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East Coast Overhead line
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tbtc
Veteran Member
My understanding is that the gaps weren't "too long", but were at the furthest possible length allowed (sorry if that looks like I'm splitting hairs!), which has caused problems.
BR's decision to do things at the bare minimum presumably saved a couple of quid at the time, but has caused significant problems over the last twenty years or so. The fact that the WCML doesn't seem to have the same problems suggests that the ECML was done on the cheap; I just don't know whether it'll be seen as a priority to "re-wire" the ECML when there are areas on the GWML/ MML that have no electrification.
Ideally I'd rip up the ECML wires and start again, but then you could say the same about Third Rail etc too - its probably not enough of a priority for the powers that be.
43106
Member
The vast majority of the OHLE on the ECML was built on the cheap on the orders of Margaret * Thatcher (insert your own obscenity at the point marked *)! She insisted that the electrification of the ECML be done as cheaply as possible, and that included the 91+82 sets. Railtrack(?) specified 34 such sets, but only got 32. The figures may not be spot-on, but they're not far off. IMO, the OHLE should be completely revamped, as it's an embarrasment - it keeps coming apart every month or so. I've been caught out twice because of it - once at Newark when it came down near a level crossing at/near Claypole, and when the train I was on ripped down about 2,500 yards of the suff near Thirsk.
captainbigun
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BR spec'd the trains and numbers.
The main issue is the headspans which, when there's a failure on any one of the lines, tend to lead to a failure across all lines. The portal structures (as seen on WCML) don't have the same issue, a failure will (generally!) only impact a single line. Everything possible has been done to ensure the ADD a) activates and b) lowers the pan as soon as possible. There had been problems in the past with the pan head becoming detached but not leading to an ADD activation as the pipework and carbons remained intact.
The main issue is the headspans which, when there's a failure on any one of the lines, tend to lead to a failure across all lines. The portal structures (as seen on WCML) don't have the same issue, a failure will (generally!) only impact a single line. Everything possible has been done to ensure the ADD a) activates and b) lowers the pan as soon as possible. There had been problems in the past with the pan head becoming detached but not leading to an ADD activation as the pipework and carbons remained intact.
Old Timer
Established Member
Jesus Christ not another one :roll: :roll: :roll: :roll:
I am struggling to find anything in your rant which is anywhere near factual. Apparantly it comes down every month but you have only been "caught out twice because of it".
Here's the deal. BEFORE I destroy your completely inaccurate rant with fact, I will give you the option to go away and research the facts and then come back with the truth. By the way as one of those who was involved in the Electrification project I rather think I know more about how it came about than you do.
ralphchadkirk
Established Member
There are cl91 + cl82 sets? Are you absolutely sure about that?
It seems you've waited a long time for this moment Old Timer!
What part were you involved with out of interest?
gordonthemoron
Established Member
was OT the BR employee who invented the tubular steel base which was used for many of the masts?
Please do tell then,i work on wcml and the ecml is classed as a laughing stock of which is neither maintainance or the installer(bicc?) fault
Old Timer
Established Member
Good afternoon, old chap.
The electrification to Peterborough came about through the hard work of a chap called Norman Howard.
He was the Head of Electrification at the BRB at the time. His idea was to push from Hitchin to Peterborough using "spare" OHL equipment from the Bedford St Pancras and the Colchester - Ipswich/Norwich Electrification schemes.
In doing so it would add weight to the case for the eventual ECML electrification certainly as far as Leeds, which was considered justifiable.
At the time when this was done the OHL Equipment used was Mk3b which was a joint BR/Balfour Beatty design. Because there was no 125mph running at that time, the equipment was designed for 100 mph EMU running and the electrical loading, distribution, feeder stations and mast spacing was set up for that criteria.
At the time this was going ahead, there was a major world recession and passenger journeys were starting to fall, thus electrifying any further or requiring any large investment was never going to get off the starting blocks at that time.
Mk3 Equipment was originally design for 75mph EMU running (GNER Inner Suburban), Mk3a was the upgrade to 90mph running for the section to Royston. Mk3b was the MML upgrade for 100mph EMU running, Mk3c was a further upgrade consisting of tensioning and contact wire changes.
MK3 was NEVER designed for 125mph running. It was also a design that was cost efficient in that it was cheaper than historic Mechanically Independent Registration (MIR) Equipment - the lineside mast/portal/gantry systems.
The longer cost was that a tension failure in the cross-span wires leads to all lines going out of registration.
About 10 years ago it was realised that the GNER system was suffering from corrosion in the Cross-span connections, due to electrical and physical changes to the structure of the fittings and in 2003/4 a programme of the replacement of the Cross-span wires was commenced, later moving onto the MML.
The extension to Peterborough was down to the hard work of one man (Norman Howard) and it is incredibly ignorant as well as highly inaccurate to suggest (as others have done - not you) that it was done on the cheap. It was not.
When 125 loco-hauled electric running on the ECML commenced, all that was done was that the Equipment on the GN Inner and Outer Suburban sections was retensioned.
