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Bakerloo Line beyond Harrow & Wealdstone
In article
, D7666 writes I'm probably wrong but I thought mirrors are an aid to driver to see guard but DOO needs CCTV ? DOO requires a clear view of the entire side of the train. This can be done through mirrors, CCTV, or a combination. -- Clive D.W. Feather | Home: Tel: +44 20 8495 6138 (work) | Web: http://www.davros.org Fax: +44 870 051 9937 | Work: Please reply to the Reply-To address, which is: |
Bakerloo Line beyond Harrow & Wealdstone
In article
, Neil Williams writes Might it be easier to fit CCTV to the train rather than the platform? You still need to fit the cameras and the wiring. All it saves is the cost of the monitors, but at the expense of a transmission system. The Northern and Central Lines have this, but that's mostly because there's no room to retro-fit the monitors in tube stations. -- Clive D.W. Feather | Home: Tel: +44 20 8495 6138 (work) | Web: http://www.davros.org Fax: +44 870 051 9937 | Work: Please reply to the Reply-To address, which is: |
Bakerloo Line beyond Harrow & Wealdstone
In article , Steve Fitzgerald
] writes Traction current is fed at +420v (positive) on the outside rails and - 210v on the centre rail (negative) the sum of these giving a traction feed of 630v dc. They are 'loosely' tied to earth through resistances in the sub stations that feed the supply. Despite being an electrician in a previous life and now a driver, I struggle to get my head round 'loosely tied to earth' and what it means in real life. There are resistors (I've seen various figures between 1 ohm and a few hundred ohms) connecting the power rails to earth. Because they are in a 2:1 ratio, in the absence of anything odd going on you get a small current flowing through those resistors and thus a potential divider. For example: +----- +ve{630V supply}-ve -----| | | Outer Centre rail rail | | |----[210ohm]---+---[105ohm]----| | | | | Ground In the idle state, there will be 630V across the pair of resistors which add up to 315 ohms, meaning 2 amps will flow through them. Since the central tap is grounded, the outer rail will be at +420V relative to ground and the centre rail at +210V. Suppose that something shorts the centre rail to ground, bridging out the 105 ohm resistor. We now have: +----- +ve{630V supply}-ve -----| | | Outer Centre rail rail | | |----[210ohm]---+---------------| | | (short) | | Ground The centre rail is at ground potential and the outer rail is at 630V because of the power supply. 3A now flows through the resistor. If, instead, we short the outer rail to ground, a similar change happens. Finally, what happens if some strange event causes a 210V potential between the outer rail and ground? We get: +----- +ve{630V supply}-ve -----| | | Outer Centre rail rail | | |----[210ohm]---+---[105ohm]----| | | | |----{210V}-----| | | | Ground The difference between the 210V and the 630V supply means that the centre rail will spring to -420V relative to ground. There will be a 1A flow through the 210 ohm resistor and a 4A flow through the 105V resistor. In other words, the resistors keep the rails at the +420V/-210V position *unless* something else happens to alter this. Hence "loosely tied". But at all times (absent a major short) the two rails are 630V apart. -- Clive D.W. Feather | Home: Tel: +44 20 8495 6138 (work) | Web: http://www.davros.org Fax: +44 870 051 9937 | Work: Please reply to the Reply-To address, which is: |
Bakerloo Line beyond Harrow & Wealdstone
On Tue, 2 Dec 2008 07:49:35 +0000, "Clive D. W. Feather"
