SEE SL4

Overview
- General data
Lines
Tower forms
Tower details
See also

Overview

SEE SL4 was a 33 kV secondary line contract in the South-East England scheme. The towers for this contract were designed by Watsham’s around 1934.

The S10 and D10 towers are of the suspension type.

General data

Designed for	CEB
Design contractor	Watsham’s
Found
Height (straight line tower)	?
Voltage	33 kV
Dates back to	1934 (drawings)
Conductors	Single
Circuit count	Single, double
Design conductor	?
Design earthwire	?

Lines

The SEE SL4 contract comprised a 33 kV ring within Essex, running between Colchester, Frinton-on-Sea, Walton-on-the-Naze and Harwich. Three extensions (a)–(c) were also recorded:

Three Bridges to East Grinstead (East Sussex, illustrated here)
Basingstoke to Alton, Hampshire
Tee-off to Ramsgate (Kent)

Tower forms

Not all drawings have been recovered. A GPO crossing tower can be found in Wivenhoe at the junction of Colchester Road and Elmstead Road, but there is presently no drawing for this. Due to the limited number of recovered drawings, it’s not presently possible to determine whether the line towers were D3 and S3 or D2 and S2.

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

Single circuit

Double circuit

The D60 GPO crossing diagram is loosely approximated according to Street View depictions of the examples in Wivenhoe and Thorrington.

Examples

None known.

Tower details

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

Tower dimensions
Type	Source	Height	Base width	Crossarm width
Line (DC)	No material recovered
D10	2264C	59′–6″ (18.1 m)	8′–6″ (2.6 m)	17′–0″ (5.2 m)
D30	No material recovered
D60	(illegible)	56′–0″ (17.1 m)	16′–0″ (4.9 m)	15′–10″ (4.8 m)
D60 GPO crossing	No material recovered
DT	2288D	56′–0″ (17.1 m)	15′–0″ (4.6 m)	18′–0″ (5.5 m)
Line (SC)	No material recovered
S10	2261B	54′–0″ (16.5 m)	6′–0″ (1.8 m)	13′–6″ (4.1 m)
S30	2271A	50′–0″ (15.2 m)	8′–4″ (2.5 m)	12′–6″ (3.8 m)
S60	No material recovered
ST	No material recovered