A stabiliser being set by theodolite on the Mangahao line, this method was first practised in New Zealand by F.H.M. Hanson on the Mangahao – Khandallah 110 KV line and quickly became the standard method. Previously stabilisers were set to templates supplied by the tower manufacturers. Hanson was late commissioner of Works and retired in 1961.The Mangahao Power Station provides hydroelectric power and is situated near the town of Shannon. It serves Wellington, Horowhenua, Taranaki, Hawkes Bay, and the Wairarapa. After being delayed by WWI, construction began in late 1919 and the station opened in November 1924.