No weld zones or HOT WORKS on vessels.

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

Construction Accident Involving Faulty Winch Leaves Worker with Serious Injuries

This incident was reported by a worker that was aboard the ship at the time of the failure. On the day of the accident, the boat was on-shore unreeling pipe from an on-board reel. A winch was used to help with the removal of the pipe from the reel during the final phase. The winch was under tension just before the event occurred. It was at this time that the worker mentioned to their supervisor that they believed that the base plate under the winch was flexing. When the winch finally came to a complete stop the welds that held the winch to the deck suddenly came apart. This resulted in the winch breaking from its sea-fastenings and hurtling along the deck in such a way that the winch and base plate crushed his left leg.

There was an investigation by the members of the IMCA (International Marine Contractors Association). Their investigation discovered a few major pieces of information as follows:

•    About two months prior to the sea-fastening welds breaking, the base plate and attachments began to buckle underneath a load. The attempted fix was to add more weld to the base to hold it where it was.

•    There was initially a 32Te constant tension winch which was malfunctioning on multiple occasions. It was replaced with a 10Te winch.

•    The new 10Te winch that was installed was not constant tension, but also was not even fitted with a tension measurement.

•    If the Management of Change process was completed, it did not correctly identify that the new winch was inadequately fastened to the deck.

•    When the initial event occurred two months prior to the incident in question, it was not investigated and fixed in an acceptable way. This could have significantly contributed to the break on this particular day.

Here are some of the investigation teams ideas’ on how this situation could have been avoided.

•    One of the main priorities should have been to identify all problems with the Management of Change requirements, and fix these problems immediately.

•    When the winch was changed, a structural engineer should have been asked to check the position and sea-fastenings to ensure the load on the winch wire could be adequately transferred to the vessel deck structure.

•   In situations where welds are in tension, often the case for winches, all welds including under deck welds should be non-destructively tested (NDT).

The result is a very serious lost time injury which is going to require time, money, and medical attention to rectify. Had the event occurred just a split second earlier this accident could have easily resulted in death? Additionally, if the vessel was offshore at the time, it may have been impossible to get the required medical attention in a timely manner. An injury like this can remain with the worker for the rest of their life. A safety incident like this will remain with the company for a very long time.

This is just part of the investigation that was done by the IMCA the entire report can be read in the IMCA Safety Flash 12/14 Newsletter.
The incident detailed above could have been avoided by having Seafasten Offshore review the challenges at hand.  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