The GN Outer Suburban section should have been upgraded by Railtrack/Network Rail. It was not, although like the GE both parties knew that the equipment was in need of attention.
The OHL Equipment installed on the GN Outer Suburban was fully compliant and capable for the purpose for which it was installed. It was never intended to run locomotive hauled train travelling at 125mph nor at the frequency they now are. Norman would NEVER have permitted a sub-standard installation and an awful lot of OHL professionals are very upset by comments made on this Forum.
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Old Timer
Established Member
You will have been engaged on the AWAC to copper magnesium cross-span campaign changes than I imagine ?
Yes old fellow,although headspans are not my cup of tea!
My next job is to rewire the Hendon Lines at west Hampstead thameslink.
Incidentally the Ole came down at weedon wed night,or somewhere near stowe tunnels,contenary i think
Old Timer
Established Member
There is an art to registering them, that is a fact
Whistler40145
Established Member
Please correct me, the worst sections have been at Sandy & Hitchin.
I remember whilst on a Pathfinder Spin & Win to Lincoln, we got to Peterborough @ got diverted via Ely, Cambridge & Cheshunt to Stratford with a Grid as the whole headspan came down blocking all lines @ Hitchin, job stopped!
I remember whilst on a Pathfinder Spin & Win to Lincoln, we got to Peterborough @ got diverted via Ely, Cambridge & Cheshunt to Stratford with a Grid as the whole headspan came down blocking all lines @ Hitchin, job stopped!
Thanks for that post OT very interesting indeed.
Old Timer
Established Member
All the OHL professionals would agree with you, but this has been a problem that they have raised continually for the last 10, maybe 15 years.
The trouble is that upgrading the ECML is not "sexy" and no-one in power would want to be associated with that. It is so much better for the longer term Political profile to be known as the Minister who announced the "so and so" large scheme.
Unfortunately this is precisely the problem the Railways always have when Politics become involved. One only has to look on here to see why Politicians "play to the audience". HS2 and GW Electrification are two very good examples, and I suspect that the Thameslink stock/Bombardier will be the next ?
YorkshireBear
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Very intersting, never realised it was like that. I agree about politicians annoucning ti, its never gonna happen, shame as most of us would take it as a very very good decision.
Old Timer
Established Member
Oh I did not mean to mislead you, it WILL happen at some time.
It is actually now becoming rather much of a hot potato along with the GE, unfortunately Network Rail having decimated the OHL Construction community will find itself on the back foot and something will have to give - such as the GW electrification which offers absolutely nothing that a refurbished HST cannot provide.
It was one of the things that GNER was unhappy about, and was something they were looking at along with taking on track maintenace and renewals off Railtrack/Network Rail.
Unfortunately GNER were not liked at all by Bliar or Brown, who cynically set them up to fail, despite them being the only TOC who actually paid the Treasury.
Yet even today, the ECML itself is one great opportunity to implement a form of vertically integrated management into the Railways. The trouble is the EU and its rules.
The same rules which force Ireland to act as if its national railway system was connected directly to the European network, even to the point of requiring them to follow wagon numbering conventions design for wagons travelling across Europe. Such is the administrative mind and the totally blind observance of EU diktats set out by Commissioners (not elected MEPs) who are no different than members of the Politbureau were 20 years ago.
LNW-GW Joint
Veteran Member
Very interesting debate by the oldies!
The WCML wiring is also Mk3 north of Weaver Jn isn't it?
There is headspan wiring on the 4-track sections around Warrington, Wigan and Carlisle.
This would have been designed for 110mph running I expect, in 1974.
Does it suffer the same problems as ECML outer suburban?
Maybe that's why there is no 110+ running from Acton Grange to Wigan?
Subjectively, I'd say there are more dewirements south of Rugby (in the new wiring) than north of Crewe, but no doubt somebody will know the facts.
The WCML wiring is also Mk3 north of Weaver Jn isn't it?
There is headspan wiring on the 4-track sections around Warrington, Wigan and Carlisle.
This would have been designed for 110mph running I expect, in 1974.
Does it suffer the same problems as ECML outer suburban?
Maybe that's why there is no 110+ running from Acton Grange to Wigan?
Subjectively, I'd say there are more dewirements south of Rugby (in the new wiring) than north of Crewe, but no doubt somebody will know the facts.
There was talk of shortening the span lenghts at certain places,and as i stated upgrades have been done at stevenage,hitchin,welwyn area's,to solve the problem a total upgrade would be needed,well as far as doncaster anyway.
O/T have you seen the new ole that is to be used on the north west scheme?
series 1 for 125mph....series 2 for 100mph its a mix of furrer frey and some italian company and comes pre made like on the GE's
Whistler40145
Established Member
Please correct me, at one time only single headed trains could draw power from the OHLE & if a Freightliner was double headed, then the rear loco was DIT, is this still the case, or have extra Feeder Stations been built to resolve this problem?
Old Timer
Established Member
The wiring north of Weaver Jct used a mixture of Mk1, Mk2 and Mk3 components.
The MK3 system was designed to replace the old Mk1 and Mk2 equipment and utilised lighter equipment and materials such as polymeric insulators as opposed to ceramic.
