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Post by Harsig on Dec 23, 2016 16:01:17 GMT
I wonder if A2550's earlier history has to do with the long, long, gone facing connection at the western end of the Farringdon platform, Outer Circle right across to the Widened lines It's very unlikely. A2250 was only installed circa 1998/9, many years (decades?) after the connection to the widened lines was removed.
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Post by Harsig on Dec 21, 2016 21:55:40 GMT
1960/61 I believe. Certainly that was when the current train described system was installed on the Met line.
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Post by Harsig on Dec 20, 2016 23:31:34 GMT
I have a couple of timetable notices for the Metropolitan Line (No. 2 section) covering the Christmas periods of 1977 and 1978. Even from one year to the next there was a noticeable reduction in the service being offered on Christmas Day. In 1977 the service operated only between Baker St and Rayners Lane. The service was half hourly between Baker St and Harrow, with alternate trains continuing on to Rayners Lane (i.e. hourly). Trains ran via the Bakerloo Line (as then was) between Wembley Park and Finchley Road, calling at all open stations. On the section of line being served Dollis Hill, Northwick Park and West Harrow were all closed. First trains were 0943 from Wembley Park to Baker St, 1002 from Rayners Lane to Baker St and 1006 from Baker St to Rayners Lane. Last trains were 1502 Rayners Lane to Baker St, 1537 Harrow to Baker St, 1602 Rayners Lane to Wembley Park, 1536 Baker St to Rayners Lane and 1605 Baker St to Wembley Park. Three trains were required for the service. The following year the service was cut back to Baker St to Harrow only. The service was still half hourly on this section, but whilst first trains were at similar times, the last trains were about an hour earlier, being the 1438 Harrow to Baker St, the 1508 Harrow to Wembley Park, the 1437 Baker St to Harrow and the 1507 Baker St to Wembley Park. Neasden and West Hampstead stations were closed in addition to the stations that had been closed the previous year. Two trains were required to provide the service.
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Post by Harsig on Dec 20, 2016 14:01:07 GMT
Just because the OS Map doesn't show any crossovers it doesn't mean there weren't any. The image below shows the arrangement at South Acton in 1907, and I imagine it was the same when the passenger service was introduced in 1905.
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Post by Harsig on Dec 20, 2016 8:52:23 GMT
Was it a permanent fault or just a 'feature' that Chesham as the destination couldn't show Not Stopping at North Harrow to Northwood, but Amersham could? It's a feature. There is only one Chesham train description available at Harrow (CM5) and this has to be used for all Chesham services regardless of whether or not the train is going to run fast or all stations. In contrast there are at least four Amersham descriptions available (AM0, AM2, AM5, AM7). The digit refers to the stopping pattern, the 5 or 7 indicating that the train is to run non stop to Moor Park from Harrow. With only one TD available for Chesham the decision had to be made as to whether it should show non stop to Moor Park (as the 5 really means) or not. Today the vast majority of Chesham services are scheduled to run all stations.
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Post by Harsig on Dec 18, 2016 20:48:31 GMT
These appeared at the "wrong" end of platforms in response to a very serious incident at Camden Town. There a driver boarded the train at the wrong end and proceeded to take the train in the wrong direction head-on towards another train. Fortunately disaster was averted that day, and this was part of the response to help ensure it doesn't happen again. Except that the incident which prompted their installation actually occurred at Kings Cross on the Piccadilly line. This was some 17 years prior to the Camden Town incident. The fixed red lights were only provided at reversing locations and since Camden Town is not a reversing location no fixed red lights were provided there under the programme of installation. The RAIB report into the Camden Town incident refers to the Kings Cross incident in paragraph 75.
