|Carries||Original:4 lanes of M2 plus hard shoulder & Bridleway
New: 4 lanes of M2 plus hard shoulder
Rail: 2 tracks of High Speed 1
|Total length||Original: 997.3 metres (3,272 ft)
Rail: 1,300 metres (4,265 ft)
|Width||Original: 34.44 metres (113 ft)
|Longest span||Original: 152.4 metres (500 ft)
Rail:152.4 metres (500 ft)
|Clearance below||Original: 35.5 metres (116 ft) at maximum
|Opened||Original: 29 May 1963
Rail: September 2003
The Medway Viaducts are three bridges or viaducts that cross the River Medway near Rochester in north Kent, England. The two road bridges carry the M2 motorway carriageways. The other viaduct carries the High Speed 1 railway line.
Original motorway viaduct
Opened on 29 May 1963, by Rt. Hon. Ernest Marples MP, Minister of Transport, the Medway bridge formed a key piece of the M2 motorway. It originally had a six-lane (two London-bound, two coast-bound, two hard shoulder) formation. In addition, a footpath either side that doubled as a small service road for maintenance and pedestrians. These footpaths were part of the North Downs Way, offering panoramic views of the Medway Valley and beyond. During the M2 widening, the original bridge was refurbished and strengthened. The central span, which was made from concrete beams, was replaced with steel girders. The concrete beams were lowered down on to a river barge underneath. As part of the M2 widening, the original bridge had street lighting fitted to it for the first time.
Second motorway viaduct
Completed in 2003, as part of the M2 widening project, the second motorway bridge is the newest of the three that cross the River Medway at this point. This bridge was built south of the original bridge. The formation of the M2 motoway crossing was changed. The original bridge would be changed to three coast-bound lanes, a hard-shoulder and both footpaths were reduced in size. The south facing footpath was closed, leaving only one path for pedestrians. The newer of the two bridges had the same formation, but changed to London-bound lanes.
In 2003, this particular bridge won the Concrete Society’s Civil Engineering Category award for, "outstanding merit in the use of concrete". It was presented to Doka UK Formwork Technologies. A small plaque can be seen on one of the upright support legs, on the Strood side.
During the construction of the new bridges, a support boat was positioned in the river. This was presumably as a safety requirement, should a member of the workforce get into difficulty near the river.
The rail viaduct is 1.3 kilometres long. The viaduct is a multi-span structure, with typical approach spans of 40.5 m, spanning the River Medway, Wouldham Road and Burham Roads in Borstal. with a central navigation span of 152 m. The viaduct substructure is of reinforced concrete pier columns supported on bored piles. A unique feature of the columns is that they are in a "V" shape. This is to provide greater lateral support and stability in the event of two high-speed trains using their emergency brakes.
The bridge deck was pushed out from the abutments on the east and west banks of the river during construction using hydraulic ram pistons.
To celebrate the tenth anniversary of the UK rail speed record, a plaque was placed overlooking the railway viaduct.
On 29 May 2013 the M2 celebrated its 50th anniversary.
|Wikimedia Commons has media related to Medway Viaducts.|