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Manchester Piccadilly OHLE question.


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26 minutes ago, The Stationmaster said:

Two questions I think -

1. Were short contact wire insulators available at that time? 

2. If a pan went past an insulator without damaging either itself or the insulator what happened next?  Presumably as the contact wire rose to terminate on a gantry the pan would also rise and hit the gantry (which might also be carrying - albeit insulated - 25kv  overhead) and might leave part of the pan to carry on into the territory of the other voltage. 

 

 

1. Yes, the original heavy type not the fibreglass and bead type.

2. The contact wire does not rise to a gantry until its out of running, ie beyond the crossover. The whole point of wiring the crossover is to make sure that an accidental erroneous routing does not rip the pan off and/or bring the OLE down.

Damage should then be limited to the specific train's electrics.

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I do seem to recall one of the batch of EM1 withdrawn around the time passenger services were withdrawn had damage to its high voltage equipment (and seen a photo of it too in one of the woodhead books).

 

Might be adding 2 and 2 together and making 6 but could have been a result of this platform mix up.

 

(PS theres a great image of a EM2 backing onto or leaving a train at midland junction ending on Ebay today, no connection to said sale but its the first image Ive seen of that operation taking place)

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Thinking about the possibilities of a 1500V DC loco or EMU crossing over to the AC lines there would have to be some huge errors, human ones.

 

First a signalman directing a train into the wrong platform. OK someone forgot to inform him the late running diesel hauled train has a sparkie pulling it so he signaled it to its normal platform, a possibility but number two thing going through my mind hopefully will come it play.

 

Second drivers have route knowledge, so if the suspect a signal is indicating it is sending them the wrong way surely they would stop the train and question the signalman, especially if the route indicator was suggesting they should drive their DC loco under the AC lines. Now back to our electric loco rescuing our failed diesel, the electric loco driver should know he is driving an electric. If the train driver had taken over the electric loco he would realise the controls that look like they came out of Frankenstein's laboratory were not the state of the art controls of a Type 3 and was driving a loco with a coat-hanger on the roof. On realising he was going the wrong way the driver would be slamming the brakes on so hard the facing passengers would launched into the laps of the rear facing passengers.

 

So we need an unattentive signalman and a clueless driver working the same shift.

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3 hours ago, Grovenor said:

1. Yes, the original heavy type not the fibreglass and bead type.

2. The contact wire does not rise to a gantry until its out of running, ie beyond the crossover. The whole point of wiring the crossover is to make sure that an accidental erroneous routing does not rip the pan off and/or bring the OLE down.

Damage should then be limited to the specific train's electrics.

However that damage could be fairly terminal for 1500V traction running into 25kV.  

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On 30/06/2021 at 13:24, Zomboid said:

Switched sections of OLE do exist, though not in the UK. I believe Aachen has some platforms which can be energised at different voltages, but quite how the control system for that works I've no idea.

The RhB has switchable sections in the stations where the Bernina and Albula/Inn Valley lines meet, at Pontesrina and at St Moritz. The Bernina line is 1,000V DC whilst the rest of the RhB network is 11kV AC at 16 2/3Hz.

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3 hours ago, Grovenor said:

1. Yes, the original heavy type not the fibreglass and bead type.

2. The contact wire does not rise to a gantry until its out of running, ie beyond the crossover. The whole point of wiring the crossover is to make sure that an accidental erroneous routing does not rip the pan off and/or bring the OLE down.

Damage should then be limited to the specific train's electrics.

So the pan will still go over-height and hit something - probably the gantry (unless 25kv catenary intervenes first).  In such a short distance immediately the contact wire rises the pan will start to go over-height and it will extend to or near its mechanical maximum before auto lower cuts in.  And that most likely means it will foul the structure and that is normally precisely what happens - and the pan hits something.

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On 30/06/2021 at 14:20, Michael Hodgson said:

We have been switching trains from 25kV overhead to third rail DC at Drayton Park for nearly half a century though and Thameslink has been doing it too. Rather easier to control the risks I think.

And on the North London Line at Acton where 3rd rail takes over for the remainder of the journey to Richmond. Also on the West London Line for the Southern services from the WCML through to the south of the Thames via Clapham Junction.

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On 30/06/2021 at 15:54, The Stationmaster said:

Another method, at passing stations, is used in a different way - quite spectacularly - by multi-current locos on non-stop trains .  They lower the pan as they approach drawing power from one system and then raise the other pan once they are under the other  system.  All done a full line speed with a bit of arcing to add to the amusement for onlookers.

I believe that happens in France where the LGV system, and many parts of the main lines are energised at 25kV, but parts of the local lines used by the TGV services to reach their final destinations are still energised at, IIRC, 2,500V. 

