Signalling Installation Handbook.

[Peter]

When I started installing DC track circuit pre moulded leads to the rail in 1997,the arrangment for the connection of the pre moulded leads on the tamper pin was as follows - Lead onto the pin with nothing between rail and moulded end ,then a washer and locking nut.
Now some are of the opinion that this has changed and that pre moulded leads use the same arrangment as L plate connectors which is washer and nut onto the pin,then the L plate ,then washer and locking nut

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Does anyone know the current standard for connecting a pre moulded DC t/c lead to the rail?

The installation handbook has not been updated on this, but the equipment has. We had a long discussion about this when using moulded leads with other types of track becasue there was the comment that we were not using the back nuts before putting the moulded end on the taper pins.

It appears that there was a mod to the moulding which created a recess making it possible to fit a backnut. However, what was clear was that this was never really communicated and the standards were not updated to reflect it. I was having the converstation with the excellent Mr Fortey before he retired from NR and he knew about the mod but could not cite revision to the standard.

There is a further twist here in that before the recessed version was made, in order to allow a back nut to be fitted, there was a longer version of the taper pin. This has a BRS-SE number and a PADS cat no, but is not supplied by Unipart, so making it effectively useless.

So the answer to your question is that the standard tells you to do what you have always done, but that is not the right thing to do!

Peter