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Post by caldridge on Oct 2, 2011 19:10:16 GMT -5
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Post by rillington on Oct 3, 2011 10:50:11 GMT -5
Excellent pictures.
L6 is my favourite type of pylon - it's a shame that no more are being built.
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Post by caldridge on Oct 6, 2011 16:56:59 GMT -5
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400kV
Junior Member
Posts: 91
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Post by 400kV on Oct 6, 2011 18:26:24 GMT -5
There are still quite a few L6 pylons around with two insulator strings on each arm. As far as I know they are all 400,000 volt lines. In Yorkshire, some L6 pylons have a single insulator string on one side and two strings on the other.
Paul
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Post by rillington on Oct 7, 2011 6:27:32 GMT -5
Indeed they do - the route between Ferrybridge and Bradford West immediately comes to mind.
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naughtyhorse
Full Member
Life sucks - get a helmet
Posts: 173
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Post by naughtyhorse on Oct 14, 2011 13:19:03 GMT -5
Did you know that there are some L6 pylons that have two insulators on one arm...
It's to do with the max tension capacity of the insulator - i think (please don't quote me!) that the older insulator strings had a max tension of 190kN, and were not quite strong enough to hold quad zebra conductor, more modern polymeric designs were strong enough that a single string could do the job.
When a line is fully refurbished then the insulator strings are replaced, this is done (obviously) 1 circuit at a time, so often you see lines with twin insulators on one Cct. and a single on the other. there is a line in my patch (east anglia) heading south from Bramford that looks like this.
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Post by rillington on Oct 14, 2011 13:27:05 GMT -5
Indeed there are.
Examples that immediately come to mind include the York to Hull line as well as routes from Ferrybridge and Monk Fryston, both of which head east to Eggborough as well as the twin route from Ferrybridge to Monk Fryston.
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Post by yv47r on Oct 17, 2011 16:39:01 GMT -5
Some other examples of L6 with quad conductors and twin insulators on the D towers until recently was the Fiddlers Ferry to Frodsham, Frodsham to Capenhurst and Capenhurst to Deeside. I think this has been largely converted now, there might still be on the Fiddlers Ferry to Frodsham. Not sure on the Fiddlers Ferry to Rainhill to Kirkby, its been a while since I have been up that way.
Others I can think of might include those that run alongside the M6 to the east of Birmingham, which is the Nechells to Hams Hall set. And those near to Chesterfield as well.
Cheers Paul
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Post by rillington on Oct 17, 2011 19:43:46 GMT -5
I wonder what proportion of L6 towers/routes have double insulators?
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Post by lesc on Oct 18, 2011 10:30:30 GMT -5
In Yorkshire, some L6 pylons have a single insulator string on one side and two strings on the other. Paul These are very visible from the M62. The insulators are a real mixed bag too with mixtures of glass and grey ceramic. The deviation towers were all quads though, some still in brown ceramic. These L6MD's coming out of Ferrybridge look slightly different than the ones out of Drax, it's really noticable on the deviation towers, perhaps they're of the BICC or BB type rather than JL Eve. To avoid the rush hour I stopped at Ferrybridge Services for a bit as i was working in Bradford all day, coming down the hill towards the power station there's another example of L2 on 132kV in the sea of 132 L3DS'ses that seem to be everywhere about there. Les
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Post by rillington on Oct 18, 2011 11:03:41 GMT -5
Indeed they are as the route runs alongside the motorway between junctions 26 and 27.
Regarding L2/L3 strung for 132, the L3 route to Harrogate starts at Ferrybridge, right next to the A1M before heading west for a short while. The route rejoins the A1M where the A1 and M1 merge and they follow the A1M, for some of this stretch actually running alongside the A1M until they turn to head to Harrogate just north of Wetherby.
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Post by mjlangford on Nov 13, 2011 16:52:52 GMT -5
L6s with two insulators on one arm.... How it should be!!! Like in the good old days before they started re-stringing them with newer (and I guess stronger) single insulators per arm. Oh god you've got me started now... and then theres the old style on deviation towers that had 4 insulators per phase/arm which are now being replaced with 2 insulators YUK! yes you might of guessed that I'm a L6 person. Although I'm quite fond of L2 and PL16 Oh and just to finish off WHAT THE HELL are they thinking when they replace one side of an L6 suspension tower with a single insulator and leave the other side as a dual for years and years. Poor things, made to look stupid and uneven. Rant over (until I start a thread about the new style insulators i've been noticing on PL16 and L7... that looks like a wet piece of string) ;oP Mark ps even though I don't like to see L6 looking uneven... this is a light-hearted rant ;D
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Post by rillington on Nov 13, 2011 17:39:26 GMT -5
Must admit that I hadn't put two and two together and realised that L6 towers with two insulators on one arm are older than the L6 towers with one insulator. I say this as I think of the two L6 routes which run through East and North Yorkshire and meet east of York at Wilberfoss and again at the Thornton substation. The older route is the York to Hull route which has two insulators and the newer route - Drax to Yarm - has one insulator. Plus to further underline the point, when they built the Thornton substation 20 years ago they had to do some route redirection to accommodate the new substation. A few towers were knocked down and replaced and two towers were L6 suspension towers, one on each route and both have one insulator on each arm, including the new tower built on the York to Hull route.
The only route I know with two insulators on one side and one on the other is the L6 Ferrybridge to Bradford route and it does look rather unusual. That said, it gives the route some uniqueness.
And yes I'm also an L6 person - L6 is my favourite type of pylon.
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Post by Flash Bristow on Nov 14, 2011 13:11:25 GMT -5
Yes, I too hate it when pylons are left uneven!
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Post by mikey72uk on Nov 16, 2011 18:25:30 GMT -5
There are L6 routes going north and South of Didcot Power Station that use double insulator strings too. The route from Didcot to Bramley passes through a Didcot housing estate as it sets off and what's more, these look nice and even too.
Having four insulator strings at a deviation tower really makes them look much more bulky (if that is the right word) than the equivalent towers on L2, L8 etc.
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