This is very true, but see Roger Ford in this month's Modern Railways for a very good expose of how NR have failed to take the lessons of the ECML electrification into account for the GW.
Except Network Rail and their design partners at Furrer+Frey have very definitely taken the lessons of the ECML into account. The Series 1 system is arguably over engineered, but as Roger Ford says - "too much is a good starting point" and that's very definitely true of OLE.
That's why we're installing heavier, more reliable catenary that has mechanically independent registration. It has 140mph capability even with two pantographs, fewer failure points, far fewer unique parts and can easily be adjusted to cope with switches and crossovers being added or removed, or other track layout changes.
The heavier, more robust OLE needs heavier, more robust foundations, that's why the foundations are far bigger and different in design to the ECML poured concrete foundations. They're far more resistant to in-situ rotational movement, which has been something of an issue on various parts of the ECML.
The actual components are designed to deform in a carefully controlled manner, causing as little damage to other parts of the system as is possible, but a dewirement at high speed puts a lot of force into the catenary, so having a stronger, more robust catenary will ensure less damage is done during a dewirement, and if there's less damage done, it's going to be much easier and quicker to repair.
It sounds dramatic, but all it takes is a huckbolt or fastener to be damaged during a dewirement and you've got the repair team having to cut bolts to continue with their repairs, a delay of 10 minutes on one bolt, repeated over a half dozen structures puts your repair an hour behind target, so the design of the components will hopefully make such instances much less frequent, making repairs after dewirements a quicker, easier process. We certainly hope never to see the sort of 2 and 3 days of disruption that a dewirement on the ECML can cause.
The whole design, for reliability and ease of repair has demanded more modern tensioning arrangements, and the removal of the slightly absurd situation where tensioning on a four track railway has the tail wires from the central pair of tracks crossing over the outside pair of tracks to reach their tensioners. That's resulted in over track tensioning, which requires much more substantial portal structures, but in return, reliability should be much improved.
The Great Western is going to have the gold standard for railway electrification in the UK when it's finished, and it'll go almost completely un-noticed - nobody is going to stop and sing its praises because there are so few dewirements, or when a rare dewirement causes just one track to be closed and services can operate with only a few minutes delay - because that's what a good quality OLE system should be capable of providing. I feel a little ashamed that we've become content in some quarters to accept just small improvements over the abomination that is the British Rail Mark 3 overhead line system. We are capable (with a bit of Swiss help) of doing something much better, and thankfully we're doing it.
