Medway Viaducts

Medway Viaducts
Kent
All three bridges seen from the north-west bank
Location
Carrying:	Original:4 lanes of M2 plus hard shoulder & Bridleway New: 4 lanes of M2 plus hard shoulder Rail: 2 tracks of High Speed 1
Crossing:	River Medway
Location
Structure
Length:	Original: 3,272 ft New: Rail: 4,265 ft Main span: Original: 500 ft New: Rail: 500 ft
Design:	Cantilever
History
	Built Original: 29 May 1963 New: 2003 Rail: September 2003
Information

The Medway Viaducts are three bridges or viaducts that cross the River Medway near Rochester in northern Kent. 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 Ernest Marples, 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. The bridge was built south of the original bridge. The formation of the M2 motorway 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, the 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 plaque can be seen on one of the upright support legs, on the Strood side.

Railway viaduct

The western bridge carries High Speed 1 (HS1), the high-speed rail link that connects London with the Channel Tunnel.

The rail viaduct is 4,265 ft long. The viaduct is a multi-span structure, with typical approach spans of 165 ft spanning the River Medway, Wouldham Road and Burham Roads in Borstal. with a central navigation span of 505 ft. The viaduct substructure is of reinforced concrete pier columns supported on bored piles. A feature of the columns is that they are in a "V" shape 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.

On 30 July 2003, a specially formed Eurostar train crossed the viaduct and in to the Nashenden Valley at 208 mph which was a new UK rail speed record.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.

All three bridges pass over the Medway Valley Line (to Paddock Wood) and the Chatham Main Line (to Victoria) railway lines.

Gallery

• 
  The new viaducts under construction in the early 2000s
• 
  All three bridges seen from the south east bank
• 
  Crossing the Medway rail viaduct, during pre-service testing in 2003

Outside links

("Wikimedia Commons" has material about Medway Viaducts)

• Location map: 51°22’33"N, -0°28’32"E
• CBRD — Opening Booklets M2 Medway Viaduct (PDF)
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