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Posted (edited)
9 minutes ago, GoingUnderground said:

I believe that happens in France where the LGV system, and many parts of the main lines are energised at 25kV, but parts of the local lines used by the TGV services to reach their final destinations are still energised at, IIRC, 2,500V. 

Look back at my post ofvThursday 1/7 on page 2, which shows exactly that, it's 1,500 DC on the classic lines.

 

Jamie

Edited by jamie92208
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1 minute ago, jamie92208 said:

Look back at my post a few days ago, which shows exactly that, it'1,500 DC on the classic lines.

 

Jamie

Thank you for the correction on the voltage. I was working from memory.

 

That's one of the problems of linear access, one responds to posts as one reads through the topic before seeing if anyone else has replied to that point on subsequent posts that you've still to read. 

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7 minutes ago, GoingUnderground said:

I believe that happens in France where the LGV system, and many parts of the main lines are energised at 25kV, but parts of the local lines used by the TGV services to reach their final destinations are still energised at, IIRC, 2,500V. 

 

Its all down to when the lines were electrified!

 

Generally speaking those in the south and south east of France were done between the 1920s the end of the 1950s. Within that time frame 25KV AC wasn't an option as the technology for on board rectification from AC to DC (traction motors were always DC up until the early 1990s) so the 1500V DC 'standard' was used.

 

Post 1960s electrification was done to 25KV AC as reliable on board rectifiers were possible but just as BR retained the 3rd rail system post 1960 - so it was the French saw no need to waste valuable capital going round changing the huge amount of 1500V DC OLE which already existed. This meant there were a large number of places across France were you had 1500V DC meeting 25KV AC and required many electric locos to come equipped as dual voltage machines as well as come up with solutions for switching between them including stations (typically done by having one end of the platform at one voltage  and the other end at the other with incoming locos dropping one pantograph as it entered the platform and the raising the other when it came to a halt at the far end.

 

 

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On 03/07/2021 at 10:04, jamie92208 said:

That would make a lot of sense. On the photos the insulators on the DC lines all appear to be hefty enough for 25Kv.

 

Jamie

 

I wonder if the DC OLE was upgraded at the same time as AC electrification? 

The DC electrification that was carried out when Tinsley yard was opened  had insulators that would have been suitable for 25kv if it had been upgraded 

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2 hours ago, Clive Mortimore said:

Thinking about the possibilities of a 1500V DC loco or EMU crossing over to the AC lines there would have to be some huge errors, human ones.

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So we need an unattentive signalman and a clueless driver working the same shift.

 

Also perhaps a Controller omission too.....

 

When the only electrified route west from Edinburgh Waverley was the Carstairs road, the two lines through the centre Mound Tunnel were not wired. One morning a Virgin XC departure, booked diesel traction, was electrically hauled instead. The NR Controller did not advise the Signaller who routed it as booked through the centre tunnel, the Driver took the road and the loco promptly became dewired, causing huge disruption and delay. All the holes in the Swiss cheese were aligned that day !

 

One question I have not seen asked is why London Road/Piccadilly would actually need six 1500v DC platforms, given that the only such trains were the half-hourly Hadfield EMUs and the hourly Sheffields.  Two platforms could have coped with that, although three or four were certainly preferable for operational flexibility.

 

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18 minutes ago, russ p said:

 

I wonder if the DC OLE was upgraded at the same time as AC electrification? 

The DC electrification that was carried out when Tinsley yard was opened  had insulators that would have been suitable for 25kv if it had been upgraded 

Certainly the bulk of it wasn't altered and retained the 1500v insulators to the end.  The Glossop Hadfield sectipn was changed over by putting new insulators on. I think that the actual wiring was left in situ.

 

Jamie

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There seem to be relatively few photos around of EM2s in Manchester London Road alongside AC locos.

 

These are the only ones that I could find on the web, but then perhaps my search criteria aren't specific/exact enough. But I'm sure that you'll all find lots more photos of EM2s and AC electrics and prove me wrong.

 

spacer.png 

 

spacer.png

This last one shows 27005 Minerva who was cannibalised in the Netherlands to keep the other 6 running after they were sold to NS. Also, judging by the position of the lamp in the left foreground, 27005 would appear to be in platform 4 which would put E3051 in platform 5. 

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Posted (edited)
1 hour ago, dave75 said:

Would anyone care to describe the shades of blue in that first picture on the Mk2 coach, AC loco and DC loco? 

I think that the AC loco is in what was called  Electric Blue and the coach in Rail Blue which was darker.

