This article gives an account of the construction and positioning of the final section of the new steel box girder bridge at Milford Haven. It is the biggest lifting operation of its kind (1100 tonnes) to be undertaken in Britain. The author first outlines the collapse of a 70 M cantilever on the south bank in 1970 and the events that led to the adoption of the Swiss losinger system to complete the bridge. Four slu 330-tonne jacks were mounted on each of the 38M cantilevers and the section lifted by means of 8 cables formed from 18 stabilized 15.2mm steel strands. The 40 metre high lift was completed in 18 hours at rates up to 5 metres an hour. Details are given of the construction of the 118M long section in a near-by dry dock, it consisted of 17M long box lengths and was floated into position for lifting. This method avoided the joining of two 100M cantilevers which would have drooped over 3M before being connected. Mention is made of the high cost (found5M) of strengthening the bridge which led to an increase in the weight of steel used of 5,000 to 6,000 tonnes. Notes are included on the completion of the structural work together with several illustrations of the project. /TRRL/

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 36-39
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00097971
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Oct 18 1975 12:00AM