Pylons .

[Daniel Beardsmore]

On 04/05/2023 at 16:31, 25kV said:

Yep - I only realised after leaving the site that the standard base was the next bar up!  The illustration where I've marked rough heights (based on eyeballing in the "base" I measured and scaling from that) was the closest to straight-on that I could get to today, without a huge amount of perspective.  :)

 

From your measurement I made the base 6.28 m wide.

 

The actual size according to the drawing is 20 feet and 7 7/16 inches, or 6.285 metres.

 

(And yes, they are Eve L3.)

 

I would say that is sufficiently close …

[25kV]

17 minutes ago, Daniel Beardsmore said:

 

From your measurement I made the base 6.28 m wide.

 

The actual size according to the drawing is 20 feet and 7 7/16 inches, or 6.285 metres.

 

(And yes, they are Eve L3.)

 

I would say that is sufficiently close …

 

I would agree!  🙂  Excellent deducing!

[IC_225]

Project PL16:

 

Having found more drawings on the PL16 family of pylons, I have decided to look into the possibility of making full scale model, with the option to scale them down to OO / N gauge and look at potentially selling 3D Prints of the towers in these scales. I have chosen the PL16 as it can suit most layouts from the late 1940s / early 1950s right up to the present day. A standard height tower in OO is roughly 34cm tall with an N gauge version being roughly 17cm tall.

 

For starters, I am currently designing the PL16 Scottish DD, this will then be followed by the Scottish D tower. 

 

This is a long term project which will take time, but hopefully something useful can come of it in the end. 

 

Attached below are the beginnings of the PL16 DD tower, with an outline one side and the bracing being done on the other.

 

[Daniel Beardsmore]

DD2 by the way — those old line towers allowed ±2° of deviation. I think it’s actually a DD2S. The “Scottish” line tower was re-designated D2S, so I assume that the double earthwire type would be DD2S. D2S vs D2 just helps keep the two types separate!

[Daniel Beardsmore]

On 07/06/2023 at 00:11, Suzie said:

I am often puzzled by this short run of pylons in Colchester, probably about half a mile from the substation (close to the former power station site) to where it goes underground. It starts at the 132KV substation with five insulators …

 

Hey!

 

Those are Watshams gantries. I have a drawing for such a tower for SEE SL8 33 kV Rayleigh to Southend, a line that no longer exists.

 

The line tower you depict however is a Blaw Knox design, matches NWE SL4 D3. I have no angle tower details for NWE SL4 though.

 

From what I understand, PL is Primary Line at 132 kV, and SL is Secondary Line, normally 33 kV but also 66 kV in the coal mining areas. The SL types are not pre-grid towers but lower voltage distribution.

 

If I ever get to a point where I am happy with naming conventions for types with no designer designation, I will be adding the SL drawings to my site also.

 

Edit: some notes from a pylon engineer when I showed him your photos (which also seems to explain the mismatch of designs between line towers and gantries):

 

Good find!

 

Interesting section of line at 5 spans.

 

Looking at an old OS map this gantry was put in as a short cable dip, the cables coming back up onto OHL approx. 200m to the west. However, this section of line has now been dismantled. Strange requirement for a cable dip in this area unless there was unidentifiable apparatus in the dip itself?

 

The 33kV OHL CCT’s originally ran to Coggeshall, they are shown on the 1940 network diagram. However, the CCT’s were not part of the original SEE electricity scheme, so in this knowledge the line construction is 1933 onwards.

 

The towers 030 to 060 and 071 to 102 appear to be still standing as PZD route. The route has been split by RAF Birch (now closed down) with towers 060 to 070 clearly dismantled for the airfield. RAF Birch opened in 1942 which confirms the line was built well before this date. Conventional towers have been used in the original construction of the line including the termination at Coggeshall. The gantries appear to have been used in later date, installed as cable dips at RAF Birch as well.

 

The cable dip at Birch or in Colchester is not shown on the 1940 CCT diagram. A guess based on the above dates the original line construction as 1933-1940 with the gantries being a 1940-1942 addition.

 

Edited July 17, 2023 by Daniel Beardsmore
Additional notes

[Daniel Beardsmore]

On 16/06/2023 at 23:56, IC_225 said:

Project PL16:

 

Having found more drawings on the PL16 family of pylons …

 

What is the K number on them? I only have one such drawing and it’s of the “Scottish” S2 (contract K1201) and I’m curious if all the PL16 types shared the same K number. Possibly the “Scottish” types used a different K number.

