[mthornton]

Could you have a movable link between the two ends of your L to provide the continuous run? Just a bare single or double track which you remove when not operating. Otherwise accomodating the loops at each end won't leave much room for scenery.

 

[mthornton]

QUOTE (Agamemnon @ 1 Feb 2007, 20:34) <{POST_SNAPBACK}>Consider that such a piece would have to be as big as the layout itself, essentially a second L-shape to complete the rectangle. Completely unfeasible, hard to make and fiendishly hard to secure.
No it needn't be as big as the main boards. You still have a about 135 degrees of turn on the ends of the main boards and then the extra piece just completes a triangular shape. it would be a about 4 metres long (probably a bit less) and could be made in two pieces supported by a 'tressle' in the middle. When not in use just store it on top of the main layout.
Reducing the turn from 180 (or more in the case of a dogbone) to 135 degrees saves more space for usefull layout than you might expect.