Lidar of some 132kV OHLs

[naughtyhorse]

Hi All,
just got these posts from a survey company i have used to get a really accurate survey of some lines near Luton.

The first is a 73 million point survey of 2.5 km of line roughly between Jct 12 and Jct 13 of the M1.
I think that the Transition tower at about 42 seconds into the clip is the one in the (old?) spotters guide - small world :-)

you can see the clip here www.digitalsurveys.co.uk/laser_scanning/pylons/pylons1.html

the second clip is of the other side of the M1, heading south from Sundon supergrid site which heads south almost as far as jct 11. this is a 120 million point survey showing the PVA line - on the right which will be staying, and getting some HUGE towers over the new motorway junction - L7(c) D E12s and possibly an E15
and the PBA line on the left which will be replaced by some 1200 mm^2 ali cable

you can see the clip here www.digitalsurveys.co.uk/laser_scanning/pylons/pylons2.html


I also have (at work, i'll post them soon I hope) a bunch of pix of an L7(c) term tower in bits scattered over a site being pre assembled ready to feed the new Marston Road Grid site in a year or so. would NOT recommend a visit, the HA are widening the A420 and the traffic is a nightmare.

take care all, hope to pose some more soon

[Flash Bristow]

Naughtyhorse! It's good to hear from you again. Will have a look at the clips tomorrow and look forward to your photos too

[poyks]

Wow, those clips are pretty amazing!

[Flash Bristow]

Fantastic clips - very nice find, thanks!

Also, you're right about that tower from the old spotter's guide - with wider arms - seem to recall being told it was designed as a transposition tower before they found that transposition wasn't really needed.

[naughtyhorse]

well yes and no :-) transposition was needed - and is still used on verly long lines with few substations. The one in the guide is 1/3 the way from Bedford to Watford and there is another transposition tower a few spans south of junction 11. When it was built in 1933 those were the only connections to that line - which was in the order of 50km. Since the 50's sundon supergrid has been added and there are also a couple of tee-offs to Redbourne, Eaton Socon, and from next year Marston Road, all of which change the charateristics of the line - effectively 4 short segments, making transposition un-necassary.

[Flash Bristow]

My father in law took a photo of a transposition pole in Cornwall...



But I thought it was only needed where the line is hundreds of miles long...

[naughtyhorse]

Thats pretty neat! didnt know it was ever done at 33kV. Permally stay insulators too!. they get replaced as a matter of course thesedays, so quite an old line.

the thing with transposition is that it reduces losses, so i guess if you are prepared to accept greater losses, then you can not use transposition.

OH btw the 132 ESI specs i mentioned in a recent post.. 43-7 is the L4M spec (1978) and 43-9 id the L7(c) (1978) spec.