wrote: In article , Steve Fitzgerald ] writes Traction current is fed at +420v (positive) on the outside rails and - 210v on the centre rail (negative) the sum of these giving a traction feed of 630v dc. They are 'loosely' tied to earth through resistances in the sub stations that feed the supply. Despite being an electrician in a previous life and now a driver, I struggle to get my head round 'loosely tied to earth' and what it means in real life. There are resistors (I've seen various figures between 1 ohm and a few hundred ohms) connecting the power rails to earth. Because they are in a 2:1 ratio, in the absence of anything odd going on you get a small current flowing through those resistors and thus a potential divider. For example: +----- +ve{630V supply}-ve -----| | | Outer Centre rail rail | | |----[210ohm]---+---[105ohm]----| | | | | Ground In the idle state, there will be 630V across the pair of resistors which add up to 315 ohms, meaning 2 amps will flow through them. Since the central tap is grounded, the outer rail will be at +420V relative to ground and the centre rail at +210V. Suppose that something shorts the centre rail to ground, bridging out the 105 ohm resistor. We now have: +----- +ve{630V supply}-ve -----| | | Outer Centre rail rail | | |----[210ohm]---+---------------| | | (short) | | Ground The centre rail is at ground potential and the outer rail is at 630V because of the power supply. 3A now flows through the resistor. If, instead, we short the outer rail to ground, a similar change happens. Finally, what happens if some strange event causes a 210V potential between the outer rail and ground? We get: +----- +ve{630V supply}-ve -----| | | Outer Centre rail rail | | |----[210ohm]---+---[105ohm]----| | | | |----{210V}-----| | | | Ground The difference between the 210V and the 630V supply means that the centre rail will spring to -420V relative to ground. There will be a 1A flow through the 210 ohm resistor and a 4A flow through the 105V resistor. In other words, the resistors keep the rails at the +420V/-210V position *unless* something else happens to alter this. Hence "loosely tied". But at all times (absent a major short) the two rails are 630V apart. They can be both at the same potential if there is a break between one conductor rail feed and the substation (or only one of the pair of switches feeding from the next section is closed) and you have a train in section. There will be no voltage between the rails but they will definitely be alive, leaving a trap for anyone who ignores the standard "do not touch any rail" warnings, |
Bakerloo Line beyond Harrow & Wealdstone
On Dec 2, 6:55*am, "Clive D. W. Feather" cl...@on-the-
train.demon.co.uk wrote: In article , Neil Williams writes Might it be easier to fit CCTV to the train rather than the platform? You still need to fit the cameras and the wiring. All it saves is the cost of the monitors, but at the expense of a transmission system. The Northern and Central Lines have this, but that's mostly because there's no room to retro-fit the monitors in tube stations. But don't the Electrostars have the cameras on the train, so there is no transmission system needed, other than feeds into the train's own systems. You can see the cameras down the side of the train in this image: http://www.railfaneurope.net/pix/gb/...377-432-mt.jpg The Northern and Central lines are more complex of course, there probably isn't space for cameras on the side of the cars. |
Bakerloo Line beyond Harrow & Wealdstone
On Dec 2, 6:55 am, "Clive D. W. Feather" cl...@on-the-
train.demon.co.uk wrote: You still need to fit the cameras and the wiring. All it saves is the cost of the monitors, but at the expense of a transmission system. The Northern and Central Lines have this, but that's mostly because there's no room to retro-fit the monitors in tube stations. Jubilee Lines stock does as well. -- Nick |
Bakerloo Line beyond Harrow & Wealdstone
On Dec 2, 6:53 am, "Clive D. W. Feather" cl...@on-the-
train.demon.co.uk wrote: D7666 writes I'm probably wrong but I thought mirrors are an aid to driver to see guard but DOO needs CCTV ? DOO requires a clear view of the entire side of the train. This can be done through mirrors, CCTV, or a combination. Thinking more on this since I made that comment perhaps my involvement with underground infrastructure has confused me ... perhaps we have a CCTV requirement that national railways do not. -- Nick |
Bakerloo Line beyond Harrow & Wealdstone
On Nov 30, 4:47 am, Charles Ellson wrote:
relays drop out causing an alarm; reset up to three times in succession before someone is sent Nope. Respond at first alarm with an emergency fault. At least thats how we do it on ''my'' bit of underground infrastructure. -- Nick |
Bakerloo Line beyond Harrow & Wealdstone
