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#144708 - 01/08/06 01:14 PM UK rural distribution  
lukemcuk  Offline
Junior Member
Joined: Jan 2006
Posts: 6
UK
Hello
I have seen pics on this site of UK rural distribution lines. I think the rural distribution network first started in the 1940s did the poles and pole mounted transformers always take the same apperence since then? Have the voltages always been 11kV and 33kV since then? What was the position with distribution before the nationalisation of the electricity industry (i think in 1948) where the many different voltages and designs of poles/transformers in use? If so are any of these lines still in use? Also an intresting question for you-does anyone know where and when the first HV power line in the UK was built?
Luke


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#144709 - 01/10/06 03:59 AM Re: UK rural distribution  
ianh  Offline
Member
Joined: Jun 2004
Posts: 54
Douglas, Isle of Man, UK
I don't have any idea when the distribution network started, so I can't help you with that.

The construction has remained pretty much the same since they started building OH lines, with changes to the designs of cross-arms over time.

The voltages varied over the country for a long time, and the HV OH has operated at 3.3kV, 6.6kV, 11kV, 20kV and 33kV at distribution voltages.

Most RECs standardised on 11kV and 33kV but we still operate at 3.3kV in some areas, and NEDL (North East) still have some network operating at 20kV, but I don't know if this includes any OH.

Cheers

Ian

Edited to correct my voltage inaccuracies!

[This message has been edited by ianh (edited 01-10-2006).]


#144710 - 01/10/06 04:14 AM Re: UK rural distribution  
Trumpy  Offline


Member
Joined: Jul 2002
Posts: 8,223
SI,New Zealand
Hi Luke,
Welcome to ECN, mate!. [Linked Image]
I take it that you are referring to the pics posted by Pauluk.
I really can't comment either being in New Zealand, but no doubt Paul will add to this thread sooner or later.
Good topic though. [Linked Image]


#144711 - 01/10/06 10:01 AM Re: UK rural distribution  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Hi Luke, Welcome aboard! [Linked Image]

[Linked Image]

Rural distribution goes back to before the 1940s, although I have to confess that I couldn't tell you the first HV line installed.

In the earliest days of mains electricity DC generators were used, which of necessity had to be located very close to the areas they served due to power being generated at the same voltage at which it was utilized. That's why the old districts of some cities still had DC power as late as the 1950s, as they were the earliest areas to be wired for mains.

HV transmission lines only became practical with AC generation. I would think that the earliest HV lines were what would today be regarded as short haul -- Just distributing AC at "low" HV voltages (3.3kV etc.) around a city. The more extensive network which eventually became the National Grid grew up gradually from that.

I don't doubt that the very early poles and xfmrs looked somewhat different, although the U.K. seems to have settled on common designs from a relatively early time: Horizontally aligned cables on cross arms for 11kV etc.
Some of the early equipment would have been different by necessity though. Back in the 1920s and before, some areas were running on 25Hz AC instead of 50, which would mean much larger transformers for a given power.


#144712 - 01/10/06 10:03 AM Re: UK rural distribution  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Quote
Most RECs standardised on 11kV and 33kV but we still operate at 3.3kV in some areas, and NEDL (North East) still have some network operating at 20kV, but I don't know if this includes any OH.


I'm not sure whereabouts, but according to the PoCo there is still a small amount of 6.6kV in my region (East Anglia).


#144713 - 01/10/06 11:51 AM Re: UK rural distribution  
lukemcuk  Offline
Junior Member
Joined: Jan 2006
Posts: 6
UK
Intresting. I see paul you mentioned 6.6kV distribution. Talking of this does anyone know what 6.6kV overhead distribution looks like-does it use the same poles/crossarms as 11kV or can you tell a 6.6kV line apart from an 11KV?


#144714 - 01/12/06 06:05 AM Re: UK rural distribution  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
I'm not sure whether they use the same insulators as on 11kV lines or whether there were actually smaller ones. Anyone?

(Remember too that on an 11kV line the actual phase-to-ground voltage is in the 6.6kV range and that phase-to-ground on a 6.6kV line will be in the order of 3.8kV.)


#144715 - 01/12/06 06:24 AM Re: UK rural distribution  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Thanks to Alan Belson for the following scans of 1920s lines and equipment.

Quote
Attached pic of 1926 UK 11kv terminal transformer pole. This is the dawn of the 'grid' - before this, individual power stations operated close to consumers, so transmission over long distances was unnecessary.


[Linked Image]

---------------------------------------------------------

Two-circuit 11kV lines in 300 ft. spans:

[Linked Image]

---------------------------------------------------------

Design of poles for 400 ft. spans:

[Linked Image]

Click here for enlarged version

---------------------------------------------------------

66kV poles & lines:

[Linked Image]

[Linked Image]


#144716 - 01/12/06 06:31 AM Re: UK rural distribution  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Quote
Heres a reference to concrete/steel poles used 'down under', same date, about 1926


[Linked Image]

Thanks for some great pics of old lines Alan. [Linked Image]



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