CE PL3

Contents

• Overview
  • General data
• Can be confused with
• Lines
• Tower forms
  • Single circuit
  • Double circuit
  • Examples
• Tower details
• See also

Overview

CE PL3 is a Central England contract constructed using Blaw Knox towers. The CE PL3 type appears to be a brief precursor to PL4: PL4 appears to be largely the same design but with additional clearance between the top phase conductors and the earthwire.

CE PL3 is possibly the tower type to which double earthwire was first introduced. The “DD” and “SS” nomenclature for double earthwire towers was yet to be introduced: the towers use only “D” and “S” (e.g. D2, S30). National Grid’s drawing schedules use “SEW” and “DEW” for single earthwire and double earthwire, while the drawings write out “single earth-wire” and “double earth-wire” in full.

General data

Designed for	Central Electricity Board (CEB)
Design contract	Blaw Knox K1611
Found
Height (straight line tower)	86′–0″ (26.2 m) (double circuit circuit single earthwire) (presumed) 73′–3″ (22.3 m) (single circuit single earthwire)
Status	Historic, in service, rare
Voltage	132 kV
Dates back to	1936–37 (drawings)
Conductors	Single
Circuit count	Single, double
Drawing ranges	K1611 / XM1276

Can be confused with

• PL4/WGR

Lines

Known lines include:

• Stourport substation to Bishops Wood substation; this is a CE PL1 single-circuit line supplemented by an adjacent CE PL3 single circuit line, with a short section on double-circuit towers. At the Bishops Wood end, the line has been undergrounded.
• Bishops Wood substation to Worcester substation via Ombersley, also single circuit (the CE PL1 single circuit line is much further west); the line is undergrounded at Bishops Wood and commences 750 m from the substation on a K1201 ST.
• Towers 2, 3 and 4 on route PXW (Stagefields substation to Meaford C substation, Stoke-on-Trent) are CE PL3, specifically D30 DEW. Tower 5 is a PL4/WGR D60. The remainder of the line is PL16 and L4(m).

A single D30 SEW tower can be found in Tir-y-berth, Wales, on a WGR line between Ebbw Vale and Upper Boat.

The single-circuit line from Stafford substation to (presumably, as the line is buried) Bushbury B–C substation in Wolverhampton uses line towers similar PL3 S2 mixed with PL1-style Blaw Knox angle tower. These are listed under SS-PL1 for now.

Tower forms

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

Single circuit

The single-circuit angle tower diagrams are traced from various lines as depicted on Google Street View, scaled to the vertical clearances used with PL3, PL4, PL16 and K1201. Due to unaccountable discrepancies even in distant views, these diagrams are only very approximate. The difference in crossarm bracing between S60 SEW and DEW is per the only known example of S60 DEW. No S10 DEW, ST or SST towers are presently known.

Double circuit

The only documented evidence to date is the drawings for D30 single and double earthwire. The remainder of the diagrams are speculative only. D2 DEW and D10 DEW are based on photographs of towers on Hartlebury Common, as they fit with the general understanding that the only difference is in the earthwire shield angle on the angle towers. D60 DEW is based on a poor quality historic photograph depicting a tower (from an angle) that seems to fit. D2 SEW is based on another historic photograph said to be CE PL3 type; another photograph from the same source depicts a tower resembling D30 SEW. D10 SEW is also tentatively confirmed from a historic photograph of Stoke-on-Trent. D10 and D60 DEW are derived from the equivalent CE PL4 diagrams.

Examples

Tower details

See dimensions on the site guide page for a key to the tables.

CE PL3 is unusual for 132 kV in having different vertical spacings for each tower type.

The single circuit angle towers are assumed to have standard 49′–3″ bottom crossarm height and 12′–0″ between crossarms on the same side (per PL3 and PL4 double circuit and K1201), and a peak height of (per the double circuit towers) 4′–0″ for single earthwire and 3′–6″ for single earthwire.

See also

• Hartlebury:
  • CE PL3 or CE PL4 DD2 (Flickr)
  • CE PL3 DD10 (unconfirmed) (Flickr)
  • CE PL3 DD30 (Flickr)
  • CE PL3 S2 and Stafford–Wolverhampton S2 (Flickr)
  • CE PL1 S60 and CE PL3 S60 (both unconfirmed) (Flickr)