The men working on this Mangahao Line power pole near Masterton are as follows: Mick Gastern, top of pole; Wally Weastell, at left on the ground; Andy Rockel, M Astwood and G Clark on the right.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.