TWS4793 SG DD Bendy bus very difficult to build, and somemore need special parts, just like SBS 0997A, SBS 0998Y and SBS 0999U. And I think no one did this before, did they?
Urroh SG DD trains will crash 1 mins after leaving depot.. ANyway DD bendy bus is a good consideration for some packed services..
stooper SG I think he means that the train will smash into the tunnel roofs, not that they don't exist...
autumncs SG A lot of trains in Europe (esp Germany) are also DD... When I was in Germany, I bought a toy model of a DD passenger car from Deutsche Bahn (German Rail).
