The Eiger Express is the world’s heaviest ever tricable gondola. The large incline of 1,385 metres and the length of the track at 6,480 metres require seven track supports and suspension cables with a diameter of 58 millimetres. The cable hoist work will take about 15 weeks.
Jungfrau Railways Director Urs Kessler explained on Thursday: “It is wonderful to see that the overall V-Cableway project is back on track with the construction sites at the Eiger Glacier, Grindelwald Grund and now with the cable hoist for the Eiger Express. This was achieved thanks to the great commitment of all those involved. The punctual completion of this project as a boost for the entire Jungfrau region and the Canton of Bern is extremely important”, added Kessler.
Various cables and auxiliary supports
The actual cable hoist begins with a light plastic rope with enormous tensile strength. This is placed on the supports by helicopter over the track. An initial stranded steel cable with a diameter of 32 millimetres and a total weight of 26 tonnes is attached to the lower end of this plastic cable.
This steel cable is now used as a front cable for a further stranded steel cable with a diameter of 48 millimetres and a total weight of 60 tonnes over the track up to the summit station. Since the ropes are thinner, they cannot be tensioned as tightly as the suspension cable installed in the end. This leads to the installation of auxiliary supports on the track, which hold the slack front cable above the trees of the forest, roads and the cogwheel railway. In order to have to erect as few of these auxiliary supports as possible, the ropes are pulled up the mountain by means of a cable hoist machine and simultaneously braked in the valley by a Zeck winch.
With the 48 millimetre thick front cable, the 58 millimetre diameter suspension cable with a total weight of 131 tonnes, which is necessary for the final stage, is now pulled in. The suspension cable is pulled through the summit station to obtain reserve lengths for winding on the cable bollard.
Long preparatory work and time-consuming cable hoist
This complex procedure is repeated four times until all four suspension cables (two cables for the track on the left and two for the track on the right) are pulled in and anchored. Now the track for the new railway has been created. Before the cable hoist is pulled in, the intermediate hangers for the cable hoist are mounted on the section between the suspension cables in place of the auxiliary supports. The intermediate hangers carry the cable hoist by means of cable pulleys.
Only now is the revolving cable hoist with a diameter of 56 millimetres pulled in. The continuous cable is used to move the cabins. The cable hoist is so heavy that it was produced in two pieces and transported to Grindelwald. To ensure that the cable hoist has sufficient basic tension, it is tensioned in the valley station using a tension weight of 26 tonnes.
The preparatory work for the cable hoist took months. The approximately 400 tonnes of assembly tools include cable winches, protective scaffolding for rail and road crossings and auxiliary supports. The four suspension cables and the cable hoist were transported to Grindelwald in several heavy transports.
Together with the Grindelwald-Männlichen Gondola Cableway (GGM), Jungfrau Railways is implementing the V-Cableway generation project for the long-term safeguarding of the future of tourism in the entire Jungfrau Region. The official ground-breaking ceremony for the 470 million Swiss franc V-Cableway project took place on 3 July 2018.
The construction work is still on track and the overall opening of the V-Cableway will be celebrated in December 2020. The interior work at the Grindelwald Grund terminal is continuing. The structural work on the multi-storey car park will be completed at the end of July. The interior fittings will then be carried out. The concrete work on the Eiger Glacier has been completed. Here too, the interior work is now continuing, both at the summit station of the Eiger Express and on the new third track for the Jungfrau Railway.