Hi, does anyone know why the headlight of english old locomotives are very small? For example with Br class 52, 08, 101 or 40.
All the things you need to see in the dark are lit. Such as signals and stations and crossings. Even the old semaphore signals had colour panels with a light behind them so you could see if they were clear or set to red.
If you think about it, in the old steam trains visibility wasnt particularly good- you had a lot of train with smoke and steam pouring out in front of you. Therefore everything that you had to look at was lit for you? When it came to diesels it was no different? Except that you didnt have the smoke, steam and whole engine in front of you- except for the 20 and 08/09? I think that is why driving at night on the NTP is so dark, its nerve wrackinginly dark. The only thing that is lit is the signals. Trying to judge where you are or what the hell the line is doing means a lot of focus.
Headlights were not mandatory on British rolling stock until the mid 1980s when older stock was retro-fitted with yellow square headlights. There were some local exceptions prior to this, such as the Central Wales line. This century it became mandatory that three headlights were fitted, two below and one above the windscreen in a triangle formation to avoid confusion with road vehicle headlights.
Train drivers rely on signals and (in more modern locomotives) on-board signaling and data. It's really pointless to have bright headlights that actually light up the scenery in front of you at night because 1) you don't have to steer anyway and 2) it doesn't matter how far you'd see, you could not stop a train within that distance. So if anything happens in front of you, you can't stop, so it doesn't matter if you see or don't at night. Drivers get all the important information through the signals while the train stops are lit anyway, so they see where to stop exactly. Headlights therefore are not really needed.
Well, except for speed boards and Morpeth boards. And on vintage lines like NTP and TVL, with the old cutout speed boards- those things are almost invisible even in daylight.
NA trains use headlights because they had more road crossings to deal with. Also our lines weren't really fenced off like in the UK.