Metalock technique decreases vessel repair downtime

Metalock technique decreases vessel repair downtime

Lack of training on the Metalock technique could be increasing time and cost of machinery component repair on board ships, says Andre Mortimer, president, of the Metalock International Association (MIA).

When a piece of metal machinery on board ships cracks and requires urgent repair, the most common response is to weld the material, which sticks the metal together. However, welding is often difficult because the fracture may be in a confined environment. It can also cause stresses and brittleness of the parent material, increasing risk of future fractures. If welding is not an option, removal and replacement are often seen as the only solution.

An alternative, the Metalock stitching process is an option, which is an in-situ repair method for cracked metal machinery. However, according to the MIA, many chief engineers trained in the last 30 years are not familiar with the technique and so it is often overlooked.

Mr Mortimer said: “Metalock has been an established technique dating back to the second world war, but we now have a lost generation of Engineers who received little or no training on the procedure. The technique offers the ability to repair the cast components of machinery without removal, disassembly and repairs can be conducted even while at sea.”

As well as being performed in-situ, reducing time and cost, the Metalock method does also not require any hot work so can be performed in any area of the vessel, retaining 90 per cent of the strength of the original metal piece. It can be applied to cast iron and other metals and is reportedly cheaper than replacement, requiring no heavy machinery or equipment to carry out repair.

The basic approach to the Metalock repair technique. Image courtesy of the Metalock Association

According to the MIA, a recent repair on a main engine cylinder indicates the efficiency gains of using the Metalock technique. A vessel in service in Bulgaria suffered from a damaged main engine cylinder and was facing 8 months of off-hire time for repair work. The shipowners decided to try out the Metalock technique using Metalock trained engineers. The repair operation lasted seven days, without removal or disassembly of the engine, and only one technician.

The MIA revealed in a white paper that many of today’s engineers, were never taught about metal stitching, and believe their only option to deal with cracked machinery is welding or replacement.

A new campaign by MIA now aims to fill the knowledge gap.

Mr Mortimer continued: “We want to restore a vital missing tool of the chief engineers’ toolbox. Between 70 and 90 per cent of Metalock repairs by our members are done over previous welding attempts. Welding is notoriously fragile on cast iron – stitching the metal is the most effective, long term solution.”

“Engineers and owners can save a great deal of wasted time and money by bringing their understanding of the technique up to speed. Machinery breakages don’t happen every day, but everyone should know their options for the day they do”, concluded Mr Mortimer.

The full whitepaper, ‘The Benefits of the Metalock Process’, is available for download here.