Safety helmets were worn during construction work on the Kiewa Hydro Electric Scheme and during its operation. Each group of workers had a different coloured helmet to identify their role.A pale green fibre glass oval shaped helmet with a small rim and with hard white plastic 'netting' inside - shaped with 6 pieces coming towards the outside from an oval in the centre. These are attached with screws. Around the circumference of the head is a plastic adjustable piece covered by soft plastic in the front. This has a wide cord attached that fits under the chin.On the outside front: a triangle colored in black with "operator" underneath. Inside rim at front: "Made in England"helmet. safety. kiewa hydro electric scheme. operator.