This page is my third SBB Ae 3/6 II page. All may be seen at the Models page. Additional search words: CFF Ae 3/6 II, SBB/CFF Ae 3/6 II.
Märklin and Roco take completely different compromises to allow the locomotoves to operate on the not to scale curves of the track. When it comes to running through curves the compromises seem to be:
- Roco applies power to one axle, Märklin to all three, with tooth wheels between them. So Märklin probably operates long before stopping on more uneven or dirty tracks. It’s like a 6 wheel drive! However, overhang is enormeous, since the free moving of each axle across the locomotive is little. The larger overhang of the Märklin body may also be seen by the large disalignment of the buffers. See picture (right)
- Power on one axle allows Roco to build the three large wheeled axles more flexibly. There is a kind of bogie inside the three axles, giving the row of wheels more flexibility to follow the track. The overhang is almost none. See picture (left)
- So, Roco can make the ladders as long as they should be, where Märklin must stop them above the smaller wheels.
- Of course, all wheels follow the track, but the body on top will position itself according to the forces of the structure below. The more snaky structure below, the more the body will follow. Provided the forces in the front and in the back become well balanced as the locomotive takes the curve. Both ends should pull the respective part of the body back on the track with the same strength.
- Update Sep2019: I fear that the new Roco 78293 with sound has a simpler frame and axle design. See here
For nice curve operation, Roco wins. (For uneven or dirty tracks, Märklin wins.)
The above picture is also used here. The interesting thing is that the Roco followed the curve so nicely that it passed the catenary mast; it was when the Märklin loco passed that it stuttered at that place.