What are the differences between Class 303s & Class 311s?

[SouthEastern-465]

My first post on here in a very long while, so please forgive me!

I have recently purchased the latest issue of Locomotives Illustrated (Scottish & Tyneside EMUs) which is very thorough and is a bible for information and technicalities.

But on reading about the chapter on the Class 303s, the article did not list the difference between them and the Class 311s. Nor did it contain a chapter about them! Now as I am aware they are very similar units externally although they were built a few years apart, but to be under an entirely different TOPs number I am under the impression there must be some thing that distinguishes them from the 303 fleet? From information I've gathered else where I know the 311s were built by an entirely different manufacturer (Cravens).

If anyone could shed any light on this, or explain to me in a little more detail it would be greatly appreciated

Kind Regards,

 

[1179_Clee2]

My first post on here in a very long while, so please forgive me!

I have recently purchased the latest issue of Locomotives Illustrated (Scottish & Tyneside EMUs) which is very thorough and is a bible for information and technicalities.

But on reading about the chapter on the Class 303s, the article did not list the difference between them and the Class 311s. Nor did it contain a chapter about them! Now as I am aware they are very similar units externally although they were built a few years apart, but to be under an entirely different TOPs number I am under the impression there must be some thing that distinguishes them from the 303 fleet? From information I've gathered else where I know the 311s were built by an entirely different manufacturer (Cravens).

If anyone could shed any light on this, or explain to me in a little more detail it would be greatly appreciated

Kind Regards,

303's were built by Pressed Steel with four MV 155 kW traction motors
311's were built by Cravens with four AEI 165 kW traction motors

 

[SouthEastern-465]

303's were built by Pressed Steel with four MV 155 kW traction motors
311's were built by Cravens with four AEI 165 kW traction motors

Thank you Very much appreciated!

 

[Southsider]

I'm sure there are many less obvious differences but my recollection's as a passenger were tungsten light bulbs in the 303s and fluorescent tubes in the 311s. Externally the 311s had cooling grilles in the guard's compartment and, I think, we're built without the wrap-around windscreens but could be wrong on that.

 

[WaveyDavey]

https://en.m.wikipedia.org/wiki/British_Rail_Class_311

 

[Siemens Staines]

I'm sure there are many less obvious differences but my recollection's as a passenger were tungsten light bulbs in the 303s and fluorescent tubes in the 311s. Externally the 311s had cooling grilles in the guard's compartment and, I think, we're built without the wrap-around windscreens but could be wrong on that.

311s were built with wrap-around windscreens in the same style as 303s. Both classes had their windscreens modified in the 1975-1976 period although one class 303 (043) ran for a while with a different windscreen type at each end. 311s were also single voltage units, whereas 303s had been dual voltage, although the latters 6.25kV had been isolated before 311s were constructed.

311s were Shields Road units and so before the opening of the Argyle line were relatively scarce on North Clydeside trains as there was no day to day inter-operation between the two networks.

 

[BelleIsle]

I am pretty sure that while both used asbestos for insulation the 311s used a different type which was superior in both sound and heat proofing. The problem was that is was also much more toxic. I believe 311s used blue asbestos and 303s white but it could be the other way around. This was probably why the 303s got refurbished and the 311s scrapped.