An element of sea-fastening which is often overlooked, by the design engineer and by on-site personnel, is welding in “No Weld Zones”. This can cause serious issues both from a safety aspect and a project scheduling aspect.
6 months ago, IMCA reported a near miss incident where personnel were attempting to weld some new installations to the tween deck of a vessel. They were unaware that on the other side of the 10mm plate they were welding to, was more than a 10,000 L of combustible diesel.
Seafasten Offshore takes this issue very seriously. Written into our procedures are steps to mitigate such risks when welding in and around no weld zones.
Every vessel should have a tank drawing showing where the oil and fuel tanks are located. If the mobilisation of the vessel will involve large amounts of welding to deck, it is worth having the engineer mark out the locations properly with spray paint or safety tape.
If the design definitely calls for welds in a “no weld zone” and the design cannot be changed, it may be necessary to empty and execute purging and gas-freeing of the tanks. Welding to the tops of t-bars is generally acceptable.
The most important take away from this is awareness. Be aware of all tanks on a vessel before welding operations begin.
Seafasten Offshore is the world leader in engineering design of vessel seafastening solutions and sea transport. If you are unsure about the condition, or adequacy in which cargo or equipment has been secured to a vessel’s deck it is best to ask an expert. Contact Us @ seafasten.com