http://www.youtube.com/watch?v=Ou-eR6HpX90&feature=related Not my video, But what are the workers doing at night in Berea Ohio lately that they need thoughs halogen spotlight bulbs?
The carriers have the need to perform major track work and still keep their networks flowing…only one party can have the track segment at any given point in time…MofW to work on it or trains to operate on it.
Track work today is done by large highly mechanized gangs that must have hours of uninterrupted track time to accomplish their tasks. The carriers have taken to slotting track work into the natural lulls of their operating plans. In some cases at some territories that lull occurs after dark, with that being the case, where it is appropriate this work is scheduled and performed at night. It could be a rail gang, a tie renewal gang, a surfacing gang…any MofW function.
And those lights are probably mercury vapor, not halogen.
Tree: You are right that they are not Halogen. Halogen lights have a rectangular look to them the width usually about 8 - 10" to accept a 300 or 500 watt 3 - 5 " bulb accordingly. Those bulbs looks like a pencil but are slightly bigger in diameter. However it is impossible to know whether the bulbs are Mercury vapor which has a very blue color or Metal Halide which has an almost orangeish white light until they are lit. The two bulbs are interchangeable using a 100 , 250 ,or 500 watt bulbs all which screw into the same socket. Almost all night time road work around here uses Metal Halide as the Mercury vapor lights have a broader light spectrum than metal Halide so you get more apparent light from the halides. Halides also last longer. The bulbs are almost identical in cost and the last time I checked Home Depot could not find any Mercury Vapors. Note the metal halides are all replacing the mercury vapors for street lights as the mercurys burn out.
I defer to your knowledge. I was pretty sure there was something else out there, but didn’t know what it was. They definitely weren’t sodium…
Tree: You mean you don’t like that awful yellow of sodium vapor lights? Also their bulbs are about 2 ft long and about 1 - 1 1/2 " diameter. Fixtures cost a lot more. A few small towns here in the south bought them and they now hate them but cannot afford to replace them except on some kind of an abnormal mechanical failure .
[thread creep] Actually, there’s two different types of sodium lights - IIRC, high pressure and low pressure. Most of the street lighting nowadays is the high pressure version. The low pressure version is more yellow, as I recall. Seems like we had it in a shop where I worked - it wasn’t real popular.
Tree: absolutely correct. It was the low pressure types in the small town southern citys. Must have been some salesman.