Blaw Knox K1641

Contents

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

Overview

Many 110 kV single-circuit wood pole lines in Northern Ireland use flat formation, single-circuit lattice towers for deviation and termination. These towers were designed as contract Blaw Knox K1641 around 1948, metricated as MK1641 in 1974; this type is also titled as “Northern Ireland 110 kV line / Contract N.I.624 / (Horizontally spaced conductors)”. The corresponding practice in Great Britain uses Blaw Knox K1420 angle and terminal towers.

Whether this type should be known as “Blaw Knox K1641”, “Blaw Knox NI624” or simply “NI624” (or “NI 624”) remains to be determined; “Blaw Knox K1641” has been selected based according to the convention of this website.

The designation “SCT” is listed in the [tower bible] but not depicted; towers of the same design exist at 132 kV substations, suggesting that K1641 SCT is simply a de-rated 132 kV tower. On this site they are classified as 110 kV for convenience.

General data

Designed for	?
Design contract	Blaw Knox K1641
Found
Height	?
Voltage	110 kV or 132 kV
Dates back to	1948 (drawings)
Conductors	Single
Circuit count	Single
Design conductor	?
Design earthwire	?
Drawing ranges	K1641 / XM2095 MK1641 / MXM2095 (metricated)

Lines

Widely used across Northern Ireland as angle and terminal towers on 110 kV single-circuit wood pole lines.

Tower forms

The following diagram is shown to scale at 12 pixels per metre:

The expansion of “SCT” is not known. The design matches that of terminal towers, and there is no reason to believe that the “T” does not denote “terminal”.

The angle and terminal towers have been added based solely on Google Street View. The S30 tower appears to be identical to the SCT from the front.

The drawing schedule includes an S90; this tower type has yet to be discovered.

Tower details

Crossarm width is the total width across the single crossarm.