Construction of The Masts
The masts were designed and constructed by Head, Wrightson & Co. Ltd. of Thornaby-on-Tees. Although the original plan was for 16 masts, tests confirmed that the field strength of 12 was more than adequate. This also helped to control costs.
Each mast was 820ft high, triangular in shape, with 10ft sides and weighed (including stays) 200 tons. Each one rested on a hemisphere and socket joint (to allow movement at the top) and was held up with fifteen stays made of galvanized, high-tensile steel wires. It took one hundred men to move the longest stays into position.
The erection of the masts involved the placing in position of almost one million separate parts, and it’s worth noting that not a single part or member was ever brought down again for alteration after being secured in position.