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Post by Harsig on Dec 18, 2016 20:18:21 GMT
The train numbers are only a useful guide to which service the train is operating during off peak periods, which on weekdays means only between the morning and evening peaks. At other times any train number can appear on any service. The Met train descriptions split into two parts. The letters give the final destination while the digit indicates the stopping pattern e.g. fast or all stations. There have been several threads in the past that explain the meaning of each digit. districtdavesforum.co.uk/post/19331
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Post by Harsig on Dec 6, 2016 10:31:00 GMT
Although for this move the points were trailing, they are also facing points for trains leaving Platform 7. Facing points are of course required to be locked As these points were used in both directions presumably some sort of substantial mechanical lock would always be engaged, therefore the blades probably could not be moved by much, if at all, by the train as it trailed the points. It would all depend on the strength of the lock and the weight of the train. The train at Ladbroke Grove also trailed through a set of points intended for facing moves (indeed the signalling did not provide for the trailing move), and they were set for the other route. As far as I am aware the 165 was not derailed by the points. I would suggest that a number of factors combine to determine the likelihood of a derailment occurring when a train tries to force its way through a set of points locked in the other position. These factors would include train weight ( the heavier a train is the less likely a derailment is), the train speed (I suspect that a derailment is more likely at very low or very high speeds than it is at medium speeds; at low speeds because of the train's lack of momentum). The third factor, I suggest, would be the geometry of the points involved; points laid out for higher speeds may well be easier to trail through because the initial contact between wheel and switch rail is at a shallower angle.
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Post by Harsig on Oct 20, 2016 13:52:46 GMT
I wonder when the LTE came up with this philosophy? In 'London's Disused Underground Stations' by J.E. Connor, it shows pictures of the original 'Osterley' station with the live rails nearest to the platforms, a similar situation at Belmont Road, and at 'Lords' Probably about five minutes after the first time someone fell on a platform side live rail. According to Alan Jackson's 'London's Metropolitan Railway' the change was not made because of the risks to people falling onto the conductor rail from the platform, but because of the operating problems caused by other objects being dropped from platform. To quote: Such a short circuit would be a positive earth, and even today these still have the potential to cause the underground problems such as signal failures. Presumably the sort of metal objects being referred might include things like umbrellas.
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Post by Harsig on Oct 17, 2016 12:32:24 GMT
Present day working timetables are very different from those of the 1950s. To take the Met line as an example differences between the 1950s and today include: In the 1950s there was still a Met service to Aylesbury. In the 1950s southbound off peak Met services only ran as far as Baker Street. Services beyond there during the peaks ran to either Liverpool Street or Aldgate. There was still some freight traffic operating on the Met line in the 1950s.
Much the same arguments could be made about the Bakerloo service and also of course the BR services on the GC line which was then still open as a through route beyond Aylesbury.
Incidentally which part of the 1950s were you intending modelling, as the track layout at Wembley Park was substantially altered in 1954?
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Post by Harsig on Oct 16, 2016 17:57:34 GMT
I have to say that we may very well see option 4 used more often in the future when ATO lines are next upgraded. This is because ATO signalled lines have rather more trainborne signalling equipment than trains operating on a conventionally signalled line. As such considerably more work would be required to convert a train from one system to the other, and it would probably not be practicable for a train to be fitted with both systems at the same time. This makes dual fitted signalling systems a more attractive alternative.
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Post by Harsig on Oct 7, 2016 13:28:47 GMT
Its actually the same answer as your other query. districtdavesforum.co.uk/post/433222/threadThe door defect on train 56 at Gloucester Road caused a sufficiently large gap in the eastbound service that train 63 was reversed west to east at Aldgate East to fill this gap.
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Post by Harsig on Oct 4, 2016 21:53:59 GMT
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Post by Harsig on Oct 2, 2016 10:56:41 GMT
R2250 is a repeater for signal A2250 which is itself a draw up signal for the eastbound station starter A225. A2250 is located just past the crossover less than halfway along the eastbound platform.
