Miller’s Crossing, Exeter (Structures)

This 45m long slender steel deck crosses the River Exe in Exeter, allowing pedestrians and cyclists to cross with plenty of space.

The deck is supported by McAlloy tie bars running up to a vertical A frame then onto raking A frames with the tie bars being held down with a 50tonne counter weight in the form of a millstone. The A frame stays are on the west bank of the river, between the river and the mill leat. Access was a major factor in erecting the masts and deck section.

The bridge was erected by installing the 2A frame masts and fixing the back stays to counter the weight. The deck was pre-fabricated into three sections, as it was to be supported by three pairs of stays.

The first section of deck was lifted on to the abutment and a temporary structure in the river and then connected to the tie bars. When the second section was lifted into position it was jacked up on the temporary structure to ensure the correct curvature before welding the first and second sections together. The third section was positioned using a similar system.

The tie bars were tensioned as the supports were lowered, monitoring the stress in each tie bar. The bridge also incorporated four dampers set into the hallow section to prevent any oscillations. This scheme was completed for Devon County Council.