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Marshall and Nicholls types

Contents

Overview

[Marshall] (1933) and [Nicholls] (1945) included the basic specifications of a number of 33 and 66 kV tower types, for which there was more variety than 132 kV.

Matching these specifications to known tower suites has proved challenging, due to the lack of data all round. Some of the unmatched types are likely to be matched once the dimensions of known tower types are found, while others may represent types that are entirely demolished.

Progress

Type Tower suite Notes
  • Marshall type 1
  • Nicholls type 1
  • Marshall figure 9
 ? Marshall and Nicholls types 1 are the same type, but Marshall figure 9 doesn’t match these tabulated dimensions. Type 1 is probably J L Eve C15 0.15 but too few dimensions have been recovered to verify this. It is not J L Eve C15 0.1 however.
  • Marshall type 2
  • Nicholls type 3
 ? 52′–3″ tall line tower, 8′–0″ base width, and minimum crossarm spacing of 6′–6″.
  • Marshall type 3
  • Marshall figures 10 and 11
 ? Almost certainly SEE SL2 and/or SEE SL3(b), both almost identical. Again, the dimensions in figures 10 and 11 don’t match the tabulated dimensions. The known SEE SL3(b) dimensions match the figures but not the tabulated data.
Marshall type 4 ? This is an unknown type; the 42′ tall line tower has as rectangular base of 4′ × 2′–6″ and a minimum crossarm spacing of a mere 5′–6″. There are no types known that would fit this.
Nicholls type 2 ? This is an exposed terrain type, with 10′–6″ crossarm spacing as with NWE SL4. It’s not clear whether there is any type known that would match these dimensions.
Nicholls type 4 NWE SL4 Good match.
Nicholls type 5 ? This type has a minimum crossarm spacing of 8′–6″ and (per Nicholls figure 9, showing the same dimensions) was designed by Blaw Knox. The design is very similar to that of SEE SL6 but different enough that, if it does represent SEE SL6, is drawn incorrectly; the diagrams can be found on the unidentified types page.
Nicholls type 6 ? This is a comparatively small type, with a minimum crossarm spacing of only 6′–0″. There is no indication at present as to what this might have been.
Nicholls type 7 ? The only candidate at present is SEE SL4; too few dimensions from SEE SL4 are presently known to confirm a match, and there are other unmapped Watsham’s types that this could be. SEE SL4 contains single circuit, which is not mentioned for any of the types in Nicholls.
Nicholls type 8 Milliken E177 This is a good match for the double circuit portion of E177, but—as with type 7—no mention of single circuit is made in Nicholls, something that E177 does contain.