Deleted
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Post by Deleted on May 23, 2005 15:41:13 GMT
Hi There!
I have obtained a copy of Set Working Book 11,
which corresponds with WTT 112, issued from 6 / 12 / 1982. Looking through it some of the running times seem very short, while frequencies were a lot wider at the time.
For example a Wimbledon - Edgware Rd takes around 4 mins less than in a more recent edition, and some of the layovers are dramatically shorter. Also Upminster - Richmond is generally 10 minutes shorter, while layover is quite similar. Looking through the book there are some quite surprising arrangements, especially at peak times.
I was wondering to myself if the use of guards at the time made all these differences possible, and as to speed of the service, is there much difference between Crew Op - OPO?
Also what was late running like in those days compared to now? I dare say if that timetable was in use now Controllers would be pulling their hair out!
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Post by trainopd78 on May 23, 2005 18:02:58 GMT
In my experience, it depended on which driver/guard you were paired with. ;D I find I can be as efficient as any crewed train whilst driving OPO. Others need to take more time depending on driving style/ experience or personal preference. There are however a number of other factors: The first one is frequency. Where there are less trains, you are less likely to be slowed down by a train in front, the junctions were under less pressure, so overall it took less time for the journey. The second one is obviously usage. When that wtt was issued, the underground was experiencing some of the lowest passenger usage in the Undergrounds history. Once the travelcard was introduced in 1984?, usage soared and of course more passengers take longer to load and is the main reason why frequncies have increased so much. We have got to the other extreme now where we are carrying record numbers of passengers. More passengers = longer dwell times The third is of course infrastucture. As far as the District is concerned, We now have more permanent speed restrictions than ever before, with more being added as I type. Most junctions from one line to another on the District are now enforced at 15 - 20mph, even those with high speed points.  with many others added to cover the infraco's rear end. Also signal installations have been added to remove any "compromised overlaps" which of course also add time to the journey. Some of these have involved tweaks to the WTT recently to take these into account. Hope that gives you a quick insight, although there are no doubt plenty of other reasons too. The layover times have increased to improve reliability. The more trains on the road, the higher the knock on effect of any incident whether it be a passenger alarm, signal failure or whatever. So now we run a higher level of service, a larger turn round is given, so if for example you are running 10 minutes late and you have 13 minutes to layover, you can be turned and be pretty much on time for your return trip. The customer doesn't lose a train to the extreme of the line due to there being no necessity to short trip, and generally everyone is happy.  |
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Post by citysig on May 23, 2005 19:05:12 GMT
Believe it or not, up until quite recently many lines were actually timetabled pretty unrealistically. There were numerous areas where there simply wasn't enough time in the timetable. The reason most of it stayed on time was mainly down to good driving/crewing, and a good dose of luck.
Until the District's WTT130, the timetable was short by 3.5 minutes between Earl's Court and Whitechapel - and we are talking clear run, normal line speeds etc.
Until the Circles were given 56 minutes in the mid 1990s, 50 minutes was the booked time to go round - with not much more during the peaks. The average trip (again, clear run, off peak) was actually more like 51.5 minutes if all dwell times were taken as booked. Though (and I think I've mentioned this elsewhere) I have seen a Circle or two do trips in under 45 minutes. Not sure how many punters were picked up along the way!!
During recent years, computerised models have meant lots of small changes to all timetables. They no longer demand tight layovers or tight timings to achieve 5 minute services. Now the emphasis is on "relaxed" layovers using additional trains and "realistic" timings, to achieve a mainly 4-8 or 3-6 minute off-peak headway along each line. They have finally realised you can only squeeze so much blood out of your stone ;D
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Tom
Administrator
Signalfel?
Posts: 4,196 
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Post by Tom on May 23, 2005 22:00:50 GMT
During recent years, computerised models have meant lots of small changes to all timetables. And lots of calls from the computer simulation man about White City it would seem as well... |
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Post by trainopd78 on May 24, 2005 6:15:49 GMT
Believe it or not, up until quite recently many lines were actually timetabled pretty unrealistically. There were numerous areas where there simply wasn't enough time in the timetable. The reason most of it stayed on time was mainly down to good driving/crewing, and a good dose of luck. Until the District's WTT130, the timetable was short by 3.5 minutes between Earl's Court and Whitechapel - and we are talking clear run, normal line speeds etc. You are spot on there!! I think it was WTT 129 that was our first realistic timetable. Under the older WTT's, If I got a completely clear run picking up on time at ECT, then I could make it to UPM around 1 minute late. This was a clear run, no red signals anywhere and nobody holding the doors open ect and obeying all the speed restrictions. Westbound on the opposite direction of things, we could still arrive at ECT 2 minutes early with a clear run. Sadly unless you were running in the traffic extremes, a clear run was unlikely, and if you arrived at UPM 10 late we were having a good day. Thankfully, with our more recent timetables, we now have something we can adhere to with no trouble and regularly hit UPM on book. |
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with many others added to cover the infraco's rear end. Also signal installations have been added to remove any "compromised overlaps" which of course also add time to the journey. Some of these have involved tweaks to the WTT recently to take these into account.
