MadMac
Member
Much talk about the Forth Bridge and wires, but how would the traction return path work? It’s axle counters because track circuits won’t work on the metal deck, so how will it get a return?
If you look at Street View images you can see that the OHLE was able to be naturally fit in on the lighting structures. https://goo.gl/maps/PEet8bErPWV7gJu2A
Unfortunately, the designers of the Tay Bridge didn't think to include any.
With AC there's no corrosion from stray current, so as far as I can see they can probably just let it find its way through the rails or structure.Much talk about the Forth Bridge and wires, but how would the traction return path work? It’s axle counters because track circuits won’t work on the metal deck, so how will it get a return?
Thanks for the correction, and that even more makes the point that they weren't changing the esthetics of the bride by stringing up OHLE as would be the case with the Forth and Tay bridges.Slight nuance.. but weren't those gantry structures actually designed for DC OHLE right from the start? There used to be two pairs of lines when the bridge opened, one either side of the bridge and both sets of gantries remain today as per the photo.
Much talk about the Forth Bridge and wires, but how would the traction return path work? It’s axle counters because track circuits won’t work on the metal deck, so how will it get a return?
Doesn't an AC trickle actually provide some protection against corrosion?Both bridges in an estuarine environment salt laden exposed to elements which accelerate corrosion hence regular painting and inspection. DC is very bad for corrosion AC not so.
Oh electrification o’er the silvr’y Tay
Wi fiendish storm and tempest blast a’ the way
How the wires would tremble and sway
If the Series 1 components they did give way
The Forth Road Bridge can't (easily or cheaply) take train tracks - suspension bridges have significant issues with train tracks and I don't really know if the Forth Road Bridge is structurally designed or capable of withstanding the specific loads imparted by trains.
There was some study done involving an option of putting trams on the Forth Road Bridge; https://www.transport.gov.scot/media/24880/j10568b.pdf appears to be it looking quickly. The rough conclusion was, IIRC, a single-track tram line is viable.
Yeah, I have a similar memory of something along those lines, but that was the only thing I could find looking quickly! I do remember both conclusions, but I have no memory about relative recency.Oh yes, I'd forgotten about that, and is it really that old. I think there's something more recent or more detailed from Arup/others which settled on two tracks situated tight to the central reservation to balance out load and/or to protect the trams a bit more from high winds.
Heavens, it only seems like yesterday we were all laughing about the planning application SNAFU for the toll plaza for the Forth Road Bridge...