 

An interesting question is how much of the CEB-L132 contract was ever fulfilled. Officially, CEB-L132 includes double and single circuit, each of which includes double earthwire (DD2 and SS2 etc) and transposition (DX and SX). I have never heard of PL16 or L16/L132 transposition nor of any double earthwire or single circuit in L16/L132. Classic PL16 seems to have no single circuit either: that is only known from “Scottish”, which may be called that because it was not built under any PL16 contract (that is, same towers used for a different contract that was not part of any PL16 contract, but the D2S and DD2S towers then got merged into the conventional “PL16” suite).

 

What I could not find any mention of in the spec is the conductor type! There was an amendment that only applied to (I think) 0.4 sq in conductors, but no sign of any expectations with regards conductor type. (The two implementations being 0.175 sq. in. SCA designed by Blaw Knox and commonly known as PL16, and 0.4 sq. in. SCA variously known as L16 or L132, designed by Eve.)

The L12 spec clearly indicates the conductor type (700 mm² AAAC phase and 425 mm² earthwire) but whether all specs included this detail, I have no idea, as I only have a few so far (L132, L4(m), L7(c) and L12).

 

(CEB-L132 also formally allows for 45° entry angles into terminal towers, which is why we see this so often with PL16 and L16/L132. That practice no longer exists: DJT towers are needed for that, with DT only taking 0–5° entry.)

Edited July 19, 2023 by Daniel Beardsmore
K1201 confirmed

[Suzie]

On 17/07/2023 at 16:43, Daniel Beardsmore said:

 

Hey!

 

Those are Watshams gantries....

 

 

Here is the termination adjacent to the B1022 where the line from Colchester dips under Birch Airfield. The B1022 loops nicely round it for a good view, sorry photo is a bit fuzzy.

 

 

Just before is an isolating tower which looks like it might not be used much now since one of the operating rods does not appear to be all there! Not seen one of these anywhere else so it might be a bit rare.

 

 

And a more recent addition I guess where the line dips under the Great Eastern at Feering made of wooden poles - quite a contrast to the 1940s structures. Presumably this was done because of clearance issues with the 1959-1962 25KV  electrification work. This is adjecent to the A12.

 

[Daniel Beardsmore]

Curious … I was not expecting this to be such a steamy subject …

 

If that is an isolating tower, what controls it? They remind me more of the fuses you get on 11 kV but I’m far from an expert on power lines and I can’t make out enough detail to be sure of what I am looking at.

[Suzie]

5 hours ago, Daniel Beardsmore said:

Curious … I was not expecting this to be such a steamy subject …

 

If that is an isolating tower, what controls it? They remind me more of the fuses you get on 11 kV but I’m far from an expert on power lines and I can’t make out enough detail to be sure of what I am looking at.

There are two rods, one going up each side of the tower, you can see them in the picture as they are fatter than the corners with cross pieces to suport them. One side appears to have an operating lever rather like the ones used on 11KV poles, but on the other side the operating rod appears to end suggesting that the lever has been 'borrowed'.

 

Looking at the lower wire on the far side it appears to not have a connection, so I wonder if both circuits are in use, or if the disconnectors have been bypassed.

 

I am sorry that the picture is not very good. I will try and get a better one.

Edited July 28, 2023 by Suzie

[Daniel Beardsmore]

Apparently I should have bought a new camera last year before I accumulated heaps of substandard photos. First ever shoot with my new camera — not corrected in any way for levels, colour balance etc:

 

 

“PL16” D2S, 54 mm focal length (300 mm equivalent, camera maximum)

 

 

SEE PL1a D30 and “PL16” D2S

 

 

”PL16” D2 × 2, “PL4” D30 (over the horizon)

 

 

“PL16” D2

 

 

L2 D suspension insulator

 

 

L2 D30

 

 

L8 D30 (27.84 mm focal length, something something in 35 mm equivalent)

[Daniel Beardsmore]

It is rumoured here that the 10° towers in PL1 are known as S10S and D10S, and there is also mention of 5° angle towers S5S and S10S.

Does anyone have any idea where these terms originated? So far there seems to be no evidence that they were ever known like that. S10S and D10S implies separate tension (S10/D10) and suspension (S10S/D10S) towers. Both CS PL1 original Milliken (Central Scotland, also SEE PL1 and SEE PL2?) and SS PL1 revised Milliken (South Scotland and other contracts using Milliken towers) have only suspension 10° towers. (In CS notation they are called B1 single circuit and B2 double circuit, where A = 2°, B = 10°, C = 30°, D = 60°/terminal.)

There is still no sign of 5° angle towers as standard anywhere. Allegedly L3 has 5° towers in Scotland but no evidence for this or any other 5° type seems to have ever been presented.

[L2's are great!]

