Platforms with huge curves

[theseaandalifesaver]

I was in the city this weekend and I forgot what station I was at, but my girlfriend pointed out metal grates every 10 feet or so that would extend when a train enters the station.

Obviously this was because of the large curve the platform was built with, but my question is how often are these used throughout the system? Why wasn't the platform just straightened out more? and have these ever caused any safety issues?

[Fan Railer]

You must have been at 14th Street Union Square on the 4, 5, 6 lex ave lines. That was the way the platform was built. Originally, they weren't as long since in the beginning, they didn't run ten car trains. but as time progressed, the southbound platform was extended up the curve to accomodate 10 car trains. I would be prohibitively expensive to straighten out the tracks to the point where the platform gap fillers wouldnt be needed. and plus, the work just fine. the only other station on the sytem that used the gap fillers was the old South Ferry station on the 1 train, which has since been replaced and abandoned.

[ExCon90]

There's also a gap filler at Times Square on one of the Shuttle tracks. Same situation as at Union Square; the tracks curve to join the West Side Line and head northwest under Broadway--no way they can do anything about the curve.

[Allan]

I just want to point out a bit of history.

The original subway cars (Hi-V and Lo-V models) had only 2 sets of doors. One at each end of the car. These would easily platform at 14th St, South Ferry, City Hall, Times Square (now shuttle) and Brooklyn Bridge so it wasn't necessary to have gap fillers. When the middle door was added and then when later car models had the end doors moved in, it was necessary to add moving platforms/gap fillers to support this (cheaper then trying to rebuild platforms).

BTW - there are moving platforms/gap fillers on the abandoned section of the Brooklyn Bridge station - just south of the present station. There were ones on the uptown side of 14th St but they were able to do away with those when the platform was extended.

City Hall never had the gap fillers because the volume of passengers could not justify the expense of adding them. What the IRT did was have a number of Lo-V cars on the local modified so that there was a separate door control for the center door. That way at City Hall, only the end doors would open.

When the Bowling Green-South Ferry shuttle ran until the mid 1970's, they also used specially modified cars (R-12s were the last ones in use) so that at the South Ferry (inner loop) station, the center doors only could be open as they platformed at the portals on the platform. At Bowling Green, then all the doors could be opened.

PArtof the rebuilding

[theseaandalifesaver]

Has this ever been a safety issue at all? Who controls the movable section of platform?

[railfan365]

Has this ever been a safety issue at all? Who controls the movable section of platform?

Years ago, the platform extenderds were controlled by a platform conductor by way of a large mechanica lever. They have since been partially automated. When a train comes in and comes to a stop, the T/O oresses a button on a switch box to trigger the gap fillers to extend out. On leaving, the train has to be accelerated very gently to start, and a gentle nudge by the train against a sensor in a gap filler triggers a retraction.

[Allan]

Has this ever been a safety issue at all? Who controls the movable section of platform?

It has never been a serious safety issue (except when a section doesn't extend or retract).

To add to what railfan said - only at the Times Square Shuttle station (tracks 1 & 3) are the movable platforms operated by the train operator by pushing a button. When leaving the station the platforms retract at the push of a button.

The ones at 14th St are totally automated (but can be controlled manually if they had to be). As the train enters the station there are sensors on the walls that register how many cars there are on the train (at one time trains were less than 10 cars during the overnight and weekend hours and if the train was shorter only a few of the platforms would actually extend). When the train is stopped at the "S" stopping mark at the front of the platform, a relay triggers the controls and the platforms extend. There is always a short delay for this action to happen and the conductor keeps the doors closed until the platforms extend and lock into place and a light goes on. After a short time the light goes off meaning that the platforms are now unlocked and will retract as the train leaves. The conductor closes the doors and the train leaves very slowly. As the a train car body moves it nudges the movable platform and it snaps back into the retracted position. There is a special signal at the end of the platform which will not clear until all the moving platforms retract.

At 14th St if the train operator upon entering the station goes past the prescribed stopping point (even by a few inches) then the platforms will not extend. This allows for situations where the train is not in passenger service and is just passing thru the station. If the train is in passenger service and the platforms don''t extend then all that can be done is to have the train continue to the next express station and passengers then have to take an uptown train back.

At the old South Ferry station it worked basically the same as 14th St although there were manual controls in the dispatachers office on the platform.

[diffusedmind]

Hi-Vs and Lo-Vs had center doors.

[Allan]

Hi-Vs and Lo-Vs had center doors.

The original IRT cars did not have center doors when the system opened. Center doors (with separate controls) were added to existing equipment in 1908/1909 and all new cars ordered after that had the center doors as standard equipment.

[HBLR]

The original line extended only to city hall, not south ferry.

One time the grates didn't extend, and the train didn't open its doors, so i had to go up one stop and come back to get where i was going. Made me late!