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Sources for British electricity pylon information

Contents

Sites and services

Tower drawings

Where possible, outline diagrams of towers are taken from the actual general arrangement (GA) and erection diagrams (ED) of the towers themselves. These drawings are not always dimensionally accurate, so some corrections are made to bring the diagrams in line with actual towers; this is especially the case with tower peaks, which for purposes of clarity were often not drawn to scale.

For the outline diagrams, the source (or sources) of each drawing (along with comments regarding corrections) is recorded in the SVG metadata, which can be most readily accessed by opening the image in a new tab and viewing the source code to the image (e.g. right-click → Open image in new tab, then right-click → View page source, then scroll to the bottom of the SVG XML data to the metadata section). For tower dimensions tables, the drawing numbers are listed as the sources for the tower types.

Documents and articles

Where publicly available at the time of reading (for free or for a cost), these documents are linked below. Documents that were freely available that are discovered to have disappeared (link rot) will be archived here. Documents below with no link were not publicly available and are listed simply to provide the details for the source.

400 kV Grid
The 400 kV grid system for England and Wales, E.S. Booth, D. Clark, J.L. Egginton, and J.S. Forrest, Proceedings of the IEE - Part A: Power Engineering, 1962 (IET Digital Library, £12.50)
Beauly to Mossford
Proposed Beauly to Mossford 132kV Line, Transmission Reinforcement, Figure NTS 2, Typical Tower Images and Dimensions, SSEN; contains a defective L7 diagram that was used as a starting point for the diagram shown here
Brechfa Forest Connection
Existing Line Survey Report, Brechfa Forest Connection Project, January 2014, Western Power Distribution
Clearances
CP420 Part 2 Chapter 15: Clearances, Issue 3, 10th March 2017 (Electricity North West document); contains diagrams validating PL16 D2S and naming L3 DS, as well as outlines for NWE PL1; sadly none of the drawings state or depict the full towers and cannot be used as a basis for diagrams here.
Castlereagh–Eden
Castlereagh to Eden Case of Need, January 2021, SONI
Coire Glas Connection
Coire Glas Connection presentation slides (January 2022)
Development Near Lines
National Grid: Development Near Lines (Planning & amenity aspects of high voltage transmission lines and substations), revised July 2008
Dounreay to Mybster
Proposed Dounreay - Mybster 275 kV / 132 kV, SSEN (source material for L8 reduced size)
EuropeAid 114479
Invitation to Tender no. EuropeAid/114479/D/S/SL, Emergency Rehabilitation of Transmission & Distribution Network
Dunoon
Virtual Consultation Booklet - August 2021, SSEN Dunoon project
East Coast 400 kV EIA
East Coast 400 kV Overhead Line Upgrade Environmental Impact Assessment Report Volume 2 | Main Text, January 2021, Scottish & Southern Electricity Networks (provides approximate tower heights for a number of L2 and L8 models)
Elmwood–Glenagnes
Elmwood-Glenagnes 132kV Cable Works Core Non-Load Engineering Justification Paper, SSEN (source material for “J.L.Eve PL16”)
Goulty
Goulty, George A. (1969) The transmission of electricity in England and Wales; land use, and amenity aspects, Durham theses, Durham University. Contains drawings of CEB L132 (1948), BES L7 (1963), BES L2 and L3 (1956), BES L8 (1966) and BEDS L6 (1966) on page 153 (PDF page 158).
Hinkley Point C
Hinkley Point C Connection Project: Design Drawings 132kV Overhead Lines (May 2014), covering wooden pole 132 kV, L4m, L7(c) DT, L8c, L12 and T pylons. Amusingly this National Grid document uses the term “pylon” instead of “tower” throughout.
Inveraray–Crossaig
SSEN — Inveraray–Crossaig brochure
Lairg–Loch Buidhe
Lairg-Loch Buidhe Overhead Line Project (December 2017), SSEN (archived as the original file has since been deleted).
Marshall
The lower-voltage sections of the British grid system, C W Marshall, Journal of the Institution of Electrical Engineers, 1933 (IET Digital Library, £12.50)
Meath–Tyrone
ESB International — Meath-Tyrone 400kV Interconnection Development Tower Outline Evaluation and Selection Report (November 2009)
NeSTS SSEN003
New Suite of Transmission Structures: NeSTS (SSEN003), SSEN (source material for L8 reduced size)
Nicholls
Recent progress in the design of the high-voltage overhead lines of the British grid system, W J Nicholls BSc, Journal of the Institution of Electrical Engineers – Part II: Power Engineering, 1945 (IET Digital Library, £12.50)
North Humber–High Marnham
North Humber to High Marnham Corridor Preliminary Routeing and Siting Study, June 2023, Issue 1, National Grid (source material for L13 design)
NSP/004/030
NSP/004/030 - Specification for the construction and refurbishment of 33-132kV tower lines, Northern Powergrid
NSP/004/127
NSP/004/127 - (OHI 27) Guidance on the Selection and Application of Insulators, Northern Powergrid
Overhead Line Conductors Carrying Optical Fibres
Overhead Line Conductors Carrying Optical Fibres, Electricity North West
Protean and POC-MAST
The Protean and POC-MAST design presentation, British Power International
Richborough 5.4.2D
National Grid: Richborough Connection Project document 5.4.2D “Proposed South East Water Reservoir - Route Options Appraisal (contains an L12 LD diagram on page 10—PDF page 18—albeit not named as such and with incorrect aspect ratio)
Skye reinforcement
Skye Overhead Line Reinforcement Strategy, SSEN
Standard Tower Types
“Standard tower types utilised in the UK for 132kV and above”, unknown origin, compiled by C Blair 7th May 1997 as “TYPL.ST1.WK4”. The authenticity of this material is not verified: do not treat the tower designations within this material as authoritative.
SWS Forum 08/06/2017
South West Scotland Forum, 8th June 2017 (contains conductor information and a traceable location of L132)
Telecoms Work on Overhead Lines
Management of Telecoms Work on Overhead Lines - Operational Safety Manual - Section 7.3, SSEN
Tower Bible
The “Tower Bible” is set of Central Electricity Authority (Eastern Division) tower plans compiled into a PDF by Jon Bruford to enable easy identification of tower types. The original plans were drawn between August and December 1956. Covered in the Tower Bible are EE PL1, SEE PL1a, CE PL4, SEE PL7, SWE PL16 and J.L.EVE (L16). Drawing numbers for SEE PL2 DT and for single-circuit EE and CE PL1, SEE PL1a, SEE PL2 and K1201 and for L2 and L3 are given but these drawings were not included. Also missing are the pages for less common types such as SEE PL1a DX and the Eve and Blaw Knox gantries.
Enhanced tower bible
This is a more complete set of Central Electricity Authority ED-series drawings, with other drawings substituted for some of the missing pages. There is significant coverage of single circuit, and double earthwire is now included, but the items in the table of contents’ bottom-right block (junction towers, gantries etc) are all still missing. While Jon Bruford made the original tower bible public, no such permission was sought or granted for the enhanced version by the person who compiled it, nor is it possible now to obtain such permission, so it is not made public here.
Transmission tower development
Transmission tower development in the UK, C. Lomas, Engineering Structures, Volume 15 Number 4, 1993 (source material for L6(m) and other technical information)
Uprating of Overhead Lines
Uprating of Overhead Lines, Roshan Bhattarai B.E. M.Tech., Cardiff University PhD thesis, 2011 (includes tower design designations for L132, L2, L3, L4 and L7 giving the conductor and earthwire types)
Wires Pipes Pylons
A publication subtitled “Guide to landowners and their advisers”, published in 1962. See limited subset of pages on Flickr. This document contains slightly distorted diagrams of L2, L3, L6 and L132 straight line towers.
Wylfa–Pentir
Wylfa to Pentir Preferred Route Corridor Selection Report (2015), National Grid (North Wales Connection Project) (source material for L13 design)
YG-DCO-048
Yorkshire Green Energy Enablement (GREEN) Project Volume 6 Document 6.1 Consultation Report Final Issue A November 2022 (page 247—PDF page 254—tentatively confirms that L66 has a 1000-foot standard span)

