What is this track equipment?

[trainmania100]

There is a long metal plate on the centre of the sleepers
Some cable connects it to the rails like its electrfied. I'll try upload a picture. The cable/wire is connected to the rails on the inside on both rails.

I see them quite a lot. Any ideas? Thanks

 

[EM2]

That looks very much like an impedance bond, although they seem to have changed a bit since my on-track days.
They provide a return path for the traction current, but block the track circuit current to keep each circuit isolated from each other.

 

[trainmania100]

That looks very much like an impedance bond, although they seem to have changed a bit since my on-track days.
They provide a return path for the traction current, but block the track circuit current to keep each circuit isolated from each other.

I see
Thankyou for your comprehensive response a rather interesting piece of equipment

 

[edwin_m]

Indeed, you can see the insulated joints in both rails. The "spider" as it's called is a low-pass filter that passes the DC traction return but blocks the 50Hz track circuit current. Routes re-signalled in the last few decades may use jointless track circuits instead.

 

[MarkyT]

Indeed, you can see the insulated joints in both rails. The "spider" as it's called is a low-pass filter that passes the DC traction return but blocks the 50Hz track circuit current. Routes re-signalled in the last few decades may use jointless track circuits instead.

Impedence bonds are neccesary even with jointless track circuits, just in smaller numbers. They're not required at individual block boundaries, but are used for cross-bonding between parallel tracks (to help reduce total return resistance), and for connecting from the rails to the return busbar at substations. Electrified lines using axle counters for train detection by contrast require no impedence bonds, as electrical isolation between the parallel rails is not necessary, and they can be connected directly by simple bonding cables.