On Tue, 2 Dec 2008 13:17:18 -0800 (PST), D7666
wrote: On Nov 30, 4:47 am, Charles Ellson wrote: relays drop out causing an alarm; reset up to three times in succession before someone is sent Nope. Well, it's been a few years since someone demonstrated the process to me. Respond at first alarm with an emergency fault. At least thats how we do it on ''my'' bit of underground infrastructure. The same procedure for both unreproducable trips and persistent trips? |
Bakerloo Line beyond Harrow & Wealdstone
"Clive D. W. Feather" wrote in message
... In article , Neil Williams writes Might it be easier to fit CCTV to the train rather than the platform? You still need to fit the cameras and the wiring. All it saves is the cost of the monitors, but at the expense of a transmission system. The Northern and Central Lines have this, but that's mostly because there's no room to retro-fit the monitors in tube stations. Less infrastructure and less cost? |
Bakerloo Line beyond Harrow & Wealdstone
"Andy" wrote in message
... But don't the Electrostars have the cameras on the train, so there is no transmission system needed, other than feeds into the train's own systems. You can see the cameras down the side of the train in this image: http://www.railfaneurope.net/pix/gb/...377-432-mt.jpg The Northern and Central lines are more complex of course, there probably isn't space for cameras on the side of the cars. But technology can allow for smaller cameras and easier installation, can't it? Retractable mirrors can also be an option in some places, though granted they might not be effective everywhere on LUL. |
Bakerloo Line beyond Harrow & Wealdstone
"D7666" wrote in message
... On Nov 30, 4:47 am, Charles Ellson wrote: relays drop out causing an alarm; reset up to three times in succession before someone is sent Nope. Respond at first alarm with an emergency fault. At least thats how we do it on ''my'' bit of underground infrastructure. -- Perhaps there is a risk that something happened, and people might be on or around the tracks? You don't want to accidentally fry them. |
Bakerloo Line beyond Harrow & Wealdstone
On Wed, 3 Dec 2008 00:19:41 -0000, wrote:
"D7666" wrote in message ... On Nov 30, 4:47 am, Charles Ellson wrote: relays drop out causing an alarm; reset up to three times in succession before someone is sent Nope. Respond at first alarm with an emergency fault. At least thats how we do it on ''my'' bit of underground infrastructure. -- Perhaps there is a risk that something happened, and people might be on or around the tracks? You don't want to accidentally fry them. Going back to the ancient version that I experienced, the "reset up to X times before sending someone out" was to allow for transient faults caused by wind-blown metallic debris, flowing/pouring water etc. There should not be anyone on the tracks unless train crew have let them out after taking appropriate measures which would include application of a SCD; this should result in immediate re-tripping when it is attempted to reset the supply breaker rather than the delayed tripping which might be caused by debris or dangling bits of train. AFAIR (this was before radio was in use) evacuation was allowed to take place as immediately as necessary in the absence of communications after X seconds had passed since the application of the SCD to give time for the "reset X times then leave the power off and investigate" procedure to be achieved; otherwise if communication was available and/or there was no immediate need to evacuate then things proceeded as required/appropriate. |
Bakerloo Line beyond Harrow & Wealdstone
On Dec 3, 12:17*am, wrote:
"Andy" wrote in message ... But don't the Electrostars have the cameras on the train, so there is no transmission system needed, other than feeds into the train's own systems. You can see the cameras down the side of the train in this image: http://www.railfaneurope.net/pix/gb/...377-432-mt.jpg The Northern and Central lines are more complex of course, there probably isn't space for cameras on the side of the cars. But technology can allow for smaller cameras and easier installation, can't it? Sure, but they still have to pertrude from the side of the train in order to cover the doors etc. My understanding is that the current Northern and Central line tube stock is a very tight fit to the loading gauge in a few places and even a couple of millimeters would be too much extra for trains to run safely at line speed. Retractable mirrors can also be an option in some places, though granted they might not be effective everywhere on LUL. |
