Tread brakes

[37057]

I don’t know if this is the reason on the 345, but a lot of trains have unbraked end axles because these are the two axles which enable the speed to be measured.

What will happen is the WSP system will vent brake pressure from an axle to get a true speed reference in times of poor adhesion. This is only for a short period of time and will be braked in normal circumstances.

Can't speak for every type of train but I doubt there'll be an unbaked axle at all times.

 

[AM9]

... Can't speak for every type of train but I doubt there'll be an unbaked axle at all times.

- especially in the summer!

 

[TRAX]

Can't speak for every type of train but I doubt there'll be an unbaked axle at all times.

I can’t speak for every type of train either, but there are trains with fully unbraked (end) axles.

 

[edwin_m]

Yes. I believe that 158's are fitted with discs and treads. (the treads were retrofitted later after their first autumn in Yorkshire resulted in 156 158 hybrid sets being formed.)

I seem to recall the treads are on the outer bogies only, and they were originally on 159s only but spread to 158s later.

 

[hexagon789]

Yes. I believe that 158's are fitted with discs and treads. (the treads were retrofitted later after their first autumn in Yorkshire resulted in 156 158 hybrid sets being formed.)

I'm not sure it's tread brakes per se, I think it's just scrubber blocks which work to prevent a build-up of leaf mulch on the wheels which was insulating the units from correctly operating track circuits.