On the ZA line near Market Harborough, i give you a rather extensively modified L2 D2!!

[L2's are great!]

Also, some updated screengrabs of the works around the ZG and VQ lines 

[Daniel Beardsmore]

Post 2 photo 1 tower 1: seems to be some kind of hybrid between L12 D90 and DT. It’s got duplicate D90 earthwire crossarmlets, duplicate crossarms from D90 outer angle, middle crossarms from DT, duplicate outer angle bottom crossarms from D90 … (D90 and DT share the same body except for the very top.) Unless I am missing something here. I don’t have proper, clear drawings for all of L12 so my diagram list is incomplete.

[L2's are great!]

3 hours ago, Daniel Beardsmore said:

Post 2 photo 1 tower 1: seems to be some kind of hybrid between L12 D90 and DT. It’s got duplicate D90 earthwire crossarmlets, duplicate crossarms from D90 outer angle, middle crossarms from DT, duplicate outer angle bottom crossarms from D90 … (D90 and DT share the same body except for the very top.) Unless I am missing something here. I don’t have proper, clear drawings for all of L12 so my diagram list is incomplete.

Yeah I believe this tower will be used to route the T-pylons coming out of Bridgwater onto the ZG line which runs back to Melksham Sub. I have a feeling it might be modified into more of a D90 when the works are complete because at the moment ZG is still connected to Hinkley via one circuit. There is another one of these towers near Quainton I believe. Not sure if its classified as L12 or L13.

[Suzie]

Another interesting tower from Colchester. This one is at the hythe and tall presumably to allow galleons to pass underneath. All of the other lines (33KV and 25KV train supply) go under the river, only the 132KV goes over.

 

 

It is unusual having floors both in the tower and on the arms.

 

Edited August 15, 2023 by Suzie

[Daniel Beardsmore]

The weirdest tower I’ve seen in that regard is this Eve L3 (C864 type) D on Beauly–Blackhillock with crossarm floors:

 

https://www.flickr.com/photos/huntsman81/5389469131/in/album-72157625909636114/

 

No idea why.

[Daniel Beardsmore]

On 14/05/2023 at 22:51, pharrc20 said:

Alan the industry guy also said-

"PL series, they were Primary Line contracts in the early days of the grid and were numbered sequentially. I suspect that some designs were rejected in favour of others, that would explain the gaps. Then a few designs became 'adopted' in other areas, like the PL7 which became quite widespread. Eventually the PL16 became the favoured tower and still dominates our landscape today.
With fewer styles, manufacturing becomes easier, therefore cheaper. Maintenance stocks become smaller. Eventually it reaches a natural level."

 

The PL numbers appear to be region-specific. NWE PL2 for example is a river crossing. SEE PL2 appears to be Bedford to Little Barford and uses CS-PL1 towers (original Milliken) instead of SS-PL1 (revised Milliken) — not proven, just hypothetical. It seems that SEE was otherwise split into PL1a (GEC/Pirelli) and PL1b (Callender’s), north and south of the Thames respectively. The Watshams design that seems to have originated as SEE PL7 was also used at least in part for EE PL3, MEE PL9, MEE PL12, MEE PL13, SWE PL10 and SWE PL11. (EE PL3 is presumably nothing to do with CE PL3 that was Blaw Knox, the precursor design it seems to CE PL4.)

 

“PL” for “Primary Line” appears to be true. There were also SL (“Secondary Line”?) contracts for 33 kV and 66 kV, which tend to be mistakenly called “pre-grid” towers.

[Daniel Beardsmore]

6 hours ago, L2's are great! said:

Yeah I believe this tower will be used to route the T-pylons coming out of Bridgwater onto the ZG line which runs back to Melksham Sub. I have a feeling it might be modified into more of a D90 when the works are complete because at the moment ZG is still connected to Hinkley via one circuit. There is another one of these towers near Quainton I believe. Not sure if its classified as L12 or L13.

 

Details on L13 are still confusing. One fellow indicated that it would likely never see the light of day as it relied on steel angles that went out of production. I’m also led to believe that it’s now being used here and there, but I have no actual formal confirmation. L13 seems to be basically a modified Eve L3. There are L13 drawings in private hands but as none of them are confirmed to represent the production design, I have decided to ignore L13 for now as there is just not enough reliable data to work from. It’s more a matter for a dedicated pylon community but, so far as I know, that no longer exists. The PAS folk of old are mostly all vanished into oblivion and on Facebook it’s just said to be place to share photos not detailed knowledge.

