Post by b***@cylonHQ.comOn Sat, 16 Dec 2017 23:44:02 +0000
Post by b***@cylonHQ.comPost by b***@cylonHQ.comAnyone know why there's an overhead wire on the southbound of highbury
station
Post by b***@cylonHQ.com(and maybe others, I didn't check) on the moorgate line? Its obviously not
some
Post by b***@cylonHQ.comold catenary since the line was always 3rd/4th rail and its only hung from
the
Post by b***@cylonHQ.comceiling by some thin wires anyway. Is it in case a pan is left up at Drayton?
I believe that's the case, yes; it's not powered, it's just to stop the
pan disassembing itself on the tunnel roof. I've a vague memory that it
was put in when the line was handed over to BR.
That seemed the most likely scenario to me. Wonder how often the pan gets
left up on that line? Must happen occasionally.
Is there nothing that will force a pan drop?
One Metro-North, for example, the M2 runs dual-mode DC on 3rd rail and
AC under the wire. I assume that the same happens with the newer M8.
As soon as that train's shoes come into contact with live 3rd rail, the
pantographs automatically come down. The train will not take power,
however, until the engineer sets the power mode switch to the proper
setting.
The engineer will normally set the mode switch to DC, which also drops
the pans, though I have at times seen them coast into 3rd rail with the
pans up, and then only switch the power made when the train is out of
the wire.