J L Eve C670 (Eve 0.175)

Contents

• Overview
  • General data
  • Origin
• Can be confused with
• Lines
  • Joint Eve/Blaw Knox lines
  • All Eve towers
• Tower forms
  • Crossarm plans
  • Strengthening
  • Examples
• Tower details
• C432/C579 and PL16
• Locations
  • Hemel Hempstead
• See also

Overview

C670 is a 132 kV UK electricity pylon (steel lattice transmission tower) series. The straight line towers are visually almost identical to those of J L Eve C534 but at 85′–8″ (26.1 m) tall they are 3′–2″ (1 m) shorter than C534 line towers at 88′–10″ (27.1 m). The larger C534 towers take 0.4^□″ SCA (ACSR) conductors, while C670 towers were designed for the more conventional 0.175^□″ SCA. C670 line towers and PL16 angle towers were intermixed on some lines in Scotland, with evidence suggesting that the line towers were designed first in 1946 and the remainder of the towers seven years later in 1953.

J L Eve drawing C670-196 (JE35/33751) from 19th November 1973 confirms that C670 is a L132 type.

General data

Designed for	North of Scotland Hydro-Electric Board (NoSHEB)
Design contractor	J L Eve
Found
Height (straight line tower)	85′–8″ (26.1 m)
Voltage	132 kV
Dates back to	1946 (line tower drawings) 1953 (angle and terminal tower drawings)
Known conductors	Single
Design conductor	0.175□″ SCA
Design earthwire	0.07□″ SCA
Circuit count	Double

Origin

Examination of a selection of drawings suggests that the towers were designed in two stages:

1. D2 and DD2 in 1946, for Tummel Bridge to Garry Bridge, Pitlochry (C432) and Beauly to Shin (C579)
2. The remaining towers in 1953, for the lines from Fort William

The dates and lines are given below (place names as on the drawings); each row of the table represents a single drawing:

The lines between Errochty Switching Station (near Tummel Bridge power station) and Clunie substation (Garry Bridge, Pitlochry) and between Beauly and Shin use Eve line towers (D2 and DD2) and Blaw Knox angle towers. The same pattern can be seen for the first half of the line between Errochty Switching Station and Abernethy; the latter half uses the Rannoch to Abernethy type. This fits with the idea that only the line towers were designed initially, although this remains unconfirmed.

The angle towers are so far only known as C670. The line towers fall under C432, C579 and C670; a CEGB drawing for the line tower uses C670, suggesting that this drawing range is a suitable representation for the whole type.

Once the complete series was designed, it was used as such in Scotland, England and Northern Ireland (not known in Wales).

Can be confused with

• J L Eve C534 (single Zebra suite)

Lines

Joint Eve/Blaw Knox lines

Joint Eve/Blaw Knox lines—lines with Eve line towers and Blaw Knox angle towers—confirmed so far:

• Rannoch to Abernethy between Errochty switching station and an unidentified location between Amulree and Buchanty. This is a diversion of the original line.
• Errochty switching station to Clunie substation (north-west of Pitlochry) (not fully confirmed due to lack of accessible views)

All Eve towers

All-Eve lines confirmed so far:

• Route PEB (Hemel Hempstead–Chesham, England): Hemel Hempstead Substation in Piccotts End (51.774° N 0.484° W) to Lye Green Grid near Chesham (51.723° N 0.59° W). From Hemel Hempstead to the tee-off point at Redbourn, PL16 is used, and from Lye Green to Watford, C670 is used. The terminal towers are DT (Piccotts End) and DT90 (Lye Green).
• Route PPB (Rickinghall Junction–Thetford, England): Rickinghall Junction (52.308° N 0.982° W) to Thetford Grid station (52.386° N 0.738° W)
• Route PKF (Rickinghall Junction–Diss, England): Rickinghall Junction (52.308° N 0.982° W) to Diss substation (52.372° N 1.107° W)
• Nairn to Keith in Scotland; this is part of the line from Beauly to Keith reported by SSEN to have been constructed in 1955. Beauly to Nairn is PL16. The whole line was reconductored and strengthened by Balfour Beatty on behalf of SSEN between 2018 and 2021.
• Macduff (57.664° N 2.498° W) to Keith in north Scotland, by way of a DT at Lintmill substation (57.673° N 2.813° W). Originally the line terminated on an Eve 0.175 DT at Keith substation (57.540° N 2.938° W), but it now terminates short of the substation on an L4(m) DT in a nearby field (57.545° N 2.935° W). The terminal towers are all DT, with “variant 2” used at Macduff and Lintmill.
• Eve 0.175 is used on the line between Kinlochleven and Fort Augustus, Scotland. Kinlochleven to Blar a’ Chaorainn is single circuit Trident. Blar a’ Chaorainn to where the line meets the (now split) Invergarry to Quoich line is Eve 0.175, with some interspersed super-strength L4(m) D towers. Between Blar a’ Chaorainn and Fort William, the line is dual voltage 132/33 kV; from Fort William it is double circuit 132 kV.

Three more lines originate at Coolkeeragh Power Station, Derry, Northern Ireland (55.043° N 7.246° W).

Route PNE, Stowmarket–Rickinghall Junction, is C534; the line splits into PPB and PKF that are each C670.

Tower forms

For a while, Eve 0.175 line towers were colloquially described as “3-X”, from the number of “X” bracing sections below the bottom crossarm; there are four of them in C534 D2 (called “4-X”), and only three in the C670 D2:

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

The DT drawing represents the most common type. Variant two represents the type used at Macduff and Lintmill, with extra front rakers on the top crossarm and no wider face to the bottom crossarm. Eve terminal towers are designed to be customisable and other variations may exist.

Uplift versions of D2, D10, D30 and D60 exist. For D2 the front and rear faces of the crossarms are braced instead of open. For D10 and D60 the crossarms appear to be strengthened but visually identical in design; D30 is likely going to be the same. Uplift towers accommodate for large changes in elevation between towers.

Crossarm plans

DT crossarm arrangement 1 is found at Macduff and Lintmill substations. Arrangement 2 is found at Piccotts End substation and formerly (before tower removal and line re-termination) Keith substation and appear to be what is used at Coolkeeragh Power Station.

Strengthening

The line between Beauly and Keith was reinforced by Balfour Beatty between 2018 and 2021. This project included reconductoring (replacement of the original 1955 conductors and fittings), foundation upgrades and tower strengthening. Both the PL16 (Beauly–Nairn) and Eve (Nairn–Keith) towers received additional steelwork. The diagrams below depict the result of the strengthening. They are not exact, but strengthening steelwork itself never seems to be exact.

Examples

Tower details

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

The DD2 combination earthwire/phase crossarm is also 5′–4″ tall.

C432/C579 and PL16

The photographs below show lines using C432/C579 line towers and PL16 angle and terminal towers.

Locations

Hemel Hempstead

The following photos are from farmland just past Hemel Hempstead to the northwest, halfway between Hemel Hempstead and Potten End; they were all taken on 9th September 2023. This is the line between Piccotts End (just north of Hemel Hempstead) and Lye Green to the southwest, outside of Chesham. The identification plates for PEB10 and PEB9 were clearly visible and are counted from the terminal tower at Piccotts End.

See also

• Eve 0.175 towers, Portsoy, Aberdeenshire, Scotland (Lintmill to Macduff line) (Flickr)