Are 323s related to Networkers?

Discussion in 'Traction & Rolling Stock' started by py_megapixel, 16 Aug 2019.

  1. py_megapixel

    py_megapixel Member

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    I can't help feeling that 323s are very similar to the Networker family, in terms of what types of services they run, their layout/design and even (on electric Networkers as opposed to Networker Turbos) the noises they make

    Can anyone confirm or deny those suspicions?
     
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  3. Agent_Squash

    Agent_Squash Member

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    Apart from the bogies (which were a common BR design), no.
     
    Last edited: 16 Aug 2019
  4. edwin_m

    edwin_m Veteran Member

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    The 323s were procured by the Regional Railways sector of British Rail and built by Hunslet of Leeds (the only recent passenger trains for the UK main line network and I think the last before they went out of business). They have some stylistic similarities to the Networker fleet which was built a few years earlier by BREL and GEC (now parts of Bombardier and Alstom) for the Network SouthEast sector. Traction packages for the 323s were by Holec of the Netherlands, also their only product for the UK, also now part of Alstom.

    One common factor is that 323s and Networkers have the same bogies. The design started with the PEP units and Class 313 in the mid-70s and was used on all multiplie units after that until privatisation except Class 158. It was a BR design and although the rights passed to BREL/Adtranz when that was privatised, they were required to license the design for any stock ordered by BR from any supplier. Hence it could be fitted to the GEC Networkers and the Class 323, but after privatisation when BR ceased to exist it only appeared on Bombardier designs.
     
  5. bramling

    bramling Established Member

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    Could RR have borrowed the Networker specification from NSE, given that they didn't have any of their own experience in procuring EMUs?
     
  6. 507 001

    507 001 Established Member

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    IIRC the management and design team for the 323s was made up of people who had previously worked on the Networker project, hence the similarities.
     
  7. LOL The Irony

    LOL The Irony Established Member

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    They mostly came from Metro Cammell IIRC.
     
  8. 507 001

    507 001 Established Member

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    Yes, that sounds familiar.
     
  9. Roast Veg

    Roast Veg Member

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    There are many time sensitive factors that also dictate the similarities, such as the most viable traction motor inverter technology (GTOs) producing the distinctive gear change sound. Curiously, the IGBTs fitted subsequently also make the noise.
     
  10. dubscottie

    dubscottie Member

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    There was issues. Roger Ford detailed the saga in Modern Railways at the time. (I will need to dig the mags out).

    I think there were concerns about the loading gauge, signalling compatibility & delivery schedules of a Networker variant.

    Met Cam was not that interested IiRC as it was a small build and they were busy with tube stock orders anyway.
     
  11. py_megapixel

    py_megapixel Member

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    The following is possibly incorrect. I'm not an expert.

    The noise is, I believe, not solely a consequence of the inverter technology used. A summary of my (almost certainly over-simplified) understanding is that it's a consequence of the need to avoid limitations of older inverter designs. So just replacing the inverters doesn't change how it sounds as the rest of the variable frequency drive will still operate in the same way.
     
  12. LOL The Irony

    LOL The Irony Established Member

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    Had the full order been realised, there would be 57 units or 171 carriages so not really a small build.
     
  13. Roast Veg

    Roast Veg Member

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    Yes I'm inclined to believe the same.
     
  14. 61653 HTAFC

    61653 HTAFC Established Member

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    Extra units were initially planned for the Leeds Northwestern "triangle" but this was cancelled and redundant 308s were sent North instead.
     
  15. dubscottie

    dubscottie Member

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    Yes but at the time there was no guarantee. Even if the WYPTE wires had been given the go-ahead at the time, there would still have been a long gap between batches of units.

    Hunslet did get overseas orders for the 323 also later on.

    Centro had a big say also if I recall. They wanted something "new" not just a electric sprinter.

    I will try to dig out the Roger Ford articles later.
     
    Last edited: 18 Aug 2019
  16. tomuk

    tomuk Member

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    The inverters have to switch at varying frequencies to drive the motors at the required speeds. As to not interfere with the line side signals ie track circuits certain frequencies and multiples thereof are avoided. Now with older GTO inverters they are unable to switch as frequently as newer IGBTs and it so happens that the frequencies they are limited to are within human hearing range. The switching design used by Holec making the 323s particularly tuneful.

    The 323s were recently updated to IGBTs as the GTO used required special cooling (CFCs) which made them difficult to maintain. To retain their existing safety case it was easier to switch the replacement IGBTs at similar frequencies to the old GTOs.
     
  17. tomuk

    tomuk Member

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    Re Hunslet TPL who built the 323s. The TPL part of the company was formed by 15 ex Metro Cammell engineers/managers. Hunslet provided the factory and some money.
     
  18. py_megapixel

    py_megapixel Member

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    That's a far better explanation! I knew about the need to switch at different speeds to correctly control an AC motor, and that you hear that switching frequency from the motor, but I never realised that GTO inverters got hot enough to require a cooling system or that the 323 ones had even been replaced. Thanks!
     
  19. supervc-10

    supervc-10 Member

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    Overseas orders? Not heard about this! Who else bought related units?
     
  20. ed1971

    ed1971 Member

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  21. supervc-10

    supervc-10 Member

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