What is a switch box for?
I have seen them in the ratio catalogue but I would like to know where on a railway they would go, what they were for and when were they introduced?
Thanks for all the replies on the ash question too :-)
'Twas Mon, 5 Jan 2004 16:14:45 -0000, when "piemanlarger" decided to declare:
If it's one of those steel grey cabinets, they contain all the fuses, relays etc for track circuits and signals. One is normally at each end of a track circuit in a lightly-tracked area. In an area of dense trackage (eg. Clapham Jct) they are incorporated into a relay room. If it's not those, sorry!
Del.
I think you mean the large grey cabinets that hold track-circuiting gear and their power supplies. The relays inside are each about half the size of a car battery, so you can see they can take up a fair amount of space. The relays are rather nice pieces of engineering, designed to give long service, but are slowly being replaced by much smaller solid-state devices. The boxes must have been around since T/C was first used, albeit of wooden construction, so whatever period you intend to model should have at least one box beside signals and points. To my mind, they are as much a feature as signals, but very few layouts seem to portray them.
In the trade we call 'em "locs" short for location cases. Relays are still going strong, my employer (Westinghouse) has a large factory still in Chippenham where 100s of the things are produced each week and/or repaired every week. New stuff like TPWS that comes out does, as you say, use solid state equipment, but for it to interface to the existing gear it still needs relays!
To see what a relay looks like, go to this link:
Not much use I know, but gives a little backgroud information. David
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