scope:

This specification applies to air cooled impedance bonds for use on lines having d.c. electric traction at 600 to 1500 volts.

The bonds shall have a continuous rating of:-

Type 2 2400 amps d.c. per bond

Type 3 3000 amps d.c. per bond

The bonds shall be suitable for use as follows:-

On 50 Hz double rail track circuits in either the resonated or auto-coupled mode when tuned with a capacitor to BR Specification 1649.

On audio frequency track circuits, in the resonated mode when tuned with a capacitor tuning unit to BR specification 1669.

Bonds offered for specific applications, eg for use with one type of track circuit, shall be accepted solely at the discretion of the Engineer.