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Post by Deleted on Jun 3, 2013 15:11:12 GMT
How can the step vary so much at the same station on the jubilee line, at Westminster for example sometimes I get on there isn't a step but at other times the step is 2cm ?
Is it something to do with how the balance of the train is (if more people are more to one side)
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rincew1nd
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Post by rincew1nd on Jun 3, 2013 18:27:55 GMT
Possibly also linked to the number of people already on the train, lots of people squishing the suspension slightly?
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Post by punkman on Jun 4, 2013 18:20:57 GMT
I guess it is as rincew1nd states due to depressed suspension. In my distant memory I seem to remember 1996 stock has / had a load weigh device (or something similarly named) which could roughly work out the loadings to adjust the braking; this I imagine would work from a calculation involving displacement. That and the fact I imagine no two trains are purely identical in that respect; I appreciate although 2cm appears very little, it is a significant amount for wheelchair users.
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class411
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Post by class411 on Jun 5, 2013 6:52:14 GMT
I appreciate although 2cm appears very little, it is a significant amount for wheelchair users. It's can also also significant if you are used to the platform being in one position relative to the train and it's suddenly somewhere else! |
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Post by Deleted on Jun 27, 2013 14:24:45 GMT
I thought all trains since the 38ts have automatically adjusted braking depending on load?
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Post by Deleted on Jul 31, 2013 18:15:15 GMT
How can the step vary so much at the same station on the jubilee line, at Westminster for example sometimes I get on there isn't a step but at other times the step is 2cm ? Is it something to do with how the balance of the train is (if more people are more to one side) The only simple reason is that the stations were created at different time periods and were thus designed for different types of trains and thats why Westminster gap seems smaller its because that station was designed for the 1996 stock type train whereas the stations betweed Baker Street and Charing Cross didnt accommodate for wheelchair access or for the new trains likewise between Baker Street and Stanmore |
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Post by norbitonflyer on Jul 31, 2013 19:01:15 GMT
How can the step vary so much at the same station on the jubilee line, at Westminster for example sometimes I get on there isn't a step but at other times the step is 2cm ? Is it something to do with how the balance of the train is (if more people are more to one side) The only simple reason is that the stations were created at different time periods and were thus designed for different types of trains and thats why Westminster gap seems smaller its because that station was designed for the 1996 stock type train whereas the stations betweed Baker Street and Charing Cross didnt accommodate for wheelchair access or for the new trains likewise between Baker Street and Stanmore Beyond Finchley Road the line used to take surface stock - the Stanmore branch was originally part of the Met and I think at some times some Met trains at the limits of the working day used to call at the Finchley Road - Wembley Park section. Are any of these stations "compromise" height? |
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Post by Deleted on Jul 31, 2013 23:17:17 GMT
The only simple reason is that the stations were created at different time periods and were thus designed for different types of trains and thats why Westminster gap seems smaller its because that station was designed for the 1996 stock type train whereas the stations betweed Baker Street and Charing Cross didnt accommodate for wheelchair access or for the new trains likewise between Baker Street and Stanmore Beyond Finchley Road the line used to take surface stock - the Stanmore branch was originally part of the Met and I think at some times some Met trains at the limits of the working day used to call at the Finchley Road - Wembley Park section. Are any of these stations "compromise" height? Yes youre correct! The two track in the middle were the all stations met trains on the slow line (now Jubilee) and the current met tracks would have been semi fast trains which is evident of the platforms at neasden and Wembley park but they would have decreased the hight of the platform to 38ts level and 83 stock level and a reasonable height of 1996 stock as a majority of those stations dont have step free access |
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Post by v52gc on Aug 1, 2013 9:56:03 GMT
The two track in the middle were the all stations met trains on the slow line (now Jubilee) and the current met tracks would have been semi fast trains which is evident of the platforms at neasden and Wembley park Apologies for going OT, but just to point out when the Met went to Stanmore the northerly two tracks were the fast, and the two the locals south of these. The layouts were rearranged for the Bakerloo extension to Stanmore as we know it now They would have decreased the hight of the platform to 38ts level and 83 stock level and a reasonable height of 1996 stock as a majority of those stations dont have step free access The relavent re-used platforms during the track layout change would have had the track beds raised to decrease the platform heights. |
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rincew1nd
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Post by rincew1nd on Aug 1, 2013 17:38:16 GMT
How can the step vary so much at the same station on the jubilee line, at Westminster for example sometimes I get on there isn't a step but at other times the step is 2cm ? Is it something to do with how the balance of the train is (if more people are more to one side) The only simple reason is that the stations were created at different time periods and were thus designed for different types of trains and thats why Westminster gap seems smaller its because that station was designed for the 1996 stock type train whereas the stations betweed Baker Street and Charing Cross didnt accommodate for wheelchair access or for the new trains likewise between Baker Street and Stanmore Whilst what you are saying is not incorrect, you have not read the OP correctly. The question was "How can the step vary so much at the same station" (my underline). |
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Chris M
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Post by Chris M on Aug 1, 2013 17:45:52 GMT
At different points along a curved platform the step will vary due to track cant and possibly end/centre throw (I know this matters for the horizontal step distance but I'm not sure if it is relevant to the vertical). This isn't going to the case at Westminster JLE though. I don't think the extension stations have platform humps, although the older stations do.
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Post by Deleted on Aug 1, 2013 22:28:02 GMT
All the extensions stations are level across the whole platform.
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Post by crusty54 on Aug 2, 2013 5:02:31 GMT
All the extensions stations are level across the whole platform. But the point in the original post is that the height varies between trains at Westminster |
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Post by Deleted on Aug 2, 2013 7:13:42 GMT
I was replying to the post above, BTW it was me who started the topic anyway and it happens at all station between Green Park and Straford,
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Post by Deleted on Aug 6, 2013 13:02:22 GMT
If the train is busy, the train suspension naturally drops slightly because of the constant running and need for repair, this is why occasionally some of the RTDI's on the platforms at certain stations don't light up when some trains which are light loaded but do when it's a heavy load train, this is because the receiver for it on the track had dropped and the heavy load train drops to a point where it picks up the signal and sends the info to the platform and gives the platform signal.
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Post by 1018509 on Aug 8, 2013 12:32:06 GMT
There are so many variable in this. On the train side there is wheel size, suspension setting and car height settings, all of which are variable within acceptable tolerances; add to this the track height and passenger loading tolerances and it is not surprising that each train is at a slightly different height.
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