Pylons .

[Ian McAulay]

Not an area I know at all, so can't comment. However, some of those 132kV lines are likely to be part of the original National Grid. It would be instructive to have a look at old mapping to work out the earlier layout.

 

The National Library of Scotland is a great resource for this. The One-inch New Popular Edition is probably most useful. It was published 1945-47, so guaranteed not to have any 275kV on it. It may not exactly reflect the electricity network at that time as updates took longer to filter through to published maps than they do now, and of course we'd just had a war.

 

Link: https://maps.nls.uk/os/one-inch-new-popular/

 

I find the seamless layer they offer if you follow that link to be the most useful as you don't need to know sheet numbers.

 

Ian

[Daniel Beardsmore]

It might offer some clues. Whether it’s enough to accommodate all the L7 oddities in Redbourn, remains to be seen.

[Daniel Beardsmore]

The plot thickens … The jumper-less L7 DT in Redbourn is now earthed on the de-energised side (as is the next tower along), and there looks to be a sealing end compound under construction around it:

 

 

A few more photos, starting with L7 D, DJT (?) and DT, then D30:

 

 

L2s:

 

 

PL1a D30:

 

[Daniel Beardsmore]

“Max total size: 10 MB — the site lies. The rest of the 3.25 MB of images in total, starting with what we seem to think is PL1a DX:

 

 

That was today’s real goal, not to redo the L7 towers (which was just good fortune!) but to get closer to that PL1a transposition tower, having finally found a (dead end, due to the M1) public footpath that gets you a lot closer, albeit through a hedge.

 

I don’t remember seeing this in the Highway Code — must be an amendment. Beware of late-night walkers struggling with their umbrellas in the wind and rain (note the lack of street lights!):

 

[Daniel Beardsmore]

Strange, I thought I had posted this photo …

 

 

I know I shared it with someone at some point but I forget who or why. Ian maybe. Plain and simple L7 D30 between Slip End and Luton. (With a height extension but otherwise quite ordinary.) Onto this has been added a top crossarm extension of a new design that is quite different from that of L7 DT (compare my earlier photo showing what appears to be a brand new sealing end compound built around an actual DT through tower).

This is a through tower being converted into a tower capable of taking downleads (not sure how you would classify that); that sealing end platform is brand new, as it does not appear on Street View from this spring. (That might explain my surprise at finding it there, and I thought that some of that steelwork looked new!)

 

[Daniel Beardsmore]

Just talking to myself here again …

 

If I collect enough thumbs up, can I cash them in for a single morsel of quality human interaction?

[pharrc20]

On 02/10/2022 at 16:33, Daniel Beardsmore said:

Strange, I thought I had posted this photo …

 

 

I know I shared it with someone at some point but I forget who or why. Ian maybe. Plain and simple L7 D30 between Slip End and Luton. (With a height extension but otherwise quite ordinary.) Onto this has been added a top crossarm extension of a new design that is quite different from that of L7 DT (compare my earlier photo showing what appears to be a brand new sealing end compound built around an actual DT through tower).

This is a through tower being converted into a tower capable of taking downleads (not sure how you would classify that); that sealing end platform is brand new, as it does not appear on Street View from this spring. (That might explain my surprise at finding it there, and I thought that some of that steelwork looked new!)

 

Hmm that is an unusual conversion of the D30 but I guess needs must dictate some sort of additional feeds. Is there any new generation or industry nearby that would warrant these alterations?

 

I have seen some L2 and L3 lines with downleads added to D30 towers but not got up close to any to photograph them just yet.

 

Cheers Paul

[Daniel Beardsmore]

That’s all I know at the moment unfortunately.

[Pylon King]

It’s been a few months due moving , fortunately all the models were undamaged thanks to the specially made foam inserts. SF60 now has both maintenance cradles installed .

[Pylon King]

Reposting a few photos which had previously been deleted due to the RM server crash . Maintenance team in 1:76 scale .

 

[Pylon King]

[Pylon King]

1:76 scale 132kV D30 model specially built for an article about model pylon construction in British Railway Modeller magazine published earlier this year.

 

Edited October 4, 2022 by Pylon King

[Daniel Beardsmore]

Seeing as there are no plans for PL16 DD30, how did you achieve such accuracy? Just by copying the photos?

[Pylon King]

12 hours ago, Daniel Beardsmore said:

Seeing as there are no plans for PL16 DD30, how did you achieve such accuracy? Just by copying the photos?

A contact who works in the industry sent the PL16 blueprints for this particular design .

[Daniel Beardsmore]

Are tower blueprints meant to be some kind of trade secret? I have two sets of L2 plans, one from Ian McAulay in poor condition and one I found here in excellent condition but shrunk down too small, possibly by the forum software. Both of them are the same annoying version that omits the D30 crossarms; one of them retains the dimensions but still lacks the bracing, and you need that for positive comparison as the tower body is the same for both. I am holding off drawing L2 for now as neither of them is really good enough to get the details right.

