180 tons per engine. As well, four tunnels including those at Manuka and Round Hill on the line restricted the physical size of what could be transported, leading to consideration being given to enlarging them. This would have been expensive and restricted use of the line while it was being undertaken. As an alternative an investigation was undertaken into lengthening the Tapanui Branch line from its terminus at Edievale though a tunnel and some clay cuttings in the Dunrobin Hills to the Clutha River where it could connect with the Roxburgh branch line. Eventually it was decided to wherever possible use the Roxburgh branch line for all construction materials and smaller items of equipment. These were transported on the Main South Line to Milton where they transferred to the Roxburgh Branch which conveyed them to Roxburgh and from there transported by road to the power station. Consideration was given to extending the line to the construction site but this wasn't proceeded with due to the difficulty of getting past the east end of the existing Roxburgh suspension bridge. To improve the line's carrying capacity some curve easements were undertaken near Round Hill. As the load carrying capacity of the existing roads was constrained by bridges at Henley (on State Highway 1) and Beaumont on State Highway 8) it was decided that as the Waikaka Branch railway line had no constricting tunnels it would be used to transport out of gauge heavy items such as the turbine runners and bottom bearing brackets. These items were transported on the Main South Line from the port at Bluff to the junction at McNab and then via the Waikaka branch line to its terminus at Waikaka. From there they were transported by road to the power station using a specialized transporter. This assist in the transfer from rail to road transport a 4-pole 30 ton (30.5 tonne) gantry was erected at the Waikaka railway station. The road between Roxburgh and the construction site was upgraded and a second bridge built on the over the Teviot River on the eastern side of the Clutha River to supplement the existing bridge. At the construction site a long single-lane Bailey bridge with a carrying capacity of 24 tons (24.4 tonnes) was installed in 1949 to provide access across the river. Timber used in the construction of the power station and the village was sourced from the Conical