Are third-rail shoes spring-loaded?

[North-Eastern T/O]

Yes they are, they have a force of about 30 lbs pushing down on them so they provide a reliable connection to the 3rd rail.

 

INDman I dont think there Spring loaded, they just hang there and there own weight to the thrid rail. The ones that were used on the old BMT and CTA was/are spring loaded you can tell buy the top of them in photos.

 

Spring Laoded. Hope this works

 

Not Spring loaded.

 

 

[metsfan]

Not too good, since it's the amps and not the voltage that ultimately do you in and 10,000 amps is a lot

 

You only need 0.10 amps to stop your heart.

 

- A

[INDman]

INDman I dont think there Spring loaded, they just hang there and there own weight to the thrid rail. The ones that were used on the old BMT and CTA was/are spring loaded you can tell buy the top of them in photos.

 

 

 

Ok, I could have sworn some were. I guess you'd know better then I would and I forgot to check it out last night.

[SubwayGuy]

Ok, I could have sworn some were. I guess you'd know better then I would and I forgot to check it out last night.

 

As I understand it it's the other way around (the way it was explained to me). The old IRT/Manhattan El as well as BRT/BMT elevated equipment used "gravity shoes" that rested on the third rail. They had a lever holding them in place, with a stop to keep them from dropping the roadbed, and when they picked up the third rail (which would pick up gradually) the gravity combined with the heavy weight of those shoes compared to today's would keep them pressed firmly against the third rail.

 

They also looked very different than today's shoes. The third rail was different too. In the case of the BRT/BMT els, it was unprotected third rail and did not look much different than a running rail. In the case of Manhattan El/IRT els, it was "partially protected" with a protection board on the outside of the third rail. That made things interesting when subway cars showed up later on the IRT with the shoes that extended past the third rail, because those cars the shoes would strike the protection board if they ever tried to run them up there. I think I remember there being a way to run them up there somehow, but I don't remember what the "trick" was to get the shoes out of the way.

 

Even during the dual contracts era, you can see on the Flushing and Astoria lines the unprotected BMT style third rail, which made those lines interesting to look at since you had IRT signal aspects and BMT style 3rd rail. Both types of equipment could use the BMT style elevated 3rd rail, although I don't know if the BMT equipment could use the IRT style elevated 3rd rail. There are some good pictures of Q types in the 1940's and 1950's showing this on nycsubway.

 

Later on, all the remaining cars were converted to subway style shoes, and most of the 3rd rail was converted to subway style, with the protection board on top. The lines that weren't were all demolished. But as I understand it, all rapid transit equipment specifically designed for the subway dating back possibly as far as the IRT Composites has used a spring loaded shoe, just the el cars didn't seem to although there are a few pictures of Composites that appear to have gravity shoes so maybe "some did and some didn't" or at a certain time or another, they replaced the gravity shoes with spring loaded subway style shoes.

 

As for the CTA, I can't speak to that since I'm not familiar with their equipment.

 

I'll see if I can find some pics of the IRT/BMT stuff and put in a post below this one.

[SubwayGuy]

I'll see if I can find some pics of the IRT/BMT stuff and put in a post below this one.

 

And here ya go:

 

BMT El Style 3rd rail on the Flushing Line (note the BMT "Q" type car in the foreground and an IRT Lo-V in the background. By this point the subway style spring loaded shoes have replaced the gravity shoes though)

 

IRT Style 3rd rail on the 3rd Ave El (note the protection board on the outside of the 3rd rail and the gradual pickup at the "beginning" of the 3rd rail section)

 

Now here's a shot of a Q with the gravity shoes before the spring loaded subway style was used:

 

Subway style, added later:

 

IRT car running on the el, gravity style shoe:

 

IRT Hi-V car with subway style shoe:

 

Also want to show this last photo, a car inspector explaining the shoe spring tension test (obviously his face is blocked on purpose). Don't know of any photo's of the actual test but there is a device that measures spring tension, so the measurement is taken at the exact height the shoe would sit at if it was resting on the 3rd rail to make sure the spring is the right tension.

[BroadwayBuffer]

Thanks, Subway Guy, for another interesting history lesson :tup::tup: