Milliken E177

Contents

• Overview
  • General data
• Tower forms
  • Examples
• Tower details
• See also

Overview

E177 is a 33 kV distribution tower type, used on scheme SWE SL2 and apparently (not verified) also SWE SL3. E177 is notable for including quad-circuit towers: these have four crossarms in long–short pairs. The upper two crossarms carried the double-circuit line from Nursling to Southampton while the lower two crossarms carried the double-circuit line from Nursling to Winchester. The quad-circuit line split out into separate double-circuit lines on a junction tower in Romsey. Today, the quad-circuit towers carry only two circuits instead of four.

One curious characteristic of E177 is that neither the double-circuit nor quad-circuit line towers have a bend line. The corners of the tower are a continuous straight line from the base of the peak to the ground. (This is called a narrow base tower.)

The D10° tower is a suspension tower, which is very unusual in the UK and a long-abandoned practice. The only known D10° towers—those visible on Google Street View—are all in straight line positions and appear to have been chosen for supporting long spans.

General data

Tower forms

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

The designation of F3 is an assumption that the F four-circuit line tower permits 3° deviation the same as the double-circuit line tower.

The outline and dimensions for the (undesignated) F3 tower are given in [Marshall]. Google Street View was used to correct the diagram.

The F72 diagram is taken from the orientation and line diagram (XM911-78A) for the junction tower where the quad-circuit line from Nursling divided at Romsey into conventional double-circuit lines to Salisbury and Winchester. This junction tower uses the F72 E20 body with the outer-angle, square-ended F72 crossarms on both sides. Very little of the tower is depicted, so the inner-angle crossarms and the body bracing were derived from Street View from the heavy angle towers in Southampton, which all appear to be F72. (The angle towers at Romsey are similar but designed for a smaller angle.)

“GPO crossing” towers carry cradle guards suspended between the extended middle crossarms and the extra fourth crossarms; these offer enhanced protection for General Post Office (GPO) telecommunication lines against fallen conductors. Two D60 GPO crossing towers straddle Braishfield Road in Romsey and the diagram for this type is derived entirely from Google Street View as the schematic has not been recovered. Earthing arms were used for road crossings:

Examples

Out of range.

Tower details

The height and clearances are obliterated from the D10 general arrangement drawing; they are instead taken from the earthing arms drawing covering D3 and D10. The tower height is thus an estimate only, as is the spacing between the peak and top crossarm. Base width is at ground level or top of stubs according to each drawing: they are not consistent.

See also

• “Pre grid pylons” album (Flickr)