Jyoti Structures Limited has successfully type-tested a set of three 132 kV double-circuit (D/C) transmission line H-frame structures using composite fibre poles supplied by RS Poles of Canada. The poles stand 25 metres above the ground with steel cross-arms and cross-braces. The heaviest structure weighs around 8.5 tonnes and was assembled horizontally on the ground and lifted on to the test bed in one piece.
The H-frame structures have been designed by UK-based Balfour Beatty and will be employed on a new 132 kV transmission line in Scotland for SSE. The structures will be installed at a high altitude and would have to withstand significant wind and ice loadings. The structures are comparatively lighter than equivalent steel H-frames, and are suitable for erection by helicopter in remote areas.