Bakerloo Line beyond Harrow & Wealdstone
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Bakerloo Line beyond Harrow & Wealdstone
"Peter Campbell Smith" wrote I was involved in specifying the video transmission system for the Central Line, and the rationale given at the time was that they wanted (or maybe were required) to allow the driver to see the images after moving off. This RAIB report explains why. http://www.raib.gov.uk/cms_resources...g_Broadway.pdf In this case, the train operator was apparently too concerned about checking signal aspects (he'd been involved in a previous SPAD) that he didn't notice in the monitor that the passenger was being dragged along the platform. Peter |
Bakerloo Line beyond Harrow & Wealdstone
On Dec 2, 9:55 pm, Charles Ellson wrote:
On Tue, 2 Dec 2008 13:17:18 -0800 (PST), D7666 wrote: On Nov 30, 4:47 am, Charles Ellson wrote: relays drop out causing an alarm; reset up to three times in succession before someone is sent Nope. Well, it's been a few years since someone demonstrated the process to me. Respond at first alarm with an emergency fault. At least thats how we do it on ''my'' bit of underground infrastructure. The same procedure for both unreproducable trips and persistent trips? Maybe we are at cross purposes here. I thought you were talking about earth faults - as in ''fully neggy earth'' or ''full pozzy earth'' as they like to say - not traction trips. Earth faults of the nature I was referring to usually don't cause traction trips or if they do they are usually single events. These earth faults are indicated the line *service* control room. They are responded to at first event as experience suggests they are generally caused by debris that needs shifting, sometimes by a very recently deceased mammal, or sometimes by a cracked pot (no not an anorak on the line) in which case the quick fix is smash the pot right out of it and sort it out in engineering hours. Traction trips yes, I agree, they re-close the breakers a couple of times - maybe it is the three you wrote - before investigating - thats done by the *power* control room. Moving faults i.e. caused by a train defect make interesting work - power control room has no indication of trains. -- Nick |
Bakerloo Line beyond Harrow & Wealdstone
"Peter Campbell Smith" wrote in message
... Andy wrote in news:2f81c2b5-8894-48a0-a547- : On Dec 2, 6:55 am, "Clive D. W. Feather" cl...@on-the- train.demon.co.uk wrote: The Northern and Central Lines have this, but that's mostly because there's no room to retro-fit the monitors in tube stations. I was involved in specifying the video transmission system for the Central Line, and the rationale given at the time was that they wanted (or maybe were required) to allow the driver to see the images after moving off. Hamburg also has an on-board system for platform monitoring. |
Bakerloo Line beyond Harrow & Wealdstone
In article , Charles Ellson
writes In other words, the resistors keep the rails at the +420V/-210V position *unless* something else happens to alter this. Hence "loosely tied". But at all times (absent a major short) the two rails are 630V apart. They can be both at the same potential if there is a break between one conductor rail feed and the substation (or only one of the pair of switches feeding from the next section is closed) and you have a train in section. Or if the feed is broken upstream of the resistors. Good point that I'd overlooked. Thanks. -- Clive D.W. Feather | Home: Tel: +44 20 8495 6138 (work) | Web: http://www.davros.org Fax: +44 870 051 9937 | Work: Please reply to the Reply-To address, which is: |
Bakerloo Line beyond Harrow & Wealdstone
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Bakerloo Line beyond Harrow & Wealdstone
On Wed, 3 Dec 2008 12:57:10 -0000, wrote:
