In this clip from our ‘Bridge For Bristol’ DVD, retired Bridge Master David Anderson explains how Brunel and his team managed to cross the gorge, 75 metres above the water.
To begin building a crossing over the River Avon, hemp ropes were taken down the side of the gorge, across the river by boat and pulled up the other side. These ropes were used to haul six wire cables across the Gorge, which were planked across and bound with iron hoops, making a footway.
Two more cables were added to make handrails – and at head height there was another cable, along which ran a ‘traveller’, a light frame on wheels that carried each link of the chain out to the centre.
As well as being a walkway the wire bridge acted as staging on which the chain rested as new links were added. The temporary bridge was anchored by ropes to the rocks below to provide stability in winds.
When the first chain was complete the second was built on top, then the third. With the chains complete vertical suspension rods were fastened to the chains by the bolts that linked the chains together.
Two huge girders run the full length of the Bridge, visible to us today as the division between the footway and the road. Two long-jibbed cranes (one on each side) were used to move 5-metre-long sections of the girders into place where they could be attached to the suspension rods.
Cross girders underneath formed a rigid structure. The floor of the roadway was then put in place using Baltic pine timber sleepers.