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GWR 802s to Plymouth - Where do they switch from Electric to Diesel?

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irish_rail

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Under normal running, at what point is Notch 5 usually applied? Say if accelerating to 100mph from rest.


Yes, although in theory a service towards Oxford calling at Didcot Parkway (for instance on Sundays) can perform the power changeover while stopped in Didcot Parkway platform. There is little benefit in doing so, however.
It varies from driver to driver , im not sure on what the official guidance is, I normally hit notch 5 about 20mph ( if I do actually risk using it). Trouble is they were not designed to run with such a lightweight load and to my knowledge this hasn't been addressed yet.
 

hexagon789

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It varies from driver to driver , im not sure on what the official guidance is, I normally hit notch 5 about 20mph ( if I do actually risk using it). Trouble is they were not designed to run with such a lightweight load and to my knowledge this hasn't been addressed yet.
One option for that would be to downrate the engines to say 2,000hp or even slightly less.

Or lock out Notch 5, that would leave the maximum nominal power output at ~1,790hp in Notch 4.
 

43096

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One option for that would be to downrate the engines to say 2,000hp or even slightly less.

Or lock out Notch 5, that would leave the maximum nominal power output at ~1,790hp in Notch 4.
And if you have one power car fail, you then don't have notch 5 available to compensate in the good one.
 

83A

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Interesting thread.


I’m curious (if anyone knows) how it’s electrically changed over.
At some point (say approaching NBY on the down line) it will have the panto up and the engines started, therefore you have two sources of power to the traction motors.
Is that changeover automatically managed or does the driver have to throw over a relay (metaphorically speaking) I appreciate it’s more advanced than that ;)
 

hexagon789

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And if you have one power car fail, you then don't have notch 5 available to compensate in the good one.
It was just a suggestion. Perhaps derating the power car engines would be better in that respect then
 
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