 

My own work has stalled, as the PL naming system has been demonstrated wanting and is now proved completely inadequate as it omits various types. That includes the “Blaw Knox PL7” that Matt is keeping quiet on. I have one crushed drawing of the DD2° and it doesn’t name the PL scheme, only the Blaw Knox scheme (K5735). I doubt it’s SEE PL7 (South East England region) — it might be some other region’s PL7 scheme.I have list of “standard” tower types that omits Watshams entirely (under any of the many PL schemes that used it); it does appear to name “PL16”, “J.L.EVE” and “L132 (1940)” separately but Watshams pre-dates CEB-L132. The “Blaw Knox PL7” DD2° drawing appears to be from 1941, so that could fall under L132.

 

I’m fairly stuck now until I can ever devise some kind of page naming arrangement to cover all the unnamed types, bridge the types with numerous designations, and handle ambiguous designations like “PL1b” and “PL3”.

[pharrc20]

On 04/08/2023 at 17:15, Daniel Beardsmore said:

It is rumoured here that the 10° towers in PL1 are known as S10S and D10S, and there is also mention of 5° angle towers S5S and S10S.

Does anyone have any idea where these terms originated? So far there seems to be no evidence that they were ever known like that. S10S and D10S implies separate tension (S10/D10) and suspension (S10S/D10S) towers. Both CS PL1 original Milliken (Central Scotland, also SEE PL1 and SEE PL2?) and SS PL1 revised Milliken (South Scotland and other contracts using Milliken towers) have only suspension 10° towers. (In CS notation they are called B1 single circuit and B2 double circuit, where A = 2°, B = 10°, C = 30°, D = 60°/terminal.)

There is still no sign of 5° angle towers as standard anywhere. Allegedly L3 has 5° towers in Scotland but no evidence for this or any other 5° type seems to have ever been presented.

There is at least one PL1 single circuit tower near me that might explain what the S5S, if that is what it is, as the suspension insulators are angled to deviate the line. I haven't had an opportunity to go and have a closer look yet as it is off down a busy country lane, but if you look at this Google Earth location and the street imagery, you should see what I am on about.

https://maps.app.goo.gl/7Am9T9Pqo4M2AbWD9

 

The next tower along south is also interesting too - would this be an Milliken S10 still? The next tower south appears to be a Milliken S30.

 

Cheers Paul

[pharrc20]

35 minutes ago, Daniel Beardsmore said:

 

The PL numbers appear to be region-specific. NWE PL2 for example is a river crossing. SEE PL2 appears to be Bedford to Little Barford and uses CS-PL1 towers (original Milliken) instead of SS-PL1 (revised Milliken) — not proven, just hypothetical. It seems that SEE was otherwise split into PL1a (GEC/Pirelli) and PL1b (Callender’s), north and south of the Thames respectively. The Watshams design that seems to have originated as SEE PL7 was also used at least in part for EE PL3, MEE PL9, MEE PL12, MEE PL13, SWE PL10 and SWE PL11. (EE PL3 is presumably nothing to do with CE PL3 that was Blaw Knox, the precursor design it seems to CE PL4.)

 

“PL” for “Primary Line” appears to be true. There were also SL (“Secondary Line”?) contracts for 33 kV and 66 kV, which tend to be mistakenly called “pre-grid” towers.

Good point, there definitely seems to be a regional split on the tower designers/builders for the PL type tower designs.

 

Yep, I have seen SL mentioned as Secondary Line too for those lines operating at 33 kV and 66 kV too. Exactly where the phrase "pre-grid" appeared from I am not certain.

 

 

[pharrc20]

6 hours ago, Daniel Beardsmore said:

The weirdest tower I’ve seen in that regard is this Eve L3 (C864 type) D on Beauly–Blackhillock with crossarm floors:

 

https://www.flickr.com/photos/huntsman81/5389469131/in/album-72157625909636114/

 

No idea why.

My guess would be is it a river crossing tower and the crossarm floors permit safer working at height at this location?

[Daniel Beardsmore]

If you mean this one, it’s just SS-PL1 S10: https://www.google.com/maps/@53.1866334,-2.4871302,3a,48.1y,159.58h,97.61t/data=!3m6!1e1!3m4!1sI4wOGB9vbKtdZUvXB8WVPg!2e0!7i16384!8i8192?entry=ttu

[Daniel Beardsmore]

Erection diagram for SS-PL1 S10° is on my PL1 page: http://telcontar.net/Power/pylons/PL1

 

No mention of “S10S” though; never seen that used anywhere. On tower schedules it’s just S10 or B1.

[L2's are great!]

Towers ZZA71 and ZZA72 at South Shields Sub. Running from just north of Hartmoor up to Blyth. Quite a few L2 D90's appear up here too!