 

(There is almost no hope of ever tracking down plans for all the rare stuff in Scotland like the L55 variations or the weird and completely unidentifiable little 22.41 m tall 132 kV towers on the Dunoon line. There is a drawing of the D or D2 for the latter in an SSEN document but that’s it. PL16 supposedly but that is likely a mistake, and they don’t respond.)

 

I found another PDF on clearances that has a lot of outlines (L2, L3 including L3 DS, PL16 including confirmation about PL16 D2 vs D2S, L4m, “NWE PL1” whatever that is, and PL7 D2), but no tower heights are noted and the tower bases are not included, so they are still of limited use (but not completly useless).

 

(NWE PL1 could be anything: since all drawings except L2 lack a depiction of the bracing (and I am not convinced about the accuracy of the L2 bracing, but I can compare it with the other plans), there is no way to match the PL1 diagrams with any known PL1 or PL1b type. The L2 pages do at least give me enough detail to be able to positively tell L2 D10 from D30 by bracing pattern.)

[SHMD]

5 minutes ago, Daniel Beardsmore said:

Are tower blueprints meant to be some kind of trade secret? I have two sets of L2 plans, one from Ian McAulay in poor condition and one I found here in excellent condition but shrunk down too small, possibly by the forum software. Both of them are the same annoying version that omits the D30 crossarms; one of them retains the dimensions but still lacks the bracing, and you need that for positive comparison as the tower body is the same for both. I am holding off drawing L2 for now as neither of them is really good enough to get the details right.

 

(There is almost no hope of ever tracking down plans for all the rare stuff in Scotland like the L55 variations or the weird and completely unidentifiable little 22.41 m tall 132 kV towers on the Dunoon line. There is a drawing of the D or D2 for the latter in an SSEN document but that’s it. PL16 supposedly but that is likely a mistake, and they don’t respond.)

 

I found another PDF on clearances that has a lot of outlines (L2, L3 including L3 DS, PL16 including confirmation about PL16 D2 vs D2S, L4m, “NWE PL1” whatever that is, and PL7 D2), but no tower heights are noted and the tower bases are not included, so they are still of limited use (but not completly useless).

 

(NWE PL1 could be anything: since all drawings except L2 lack a depiction of the bracing (and I am not convinced about the accuracy of the L2 bracing, but I can compare it with the other plans), there is no way to match the PL1 diagrams with any known PL1 or PL1b type. The L2 pages do at least give me enough detail to be able to positively tell L2 D10 from D30 by bracing pattern.)

 

I must admit I just can't help much in this thread, because I can't differentiate between a PL1 and my elbow - even though I think there is a  PL1 (perhaps PL2???) at the end of my street!

 

...but I do find this thread informative and interesting.

 

I wish there really was a "bible" of towers, and I applaud your efforts in trying to understand the chronological history of tower design and erection.

 

 

Kev.

 

[Daniel Beardsmore]

The “bible” of towers is in some sense what I am putting together, amidst the shroud of secrecy and swirling tides of data loss. The existing “tower bible” is a good starting point, but half of it is missing, and it only covers part of the 132 kV range of suites/families/series (whatever you want to call them) — nothing on 66 kV and below or 275 or 400 kV (the L2 and L3 sections are completely gone).

[Daniel Beardsmore]

On 18/08/2019 at 08:51, LMS_LNER_SR_GWR_fan2004 said:

One more thing, I noticed some of the PL16 DD towers have a different top to the standard versions. Is there a reason for this? The first one is a standard DD60 and the next 3 are the other version I have seen.

 

The first photo is PL16 DD60 as you figured.

 

The second appears to be PL4 DD60, and the third appears to be PL4 DD30.

 

The fourth one is a little odd. The crossarm bracing is (rotationally) symmetric, so that implies DD10 considering that it has tension insulators and the crossarms are in the deviation position. The crossarm bracing across the tower body is inconsistent with existing PL4 photos (mine and Ian’s), but the tower bible does show that pattern for DD2 (contradicting what we have seen for real), so possibly some DD2 and DD10 towers were fitted with the additional bracing members between the two sides of each crossarm.

 

In any case, the last photo is most likely PL4 DD10.

[Ian McAulay]

Pylon King: I'm really enjoying your 1/76 pylon models. I've just reread the article in May BRM but my favourite has to be the SF60 with maintenance cradles.

Sadly, neither of the micro-layouts I'm working on really have space for a pylon. Maybe I'll just have to build one anyway!

