|
|
Post by paterson00 on Jul 8, 2009 22:49:27 GMT
I have come from overground where we had four, three and two aspect signalling. It looks like Lul only has two aspects is that true?
|
|
Ben
fotopic... whats that?
Posts: 4,282 
|
Post by Ben on Jul 8, 2009 23:12:26 GMT
Historically it deffinitely isn't. The Met had three aspect signals. The vic and central have three aspect signals because of ATO.
|
|
|
|
Post by 21146 on Jul 8, 2009 23:22:53 GMT
Historically it deffinitely isn't. The Met had three aspect signals. The vic and central have three aspect signals because of ATO. And 4-aspect on Met |
|
mrfs42
71E25683904T 172E6538094T
Big Hair Day
Posts: 5,922
|
Post by mrfs42 on Jul 8, 2009 23:24:05 GMT
True - standard 2-aspect 'metro' signalling: clickety click . When you have a standard range of stock with guaranteed stopping (trainstops), you only need 'stop', 'go' and 'get ready to stop'. The white aspect on the ATO lines means 'if you are an automatic train you can follow the previous train more closely than a manually-driven one'. NR needs D/H/HH aspects because of the standardised overlap (183m), no guaranteed braking [1] and the differing braking rates of mixed stock working - eg. DMU vs EMU vs HST vs MGR. Closely spaced 2-aspect signalling with constant train lengths can handle a greater density of traffic than 4 aspect signalling. [1] disregarding TSS/OSS loops.  |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 9, 2009 11:07:03 GMT
Historically it deffinitely isn't. The Met had three aspect signals. The vic and central have three aspect signals because of ATO. And 4-aspect on Met The Met still has 4 aspect signalling. And of course the District and Bakerloo inter-run with Network Rail in areas with 3 aspect signalling. |
|
Ben
fotopic... whats that?
Posts: 4,282
|
Post by Ben on Jul 9, 2009 11:54:22 GMT
Well I wish I had included that in my first post now!! God knows why I didnt; I used the line every day for ten years... Anyone want to share my humble pie? Theres quite a bit of it... This explains it as consisely as one would require: www.anorakheaven.com/signalling-1.htm |
|
|
|
Post by happybunny on Jul 9, 2009 14:19:21 GMT
Some other lines have a few 3 aspect signaling, i.e. the Jubilee has a few 3 aspect signals in the Stratford - Canning Town areas. There is also the odd 3 aspect on other LUL lines but quite rare, and usually operate as a draw-up.
|
|
mrfs42
71E25683904T 172E6538094T
Big Hair Day
Posts: 5,922
|
Post by mrfs42 on Jul 9, 2009 14:43:37 GMT
Some other lines have a few 3 aspect signaling, i.e. the Jubilee has a few 3 aspect signals in the Stratford - Canning Town areas. I think [1] those are quite rare being combined headway splitters/approach signals. IIRC there are 4 that are 'mixed' numbers, rather than (number plus)00 plates. [1] well, I'm guessing really!! |
|
|
|
Post by railtechnician on Aug 13, 2009 5:20:03 GMT
Some other lines have a few 3 aspect signaling, i.e. the Jubilee has a few 3 aspect signals in the Stratford - Canning Town areas. There is also the odd 3 aspect on other LUL lines but quite rare, and usually operate as a draw-up. Baker Street platform 5 springs to mind for a three aspect draw up approach mid platform. I also recollect something odd at Arnos Grove where eastbound 2 aspect signals work as auto or semi-auto, PJ3/500 & PJ4/600 and of course the westbound platform has 3 aspect PJ320 |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Aug 13, 2009 13:03:45 GMT
If the Jubilee Line ever goes TBTC look out for Blue signals at the boundary area of the new system.
Originally expected to be at Westminster but now in doubt as the project is woefully behind schedule.
New "migration" boundary are expected to be at Dollis Hill.
|
|
mrfs42
71E25683904T 172E6538094T
Big Hair Day
Posts: 5,922
|
Post by mrfs42 on Aug 13, 2009 14:17:14 GMT
Are they actually 'signals' as such - or are they indicators? Blue is often used as a indication these days. Presumably blue is being used as they are a standard colour with WESTLED signals?