Hamburg also has an on-board system for platform monitoring. Indeed. It was the introduction of this on the S-Bahn in 2000 (the U-Bahn had had it for years, though not at all stations) that finally did away with the charming old tungsten-lit pre-war EMUs. Neil -- Neil Williams Put my first name before the at to reply. |
Bakerloo Line beyond Harrow & Wealdstone
On Tue, 2 Dec 2008 13:03:35 -0800 (PST), D7666 wrote:
I'm probably wrong but I thought mirrors are an aid to driver to see guard but DOO needs CCTV ? DOO requires a clear view of the entire side of the train. This can be done through mirrors, CCTV, or a combination. Thinking more on this since I made that comment perhaps my involvement with underground infrastructure has confused me ... perhaps we have a CCTV requirement that national railways do not. IIRC, the NR platforms at Harrow-on-the-Hill only have mirrors. The north/westbound NR platform is occasionally used by Amersham-bound LU trains. |
Bakerloo Line beyond Harrow & Wealdstone
On Wed, 17 Dec 2008 22:00:51 +0000, asdf
wrote: On Tue, 2 Dec 2008 13:03:35 -0800 (PST), D7666 wrote: I'm probably wrong but I thought mirrors are an aid to driver to see guard but DOO needs CCTV ? DOO requires a clear view of the entire side of the train. This can be done through mirrors, CCTV, or a combination. Thinking more on this since I made that comment perhaps my involvement with underground infrastructure has confused me ... perhaps we have a CCTV requirement that national railways do not. IIRC, the NR platforms at Harrow-on-the-Hill only have mirrors. The north/westbound NR platform is occasionally used by Amersham-bound LU trains. Do they stop there these days? When I lived in Harrow it was the through line for trains that didn't stop. There was the famous occasion when the signalman thought the Master Cutler was a Uxbridge fast and routed it down the line to West Harrow. I never did find out how they got it back on the main line. |
Bakerloo Line beyond Harrow & Wealdstone
On Dec 17, 10:13*pm, Christopher A. Lee wrote:
On Wed, 17 Dec 2008 22:00:51 +0000, asdf wrote: On Tue, 2 Dec 2008 13:03:35 -0800 (PST), D7666 wrote: I'm probably wrong but I thought mirrors are an aid to driver to see guard but DOO needs CCTV ? DOO requires a clear view of the entire side of the train. This can be done through mirrors, CCTV, or a combination. Thinking more on this since I made that comment perhaps my involvement with underground infrastructure has confused me ... perhaps we have a CCTV requirement that national railways do not. IIRC, the NR platforms at Harrow-on-the-Hill only have mirrors. The north/westbound NR platform is occasionally used by Amersham-bound LU trains. Do they stop there these days? When I lived in Harrow it was the through line for trains that didn't stop. There was the famous occasion when the signalman thought the Master Cutler was a Uxbridge fast and routed it down the line to West Harrow. I never did find out how they got it back on the main line. Don't all LU trains stop at Harrow on the Hill? Last time I got an Amersham-bound LU train I was slightly surprised that it used platform 1 at HoTH, which I expected to be used mainly by Chiltern when they stopped. However, it had stopped at Wembley Park in platform 1 as well, where I got on (still requiring a crossover to get to platform 1 at HoTH). I put both down to changed patterns in the many years since I had been that way before. Firstly, you now get fast plus Wembley Park (where stopping at Wembley Park used to be only done by the extra stopping Amershams that ran on Sundays) and secondly, all Metropolitans seemed to cross after HoTH rather than before. It does make sense to group Chiltern and LU fast Amershams in the same platform though. |
Bakerloo Line beyond Harrow & Wealdstone
On Dec 18, 12:19*am, MIG wrote:
