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Post by goldenarrow on Feb 28, 2024 9:49:14 GMT
Formalisation of the Harrow 'Hot Weather' plan, in operation until 29 September conditions permitting
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trainwizard
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Posts: 124
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Post by trainwizard on Feb 28, 2024 10:19:33 GMT
Could you explain what this means in simpler terms? Why would hot weather mean that Metropolitan services won't have access to the Main lines?
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DWS
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Post by DWS on Feb 28, 2024 10:59:08 GMT
The points are more likely to fail in the hot weather.
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Post by goldenarrow on Feb 28, 2024 11:09:18 GMT
Harrow North Junction (215 & 217 points), which links the Local and Main Lines, is one of the three sets at Harrow with moveable angles (also referred to elsewhere as switch diamonds) deemed at high risk of failure during mild/hot weather due to their age and design. To protect against this, they are not operated when the rail temperature exceeds a set threshold, with everything running "straight through" over the affected points. During those times, there is no access to/from the Main Lines for through LU trains at Harrow, with fast trains having to use Watford South Junction near Moor Park instead.
This has been the informal status quo for several years, but the periods of operation for the Harrow "Hot Weather" plan has significantly expanded in recent years to the point where a timetable notice makes operational sense.
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Post by A60stock on Feb 28, 2024 11:10:23 GMT
1. So this only occurs when the weather is too hot right? What's the threshold?
2. Why are Amersham's and Chesham's (off peak), routed through the fast lines north of Wembley but the Watford's are not? Aren't these the same service (if originally all stations services) until Moor Park? I am guessing this is because you need the use of two platforms at harrow northbound rather then routing the whole service via Platform 4.
3. With the timetable changes, will these be designed to ensure that fasts using the local lines north of Harrow are not held up by a local train ahead?
4. Points 200 (giving access to platform 1), I did not realise these points were an issue?
With the re-signalling soon due, its really about time these points were just renewed to avoid having to do this.
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Post by goldenarrow on Feb 28, 2024 12:12:21 GMT
1. Down to 27 degrees IIRC. Worth noting that this is rail temperature, not air temperature, so this regularly applies in quite mild conditions as we experience it.
2. Indeed, a 16tph Met service through a single platform is asking for trouble, as Wembley Park platform 6 is currently finding out.
3. Yes, one of the reasons for formalising what were previously ad-hoc arrangements is to minimise collateral disruption where allowances previously didn't exist.
4. If it's got movable angles, it's not moving.
There are doubtless other folks on here better qualified to talk about the sustained pressures affecting LU renewals in recent years. Suffice to say, it will be several years post-CBTC before these restrictions are relieved
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Post by xplaistow on Feb 28, 2024 15:17:09 GMT
Question: Does the SB crossover that allows trains from either plat 5 or 6 to access either the fast or local also use a movable angle and if so, why are those points not also mentioned in the TTN?
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Post by goldenarrow on Feb 28, 2024 16:37:03 GMT
Replaced during the Easter 2017 blockade with two sets of conventional points, thus completely unaffected
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Post by jimbo on Feb 28, 2024 20:40:26 GMT
Replacement has been planned for some years! August 2011 U.News; June 2015 U.News; in 2019 the northbound points south of the platforms were listed as scheduled for replacement in 2021! |
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Post by A60stock on Feb 29, 2024 9:07:07 GMT
1. Down to 27 degrees IIRC. Worth noting that this is rail temperature, not air temperature, so this regularly applies in quite mild conditions as we experience it. 2. Indeed, a 16tph Met service through a single platform is asking for trouble, as Wembley Park platform 6 is currently finding out. 3. Yes, one of the reasons for formalising what were previously ad-hoc arrangements is to minimise collateral disruption where allowances previously didn't exist. 4. If it's got movable angles, it's not moving. There are doubtless other folks on here better qualified to talk about the sustained pressures affecting LU renewals in recent years. Suffice to say, it will be several years post-CBTC before these restrictions are relieved What's the reason 16tph can't be handled at one platform at Harrow when during the off peak, Finchley Road, Wembley park, Preston road and Northwick park handle this amount through one platform just fine? |
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Post by goldenarrow on Feb 29, 2024 11:25:52 GMT
Harrow is a crew changeover point unlike the locations you mentioned and its platforms are regularly used to shuffle the service as necessary. Those dwell time factors combined with large signalling overlaps in a complex area means platform reoccupation times can be slower hence the NB split to enable continued use of both platforms
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Post by wonderwaller on Feb 29, 2024 11:33:11 GMT
Plus the am peak stablers de training at Harrow take a long time to clear to the sidings if everything was sent up the northbound local it wouldn’t take long for trains to be blocking back beyond Wembley
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Post by plunet on Mar 28, 2024 15:37:43 GMT
Customer facing email has now been dispatched from TfL towers.
