The old MK1s and the old class 101 DMU have the steam pipes that face the ground, assuming the theory is that excess steam exists there along with water etc whilst steam heating is occurring. Would love to actually see this reflected in the game, would add a very nice touch to the game and the way we spend time driving these machines. Would be so stunned to see steam heating technology being reflected where applicable, there is a beautifully soft white cloud of steam that eventually forms (according to the intensity of heating or strength) I believe all UK content,excluding the freight wagons should actually feature steam heating effects, this actually includes the diesels, MK1s and I think MK2 carriage variants, the 47's, the 45's and 101dmus. In theory Diesel locomotives carried a steam generator (posh term for boiler), which was fuelled by diesel, usually from the locomotive's main fuel tanks. The steam produced was then passed, in the time honoured fashion, via a flexible pipe to the carriages. More often than not there would be a leak somewhere on the train which could produce some quite spectacular effects and of course there is the pipes which do actually help revive the excess steam as mentioned above. Hope this gets plenty of thumbs up so the devs get inspired so it can make a spectacular experience.