Class 91 Tech specs, please help!

[researcher]

Hi, I really hope someone can help me, I am a PhD student looking into the potential energy saving effects of new electrical technologies in transportation, I am modeling these effects on various typical trips, including the London-Edinburgh ECML.

I really need some basic technical information on the Class 91(intercity 225), specificaly the weight of traction motors and power transformer. I have spent a lot of time trying to find technical details of the class 91 and have failed to find much of use, could anyone please point me in the direction of some good technical specs for the class 91?

I really appreciate any help people can give.

Thanks!

 

[Pumbaa]

Hmm - the railway centre tech data page seems to be unavailable. Some limited info here though on the recognition page.

http://www.therailwaycentre.com/Pages Loco/Recognition loco/Illus_91.html

 

[O L Leigh]

You'll be struggling to find information about the weight of individual components.

I'm guessing that the premise of your research is based on weight-saving. While this is a good way of reducing energy consumption you have to allow that the very low rolling resistance of rail vehicles means that weight is not such a massive penalty, particularly on intercity stock like the Cl91 + Mk4 sets, as they spend a lot of time cruising. The other thing to bear in mind is the role the weight of a traction unit has in deriving it's adhesion. Making the traction unit lighter is likely to reduce it's adhesion on the rail and induce more slip and, consequently, energy wasteage.

Practical experiments using existing rolling stock has shown that the greatest energy saving comes from changes in driving techniques. However, I seem to recall that Hitachi made some very bold claims about the power consumption of their Cl395 "Javelins" while they were still under construction. I seem to recall that Hitachi were making great play that their trains would not use any more juice than an Electrostar of equivalent length and would be able to keep to the same timings. Given that the Javelins are significantly heavier than the Bombardier opposition and are pulling a much higher gearing to allow for 140mph running when on the CTRL, either Hitachi are lying Newton is. I've not seen any figures to back up these bold claims now that they have entered service so who knows. However, it may be that new technology is playing at least some part in this.

O L Leigh

 

[locotronic]

It's probably worth bearing in mind that Alstom/Parizzi have actually superseded the technology in the class 91.

Most recent rail vehicles already use smaller, lighter, distributed ac traction systems and more efficient IGBT inverters.

Perhaps the new technologies you're proposing already exist.

A mate of mine works for Alstom in Preston in the rail side of the company - I could probably find out from him how much the transformers in and traction motors weigh in the Pendolino/Class390 (which might be a more relevant study).

Alternatively - call Alstom and explain who you are and what you're doing and they might tell you what you need to know. The Pendolino uses 'Onix 800' motors and 'Onix' Traction, Agate subsystem/inverter control. Just a marketing name for standardised systems.

GEC Alsthom /Brel were involved in building the Class 91 - this is now all merged into Alstom. Alstom were also the last company to give the class 91 its heavy general repair/mid life rebuild and upgrade of electrical and mechanical systems.

I do know for a fact that the traction motors in the class 91 (of which there are 4; frame mounted) weigh 4 tons each - GEC model G426 AZ. There is also a transfer gear box and quil coupling which is bogie mounted (of which there are 4).

Also consider that the Pendolino has 4 quadrant converters - bi directional power transfer; which also improves the power factor and conducted line harmonics. The Power Factor of the Pendolino will be much better than the Class 91 as a function of the converter (so the class 91 will appear to pull more power than it is (not true power) to the distribution network; additionally the Pendolinos have regenerative braking - whereas the Class 91's only have rheostatic and air braking. So the Penolino is also more efficient in light of these things.

Hope this helps in some way..

 

[Dolive22]

I would think that air resistance would be a major factor at 140 mph, which they could change without having to mess with Newton.