Dear plunet,
From Monday 8 April until Sunday 29 September, a summer timetable will be in operation on the Metropolitan line.
Some trains to and from Amersham, Chesham and Watford, including Chiltern Railways services, will be slightly re-timed.
Between 10:30 and 21:00 fewer northbound trains towards Amersham and Chesham will stop at Northwick Park and Preston Road. If you are travelling northbound from Northwick Park and Preston Road when no through train is shown, take any Uxbridge or Watford service and change at Harrow-on-the-Hill if necessary.
To check for the revised times, visit Journey Planner.
Yours sincerely,
Customer Information Team
Transport for London
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Post by spsmiler on Mar 31, 2024 12:55:50 GMT
Formalisation of the Harrow 'Hot Weather' plan, in operation until 29 September conditions permitting I am convinced that I have travelled on northbound trains making that very move. Admittedly it was years ago. |
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Post by Dstock7080 on Mar 31, 2024 13:31:10 GMT
I am convinced that I have travelled on northbound trains making that very move. Admittedly it was years ago. Indeed, but as 200 points will not be used during the Hot Weather Plan the statement is correct, for the duration of the Timetable Notice |
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Post by A60stock on Apr 2, 2024 14:48:03 GMT
Sorry, could I just confirm, is this saying that the Harrow Hot weather plan will come into effect when the conditions are so that it is needed OR
Are we saying that this plan will be in place every day between those given times, regardless of conditions? Therefore, the Met will no longer use the fast lines AT ALL between those hours, at all, until late September? No matter the weather/temperature?
I know it says conditions permitting so suspect it is the former.
Mod edit [Dstock7080]: Quote removed. Please be selective about the part of a post you wish to quote rather than the whole post verbatim, particularly if you are replying to the previous post in the thread.
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Post by wonderwaller on Apr 2, 2024 16:41:12 GMT
The hot weather working will be in at all times between the stated times it’s much easier for everyone to have one timetable than try and switch between them depending on the weather forecast plus the trigger temperature is so ridiculously low now that it’s introduced on even fairly cool days (already implemented one day earlier in March)
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Post by tubetraveller on Apr 3, 2024 2:55:24 GMT
The trigger temperature is so low that the 'Harrow Hot Weather Plan' was even brought in several times early in the 2023 leaf fall season
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Post by A60stock on Apr 3, 2024 9:59:09 GMT
The hot weather working will be in at all times between the stated times it’s much easier for everyone to have one timetable than try and switch between them depending on the weather forecast plus the trigger temperature is so ridiculously low now that it’s introduced on even fairly cool days (already implemented one day earlier in March) Thanks, so this basically means that every single evening rush hour from now on (well sorry, 8th April), until the end of the notice, all fasts will run on the local lines between Harrow and Moor Park. Gosh I hope the re timetabling of services ensures these don't get held up behind late running stoppers. Not complaining about pretty much most Amersham and Chesham services now being Semi fast for most of the day though! Thank goodness this doesn't impact the morning rush hour, sending fasts southbound down the local lines from Moor Park to Harrow. |
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Post by Chris M on Apr 3, 2024 10:49:00 GMT
The trigger temperature seems low because the critical factor is the rail temperature, which can be significantly higher than the air temperature.
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