Selective Door Operation

[swt_passenger]

Ah, I'll bow to your superior knowledge, I was going by what I'd been told, or what I could remember being told at least. It begs the question then why isn't there a reader on each coach, it would have the ability to prevent a door release on unaccomodated coaches on a stop short.

I can't disagree with that point, it is intuitively more "fail safe" isn't it. I'm sure it has also come up in previous discussions comparing the two slightly different systems.

But the 458/5 system also has a down side such that you can have a coach in the middle of a platform that fails to open while those either side do. Fortunately when it happened to me I was trying to get in and could wave to the guard, as I ran to another coach...

 

[jopsuk]

Fascinated, via the GA Franchise Agreement that has been published, that 27 of the Class 317 fleet are being fitted with an SDO system

 

[BestWestern]

The GWR Turbo fleet is also being retrofitted.

 

[philthetube]

Ah, I'll bow to your superior knowledge, I was going by what I'd been told, or what I could remember being told at least. It begs the question then why isn't there a reader on each coach, it would have the ability to prevent a door release on unaccomodated coaches on a stop short.

would be an issue to solve in it would have to be equipment provided to allow the doors to open and not to prevent them from opening. Equipment preventing doors opening would be difficult to design fail safe.

 

[pompeyfan]

would be an issue to solve in it would have to be equipment provided to allow the doors to open and not to prevent them from opening. Equipment preventing doors opening would be difficult to design fail safe.

Surely that's just what the purpose of the green egress handles are. Should the doors need to be manually opened in an emergency the passengers can pull the handle. Should there be a fault with the system and the train is fully accommodated the guard can ask the driver to do an SDO override.

 

[BMIFlyer]

• 170 - South West Trains (i presume the 168/3 as they are now known as still have it)

Not quite. They had DDS - Door Deselect - basically an example as follows:

Drivers key is in, 4 car unit, 3 car platform, operate DDS / activate doors from control panel in the car 3 GOP and only the front 3 cars will release - car 4 remains locked. Each cab and guard panel within the coach had a DDS button. For a while at TPE these buttons were sealed as TPE wasn't safety cased for the use of DDS.

This eventually changed. Operational requirements required it to be used when certain class 170 diagrams became 6 car sets so it was unsealed and then used.

DDS can be used to lock out a single car or whole unit behind the location of the DDS switch if you get my drift.


The TPE 185 fleet is being fitted with a system similar to the SWT desiro fleet.