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Post by Deleted on Oct 3, 2017 19:16:04 GMT
Isn't the current fashion to remove turnback and refuge points...eg Mansion House, Holborn? Not sure it is fashion but there is an intent to remove a few sidings for example as part of the SSR upgrade as part of the balance between improving headways for hundreds of regular trains a day against the disbenefit of not being able to use a siding for a few trains when the service goes up the wall. Some of the decisions are a bit marginal but if the location isn't a scheduled reversing point it is often hard to make a business case to retain it. |
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Post by superteacher on Oct 3, 2017 19:24:47 GMT
Isn't the current fashion to remove turnback and refuge points...eg Mansion House, Holborn? Not sure it is fashion but there is an intent to remove a few sidings for example as part of the SSR upgrade as part of the balance between improving headways for hundreds of regular trains a day against the disbenefit of not being able to use a siding for a few trains when the service goes up the wall. Some of the decisions are a bit marginal but if the location isn't a scheduled reversing point it is often hard to make a business case to retain it. It's just annoying when a business case is prioritised over operational convenience. But that's the way of the world nowadays I suppose. |
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Post by Deleted on Oct 3, 2017 20:25:53 GMT
Not sure it is fashion but there is an intent to remove a few sidings for example as part of the SSR upgrade as part of the balance between improving headways for hundreds of regular trains a day against the disbenefit of not being able to use a siding for a few trains when the service goes up the wall. Some of the decisions are a bit marginal but if the location isn't a scheduled reversing point it is often hard to make a business case to retain it. It's just annoying when a business case is prioritised over operational convenience. But that's the way of the world nowadays I suppose. I'm not saying this is always the right approach but the business case could go like this (and I am not a business case expert). 500 trips a day save 5 seconds per passenger for an average 800 passengers per train x the value of time that LU calculates for a passenger. That adds up to quite a big number. My maths is terrible but I make that about £1m a year. Bigger still if this is the one site that is constraining headways for a whole line. Compare that with a slightly quicker recovery for a small number of trains on a small number of occasions a year when a failure occurs. Operational convenience can have a real cost to the scheduled service on a line. Obviously if the removal of the facility makes no difference to the run time or headway then it is only maintenance cost vs operational benefit. The other factor that is considered is the risk of an asset failing. If it doesn't exist it can't fail. As an example, the points on the Jubilee at Waterloo are very useful but they were in past years very unreliable and probably caused more problems than they helped to solve. Somebody like snoggle could, i'm sure, come up with a better example of a business case. |
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Post by rheostar on Oct 4, 2017 9:35:42 GMT
The Picc has suffered from having two superdepots located some way from the platforms, an error of judgement which has only recently been (partially) rectified. A decade and a half of chronic blocking back through Arnos and Acton during disruption was the legacy of the person who decided to create the two superdepots. You're right, the two superdepots on the Picc have caused problems ever since they opened. At the time though, LU was under pressure to improve conditions for T/Ops. The T/Op's accommodation at Wood Green was in a dingy room opposite the escalators, with the Duty Managers around the corner in a room off the eastbound platform. Oakwood was better, with the T/Ops being in a mess room on one side of the stairs and the DMs on the other, although it needed some serious refurbishment. Acton Town and Northfields depots weren't quite so bad, but a superdepot was built to fit in with the concept. However, the main advantage of these four locations was that they were very close to the railway. A spare driver could be on a late running train in under 30 seconds, if that. Now, at both Arnos and Acton, a spare driver's seven minutes walk away. I'm not too familiar with the build of Acton depot, but I know a little about Arnos Grove. At Arnos Grove, it was decided that a new depot would be built on the unused ground to the north of the sidings. At the time, some of us said that the depot would be in the wrong place and too far from the railway. We were told quite bluntly that if we didn't like it we could always go somewhere else. The build was beset with problems from an early stage. The original design had used girders of a certain length being delivered on standard size lorries. Unfortunately, on the first delivery of the girders they found that the lorries couldn't go around the 90 degree turn at the top of the building site. The old signal cabin and IMR are on one side, with residents back gardens on the other, so nothing could be moved. The whole building had to be redesigned using smaller girders that could be delivered on smaller lorries. In consequence, the costs soared and it opened about a year later than originally planned. Once the depots opened, to their horror the powers that be realised that the T/Ops duties had become less efficient with increased walking times for picking up their trains. Remote booking on had to be introduced at Oakwood as the T/Ops were based at Arnos, but the trains were in Cockfosters depot. I could go on, but for the Piccadilly line the two superdepots have been a disaster. It's made service recovery so much harder, with the resulting blocking back into both Acton and Arnos. |
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