Google

Google Street View is utilised for multiple purposes, in particular:

Because Google use intractible URLs for Street View, all links to Street View material are relegated to the finds section. Now that Google enforce the newer format hideous URLs universally (with no way to kick a page back into the simpler URL format), no new discoveries are being documented there.

It should be noted that most if not all of this could be illegal. Per the Google Maps Platform Terms Of Service:

(c) No Creating Content From Google Maps Content. Customer will not create content based on Google Maps Content. For example, Customer will not: (i) trace or digitize roadways, building outlines, utility posts, or electrical lines from the Maps JavaScript API Satellite base map type; (ii) create 3D building models from 45° Imagery from Maps JavaScript API; (iii) build terrain models based on elevation values from the Elevation API; (iv) use latitude/longitude values from the Places API as an input for point-in-polygon analysis; (v) construct an index of tree locations within a city from Street View imagery; or (vi) convert text-based driving times into synthesized speech results.

Even documenting the location of power lines of a specific series (e.g. listing Eve 0.175 lines) identified by Google Street View surveys could be deemed illegal. The example violations given however are more in line with using Google’s services to create rival services or services that unfairly appropriate Google’s data. Using a Street View depiction of a tower as a basis for an outline drawing is unlikely to be a problem, but Google do not set a lower bound on what they consider unjust.

Correspondence

Where possible, public disclosure of information obtained by private correspondence with both industry employees and other amateurs is avoided due to the lack of formal verifiability, and because it does not seem appropriate to quote or name people with whom the reader will not be familiar. Various information thus obtained has been later proven false, for example the widespread misconception that “PL1” and “PL1b” are the same tower series. Where such information is corroborated or backed by evidence (e.g. industry drawings and manuals), the information can be treated as at least tentatively verified.