On Wed, 6 Aug 2003 22:35:04 +0100 John wrote:
} In article , Acrosticus
} writes
} From: Matthew Malthouse
} Date: 06/08/2003 20:13 GMT Daylight Time
}
} Anyway, anyone know the nature of the damage? Overheads stretching in
} the heat? Or something more esoteric?
}
} Well, not too esoteric. The wire expands and contracts like everything else
} acccording to temperature, but it needs a certain amount of tension as well so
} that pantographs don't get round the wrong side of it and bring the lot down.
}
} On occasional OHLEs you'll see an assembly with removable weights that are
} connected to the overhead to tension it. These weights are slotted onto a bar
} and plate arrangement. If you can't get enough weights on the bar to remove the
} sag (and, after all the bar has a finite length so it'll happen some time)
} you're not tensioning the wire enough so it will sag, probably bounce as trains
} pass underneath and could allow the panto to "wrong side" it thus pulling the
} lot down.

So was the disruption precautionary or was there actually an incident?
The info sceens yesterday afternoon calimed problems at several places.

} IIRC the OLE out of Liverpool Street is pre tensioned and does not have
} the weights you mention to re tension it when it stretches. I think once
} one gets past about Gidea Park there is tensioning.

I recall tensioning weights at Forest Gate but can't at this moment
swear that they are still there - memory might well be from before the
section had the overheads renewed a few years back.

This morning most seemed back to normal although there was one
Shenfield bound service around half seven marked as canceled.

Wonder what it'll be like this afternoon.

Matthew
--
Il est important d'être un homme ou une femme en colère; le jour où nous
quitte la colère, ou le désir, c'est cuit. - Barbara

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