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Post by Harsig on Oct 2, 2016 7:45:35 GMT
A & B Wembley Park
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Post by Harsig on Sept 30, 2016 4:24:46 GMT
C between West Ruislip and Ruislip Gardens
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Post by Harsig on Sept 18, 2016 16:29:39 GMT
Croxley southbound.
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Post by Harsig on Sept 13, 2016 20:38:13 GMT
OB300 was installed because OB30 had to be moved closer to the points in order for S7 trains to fit into the platform.
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Post by Harsig on Aug 28, 2016 16:27:55 GMT
Not at work at present, but the most likely scenario is a points failure at Chalfont that prevents the route being set onto or off the branch, and that requires sufficiently extensive repair work such that it cannot be carried out while trains are running to and from Amersham. Presumably in this case a service suspension to Chesham for the rest of the day is considered more desirable than a total service suspension to all destinations for an unknown period while repairs are carried out.
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Post by Harsig on Aug 15, 2016 3:36:46 GMT
Location B - Harrow On The Hill
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Post by Harsig on Aug 4, 2016 4:30:21 GMT
The anti clockwise Curcle line was running, so it can't be blamed for holding up the Met. It most certainly can be blamed. The outer rail circle services were reversed at Moorgate and Aldgate, adding to the trains on the Inner Rail. There then followed a series of crew relief problems at Edgware Road which led a queue of trains stretching back to Aldgate. Westbound trains were as much as forty five minutes late arriving at Baker Street.
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Post by Harsig on Aug 1, 2016 6:36:38 GMT
Hillingdon
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Post by Harsig on Jul 31, 2016 6:18:26 GMT
Chesham
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Post by Harsig on Jul 28, 2016 4:15:11 GMT
Between Harrow On The Hill and Northwick Park
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Post by Harsig on Jul 27, 2016 6:41:23 GMT
B Bridge over Forty Avenue north of Wembley Park
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Post by Harsig on Jul 21, 2016 8:04:33 GMT
It's Amersham station. They've raided the archive for this footage as the same shot appears in John Betjeman's film Metro-land. This was first broadcast in early 1973, and was thus presumably filmed in 1972.
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Post by Harsig on Jun 24, 2016 11:56:28 GMT
The fault was down to the flooding but when they tried to boost up the track to compensate for the dampness they found a faulty capacitor Could you explain "boost up the track", please? That's a little too technical for me. Basically it means increasing the power in the track circuit. At all times a certain amount of current leaks from one rail to the other in a track circuit via the ballast, sleepers etc. The size of this partial short circuit is determined by the ballast resistance. Generally a track circuit is set up such that, despite this leakage sufficient power reaches the relay at the far end to operate it. When there is a sudden decrease in the ballast resistance, such as might be caused by heavy rain saturating the track bed, the size of the partial short circuit may increase to the point where insufficient power reaches the relay to operate it, causing the track circuit to fail. This is got round by increasing the power in the circuit and is known as boosting the track. When the ballast resistance increases again as the track dries out, the track must be de-boosted. Failure to do so introduces a risk that the track circuit may fail to detect the presence of a train as sufficient power may still reach the relay despite the short circuit applied by the train wheels. In practice such a short circuit can never be relied upon to have a zero resistance, so some current will always flow via alternative paths such as the relay coil. Certain sections of line are more prone to track circuits requiring regular adjustments, and this depends largely on the state of track drainage. Baker Street to Finchley Road is currently one of the worst sections of line in this regard, hence the current evening closures of this section.
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Post by Harsig on May 17, 2016 6:37:49 GMT
C Preston Road Sub-station
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Post by Harsig on May 4, 2016 7:54:32 GMT
Between Dollis Hill and Neasden
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Post by Harsig on Apr 23, 2016 21:42:24 GMT
The crossover can only be used for south to north reversals. I've done this move in passenger service once. On that occasion a failure occurred at Baker St as my train was leaving Finchley Road. This is about the only scenario where being able to make the move in passenger service is useful.
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