 

Jamie

Edited by jamie92208
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1 hour ago, jamie92208 said:

Certainly the bulk of it wasn't altered and retained the 1500v insulators to the end.  The Glossop Hadfield sectipn was changed over by putting new insulators on. I think that the actual wiring was left in situ.

 

Jamie

The gantries/portals certainly remained unchanged despite the higher voltage, with that distinctive "Y" bracket, also seen on the Liverpool St-Shenfield line, and the 1500V lines in Belgium and The Netherlands.

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3 hours ago, caradoc said:

 

Also perhaps a Controller omission too.....

 

When the only electrified route west from Edinburgh Waverley was the Carstairs road, the two lines through the centre Mound Tunnel were not wired. One morning a Virgin XC departure, booked diesel traction, was electrically hauled instead. The NR Controller did not advise the Signaller who routed it as booked through the centre tunnel, the Driver took the road and the loco promptly became dewired, causing huge disruption and delay. All the holes in the Swiss cheese were aligned that day !

 

One question I have not seen asked is why London Road/Piccadilly would actually need six 1500v DC platforms, given that the only such trains were the half-hourly Hadfield EMUs and the hourly Sheffields.  Two platforms could have coped with that, although three or four were certainly preferable for operational flexibility.

 

Hi Caradoc

 

I did think of control as well but surely they don't make mistakes, after all they are in control.

 

In the scenario I suggested of a DC loco rescuing a failed diesel, wouldn't/shouldn't control advise the signalman to route the train into a DC wired platform? Wouldn't/shouldn't the signalman question what type of motive power has replaced the dead diesel on the delayed train? 

Wouldn't/shouldn't the driver with his knowledge be looking out for being correctly routed to an appropriate platform and prepared to stop if not.

 

With your example we have a non-commutative controller, an un-attentive signalman and a clueless driver working the same shift. Oh (please use your own non RMweb word) !!!!!!

 

Things like this only happen in the real world.

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3 hours ago, jamie92208 said:

I think that the AC loco is in what was called  Electric Blue and the coach in Rail Blue which was darker.

 

Jamie

Is the DC Loco in "Reddish blue"? 

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4 hours ago, jamie92208 said:

 

I wonder if the DC OLE was upgraded at the same time as AC electrification? 

The DC electrification that was carried out when Tinsley yard was opened  had insulators that would have been suitable for 25kv if it had been upgraded 

It was between the terminus and Ardwick, the station was rebuilt and the 1500v gantries which only covered the ex-lner lines were replaced with the portals we see today. 

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8 hours ago, dave75 said:

I do seem to recall one of the batch of EM1 withdrawn around the time passenger services were withdrawn had damage to its high voltage equipment (and seen a photo of it too in one of the woodhead books).

 

Might be adding 2 and 2 together and making 6 but could have been a result of this platform mix up.

 

(PS theres a great image of a EM2 backing onto or leaving a train at midland junction ending on Ebay today, no connection to said sale but its the first image Ive seen of that operation taking place)

Do you have an EBAY link for that please.

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Posted (edited)
1 hour ago, dave75 said:

Is the DC Loco in "Reddish blue"? 


AFAIK the EM1s were overhauled at Crewe after Gorton closed and were repainted in rail blue (as per the as built colour of the AL6 locos from 1965). However the repaints were given the second British Railways logo (as used, say on most of the class 47s as built in two tone green), until the new British Rail logo began to be used by BR works in 1966. 76022 still had this livery, including the old logo, up to closure in the early 80s but with full yellow ends. I would have thought the EM2s which were repainted blue went though this same process (but that may be too much of an assumption)? 

Edited by MidlandRed
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8 hours ago, The Stationmaster said:

So the pan will still go over-height and hit something - probably the gantry (unless 25kv catenary intervenes first).  In such a short distance immediately the contact wire rises the pan will start to go over-height and it will extend to or near its mechanical maximum before auto lower cuts in.  And that most likely means it will foul the structure and that is normally precisely what happens - and the pan hits something.

How does the pan go overheight when its running under the contact wire? That's the whole point of wiring the crossover!

 

PS I'm 90% certain that the DC pans did not have overheight trips to auto lower, and I don't think the early AC ones did either, someone may know the date when such sophistication was introduced.

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17 hours ago, caradoc said:

 

One question I have not seen asked is why London Road/Piccadilly would actually need six 1500v DC platforms, given that the only such trains were the half-hourly Hadfield EMUs and the hourly Sheffields.  Two platforms could have coped with that, although three or four were certainly preferable for operational flexibility.

 

Trains to Marple, Hayfield, New Mills, and via High Lane to Macclesfield, etc., also used those platforms. Trains to New Mills and Rose Hill Marple still do, as well as TPE "expresses"

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