Deleted
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Post by Deleted on May 23, 2011 14:22:37 GMT
Does anyone know if the S stock performance has been improved lately? Acceleration seems to have increased and between Northwood and Moor Park speed reached 56 mph on a stopper!
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prjb
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Post by prjb on May 23, 2011 22:59:07 GMT
There have been some traction software modifications but the train will still operate within a nominal 'A' stock profile. If you are 'notatraindriver', and just out of interest, how do you know how fast the train was going?!!
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Post by Deleted on May 23, 2011 23:02:47 GMT
Between Baker Street and Aldgate today, I did notice that the acceleration seemed to be much better than that of the typical A stock operating in that section of the line...
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prjb
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LU move customers from A to B, they used to do it via 'C'.
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Post by prjb on May 23, 2011 23:05:54 GMT
It could just be that the smoother acceleration and the effect of the tunnel gave that impression. I do stress though that the train is limited to a nominal 'A' Stock profile, so if there are some 'clapped out' ones out there they will be slower than the 'S'.  |
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Post by Deleted on May 24, 2011 6:38:10 GMT
There have been some traction software modifications but the train will still operate within a nominal 'A' stock profile. If you are 'notatraindriver', and just out of interest, how do you know how fast the train was going?!! I'm just an interested enthusiast. Well with good old GPS. Its reasonably accurate given enough satellite signals and a good view of the sky. The Railway Performance Society have some logs in railway magazine. |
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Post by jardine01 on Jun 22, 2011 5:56:23 GMT
Yes the S stock is limited in power but the driver could of just put the TBC into max making the train accerate faster?
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Post by Deleted on Jun 22, 2011 8:32:17 GMT
I think most drivers use full power when pulling away out of stations (not terminal stations). I personally use half power to get the thing moving then a bit more once under way. But I myself only use full power when late as the timetable is quite generous.
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Deleted
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Post by Deleted on Jun 22, 2011 12:35:12 GMT
So Eco driving hasn't hit the met yet!! Full power sounds great to me, but again, given all the variables - line voltage - railhead condition, driving style etc, there are many reasons why acceleration will differ especially in the open. How do the power controllers differ in terms of notches and performance? Is full power computer controlled and subject to whee slip protection on the 's' stock? Will the performance be increased once 'A' stock is fully withdrawn?
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Post by redsetter on Jun 25, 2011 16:50:58 GMT
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Post by citysig on Jun 25, 2011 21:41:20 GMT
"The new "S Stock" trains are slowly coming into service but the rush-hour service continues to be appalling."
Last updated in March, which is probably why that since before then, the line has enjoyed many trouble-free peaks with and without the S-stock.
Seems to be full of all those minor inaccuracies that these sort of reports try and use to get Joe Public on-side. 191 trains by December 2011? That was never going to happen.
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metman
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Post by metman on Jun 25, 2011 23:34:16 GMT
Oh my goodness, what a total load of tosh!! The Ricky crowd don't know what they're learned friend is wittering on about!! ;D
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Deleted
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Post by Deleted on Jun 26, 2011 2:32:07 GMT
Good heavens. Now, I'm not on the inside on such matters. But metman's so right. The stuff they're saying is so wrong it's actually quite funny.
I think my favourite quote is: "problems with the build quality". That's really funny!
Even if it were totally true, a lesson about the bathtub curve would be worth giving to them...
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Post by jardine01 on Jun 27, 2011 12:03:09 GMT
The S stock is limited in power at present and will only be inproved when the new siganling systems are in place. However when all the S stocks are on the line i can't see why they could not up the power just a bit?
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Deleted
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Post by Deleted on Jul 18, 2011 10:37:26 GMT
Performance definitely seems to be better than A stock. I recorded:
0-30mph 24 secs
0-50mph 56 secs
Acceleration tails off after 40 mph. Recorded a maximum 55mph, driver immediately braked back to 50, so assuming he reacted to a slight overspeed, possibly due to falling gradient. Time taken to reach 55mph from 50mph was quite long so o sm guessing the driver had shut off power or was in a lower power notch , or possibly even the software reducing power available over 50mph if the units are artificially being capped to this maximum - despite being designed for 60mph. I'm guessing the advantage of modern traction electronics on the S stock is that you get good acceleration throughout the speed range. Whereas on A stock, it depends on whether driver is in weak field mode or not. On a Watford stopper, we were very close to most of the fastest station to station times, most of which were recorded before the current era of more cautious driving.
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Post by Deleted on Jul 19, 2011 11:31:44 GMT
Thats a lot better than the previous 0-30 time I recorded which was 35 seconds. They've obviously been tweaked a bit.
I don't know of many trains that have top speed governers apart from the HST. (i don't include systems such as ATP or TASS which I feel are more part of the signalling system)
It will be very interesting to compare performance between S stock and Class 378 once they are de-restricted.
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Deleted
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Post by Deleted on Jul 19, 2011 13:51:26 GMT
This was a start northbound out of willesden green, so level start, then slight falling gradient. Just checked the gps data and there was indeed a steepening of the fall in gradient at the 50mph mark that would account for the slight rise to 55mph. 51-52mph the norm which is more than acceptable.
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