It also introduced the Headpsan as a lightweight system that would allow the quick and cheap electrification of suburban lines.
The Mk3 headpsan units on the WCML were mainly around large junctions and in station / yard areas where train speeds were pretty much reduced.
The spacing of the structures was based upon 100 mph locomotive running.
110 mph running did not happen until 1985.
The OHL Equipment along the WCML is UK1 equipment on the main/fast lines, with the older Mk1 equipment on the slow/goods lines. although at some stage this will be replaced.
UK1 was specifically designed for 125+ mph running and is much heavier equipment.
Not quite true.
The issue with double-heading was due to the contact wire "uplift" caused by the dynamic operation of two pantographs.
What happens is that as the pantograph passes through, there is an upwards force on it of about the weght of a bag of sugar. This weight is necessary to ensure that the pantograph stays in electrical/mechanical contact with the contact wire. The whole catenary system then "bounces" for a period, the height and length dependent upon the speed of the train. This means that a second pantograph will be subject to losing contact with the contact wire at high speeds. It was discovered that up to 75/80 mph it was not a problem.
The double-heading of trains on the WCML started with 4E77 1930(SX) Coatbridge FLT to Felixstowe FLT, which ran as a 30 wagon Freightliner as opposed to a maximum of 20 wagons. Double-heading was only an issue when the locomotives took power, as togther the power demand was so high that they automatically tripped the overload breakers unless power was taken slowly. They thus required a revised driving technique. Operationally the train was very restricted in where it could be looped and how it was regulated given the train services around it were also pulling power.
Of themselves the double-headed trains did not require any additional power to be feed into the OHL, it was just that they were hungry if the taps were run up too quickly.
As far as I am aware there was never any double-heading of any passenger service or any services other than dedicated Freightliner services.
There was no direct 30-wagon return service to 4E77, other than if I recall correctly 4M74 Tilbury FLT to Trafford Park, which conveyed wagons which were set out at Basford Hall into 4S52 which I think was the Felixstowe FLT to Coatbridge FLT.
F/liner wagons were sometimes like newspaper vans in that they were tripped back to origin on various services. As I recall 4E77 set down a number of wagons at Straford FLT for Tilbury FLT
4M74 was so long that it HAD to run via Northampton because the tail end of the train stood back through the Down Main/Down Goods crossover at Rugby and onto the Northampton flyover.
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Barrett M95
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This is an interesting discussion. I have a few points;
1 - The uplift force you liken to a bag of sugar. If I may assume a typical bag of sugar as 1kg, therefore a force of approx 10N - is that what you have in mind? Vehicles I have worked on have had static uplift forces of between 50N and 80N, some 5 to 8 times a typical bag of sugar. The dynamic force is different than this static case due to aerodynamic forces (many pantographs have an aerofoil) and the motion and dampening of the pan head. I wouldn't let a train into service with only 10N of pan head uplift, but of course, you are likely to have experience of different vehicles and your figure of 10N may well be accurate. I only bring the experience I have to the discussion.
2 - Not only is the uplift an issue in my experience, but the distribution of this force is not even between the leading and trailing carbon due to the effect of friction at the carbon/catenary interface and the distance to the pivot or mounting point of the pan head creating a moment that creates the force offset. This moment if often counter-acted by various means - torsion springs on some B/W pans or flat plates on the end of the horns which have an aero drag effect that opposes the friction and because they are below the pivot, they "push" the rear carbon back up again.
3 - Running units in multiple usually results in a level of compromise for the trailing pantograph(s) because of oscillation as you have indicated. The speed of 75/80mph you quote - is that based on a certain catenery (Mk2 for example)? On ECML, class 373/2 sets ran at 125mph with both pans raised however the rear pantograph was some 340m behind the leading one so is not the same as double-heading in the context of this discussion. Class 365's run at 100mph with up to 3 pans in relatively close proximity, which perhaps is more relevant. On LGV it is common for two TGV sets to run with a pan up at the rear of both sets, therefore only 200m apart at speeds up to 320km/h, however I acknowledge that this catenary is built to a different standard to UK Mk3 design.
Hydro
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I have 20N in my head for some reason, from running MENTOR. Not being primarily a MENTOR/OLE guy and basically being reduced to twiddling telemetry and making sure we didn't rip the wires down, I can't exactly remember what the 20N actually refers to. It uses a B/W high-speed pan if that helps.
Old Timer
Established Member
Firstly welcome to the site. I am sure there will be a high demand for your knowledge.
You make good points but to explain...I had tried to deliberately "dumb down" what I had written because people asked me to simplify it and make it easier for the laymen, so I had not wanted to add-in those types of factor.
Insofar as 3 is concerned, the OHL catenary wire is tensioned to the specific requirements of each line in terms of speed and number of pantographs per train. For example UK1 is tension to a higher level than even Mk3 for 125mph running.
The higher tensioning reduces the bounce caused by the passage of the pantographs, and as you say does allow trailing pans to collect power but they are not as efficient as the leading pan I believe because of the pan bounce.
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