J L Eve C772

Contents

• Overview
  • C1415
  • General data
• Lines
• Tower forms
• Tower details

Overview

J L Eve C772 is transmission tower type used for the line constructed by NoSHEB (North of Scotland Hydro-Electric Board) in the 1950s between Inveraray and Carradale. These towers fall under the J L Eve 0.125 family. The Inveraray–Carradale was unusual in several respects. 132 kV lines were originally strung with 0.175^□″ SCA (ACSR) conductor; later, heavier and higher-capacity 0.4^□″ SCA conductor was also used, suspended from J L Eve 0.4 towers. The Inveraray–Carradale towers however are very small with low ground clearance, reduced vertical phase clearance of only 11′, used a low-capacity 0.125^□″ SCA conductor and the line was not fitted with an earthwire. Of these towers, SSEN noted in [Inveraray–Crossaig], “On average the existing 132kV towers are approximately 26 metres high with a span of 220 metres, giving a total of 384 towers between Inveraray and Crossaig.” (The line tower height is 72′–6″, or 22 m. The standard span for 132 kV towers is 900 or 1000 feet, 274 or 305 metres.)

J L Eve’s drawing series was C772. SSEN’s Inveraray–Crossaig brochure describes them as “PL16” but this is incorrect.

SSEN reported in 2021 that the “existing Inveraray-Crossaig overhead electricity transmission line was built back in the 1950s”; the only known drawing—the D2 tower clearance diagram—dates to January 1957. J L Eve referred to the line as “Clachan–Carradale”, possibly because Inveraray to Clachan also uses Eve towers, just of a different type.

It’s not clear how many of these towers still exist. Carradale to Crossaig was replaced around 2015 with L7(c), and Crossaig to Inveraray is now all believed to be L8(c). Tentatively it appears that the start of the portion from Port Ann to Crossaig is now a spur off the L8(c) line (which bypassed Port Ann) and remains on the original Inveraray–Carradale towers.

The tower type has also been described as “PL6” and as running from Sloy to Carradale. In the members-only area of the Pylon Appreciation Society forum, “lesc” stated the following in July 2009:

Brenchcoillie is near where the Scottish Hydro mysteries pass from Sloy to Carradale. They were undergoing maintenance and being painted a pale green colour perhaps as they pass through the loch lomond national park. Asking the Southern plc linesmen what kind of pylons (and showing the PAS stuff and other pics on my camera) they were got an old Scottish bloke telling me he thought they were PL6 put up shortly after WW2.

Little is known about the lines between Sloy and Inveraray, but one section is K9857 (PL16). The line from Inveraray to Clachan can only be observed at the Clachan end and appears to be J L Eve 0.175. The idea that the whole line from Sloy to Carradale was ever all the same tower type seems unlikely.

The use of a “PL” (CEB/CEGB primary line) designation seems unlikely considering that these are NoSHEB towers. Although the same towers could have been used in the CEB/CEGB portion of Scotland (South Scotland and Central Scotland) under a PL6 scheme (SS PL6 or CS PL6), a May–June 2024 visual inspection of Scotland’s entire 132 kV network found no other examples of these towers. No towers of this type are known to exist in the rest of the UK.

C1415

The C772 tower suite was revised as C1415 circa 1970; the only change appears to be greater earthwire shade.

General data

Design contractor	J L Eve
Found
Height (straight line tower)	72′–6″ (22.1 m)
Dates back to	1957 (only recovered drawing)
Voltage	132 kV
Known conductors	Single
Design conductor	0.125□″ SCA
Circuit count	Double

Lines

• Inveraray to Carradale, now reduced to a spur to Port Ann from the new Inveraray–Crossaig L8(c) line

Tower forms

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

The angle tower diagrams above are simply the C1415 drawings with their dedicated earthwire peaks removed; this so far is the only known difference between the two types.

[Lairg–Loch Buidhe] contains a drawing captioned “PL1” and implied to be the tower used on the line between Shin power station and Lairg grid supply point:

In reality this line is all K1201 and this is what is shown in the brochure’s photographs. K1201 S2 is 74′–3″ tall, or 22.6 metres, while the drawing of “PL1” is shown to be 22098 mm tall, precisely the height as the Inveraray–Carradale D2 (72′–6″). This is not really a single circuit tower: it is a double circuit tower configured as single circuit using custom crossarms, as one might expect for a more recent tower design. A visual inspection via Google Street View of the entire of Scotland’s 132 kV network in May–June 2024 has revealed no lines using this tower type, although it may have been used on isolated replacement towers or on a line now de-rated to 33 or 11 kV.

Tower details

Crossarm width is the total width across the widest crossarm. Vertical phase clearances are the vertical distances between the heights of the crossarms.