(6) train terminating at 3 avenue-138th street

[Subwayfan12]

Why do some northbound trains terminate at 3 avenue-138th street. The first one leaves 125th street around 8:30am and three or so more follow on an 8-10 minute interval. The question is why does this happen?

[JubaionBx12+SBS]

Why do some northbound trains terminate at 3 avenue-138th street. The first one leaves 125th street around 8:30am and three or so more follow on an 8-10 minute interval. The question is why does this happen?

 

So the MTA doesn't have to "overserve" the rest of the Bronx. Plus those trains are needed to turn back quickly and serve Manhattan being that the rush hour shoulder load on the Lex is quite high.

[RollOver]

As far as I know, I would say is because there are much more and more demands for the Lexington Avenue Local service than the Pelham Local service.

[Snowblock]

Not only that, but those short turns come back into Manhattan EMPTY. Same reason why some of the 1's get turned at 137, why some of the 4/5's get turned at Bowling Green or 149, etc

[TwoTimer]

It has nothing to do with overserving the rest of the Bronx, as those trains eventually have to go uptown to lay up. Empty trains going into Manhattan is just a nice side effect, not a direct reason. Its primary reason is to maintain rush hour headways (3 min) on the in Manhattan until 10 AM. 3Av-138 is the fastest turn around point on the line. Most other lines begin to ramp down service to midday levels at 9AM (including some rush-hour only services, expresses or extensions ending), including out of both Parkchester and Pelham. Rush hour headways on the Lex local has been clearly needed until 10.

[RollOver]

It happens with just about most other lines in the subway as Snowblock pointed out. During the rush hours, some 's turn at Broadway Junction, some 's turn at Burnside Avenue, some 's at turn Kings Highway, some 's turn at 168 St-Washington Heights etc etc. This is to maintain three or five minute headways as TwoTimer said also.

[TwoTimer]

It happens with just about most other lines in the subway as Snowblock pointed out. During the rush hours, some 's turn at Broadway Junction, some 's turn at Burnside Avenue, some 's at turn Kings Highway, some 's turn at 168 St-Washington Heights etc etc. This is to maintain three or five minute headways as TwoTimer said also.

 

Well the at Kings Highway is because of capacity issues at Stillwell. The at 168 (and Dyckman) actually goes out of service there and run empty to the yard. at 137 share the same primary reason as the at 138. The headway between 96-Chambers local needs to remain low until about 10 AM, just as they are that low on the other trunk lines in Midtown.

[JubaionBx12+SBS]

It has nothing to do with overserving the rest of the Bronx, as those trains eventually have to go uptown to lay up. Empty trains going into Manhattan is just a nice side effect, not a direct reason. Its primary reason is to maintain rush hour headways (3 min) on the in Manhattan until 10 AM. 3Av-138 is the fastest turn around point on the line. Most other lines begin to ramp down service to midday levels at 9AM (including some rush-hour only services, expresses or extensions ending), including out of both Parkchester and Pelham. Rush hour headways on the Lex local has been clearly needed until 10.

 

This can't be done running all of the uptown trains to Parkchester or Pelham Bay?

[RollOver]

This can't be done running all of the uptown trains to Parkchester or Pelham Bay?

 

 

I'm guessing he's saying that 3rd Avenue-138th Street is the easiest because it is the first three-track station for northbound 's. Therefore, you have three southbound 's all within ten minutes between 125th Street and Brooklyn Bridge-City Hall. If they ran further on the Pelham Line, you won't be able to maintain the three minute headway for southbound Lexington Avenue Local service. The reverse goes true for northbound in the PM Rush. The longer it takes to go further north and then turn south, the more five minute headways that the Lexington Avenue Local services.

[TwoTimer]

To turn a train at Parkchester as we all know, it has to relay. To turn a train at Pelham as we all know, it traverses a slow switch and comes into the station on time. To turn a train at 3Av, it comes into the middle full speed and dumps. The next crew comes aboard, charges up and leaves. The entire process can take only about two minutes if that was the next train to go. It's the most efficient and cheapest location on the line to turn a train, and it allows the other two terminals to raise their headway accordingly. When those trains go back around the loop and end up uptown again, they will lay up. Just a reminder, by that time (9AMish), the demand for Pelham line service northbound is very low, save a few student straglers. It is not uncommon to ride a train between 9 and 10 uptown and there be less than 100 people on the train (and I'm being conservative with that number).

[RestrictOnTheHanger]

How fast are those switches at 3/138 good for?

[JubaionBx12+SBS]

To turn a train at Parkchester as we all know, it has to relay. To turn a train at Pelham as we all know, it traverses a slow switch and comes into the station on time. To turn a train at 3Av, it comes into the middle full speed and dumps. The next crew comes aboard, charges up and leaves. The entire process can take only about two minutes if that was the next train to go. It's the most efficient and cheapest location on the line to turn a train, and it allows the other two terminals to raise their headway accordingly. When those trains go back around the loop and end up uptown again, they will lay up. Just a reminder, by that time (9AMish), the demand for Pelham line service northbound is very low, save a few student straglers. It is not uncommon to ride a train between 9 and 10 uptown and there be less than 100 people on the train (and I'm being conservative with that number).

 

I rest my case then. Also this is true for most outer borough trunks in the reverse peak.

[TwoTimer]

How fast are those switches at 3/138 good for?

 

Many operators come in wrapped, technically 20/25mph.

[paulrivera]

It happens with just about most other lines in the subway as Snowblock pointed out. During the rush hours, some 's turn at Broadway Junction, some 's turn at Burnside Avenue, some 's at turn Kings Highway, some 's turn at 168 St-Washington Heights etc etc. This is to maintain three or five minute headways as TwoTimer said also.

 

Those 's to Burnside do not turn they go straight to the yard, which actually crowd up the trains that go through to Woodlawn since all but a couple of the line's heaviest used stations in the Bronx are north of Burnside. Of all the better ideas they scrapped from the "line manager" era *ahem ahem* and they kept this pattern.

 

I don't think the has a "reverse peak" in the Bronx, except maybe southbound in the PM between November and March...