Are these complemetary to the testing stage where the TBTC is acually 'in control' rather than being passive?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Aug 13, 2009 20:07:39 GMT
The Met still has 4 aspect signalling. And of course the District and Bakerloo inter-run with Network Rail in areas with 3 aspect signalling. The Met has 4 aspect signals and fog repeaters, so would that make it 5 aspect signalling I wonder. |
|
|
|
Post by d7666 on Aug 14, 2009 18:38:12 GMT
Are they actually 'signals' as such - or are they indicators? Blue is often used as a indication these days. That is a good question ... and one that i was never able to get a satisfactory answer to. One can argue an RGI is a signal and one can argue it is an indicator. There are two sides to the argument, and I am sure train operators or signal operators or. signals technicians or signals engineers could all come up with valid arguments to support or deny each way of looking at them. I am not sure about specifically those reported to be for Dollis Hill, but in general where they exist IIMU they are permanently part of TBTC. Stratford depot with have [or already has in place] such signals / indicators (delete as applicable) on the relevant roads leading to the start of TBTC controlled running lines - SMD itself will not be TBTC. These devices were described in the TBTC training I have already done, and I believe they are in the T/Ops training. I *assume* (1) there must be a similar arrangement at both Neasden and Wembley Park for Neasden depot access. The stabling sidings used by Jubilee trains lie outside TBTC and - IIRC - there are TBTC entry points in the ''throats'' of the north and south end fans. The Neasden south headshunt, the one that runs partially behind the southbound Neasden station Met. line platform is set up with TBTC loops but is an area that is [or was planned to be] a TBTC test loop for dealing with local on board train faults. (1) I say assume [dangerous things assumptions] because I am not sure if a train - or rather the T/Op - in these locations will need to see some kind of visual TBTC indication in addtion to conventional signals in the depot area and crossing Met. lines. (I am thinking here the need for an indication that the T/Op might need to know if TBTC ahead is functioning even though they are not actually under TBTC departing the depot area.) -- Nick |
|
North End
Beneath Newington Causeway
Posts: 1,769
|
Post by North End on Aug 14, 2009 21:11:53 GMT
That is a good question ... and one that i was never able to get a satisfactory answer to. One can argue an RGI is a signal and one can argue it is an indicator. There are two sides to the argument, and I am sure train operators or signal operators or. signals technicians or signals engineers could all come up with valid arguments to support or deny each way of looking at them. In operating terms, none of the above matters at all. The procedures for dealing with an RGI are described in the Rule Book, and this is what staff should work to. |
|
mrfs42
71E25683904T 172E6538094T
Big Hair Day
Posts: 5,922
|
Post by mrfs42 on Aug 14, 2009 23:49:11 GMT
Indeed, but the drafting of a rule book makes quite critical distinctions between a signal and an indicator. I know, because I've had a hand in writing several rule books! That's why I asked the question......
|
|
|
|
Post by paterson00 on Nov 26, 2009 4:37:38 GMT
True - standard 2-aspect 'metro' signalling: clickety click . NR needs D/H/HH aspects because of the standardised overlap (183m), no guaranteed braking [1] and the differing braking rates of mixed stock working - eg. DMU vs EMU vs HST vs MGR. quote] MGR? |
|
|
|
Post by norbitonflyer on Nov 26, 2009 7:38:16 GMT
True - standard 2-aspect 'metro' signalling: clickety click . NR needs D/H/HH aspects because of the standardised overlap (183m), no guaranteed braking [1] and the differing braking rates of mixed stock working - eg. DMU vs EMU vs HST vs MGR. MGR? Merry go round: bulk freight trains (usually coal, but iron ore has been done too) loaded and unloaded on the move. Locomotives must, of course, be fitted with SSC* The only passenger service I can think of which worked on that principle was the "Never Stop" at the British Empire exhibition in Wembley in 1924, although you could think of an escalator as such. * slow speed control |
|