On Dec 17, 10:13*pm, Christopher A. Lee wrote: On Wed, 17 Dec 2008 22:00:51 +0000, asdf wrote: On Tue, 2 Dec 2008 13:03:35 -0800 (PST), D7666 wrote: I'm probably wrong but I thought mirrors are an aid to driver to see guard but DOO needs CCTV ? DOO requires a clear view of the entire side of the train. This can be done through mirrors, CCTV, or a combination. Thinking more on this since I made that comment perhaps my involvement with underground infrastructure has confused me ... perhaps we have a CCTV requirement that national railways do not. IIRC, the NR platforms at Harrow-on-the-Hill only have mirrors. The north/westbound NR platform is occasionally used by Amersham-bound LU trains. Do they stop there these days? When I lived in Harrow it was the through line for trains that didn't stop. There was the famous occasion when the signalman thought the Master Cutler was a Uxbridge fast and routed it down the line to West Harrow. I never did find out how they got it back on the main line. Don't all LU trains stop at Harrow on the Hill? *Last time I got an Amersham-bound LU train I was slightly surprised that it used platform 1 at HoTH, which I expected to be used mainly by Chiltern when they stopped. *However, it had stopped at Wembley Park in platform 1 as well, where I got on (still requiring a crossover to get to platform 1 at HoTH). I put both down to changed patterns in the many years since I had been that way before. *Firstly, you now get fast plus Wembley Park (where stopping at Wembley Park used to be only done by the extra stopping Amershams that ran on Sundays) and secondly, all Metropolitans seemed to cross after HoTH rather than before. *It does make sense to group Chiltern and LU fast Amershams in the same platform though. Northbound platforming at HotH is normally Plat 1 for Chiltern, 3 for Watford or Amersham and 4 for Uxbridge. During the peak there are several occasions when a NB Amersham and a NB Watford are due at Harrow at the same time. These are the northbound Amersham trains that will generally use Platform 1. I've still not quite worked out the rationale behind the Wembley Park stops during the peak, as the pattern seems a bit inconsistent for the 'fast' services. It might have to do with crewe changes though. |
Bakerloo Line beyond Harrow & Wealdstone
On Wed, 17 Dec 2008 16:19:03 -0800 (PST), MIG
wrote: On Dec 17, 10:13*pm, Christopher A. Lee wrote: On Wed, 17 Dec 2008 22:00:51 +0000, asdf wrote: On Tue, 2 Dec 2008 13:03:35 -0800 (PST), D7666 wrote: I'm probably wrong but I thought mirrors are an aid to driver to see guard but DOO needs CCTV ? DOO requires a clear view of the entire side of the train. This can be done through mirrors, CCTV, or a combination. Thinking more on this since I made that comment perhaps my involvement with underground infrastructure has confused me ... perhaps we have a CCTV requirement that national railways do not. IIRC, the NR platforms at Harrow-on-the-Hill only have mirrors. The north/westbound NR platform is occasionally used by Amersham-bound LU trains. Do they stop there these days? When I lived in Harrow it was the through line for trains that didn't stop. There was the famous occasion when the signalman thought the Master Cutler was a Uxbridge fast and routed it down the line to West Harrow. I never did find out how they got it back on the main line. Don't all LU trains stop at Harrow on the Hill? Last time I got an Amersham-bound LU train I was slightly surprised that it used platform 1 at HoTH, which I expected to be used mainly by Chiltern when they stopped. However, it had stopped at Wembley Park in platform 1 as well, where I got on (still requiring a crossover to get to platform 1 at HoTH). Not when I lived there. Fast Uxbridge trains were non-stop from Finchley Road to Rayner's Lane, and fast Aylesbury (later Amersham) were non-stop from Finchley Road to Moor Park (AFAIR) or perhaps Rickmansworth. There was a curve from the down BR main line to West Harrow instead of using the flyunder. I put both down to changed patterns in the many years since I had been that way before. Firstly, you now get fast plus Wembley Park (where stopping at Wembley Park used to be only done by the extra stopping Amershams that ran on Sundays) and secondly, all Metropolitans seemed to cross after HoTH rather than before. It does make sense to group Chiltern and LU fast Amershams in the same platform though. |
Bakerloo Line beyond Harrow & Wealdstone
On Dec 18, 1:12*am, Christopher A. Lee wrote:
