455 retractioning work

[59CosG95]

Anyone know when the new Vossloh Kiepe motors go into SWT's 455 fleet? I heard someone on here say it was about May-June when testing began.

 

[cjmillsnun]

I'm guessing that they may wait for some refurbed 456s to come on stream. 2 sets could release a 455 so it can be reengineered.

 

[Tio Terry]

Anyone know when the new Vossloh Kiepe motors go into SWT's 455 fleet? I heard someone on here say it was about May-June when testing began.

I wonder if anyone has considered what effect the AC chopper controlled motors are going to have on track circuits and the signalling system in general? Also, what effect will regenerative braking have on the traction supply equipment?

 

[jopsuk]

On almost all routes the SWT 455s run all other electric services use AC-motored, regenerative breaking 458s, 450s and 444s. So there's plenty of experience and knowledge. I would rather hope that the answer to your first question is "yes" and the second "it is well understood" and accounted for".

 

[overtonchris]

Could anyone tell me please where (Depot / Works) these modifications are due to be undertaken?....I assume any contracts have been "signed, sealed and delivered" by now? Also on average, how long would a unit likely to be out of action and again I assume (in ignorance) this would be correlated with a planned maintenance of the complete set?

 

[TheJRB]

Could anyone tell me please where (Depot / Works) these modifications are due to be undertaken?....I assume any contracts have been "signed, sealed and delivered" by now? Also on average, how long would a unit likely to be out of action and again I assume (in ignorance) this would be correlated with a planned maintenance of the complete set?

To answer the first part of your question, this is from the Vossloh Kiepe website:

The work is going to begin at the Wimbledon depot in January 2014. At the end of May 2014 the first modified Class 455 unit will be ready for testing and in November 2014 it will be put into service. It is anticipated to modify the remaining 90 EMUs at the Eastleigh depot.

 

[swt_passenger]

...and again I assume (in ignorance) this would be correlated with a planned maintenance of the complete set?

Not really, the 455 sets are already being cycled through Bournemouth for re-painting and DDA mods on a completely separate contract. I'd expect them to try and align the re-tractioning when planned maintenance of the existing traction equipment becomes due, but that's all.

 

[SpacePhoenix]

Are they old traction motors life expired or are the new ones way more energy efficient then the old ones and quicker accelerating?

 

[hassaanhc]

Are they old traction motors life expired or are the new ones way more energy efficient then the old ones and quicker accelerating?

Some of the motors are meant to be pretty ancient given the old Southern Region's policy of recycling parts from old trains wherever possible. However the reason given in press releases is to do with both further improving their already high reliability and making them more energy efficient. They have had a few problems with motors recently, well that was the reason given for the recent spate of '455 short formations. If they're considered slow then I'm not surprised, who on earth thought that it was a good idea to have only two motored bogies out of 8 per unit?!

 

[jopsuk]

, who on earth thought that it was a good idea to have only two motored bogies out of 8 per unit?!

I guess the is because of the 50s/60s 4-car units, I'm pretty sure only the 4REPs had more than four powered axles?

 

[bigdelboy]

I guess the is because of the 50s/60s 4-car units, I'm pretty sure only the 4REPs had more than four powered axles?

Practice dates well before the 1950's .... e.g. 4-CORs (1938) and probably far earlier. In general the motor bogies were placed over guards brake coaches; which i suspect helped access to the electrics controls. Same applied to 2 coach units. e.g. 2-bil, 4-cor, 4-cig, 4-cep(original) 4-vep; and probably those of earlier ilk to.

The design of Motor Coacher(s) + trailers versus all coaches powered possibly had some advantages in terms of simplicity and possibly maintaince costs.

Additional weight on fewer heavier motors may help grip as opposed to more axles with less weight on them ... but I welcome those who know about these things to shoot down this comments. Certainly 4-cor heavyweight (or even 4-cep) shoes were far better on the conductor rail than than a 5-wes ... and i recall 4cep/2bil/4cor being better in ice that a 377/5wes etc. !

 

[edwin_m]

Additional weight on fewer heavier motors may help grip as opposed to more axles with less weight on them ... but I welcome those who know about these things to shoot down this comments. Certainly 4-cor heavyweight (or even 4-cep) shoes were far better on the conductor rail than than a 5-wes ... and i recall 4cep/2bil/4cor being better in ice that a 377/5wes etc. !

Other things being equal, "grip" depends on the proportion of the train's weight that is resting on powered axles. So a 4-car unit with four motorized axles on one coach will have less grip than one with eight motorized axles on two motor coaches.