Canadian Niagara Power is a supplier of electric power to the Buffalo market. The company's distribution network of 25 cycle power consisted of six 34 KV transmission lines between three towers over the Niagara River between Fort Erie and Buffalo. Ausenco was retained to assess the condition of one of the towers originally built in 1926 and recommend remedial action.
It became readily apparent that the 60 foot high tower could not be rehabilitated as it stood. The challenge: to build a new tower while allowing at least 50% of the transmission to continue at all times. Faced with this situation, Ausenco decided to build the new tower around and over the existing tower in two phases.
New foundations were installed adjacent to the existing foundations and a new, completely galvanised structure was erected.
The use of an all-galvanised design required careful engineering to ensure competitive capital costs.
Computer modelling was carried out to design the three central A-frames and transverse bracing. As each construction phase was completed, 50% of the transmission lines were decommissioned and recommissioned on the new half.
This process was repeated for the opposite side of the tower. Once all of the new conductors were in place on the new tower, the old abandoned tower inside was demolished. Capital Cost of the project was $450,000.