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Class 73 locos and AWS

Current and future British signalling (UK except Northern Ireland)

Class 73 locos and AWS

Unread postby scarpa » Sat Jun 24, 2017 3:17 pm

In the old days when Class 73 locos visited Reading failures would be reported by the traincrew of AWS indications or sometimes nothing received. The same would happen on Sundays when class 205 units travelled from Basingstoke. The AWS s are of the yellow pattern at Reading,and where this traction usually operated was on the Southern employing green AWS s.. With the introduction of TPWS was the loco AWS equipment changed. Now that Class 73 s will be used on the sleeper train services and some operate over NWR . Has the problem been eradicated?
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Re: Class 73 locos and AWS

Unread postby Romsey » Sat Jun 24, 2017 9:31 pm

As I understand things, the rebuilt class 73's have been completely stripped and rebuilt with new diesel engines, complete rewiring and completely refitted cab equipment. The only thing unaltered (allegedly) are the class number and bogies.

After that level of rebuilding I hope any AWS fault has been eradicated! ( There are a number of other problems which don't affect signalling unless the locos fail.)

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Re: Class 73 locos and AWS

Unread postby Fast Line Floyd » Sun Jun 25, 2017 8:13 pm

It wasn't a fault as such, class 73's in common with other Southern motive power had the AWS receiver mounted higher up on the bogie or chassis of the unit which demanded stronger AWS track equipment. The reason for this (IIRC) was to help prevent false AWS indications caused by the high traction currents and hence high magnetic fields that occur in cross bond cables and impedance bonds.
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