weight on the underside of the traverser.
I did mess things up a bit when it came to powering the traverser. My first thought was to run the power through the supporting rails, with copper strips resting above them on the underside of the traverser to pick up the current and feed it to the track. I still think that should work well, but I decided connecting the track on the traverser directly to the controller was a simpler solution which meant I wouldn’t have to keep cleaning the supporting rails all the time.
My soldering is barely adequate on a good day, and I wanted to make sure the wires to the track were strong enough to cope with any stresses and strains as the traverser slides backwards and forward. I had planned to investigate ready-soldered fishplates for some time, so building the traverser gave me a good reason to buy a pack of Peco's PL-81 pre-wired fishplates. So far I'm very impressed and I can't see myself trying to solder a wire to a length of rail again in a hurry!
But then I decided to be clever and run the two wires horizontally under the traverser and into a groove cut into the baseboard at an angle. It works now, but the friction of the wires dragging on the underside of the baseboard meant I had to hack chunks out of the foamcore beneath the board to allow the wires sufficient play. In retrospect it would have been easier to simply drop the wires vertically down into a groove directly beneath the traverser bed to keep friction to a minimum.
My next job is to build a platform to sit between the tracks, and also to add some sort of backscene. But my next post will probably be my long-promised blog on altering the Bachmann Prussia coach. I have been doing some work on this, as the photo below shows. (BTW the north-eastern style cauldron wagons in the foreground are Smallbrook Studio's 4 mm model, adapted for HO scale by removing the top plank and replacing the 12 mm wheels supplied with the model with 10.5 mm ones.)