edwin_m
Veteran Member
It would depend on the detail of the bridge in question. There would have to be some clearance on the Cardiff one, enough for the wire to be set at the minimum pantograph working height and far enough from the roof of a train to avoid arcing. Possibly this clearance existed already (GWR had a slightly bigger loading gauge than other companies) or could be created by moderate lowering of the track.I've just read August's "Modern Railways" report of the 2018 Railway Industry Innovation Awards. The Small Scale Business Project award reported on page 63 made my lower jaw drop. The preamble says the award "recognises innovations which may not figure large on the national stage but are still worthwhile initiatives that deserve to be recognised."
The text reads:
"The winning entry here concerned an innovative solution for electrification of the railway beneath the Cardiff Intersection Bridge, where the Queen Street lines cross the Great Western main line east of Cardiff Central station […] this particular bridge has very low clearances and could have cost as much as £50 million to rebuild […] Consultancy firm Andromeda Engineering worked with Network Rail for a radical new solution to resolve this problem, which cost less than £1 million and caused minimal disruption […] This saw a coating applied to the underside of the bridge to insulate it from the wires on the main line."
Am I missing something, or could this mean that (say) the line into Wigan Wallgate could be electrified by the simple expedient of painting the underside of the road bridge instead of demolishing half the town and taking a lifetime to get the OK to do it then a few years to do it at huge cost?
I have just pinched myself, I am awake, I haven't had a drink and I've re-read it three times. Worramimissing?
PS: "may not figure large on the national stage but are still worthwhile initiatives" ?! Couldn't this change the future of electrification?
PPS: here's a shot I took of the said bridge in 2013. Not a trivial structure:
https://www.flickr.com/photos/127646831@N03/15579576553/in/album-72157656353108448/
We don't know what the exact clearance is at Wallgate. Also it has a platform immediately after, which may make track lowering more difficult and definitely raises the thorny question of minimum wire height at the platform, constrained by the maximum gradient the wire can take when coming out from under the bridge. The platform at Cardiff is at least 400m from the bridge so plenty of room to slope the wire up in between.