Belfast four-circuit towers
Contents
Overview
This is a type of UK electricity pylon (steel lattice transmission tower) used for a dual-voltage line in Belfast. According to NIE Networks, the towers were designed by Callender’s and originally carried dual-voltage 110 kV plus dual-voltage 33 kV; the line is said to date to 1932. The crossarms for the 33 kV circuits have since been removed. In contrast to the Rannoch–Abernethy type, the upper 33 kV crossarm carried two phases per side, with the lower 33 kV crossarm carrying one phase per side.
All the towers have ladders instead of step bolts.
General data
| Design contractor | Callender’s |
|---|---|
| Found | |
| Height (straight line tower) | Unknown |
| Voltage | 2 × 110 kV + 2 × 33 kV (design) |
| Conductors | Single |
| Circuit count | Dual voltage double+double |
| Design conductor | Unknown |
| Design earthwire | Unknown |
| Normal span | Unknown |
Lines
The towers are used for a single line in East Belfast that presently runs from Airport Road substation (where it terminates on a PL16 DT) to Rosebank substation. The line has been de-rated and is likely now operating at 33 kV. This includes replacement arcing horns to reduce the arc gap length. The original line ran a little further at the north end, but the last few towers have been demolished and the PL16 DT erected outside Airport Road substation.
Tower forms
No material obtained yet.
The line tower peak is very similar to the peak of the Callender’s-designed SWE PL1(a)&(b) S2 single-circuit line tower. The line towers are similar to those of SEE PL1(b) but this is where the similarity ends.
Examples
The designations and deviation limits of each of the tower types is yet to be determined; the angle tower types are simply numbered here by ascending deviation limit. Angle 3 seems to have a 90° limit however.
Examples
See also
Four circuit configuration. No response from copyright holder, so these images are just dumped into a list for your inconvenience …
- Line tower, Beersbridge Road, July 1981
- Line tower, East Bread Street, October 1982
- Line tower, Grand Parade, July 1980
- Line tower obscured by watermark, June 1986
- Line tower, Newtownards Road, March 1982
- 33 kV crossarm detail, June 1984
- Smallest angle, Dee Street Bridge, March 1984
- Smallest angle, Sydenham By-Pass, May 1991
- Largest angle, Mersey Street, June 1981
- Largest angle, Victoria Park Station, September 1981
- Ladder detail, March 1984
- Possible 33 kV termination point, Connswater, August 1987
- Retermination on PL16 DT, Sydenham By-Pass, March 1984