What determines a train as a class 7xx emu?

[trainmania100]

I'm sure it's already been discussed for which I apologise but can't find the thread.

What makes an EMU a class 7xx ?

I understand sub 100 is locomotives
Sub 300 is diesel multiple units

Classes 300 up to 508 being electric, varying power types , including dual modes like 377/7s (DC and AC), but 700s are like 319s in that they're dual mode too.
So what defines a 7xx unit? To use those numbers instead of the last of 4xx and 5xx

Is it the gangways between the units , in that they're walkthrough without doors?

 

[Bletchleyite]

I think 7xx is just any EMU, isn't it? Being used as 3xx has nearly run out of numbers?

4xx and 5xx are third rail only EMUs, I don't think there are any of these on order, as a minimum they have pantograph wells and passive provision for installation, I think? (4xx is South East, 5xx is non-South East e.g. Merseyrail).

 

[swt_passenger]

I'm sure it's already been discussed for which I apologise but can't find the thread.

What makes an EMU a class 7xx ?

I understand sub 100 is locomotives
Sub 300 is diesel multiple units

Classes 300 up to 508 being electric, varying power types , including dual modes like 377/7s (DC and AC), but 700s are like 319s in that they're dual mode too.
So what defines a 7xx unit? To use those numbers instead of the last of 4xx and 5xx

Is it the gangways between the units , in that they're walkthrough without doors?

There was a thread started Sunday in the rolling stock sub forum here:

Class 7xx - seemingly random numbering?

One thing that's striking me about the class 7xx, which was presumably introduced recently because they were running out of spare 3xx classes to use, is the rather bizarre numbering scheme. First one was, IIRC, the 700 - fair enough. However since then the numbering seems to have been almost...

www.railforums.co.uk

 

[DanNCL]

I'm sure it's already been discussed for which I apologise but can't find the thread.

What makes an EMU a class 7xx ?

I understand sub 100 is locomotives
Sub 300 is diesel multiple units

Classes 300 up to 508 being electric, varying power types , including dual modes like 377/7s (DC and AC), but 700s are like 319s in that they're dual mode too.
So what defines a 7xx unit? To use those numbers instead of the last of 4xx and 5xx

Is it the gangways between the units , in that they're walkthrough without doors?

It's an overflow for the 3xx range and can be used for any new class that previously would have been allocated a number in the 3xx range, though the spare numbers in the 3xx range can be used too.

The ranges if I recall correctly are as follows:
0-19 Shunters
20-79 (excl 73) diesel locomotives
73 ex southern region bi-mode locomotives
80-96 electric and bi-mode locomotives
100-199 diesel multiple units with mechanical or hydraulic transmission
200-299 diesel multiple units with electric transmission (not bi-modes)
300-399 electric multiple units using overhead wires and dual voltage units
400-499 third rail multiple units (Southern region)
500-599 third rail multiple units (rest of UK, now only used for Merseyrail)
600-699 diesel/alternative fuel multiple units, not currently used
700-749 electric multiple units, top speed 110mph or less
750-799 was supposed to be bi-mode units, although the allocation of class 777 to the new Merseyrail units goes against this
800-899 new "high speed" units, so far only used for units built by Hitachi
900-999 departmental units

 

[Mag_seven]

Please use the existing thread for discussion of this issue.

Class 7xx - seemingly random numbering? | RailUK Forums (railforums.co.uk)

thanks