The M6 Motorway: Widening between Junctions 20 and 21A (Thelwall Viaduct) and Connecting Roads Scheme 1990

SCHEDULE 4 WITH KEY PLAN AND SITE PLAN PLANS AND SPECIFICATIONS FOR THE VIADUCT CROSSING THE RIVER MERSEY AT WOOLSTON

Points of Commencement and Termination

From a point south of the centreline of the River Mersey in the Borough of Warrington in the County of Cheshire 45 metres north of the north east corner of the pilecap of Thelwall Viaduct Pier HH and 93 metres south east of the north east corner of the eastern wingwall of the northern abutment of Thelwall Viaduct.

To a point north of the centreline of the River Mersey 88 metres north of the north east corner of the pilecap of Thelwall Viaduct pier HH and 49 metres south east of the north east corner of the eastern wingwall of the northern abutment of Thelwall Viaduct.

Construction

Composite steel girder and reinforced concrete deck on reinforced concrete piers.

Headroom

Headroom to be not less than 9.12m above normal navigation level which is 8.41m above Ordnance Datum to be maintained for a distance of 22 metres each side of the centreline of the navigable waterway.

Waterway

As defined by the above limits at normal navigation level.

Diversion of the Waterway

This would have the effect of diverting the southern bank of the waterway northwards by a maximum distance of 6 metres. The existing waterway width of 50 metres would be reduced to a minimum width of 44 metres.