Why is the s stock slow

[pethadine82]

Why is the S stock so slow, the acceleration is really bad. Jubilee line trains have much better acceleration. Can anyone explain this?

 

[Charlie2555]

Probably the weight of the S stock is much larger and also, the S stock doesn't stop at as many stations as the 1996 stock so does not need the same acceleration. The S stock the same top speed of 62 mph but I don't think the Jubilee Line trains often reach that speed.

 

[starrymarkb]

S-Stock is Power restricted at the moment, Long term there is going to be a voltage boost on the Met at least to 750V

 

[transmanche]

Why is the S stock so slow, the acceleration is really bad. Jubilee line trains have much better acceleration. Can anyone explain this?

ISTR reading that the S stock would have its performance capped to match the A stock - until the Met is resignalled.

 

[Voyager 2093]

If you notice, the trains are very jerky as well, its because they are trying to draw power from a line with inadequate power.

 

[D365]

ISTR reading that the S stock would have its performance capped to match the A stock - until the Met is resignalled.

Or C/D Stock, whichever is slowest. Once the new signalling is up and SSL voltage is upped to 750v DC, they should be a lot faster.

Although, how will that work where SSL and tube trains share lines? Would make it more complicated if Bakerloo returned to Watford Junction with Met/Croxley Link (and Watford DC?).

 

[Class377/5]

Or C/D Stock, whichever is slowest. Once the new signalling is up and SSL voltage is upped to 750v DC, they should be a lot faster.

Although, how will that work where SSL and tube trains share lines? Would make it more complicated if Bakerloo returned to Watford Junction with Met/Croxley Link (and Watford DC?).

You already have this situation with the 750v 378 and 72ts on the south end of DC lines and with D stock on Richmond branch. Not sure what the voltage is tho but proves it can work.

 

[D365]

You already have this situation with the 750v 378 and 72ts on the south end of DC lines and with D stock on Richmond branch. Not sure what the voltage is tho but proves it can work.

I'm thinking if Watford Junction (and High Street section) was to be served by 750V third-rail for 378, 750V fourth-rail for S Stock and 630V fourth-rail for 1972/Evo Stock. Although the latter probably won't return for a while, if ever.

Overall, what I'm saying is that there might be a problem with the S Stock sharing tracks with deep-level stock designed only for 630V. I guess that since S Stock is designed for both voltages, that shouldn't be a problem? Not clear on how this will work exactly.

 

[CCF23]

Once the S Stock become automatic in a few years they will accelerate just as quick as the 2009 Stock on the Victoria Line. At the moment their acceleration is still limited to match that of the A and C stocks.

And in reply to one of the posts above the 1996 stocks now usually reach around 60mph in between stations.

 

[notadriver]

Interesting that the S stock is restricted but the 378s aren't.

 

[Nym]

Interesting that the S stock is restricted but the 378s aren't.

Not really, the 1972 stock has always shared tracks with BR trains, be it the 378s or the other stock that used to run on the DC lines.

 

[CCF23]

Interesting that the S stock is restricted but the 378s aren't.

You also have to remember that the 378s between Euston and Watford Junction run only every 20 mins and Bakerloo trains to Harrow & Wealdstone every 10 mins. So there isn't really so much of a chance that trains will catch up with each other.

 

[notadriver]

In theory you are correct - in practice with late running trains etc one can closely follow the other signal sections permitting.

What's interesting here is that whilst a 1972 stock train will run out of puff above about 40 mph and struggle to reach 45, a 378 accelerates quicker and could easily exceed 45 as it isn't limited to that speed in the same way that the 313s are limited to 30 on the Moorgate section.

 

[notadriver]

Not really, the 1972 stock has always shared tracks with BR trains, be it the 378s or the other stock that used to run on the DC lines.

S stock also share with the Chiltern 165s.

 

[Daniel]

Once the S Stock become automatic in a few years

Do you know something I don't...?

 

[Lewisham2221]

Why is the S stock so slow, the acceleration is really bad. Jubilee line trains have much better acceleration. Can anyone explain this?

Didn't you know that the 'S' stands for slow...

 

[Nym]

Do you know something I don't...?

ATO is being brought in with the advent of the Bombardier CitiFlo systems being installed in place of the current signalling. Only once all of SSR is converted to S Stock. (And the system retro-fitted to the 73 stock).

Some cracks are currently being ironed out on things though.

 

[Daniel]

ATO is being brought in with the advent of the Bombardier CitiFlo systems being installed in place of the current signalling. Only once all of SSR is converted to S Stock. (And the system retro-fitted to the 73 stock).

Some cracks are currently being ironed out on things though.

ATO in a few years, though? I believe we'll still have cabins till 2018...?

 

[Nym]

ATO in a few years, though? I believe we'll still have cabins till 2018...?

I could check on it when I get back into work, but I suspect you have the same access as I do...

 

[bronzeonion]

Straight answer to the question asked.

The S stock are currently limited in the software to match the performance of the A60/62 stock they unfortunately replaced. This is because of signal overlaps and whilst the A60/62 stock were still in service, so they didn't run early.

 

[notadriver]

But what about on the rural sections such as Rickmansworth to Amersham where signals are far apart ?

 

[Nym]

But what about on the rural sections such as Rickmansworth to Amersham where signals are far apart ?

Doesn't affect the overlap, this isn't dependant on the actual distance between signals.

 

[notadriver]

If the signals are further apart and line speeds higher you could have longer overlaps.

 

[Poggs]

If the signals are further apart and line speeds higher you could have longer overlaps.

Changing the overlap means moving signals.

 

[Nym]

Changing the overlap means moving signals.

And it's being re-signalled anyway as part of the SSR Upgrade with in cab signalling...

And hopefully significantly more trains per hour in both directions and a return to a semi fast and fast calling pattern off peak. (One can hope)

Although I suspect that would require more units.

 

[Manchester77]

Do you know something I don't...?

I think he meant ATO so the drivers the but not actually driving it just pressing the start buttons and door controls (like on the Victoria, central and jubilee)

 

[Nym]

I think he meant ATO so the drivers the but not actually driving it just pressing the start buttons and door controls (like on the Victoria, central and jubilee)

Yes, hence why I said ATO and not UTO.

 

[Daniel]

I think he meant ATO so the drivers the but not actually driving it just pressing the start buttons and door controls (like on the Victoria, central and jubilee)

Yes, however, the Met line still uses signal boxes, with manual signalling using levers (believe it or not)! To my understanding this method of signalling is not compatible with ATO.
A process to close the signal cabins and migrate to a new, purpose built Service Control Centre is well under way, but my understanding was that the signal cabins were to remain till around 2018, (with rolling closures leading up to this date), which is why I was surprised as ATO being talked about 'within a few years'.

 

[Manchester77]

Yes, however, the Met line still uses signal boxes, with manual signalling using levers (believe it or not)! To my understanding this method of signalling is not compatible with ATO.
A process to close the signal cabins and migrate to a new, purpose built Service Control Centre is well under way, but my understanding was that the signal cabins were to remain till around 2018, (with rolling closures leading up to this date), which is why I was surprised as ATO being talked about 'within a few years'.

Well 2018 is only five years away (from when we go into 2013 in a few weeks

 

[notadriver]

I bet it will happen in sections as is/was the case on the Northern and Jubilee lines. I expect the closer to Central London to go ATO first with manual driving taking place beyond say Wembley Park or Harrow on the Hill.