J L Eve C772

Contents

• Overview
  • C1415
  • General data
  • “PL6”
• Lines
• Tower forms
• Tower details
• See also

Overview

J L Eve C772 is a custom 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 light construction family and use lighter weight, lower capacity 0.125^□″ SCA (Tiger) conductors. The complete project ran between Clachan and Carradale, with the Clachan–Inveraray section using C670 towers with standard 0.175^□″ SCA (Lynx) conductors.

The Inveraray–Carradale line did not use an earthwire. As with other light construction types, C772 towers used reduced 11′ phase clearances and a reduced height to the bottom crossarm. 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.)

C772 is one of several types classified in Scotland as “PL16”, although they are not interchangeable with Lynx and Zebra 132 kV towers.

SSEN reported in 2021 that the “existing Inveraray-Crossaig overhead electricity transmission line was built back in the 1950s”; the drawings date between 1957 and 1960.

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.

C1415

The C772 tower suite was revised as C1415 circa 1970; the only change appears to be the provision for an earthwire.

General data

Designed for	NoSHEB (North of Scotland Hydro-Electric Board)
Design contract	J L Eve C772
Found
Height (straight line tower)	72′–6″ (22.1 m)
Dates back to	1957–60 (drawings)
Voltage	132 kV
Known conductors	Single
Design conductor	0.125□″ SCA (Tiger)
Circuit count	Double
Drawing ranges	C772

“PL6”

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.

The use of a “PL” (CEB/CEGB primary line) designation seems unlikely considering that these are NoSHEB towers and appears to be a mistake or misunderstanding. Possibly “PL16” was intended, as this type—despite taking a lighter conductor and not supporting an earthwire—is classified as a “PL16” type.

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.

The DT45 tower, as found at Carradale, appears to be the same as that of C1415 DT (0–10°) minus the earthwire peak. Eve 0.175 DT was used at Inveraray and Clachan (confirmed) and Port Ann, per drawing C772/147: Clachan–Carradale was a mixture of 0.125 and 0.175 conductor. No such tower presently exists at Port Ann.

[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.

See also

• Carradale substation (Geograph)