J L Eve C1415

Contents

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

Overview

J L Eve C1415 is transmission tower type used for the line constructed by the North of Scotland Hydro-Electric Board (NoSHEB) out to Dunoon. The line supplies the Dunoon Grid Substation outside Sandbank (near Dunoon), Argyll and Bute, Scotland (55.976° N 4.948° W). It crosses Loch Long, and presently terminates on a junction with a PL16 line at Garelochhead (56.090° N 4.816° W). The line uses a mixture of C1415 towers, Eve 0.175 and an unspecified Blaw Knox 0.175 type. Special towers are used for the Loch Long crossing and this might be what SSEN referred to as the Blaw Knox type.

These are “light construction” towers, designed for lightweight 0.125^□″ SCA (125 mm² Tiger ACSR) conductors. The towers are unusually small, with 11-foot phase clearances and line towers only 22 metres tall.

C1415 is a derivative of the earlier C772 type; C772 did not support an earthwire, while C1415 does.

The only C1415 drawing recovered is for the D10 and dates to 20/02/1970. SSEN’s drawing set is C1824, from 1975. The C1824 drawings are metricated. The very early metrication raises the possibility of a second line built with these towers, but no such line is known. Alternatively, the drawings could have been pre-emptively metricated early on ahead of any future tower damage or failure.

The C1415 line is scheduled for replacement in 2025; a new line built on L7(c) towers will be taking its place, re-using the existing Loch Long crossing.

General data

Design contractor	J L Eve
Found
Status	Pending replacement and demolition
Class	Light construction
Height (straight line tower)	73′–3″ (22.3 m)
Voltage	132 kV
Dates back to	1970 (sole recovered C1415 drawing)
Known conductors	Single
Design conductor	0.125□″ SCA (125 mm² Tiger ACSR)
Design earthwire	?
Circuit count	Double

Lines

• Dunoon to Garelochhead, until its upcoming replacement and demolition

Tower forms

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

Note the asymmetric bracing on the transverse faces of the D30 and D60 towers, an Eve trait.

The DT general arrangment and erection diagram didn’t include the extended top crossarm, so this is estimated from Google Street View based on a diagonal view of the terminal tower at Sandbank.

The D10, D30 and D60 GA&EDs depict the earthwire peaks taller than the stated 8′–3″ height. The D10 and D30 diagrams were simply tweaked as the error was minor. For the D60, where the error was significant, the height of the top crossarm has been preserved in order to best approximate the actual towers (as best as can be made out from Google Street View) and the remainder of the peak reduced in height.

Some of the towers have additional crossarm bracing; it’s not clear whether this is strengthening or whether these are uplift crossarms.

Tower details

Crossarm width is the total width across the widest crossarm, to the conductor centrelines and not end of steelwork. Tower height is to the bottom of the top of the peak.

National Grid’s C1415 drawing schedule includes a DJT type, of which nothing is known; and National Grid do not list many drawings for the DJT, and there is no general arrangement or erection diagram recorded.

The terminal tower’s entry angle range is 0–10°, which is very unusual.