96ts traction motors in rain

[Silent]

It seems like 96 ts have different sounding motors in rain, like the rain affects them. I think I’ve noticed this with 72ts but it seems more prominent with 96ts. I don’t think I notice this much with s stock.

Why is this?

 

[hexagon789]

It seems like 96 ts have different sounding motors in rain, like the rain affects them. I think I’ve noticed this with 72ts but it seems more prominent with 96ts. I don’t think I notice this much with s stock.

Why is this?

Wheelslip?

 

[Silent]

Yep seems like it. Perhaps the s stock has better tech to prevent wheel slip.

 

[AM9]

Yep seems like it. Perhaps the s stock has better tech to prevent wheel slip.

Comparing a nearly 30 year old train accelerating from standstill with a train about half as old passing at cruising speed is unlikely to be that similar, rain or dry.

 

[hexagon789]

Yep seems like it. Perhaps the s stock has better tech to prevent wheel slip.

I would expect so, simply given the improvements in WSP with modern systems compared to those of even just 20 years ago.

 

[Dstock7080]

S Stock do slip when accelerating in heavy rain/light sleet

 

[Silent]

Comparing a nearly 30 year old train accelerating from standstill with a train about half as old passing at cruising speed is unlikely to be that similar, rain or dry.

I wasn’t comparing, just stating what I’ve noticed

== Doublepost prevention - post automatically merged: 28 Nov 2024 ==



== Doublepost prevention - post automatically merged: 28 Nov 2024 ==

S Stock do slip when accelerating in heavy rain/light sleet

I am going to look out for that

 

[edwin_m]

I know braking rates on Automatic Train Operation lines are reduced on open-air sections in poor adhesion conditions (discussed on another thread not long ago) and the same may happen with acceleration. The ATO system compensates for this by braking earlier.

96 stock is one fleet with the first-generation three-phase drives with Gate Turn Off thyristors that sweep up and down through the audio frequencies when accelerating or regenerative braking, so any change in behaviour is very obvious. S stock is of a later build, using more advanced semiconductors (Insulated Gate Bipolar Transistors) that operate at higher frequencies, not to mention different software controlling them. These newer systems are quieter overall, and the sound produced varies much less according to what it is doing.

 

[Silent]

I know braking rates on Automatic Train Operation lines are reduced on open-air sections in poor adhesion conditions (discussed on another thread not long ago) and the same may happen with acceleration. The ATO system compensates for this by braking earlier.

96 stock is one fleet with the first-generation three-phase drives with Gate Turn Off thyristors that sweep up and down through the audio frequencies when accelerating or regenerative braking, so any change in behaviour is very obvious. S stock is of a later build, using more advanced semiconductors (Insulated Gate Bipolar Transistors) that operate at higher frequencies, not to mention different software controlling them. These newer systems are quieter overall, and the sound produced varies much less according to what it is doing.

That explains why wheel slip may sound just as obvious or even more than in a 1972 stock despite probably not being as bad in a 1996 stock.