I've been thinking about a new fiddle yard for Awngate - and for possible use on future layouts too. There's nothing really wrong with the current cassette system - it's compact, flexible, and easy enough to use, at home at least. However the few exhibitions I've done have shown something even easier, faster, and with less handling would be advantageous. It's surprising how quickly people move on while cassettes are changed, so simply sliding the next track over would be quicker, plus the distractions of exhibiting adds risk of damage to the trains while moving cassettes around. Another factor is that my Son likes to help out, but struggles to reach over to move cassettes about.
A turntable would be ideal as it allows the trains to be turned around, avoiding all handling. It may not be prototypical for such a line to reverse the whole train, but who really cares! However the layout sits against a wall at home, meaning not only is there not enough space to turn the table round, there would be limited tracks that can be lined up before the table hits the wall. A traverser is more compact as the lines are all parallel, so should have space for all (or at least most) tracks to be used at home. But locos need to change ends which means handling, or fiddly and time consuming shunting.
So after much thought and some ideas posted on the NGRM forum I'm planning a hybrid - but to check it is feasible I've knocked up a prototype from a cardboard box of a convenient shape, sellotape, and one of those split-pin paper fasteners! As you can see it consists of a traverser with up to 5 tracks, and all can line up with the exit track to Awngate without fouling the wall.
But slide the deck forward far enough and the top deck can be rotated right round to reverse the trains. Note how the deck (2' long) turns inside of the far side of the board - so clear of the wall. Of course at an exhibition it could be slid away from the operator to rotate if preferred. No accurate curved cuts are needed, just a pivot through the middle (which may mean the centre track is two separate "railcar" tracks).
Having turned 180 degrees the deck is slid back to line up the next track. The mock-up proves the concept works, of course making it for real could be more challenging. Practically the baseboard of Awngate is very shallow, so this has to be shallow too (tricky when it has three layers), or Awngate will need to be raised. I also want it to be easy to operate, so I'm wondering about self-aligning and electrically connecting tracks, but the latter is more tricky as the polarity to the tracks will need to reverse when rotated. Even the tried and tested sliding bolt alignment and connection method would need to deal with the polarity reversal - so using a common return won't work!