This description is rather dull, I want to get it over with now before I move on to the history and economy of the island, and then the railway.
I want a test track which will let me do more than run-in a new loco, and I have made a list of the parameters I can check. I am using a Hornby Mk3 coach as the gauging vehicle, so hopefully anything I can expect to want to run will fit through the layout. Back in the late 1970s someone told me BR took these coaches through the tunnel to Blaenau Ffestiniog for much the same reason.
1. Kadee coupler installation location - the c. 24-inch radius reverse curve
2. Kadee coupler alignment - the transition from level track to a 1:20 descent
3. Pickups on an 0-4-0 chassis - the Setrack point
4. Wagon free-running and weighting - the 1:30 descent to a level track
5. Controller feedback performance - the various gradients
6. Axle alignment - the transition from a 1:20 descent to an 18-inch radius curve
7. Loco starting torque and adhesion - 1:20 gradient
8. Compatibility with four track standards: Peco/Hornby Setrack, Peco code 75, 00-BF (much the same as the Peco) and 00-SF / HO-SF (but not DOGA Fine)
Having written this out, I have tried to make the transitions at the ends of gradients as gentle as I can, and the track work as flowing as possible within the space available. Section breaks are cuts into the rails made with a cut-off disc in a mini drill and then filled with an epoxy resin. I am trying to avoid track faults and to keep everything as good I can, for the sake of the layout to follow.
The geometry of curving track on a gradient is complex. Logically, the track should have a definite super-elevation, and this means a Y point on a gradient should be raised in the middle, with the crossing above the two stock rails. I have resisted this temptation, and made the point flat.
I worked out this list on the coach to Ally Pally (30th March 2015) and I expect I'll add to it - I'd welcome any comments on additional details I might be looking for. Since then I have added some more:
9. Wheel back to back dimensions - the 00-SF section
10. Vertical gauging below the railway bridge, especially for long vehicles which are straddling across from 1:20 section below the bridge to the level track beyond it - thank you Stu (Stubby 47)
11. Pivots of bogies and pony trucks - gradient transitions
12. Bogie vehicles bottoming-out on the transitions at the tops of gradients