The Anonymous Widower

Station Dwell Times On The London Overground

This afternoon, I had to go to Walthamstow for lunch, so on the way out, I checked how long it was between brakes on at James Street station and the Class 315 train was moving again.

The dwell time was a very respectable thirty seconds, which is probably more down to the driver and the signalling, than the nearly-forty-year-old train.

Coming back, I took the Gospel Oak to Barking Line to Gospel Oak station..

The driver gave a display of precision driving a Class 172 train, with the intermediate stops, all taking thirty seconds or less.

From Gospel Oak, I switched to the North London Line and took a Class 378 train to Canonbury station, from where I walked home.

The dwell times on this line were more variable, with two times at thirty seconds or less, two at nearly two minutes and the rest in-between.

From these small number of observations, it would appear that the minimum dwell time on the London Overground is thirty seconds.

Various factors will determine the actual dwell time.

  • Trains must not leave early, as passengers don’t like this.
  • Trains must not leave, before the driver has ascertained it is safe to do so.
  • If a train arrives early, then the dwell time might be lengthened, even if the train leaves on time.
  • Large numbers of passengers or a passenger in a wheelchair, who needs a ramp will lengthen the dwell time.

I should say that today, the trains were not full and there were plenty of empty seats.

Conclusions

If trains and drivers can handle thirty second dwell times, then everything else associated with a station stop, must be capable of the same fast response.

This thirty-second dwell time may have repercussions for rapid charging of battery/electric trains, that I wrote about in Charging A Battery-Powered Class 230 Train.

I think there are three options for charging a train at a station stop.

Plug the Train Into A Power Socket

Can you plug you mobile phone into the mains, give it a reasonable charge and then disconnect it and store all leads in thirty seconds?

Use a Pantograph To Connect To 25 KVAC Overhead Electrification

Even if a driver or automation is very fast at raising and lowering the pantograph, I don’t believe that in a total time of thirty seconds, enough electricity can be passed to the train.

This method might work well in longer stop at a terminal station, but it is unlikely, it could be used successfully at an intermediate stop.

Use 750 VDC Third-Rail Electrification

750 VDC third-rail electrification has a very big advantage, in that, trains can connect and disconnect to the electrification automatically, without any driver intervention.

Look at this picture of a train going over a level-crossing.

The ends of the third-rails on either side or the crossing are sloped so that the contact shoes on the train can disconnect and connect smoothly.

As you have to design the system for a possible thirty-second stop and don’t have the time available for the first two options, I am fairly certain, that the only way a worthwhile amount of electricity can be transferred to the train’s battery, is to use some form of system based on tried-and-tested 750 VDC third rail electrification.

There may also be advantages in using a longer length of third-rail, so that the connection time is increased and more than one contact shoe can connect at the same time.

Automation would control the power to the third-rail, so that no live rail is exposed to passengers and staff.

After all a train on top, is a pretty comprehensive safety guard.

 

 

 

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October 28, 2018 - Posted by | Travel | , , , ,

1 Comment »

  1. […] Dwell Times On The London Overground anonw.com/2018/10/28/sta… https://t.co/QN4t20riJK […]

    Pingback by Could A Class 450 Battery/FLEX Train Be Used Between Waterloo And Exeter? « The Anonymous Widower | October 28, 2018 | Reply


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