SEE PL7

Contents

• Overview
  • General data
• Contracts
• Can be confused with
• Lines
• Tower forms
  • Examples
• Tower details
• Examples
  • Bedford
• See also

Overview

SEE PL7 was a South East England (SEE) contract. This contract used a suite of Watshams towers that were conceivably designed for it specifically. The majority of examples depicted on Flickr are indicated to be within the SEE region, although one D2 tower in shown to be in Sheffield, putting it within the MEE (Mid East England) region.

General data

Note that no height options were given for D10 or DT. For DDT and DDT90 only E10 and E20 are known, but the far right of the chart is cut off at E20 and thus E30 may have also been present.

Contracts

PL7 was used for a single WGR (War Time Grid/Wartime Grid Reinforcement) contract; the remainder of the WGR contracts used CE PL4 towers.

Several PL7 drawings are annotated to indicate that the same tower type was used in other contracts. So far the data is inconclusive as very few drawings have been recovered.

• = recovered drawing, ✓ = listed on drawing as additional contract, ◈ = observed visually (undocumented)

Separate table due to the lengths of the scheme names:

Can be confused with

• L16/L55 (D2)
• PL16 (DD2)
• Eve 0.175 (D2, DD2)

Lines

Lines confirmed so far:

• Route PHA: Cut Throat Lane Switching Station to Austin Cannon Substation, Bedford; this 11-tower line is all double earthwire
• Carrington Substation (on the west edge of Manchester) to Crewe Substation. The Crewe end is double earthwire although the line terminates on a PL16 DDT90. At the Carrington end the line appears to have been remodelled as it finishes up on PL16 towers, all single earthwire. A short spur of “PL7” double earthwire towers connects the line to Knutsford Substation. Near Middlewich Power Generation Plant a short PL16 line tees off to Elworth Substation. There is also a junction south of Lach Dennis to an Eve 0.4 line to Lostock Substation outside Lostock Gralam, with its own junction to an L4(m) line to Lostock Works Anaerobic Digestion Plant.
• T(12) BEA – L36 is “Carrington–Broadheath–Sale”. Carrington to Broadheath is Eve 0.4, although the terminal tower at Broadheath is a PL7 DDT. Part-way along this line, there is a tee to Sale, which is mostly PL7 including the DDT.
• EE PL3, Ipswich–Stowmarket; confirmed PL7 at the Ipswich end, towards Bramford substation; from Bramford to Stowmarket the line is PL16, although at Stowmarket itself the line terminates on a PL7 DDT preceded by a PL7 angle tower (DD10 or DD30).

Former lines confirmed so far:

• MEE PL9, Osbaldwick–Melrosegate, undergrounded ca. 2011–2012; the east end is at Melrosegate substation; the west end is unclear, but it appears to have been later diverted on PL16 towers to Osbaldwick Grid Substation.

Other lines exist.

Tower forms

The following diagrams are shown to scale at 12 pixels per metre:

D90 and DD90 are omitted from the Tower Bible but such towers appear to have been constructed. A tower likely to be DD90 previously existed in Slough and a tower likely to be D90 can be found in Severn Way, Hunslet Trading Estate, Leeds.

There are also DT and DDT towers with extended top crossarms (here, “ETC” for short) for use with vertical downleads, of unknown designation:

These extended top crossarm terminal towers can be seen at the substation in Crawley, West Sussex, England (51.115° N 0.163° W).

PL7 line towers have an interesting design of middle and bottom crossarm. The rakers (top bars) merge part-way along the width of the crossarm and continue as a back-to-back double bar from there to the tip:

Examples

Tower details

Crossarm width is the total width across the widest crossarm.

Examples

Bedford

A short line of 11 PL7 towers, route PHA, runs from Cut Throat Lane Switching Station to Austin Cannon Substation, Bedford. Starting at Austin Cannon Substation on DDT tower PHA1, the line line crosses the River Great Ouse on two DD60 towers then goes north to Cut Throat Lane Switching Station. Being a short route, all of the towers are double earthwire.

From there, the line transitions to L4(m) briefly (three towers), then two PL4 DD2 double earthwire towers, before terminating on an L7(c) DJT in Manton Industrial Estate.

The photographs were all taken on 2nd September 2023.

See also

• PL7 D10 and D2, Sussex (Flickr)
• PL7 D2, Sussex (Flickr)
• PL7 D2, Sheffield (Flickr)
• PL7 D2 wired single-circuit, Hampshire (Flickr)
• PL7 D2, unknown location (Flickr)
• PL7 D10, Sussex (Flickr)