Kingston/Hounslow loop stock allocation

[racklam]

Hi,

It seems to me that on the Hounslow loop, the vast majority of services are operated by 450s or 458/5s, whereas on the Kingston loop, the stock is mostly 455s and 456s.

Is there a specific reason as to why this is?

Thanks

 

[JonathanH]

It keeps 455/456 on all services into the suburban part of Waterloo - these trains have quicker door cycles which is important given the number of trains in from Wimbledon to Waterloo.

Also, for the time being platforms 1-4 at Waterloo can only accommodate 8-car trains.

There are insufficient 455s to operate all of the South West Trains suburban network following the change to the timetable in December 2004 so 450s had to be used somewhere - hence their appearance on Windsor side inner-suburban services.

 

[swt_passenger]

In addition to the above, 455/456 combinations do not have the ASDO system, which has been fitted to the newer trains to deal with the short platforms on the Windsor side, and on the Weybridge services etc

So if you want ten car trains in that particular area of the SWT network they cannot be the older 455/456 that do not have SDO at all

 

[bb21]

Eh? 455+456 operate in 10-car formation on the mainline side on some diagrams - the Class 9s. Am I misunderstanding you?

 

[swt_passenger]

Eh? 455+456 operate in 10-car formation on the mainline side on some diagrams - the Class 9s. Am I misunderstanding you?

All the stations they call at en route, and their terminating platform at Waterloo, will already be long enough for 10 cars. There was a suggestion that running under class 9 was chosen to remind the signallers to keep them in the right platforms at Waterloo.

Earlier post amended for clarity.

 

[racklam]

Thanks for the replies. I thought the slow Desiro doors might have had something to do with it!

 

[hassaanhc]

Thanks for the replies. I thought the slow Desiro doors might have had something to do with it!

It is also down to history. The Hounslow Loop used to be a mix of 423s and 455s, which were replaced by 450s on most weekday services. As 450s had some sort of SDO facility, it allowed sets of more than 4 cars to be able to call at the short platforms at Virginia Water and Chertsey.

It is a common misconception that *all* Hounslow Loop services are 450s or 458s. On weekdays there are still 4 services (used to be 6 until December 2015) that use 455s (8 cars as they're planned to not go near the two problem stations), and until December 2015 almost all weekend services were still single 455 units.

Even the Windsor & Eton Riverside services, which are normally all 450 or 458, instead get 455s if diverted via Kingston or sometimes if Hounslow Loop needs longer services on weekends due to events.

Until the 10 car extensions you couldn't fit a pair of 450 units at New Madden, Norbiton and Hampton Wick (plus several other stations on other suburban lines), meaning only the front 4 coaches opened, as platform lengths were that tight.