Wet-Welding comes of age

Hydroweld and Underwater Technical Services have recently pooled their technical and administration expertise to successfully complete a contract for DML (Devonport Management Ltd), the newly privatised company operating in Devonport dockyard, who carry out work on behalf of the MoD (Ministry of Defence). The project, the first of its kind, required the wet-welding of just under 40 blanking plates, the largest being 2.6 x 1.2 metres to the main ballast tanks of a submarine. The contract was completed on time, in budget with no lost time accidents and at a fraction of the cost of dry docking.

All of the wet welding was completed using Hydoweld FS wet welding electrodes which are approved by the MoD for permanent and temporary repairs to war ships. This project further proved the electrodeÕs capabilities and welding techniques used by Hydroweld, through the successful completion of wet-welding procedures and production welding on materials with a high carbon equivalent, up to 0.47%. (The accepted normal upper limit is 0.40%) using ferritic electrodes. The welding was carried out by a select team of 20 coded wet-welder divers, whose variety of skills and commitment to the project was invaluable and must be commended. All of the wet welds were subjected to 100% visual inspection and MPI by the client with a 100% pass rate.

The welding procedures and welder qualifications testing was completed in three positions, Horizontal, Vertical and Overhead, in 8 metres of water at HydroweldÕs underwater welding facilities at Stoney Cove in Leicestershire. The coupons were welded and tested an accordance with the ANSI/AWS D3.6 - 93 Specification for Underwater Welding and were witnessed by Lloyds Register of Shipping and DML. All of the welding was monitored via hat-mounted CCTV.

'The project's success has generated a lot of interest both in the UK and overseas' said Michael Pett from Hydroweld, Òyet again we are breaking new ground and pushing back technological boundaries. This project was monitored very closely, by the MoD and DML, with every step being subjected to an unparalleled and rigorous set of quality control measures, which were implemented to the letter.

In a recent presentation given in the presence of some leading officials involved with underwater engineering from the MoD and overseas naval guests, Barry Richards (welding and NDT manager for DML) declared that wet- welding has at last Òcome of ageÓ. Mr Richards who was responsible for ensuring the wet welding was completed to specification said ÒIf I hadnÕt seen it for myself I would never have believed that such high quality welding could be achieved underwater. A lot of samples taken from coupons produced during the welding procedures, are almost impossible to distinguish from welds completed in the dry and their mechanical properties more than met the specification.

Hydroweld is commited to excellence in wet-welding and to this end has joined forces with TWI (The Welding Institute) to run selected wet-welding courses in the UK and Singapore.

The courses are intended to provide the student with the necessary skills to produce the quality of welds required by today's industry.

For further information contact:

Mike Pett, Hydroweld, 46 Bedford Drive, Sutton Coldfield, West Midlands. B75 6AX.

Tel: +44 (0) 121 378 1230.

Fax: +44 (0) 121 378 1281.