Mike,
it was . Sped of trains with sg cars on n g "Rollböcke" als wee call them was restricted to 7- 15 mph depending on track, curvature and steepness. But is was fun looking a trian with 4 -5 s g cars on Rollböcken waddeling down the tracks. Also inetresting was how the s g cars got onto the n g ones. A bit similar to a Ramsey Transfer but the s g car keeps it wheels or trucks.
b.t. w. severe accidents happened not so often as you might think (5- 6 a year on app 25 - 30 lines using the technology .
Steffen