On Wed, 17 Dec 2008 16:19:03 -0800 (PST), MIG wrote: On Dec 17, 10:13*pm, Christopher A. Lee wrote: On Wed, 17 Dec 2008 22:00:51 +0000, asdf wrote: On Tue, 2 Dec 2008 13:03:35 -0800 (PST), D7666 wrote: I'm probably wrong but I thought mirrors are an aid to driver to see guard but DOO needs CCTV ? DOO requires a clear view of the entire side of the train. This can be done through mirrors, CCTV, or a combination. Thinking more on this since I made that comment perhaps my involvement with underground infrastructure has confused me ... perhaps we have a CCTV requirement that national railways do not. IIRC, the NR platforms at Harrow-on-the-Hill only have mirrors. The north/westbound NR platform is occasionally used by Amersham-bound LU trains. Do they stop there these days? When I lived in Harrow it was the through line for trains that didn't stop. There was the famous occasion when the signalman thought the Master Cutler was a Uxbridge fast and routed it down the line to West Harrow. I never did find out how they got it back on the main line. Don't all LU trains stop at Harrow on the Hill? *Last time I got an Amersham-bound LU train I was slightly surprised that it used platform 1 at HoTH, which I expected to be used mainly by Chiltern when they stopped. *However, it had stopped at Wembley Park in platform 1 as well, where I got on (still requiring a crossover to get to platform 1 at HoTH). Not when I lived there. Fast Uxbridge trains were non-stop from Finchley Road to Rayner's Lane, and fast Aylesbury (later Amersham) were non-stop from Finchley Road to Moor Park (AFAIR) or perhaps Rickmansworth. There was a curve from the down BR main line to West Harrow instead of using the flyunder. When was that taken out? I don't remember that one at all. I expect the patterns I remember would be from going that way a lot in the late 1970s. |
Bakerloo Line beyond Harrow & Wealdstone
On Dec 18, 1:01*am, Andy wrote:
On Dec 18, 12:19*am, MIG wrote: On Dec 17, 10:13*pm, Christopher A. Lee wrote: On Wed, 17 Dec 2008 22:00:51 +0000, asdf wrote: On Tue, 2 Dec 2008 13:03:35 -0800 (PST), D7666 wrote: I'm probably wrong but I thought mirrors are an aid to driver to see guard but DOO needs CCTV ? DOO requires a clear view of the entire side of the train. This can be done through mirrors, CCTV, or a combination. Thinking more on this since I made that comment perhaps my involvement with underground infrastructure has confused me ... perhaps we have a CCTV requirement that national railways do not. IIRC, the NR platforms at Harrow-on-the-Hill only have mirrors. The north/westbound NR platform is occasionally used by Amersham-bound LU trains. Do they stop there these days? When I lived in Harrow it was the through line for trains that didn't stop. There was the famous occasion when the signalman thought the Master Cutler was a Uxbridge fast and routed it down the line to West Harrow.. I never did find out how they got it back on the main line. Don't all LU trains stop at Harrow on the Hill? *Last time I got an Amersham-bound LU train I was slightly surprised that it used platform 1 at HoTH, which I expected to be used mainly by Chiltern when they stopped. *However, it had stopped at Wembley Park in platform 1 as well, where I got on (still requiring a crossover to get to platform 1 at HoTH). I put both down to changed patterns in the many years since I had been that way before. *Firstly, you now get fast plus Wembley Park (where stopping at Wembley Park used to be only done by the extra stopping Amershams that ran on Sundays) and secondly, all Metropolitans seemed to cross after HoTH rather than before. *It does make sense to group Chiltern and LU fast Amershams in the same platform though. Northbound platforming at HotH is normally Plat 1 for Chiltern, 3 for Watford or Amersham and 4 for Uxbridge. During the peak there are several occasions when a NB Amersham and a NB Watford are due at Harrow at the same time. These are the northbound Amersham trains that will generally use Platform 1. I've still not quite worked out the rationale behind the Wembley Park stops during the peak, as the pattern seems a bit inconsistent for the 'fast' services. It might have to do with crewe changes though. Whoops, that should read 'It might have to do with crew changes' ;) |