 

Ian

[Daniel Beardsmore]

Are L4 and L4M/L4m/L4(m) separate, i.e. did L4m supersede L4, or are all L4 towers L4m? That is, are L4 and L4m synonymous? (Not true with metric conversions like L8c and L7c as I understand it, but there is a suggestion that L4 was metric from the start.)

 

I also wonder whether there is any industry preference for “series”, “family”, “suite” or some other word for each tower series? There is very little in the way of examples, although I have seen each of “family” and “suite” in about one source each.

[Ian McAulay]

It depends who you ask...

 

I've seen L4M, L4(M), L4m and L4(m) from different sources. For what it's worth, the Blaw Knox drawings for them say L4(M), but that may be the whim of the draughtsman, and all the other lettering on the drawing is in capitals too. Also, the drawing is referring to a CEGB specification and I have no idea how that was bracketed or capitalised.

 

On the other hand, CEGB drawings for L6M (punctuate according to taste) are labelled L 6 M - no brackets, all caps and spaces between characters. Their drawings for L7C don't have spaces or brackets.

 

I don't think there ever was a pre-metric L4. The numbering of tower series seems to have been fairly random, certainly not sequential and with gaps.

 

I go for 'series' for L2, L3, L6 and so on. The appropriate field on the National Grid tower database is LINE_SERIE  (presumably there's a field limit of 10 characters somewhere). Blaw Knox drawings say 'specification' on L2 and L4M drawings, which is probably strictly correct. CEGB for L6M, L7C and L12 have 'tower series'. Just to be different, LSTC use 'tower design' on their drawings for the proposed (and I think abandoned) L4S and L7H series. Given that CEGB used 'series', I think that's authoritative.

 

'Tower type' seems to be universal for D, D30, D60 and so on.

 

I think that may actually have clarified things a little. Answers to questions like that usually just make the subject murkier.

 

Ian

 

[Daniel Beardsmore]

I meant, is there a pre-metric L4 that is distinct from the m-type (regardless of how it’s formatted). In terms of conductor/insulator configuration, one table has four types:

 

L4 (Lynx + Horse)
L4/1 (Zebra + Lynx)
L4M (L4 sag) (Upas + Keziah)
L4M (L4/1 sag) (Upas + Keziah)

 

(https://orca.cardiff.ac.uk/id/eprint/55094/1/U585483.pdf page 205)

 

 

There is no guarantee that “M” here is the same designation. “M” here may simply indicate enhanced conductor rating¹. The table seems to be incomplete, too — it just stops after one line of L8 and only has L8 as operating at 132 kV.

This table has another instance of “L132”, which I am guessing is L16/L55 again, even though “CEB-L132” covered both PL16 Scottish and L16/L55!

 

¹ Clydesdale’s spec sheet is hilarious. Calculated DC resistance in “Uohmns/km”, weight in metres, diameter in mm² … Almond has 1,093 “Uohmns/km” resistance, but the next size up Cedar is 0.9281, so someone’s got their decimal points and commas mixed up! DC resistance of 1 μΩ/km? Is that realistic? I checked another set of data, and it’s ohms/km. The “U” can’t mean “μ” here, it must just be a totally spurious character.

 

I think I have some figures somewhere that indicate the actual rated load capacity of a number of conductor types, that would indicate what these changes mean, i.e. what the quantitative benefit is of changing L4 from Lynx to Zebra to Upas. (The figures also took partially into account summer and winter loadings and temperatures, capped by clearance according to changes in sag I am assuming although no detailed explanation was given.) I lose track of what is in what document!

[Daniel Beardsmore]

For what it’s worth, PL16 DD90, DD30, and what I am taking to be DD2S — the “Scottish” version of DD2. (I can’t get the designation, but they have the D2S body plus double earthwire adaptation. One of Ian’s photos is of a weird version with different bracing.)

 

The DD30 photo is a bit lame as it was taken facing the sun.

 

Letchmore Heath, Hertfordshire; they connect to a PL16 DDT at Elstree Substation.

 

[Daniel Beardsmore]

On 09/09/2022 at 20:16, pharrc20 said:

I am not certain of where the L55 designation originated but will look throigh my info or phone a friend who might just know

 

So far, it looks like L55 is a Scottish designation, while L16 is the English designation, and L132 is used everywhere. One document notes, “This is a type D10 E10’ tower constructed to specification CEB L132 (0.4 sq in conductors), and adding a standard 3.04m (10ft) extension to make the tower an E20’ will rectify the clearance problem.” This would suggest that, with no official name for these towers, in some instances they are referred to just by the CEB specification name, while in other places they got designated L16 or L55.

[bradfordbuffer]

Saw title of thread.....thought at last might get some answers why my bum is saw.....! Reading wasn't my best subject at school!

 

 

In all honesty well worth a read as some passionate and informed contributions hear all for power distribution