Bakerloo Line beyond Harrow & Wealdstone
On Dec 18, 1:01 am, Andy wrote:
I've still not quite worked out the rationale behind the Wembley Park stops during the peak, as the pattern seems a bit inconsistent AIUI it is related to Met. - Jubilee interchanging with Wembley Park relieving Finchley Road. If all passengers requiring interchange had to do this at Finchley Road dwell times of both lines would increase and/or platform overcrowding would occur at FIR. Yes I am aware there are both busier and less well laid out interchanges - but if there a way to provide some relief where possible it is better to do so for all round journey flexibility. -- Nick |
Bakerloo Line beyond Harrow & Wealdstone
On Dec 18, 10:45*am, wrote:
On Dec 18, 1:01 am, Andy wrote: I've still not quite worked out the rationale behind the Wembley Park stops during the peak, as the pattern seems a bit inconsistent AIUI it is related to Met. - Jubilee interchanging with Wembley Park relieving Finchley Road. If all passengers requiring interchange had to do this at Finchley Road dwell times of both lines would increase and/or platform overcrowding would occur at FIR. Yes I am aware there are both busier and less well laid out interchanges - but if there a way to provide some relief where possible it is better to do so for all round journey flexibility. I understand this for the trains on the 'slow' lines at Wembley Park, but these all stop anyway. What I can't work out is why only some of the trains on the 'fast' lines are timetabled to stop. Surely very few passengers would choose to change at Wembley Park to / from these trains (if heading in the same direction, i.e. NB to NB) as it would involve using the footbridge instead of a cross-platform change at Finchley Road. |
Bakerloo Line beyond Harrow & Wealdstone
On Dec 18, 2:12 pm, Andy wrote:
What I can't work out is why only some of the trains on the 'fast' lines are timetabled to stop. Apart from suggesting thats the only way to get enough platform capacity I don't know. I will look at a Met. WTT and/or try and find out more. -- Nick |
Bakerloo Line beyond Harrow & Wealdstone
On Thu, 18 Dec 2008 00:36:22 -0800 (PST), MIG
wrote: On Dec 18, 1:12*am, Christopher A. Lee wrote: On Wed, 17 Dec 2008 16:19:03 -0800 (PST), MIG wrote: On Dec 17, 10:13*pm, Christopher A. Lee wrote: On Wed, 17 Dec 2008 22:00:51 +0000, asdf wrote: On Tue, 2 Dec 2008 13:03:35 -0800 (PST), D7666 wrote: I'm probably wrong but I thought mirrors are an aid to driver to see guard but DOO needs CCTV ? DOO requires a clear view of the entire side of the train. This can be done through mirrors, CCTV, or a combination. Thinking more on this since I made that comment perhaps my involvement with underground infrastructure has confused me ... perhaps we have a CCTV requirement that national railways do not. IIRC, the NR platforms at Harrow-on-the-Hill only have mirrors. The north/westbound NR platform is occasionally used by Amersham-bound LU trains. Do they stop there these days? When I lived in Harrow it was the through line for trains that didn't stop. There was the famous occasion when the signalman thought the Master Cutler was a Uxbridge fast and routed it down the line to West Harrow. I never did find out how they got it back on the main line. Don't all LU trains stop at Harrow on the Hill? *Last time I got an Amersham-bound LU train I was slightly surprised that it used platform 1 at HoTH, which I expected to be used mainly by Chiltern when they stopped. *However, it had stopped at Wembley Park in platform 1 as well, where I got on (still requiring a crossover to get to platform 1 at HoTH). Not when I lived there. Fast Uxbridge trains were non-stop from Finchley Road to Rayner's Lane, and fast Aylesbury (later Amersham) were non-stop from Finchley Road to Moor Park (AFAIR) or perhaps Rickmansworth. There was a curve from the down BR main line to West Harrow instead of using the flyunder. When was that taken out? I don't remember that one at all. I expect the patterns I remember would be from going that way a lot in the late 1970s. I don't know. I grew up there and moved away in the 1970s. |
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