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Marine Accident Reporting Scheme (Mars) Report No. 293
Open manhole hazard: MARS 201715
As edited from Marine Safety Forum Safety Alert 16-17
During vessel loading, a shoreside foreman was walking on deck here other maintenance activities were taking place. As he made his way on deck the foreman inadvertently stepped into an open manhole.
He was able to catch himself and prevent a free fall of 5 metres into the tank. The victim suffered a laceration on his shin, which required three stitches, and some bruising on his forearm.
Lessons learned
• Once opened, a manhole should be cordoned off to provide protection and warning concerning the hazard.
• When a variety of activities are going on simultaneously that involve different work teams the risks are increased. Coordination and toolbox meetings before starting the work can help mitigate these risks.
Unexpected bottom contact: MARS 201716
As edited from US Coast Guard Marine Information for Safety and Law Enforcement (MISLE) activity report 5177142
An ice-strengthened oil exploration support vessel left port under the con of a pilot; the Master and OOW were also on the bridge. About five minutes after having left the berth, and while proceeding at about 3.5 knots, a loud noise was heard and a slight shudder was felt throughout the ship. At the time it was thought that the noise and shudder were caused by the anchor being secured in the anchor pocket.
A few minutes later the pilot disembarked and the vessel continued on its voyage. Over the next few hours it was discovered that the number 4 port ballast tank was taking water at a rate of about 8m3/hr. Even though the vessel’s ballast pumps could discharge at 100m3/hr, the Master turned the vessel around and they returned to berth for further inspections. Once at berth, divers confirmed a fracture on the bottom plate of number 4 port ballast tank. New depth surveys of the area of presumed bottom contact were conducted by the National Hydrographic Service.
Several previously uncharted shallow areas and rocks were discovered and a new chart was subsequently published.
Lessons learned
• Some isolated ports still rely on charts that are based on relatively old surveys. In this case, the chart used had been issued by the National Hydrographic Service and was based on a 1935 survey.
• Unexpected noises and a shudder were an indicator that something out of the ordinary had happened. Because the ballast tanks were equipped with tank level gauges the crew quickly noticed that one of the ballast tanks was taking water. If you experience unexpected noises, always assume bottom contact and sound all tanks.
Improper hook-on leads to incident: MARS 201717
As edited from Marine Safety Forum Safety Alert 16-15
A supply vessel was working alongside an offshore installation carrying out cargo operations which included the discharge of a small cargo basket. After unhooking the previous back-loaded cargo unit the deck crew ‘walked the crane’ approximately 15 metres and hooked on a cargo basket. They then left the area and the crane began to take the strain.
As the slack was being taken up the lifting bridle caught under the lid of the basket. The crane driver noticed the lifting bridle snagging and lowered the load. Unfortunately, both deck crew had walked away from the basket in different directions and neither was observing the lift. Neither was therefore aware that the lifting bridle had snagged, nor could they see
each other to highlight the problem.
After a short time both crew members made their way back to the basket and cleared the lifting bridles. They then stood clear in a safe haven nearby while the crane took up the slack, but once again the lifting bridle caught on the lid, this time buckling the lid and exposing the cargo inside. All involved, both on the vessel and on the installation, were reported as being experienced in platform support vessel(PSV) operations.
Lessons learned
• Good communication between deck crew and crane operator is essential. Repetitive work cycles can leave workers complacent. Complacency eventually leads to accidents.
• The operation and difficulties encountered were witnessed by at least three individual parties (the deck crew, the vessel’s bridge team and the installation), but no-one stopped the job.
• ‘Walking the crane’ (or more precisely the hook) is not best practice.Allow the hook to be repositioned directly over the load, have it lowered, hooked on and then lifted.
Inert gas plant not used for fear of pollution: MARS 201718
A 13,000dwt tanker was in port to load cargo. The shore-based loading master requested that ship’s crew run the inert gas system (IGS) to inert the tanks prior to loading. After consultation with the vessel’s Chief Officer, the vessel’s Master decided not to inert the tanks.
The Master cited operational problems with the IGS. Recent past experience had shown that it was possible that carbon residue and sediments could be introduced into the seawater that was used in the cooling/cleaning phase in the scrubber. These could then be washed overboard and cause pollution.
Since the vessel was below 20,000dwt the Master was able to justify the decision to not inert, as this was in compliance with SOLAS.
Lessons learned
• Even if tankers of less than 20,000dwt were previously not required to have inert gas systems as per SOLAS, this equipment is highly recommended irrespective of vessel size. Reflecting this safety measure, SOLAS now requires new tankers and chemical ships of 8,000dwt or more and built on or after 1 January 2016 to be provided with inert
gas installations.
• In this case, the inefficient gas quenching/ cleaning was apparently due to a worn de-mister. Proper maintenance and regular cleaning of the scrubber unit could have solved the operational problem.
Editor’s comment: Inert gas systems provide a vital layer of protection on tankers and chemical carriers regardless of vessel size. The International Safety Guide for Oil Tankers and Terminals
(ISGOTT) states: ‘It must be emphasised that the protection provided by an inert gas system depends on the proper operation and maintenance of the entire system.’
Experience doesn’t always equal safe practice: MARS 201719
As edited from Marine Safety Forum Safety Alert 16-24
A vessel was in the process of berthing. The engines and thrusters were still running, and the aft mooring station personnel had just confirmed to the bridge team that the vessel was all fast aft. Before coming to berth, the side (pilot) door had been opened to facilitate monitoring of the rescue boat, which had been launched and recovered for survey purposes.
The door was still open during the berthing manoeuvre but a safety chain was in place to indicate the hazard. The open door was about at the same height as the quayside.
A classification society surveyor, who was on the wharf waiting to board the vessel, removed the chain himself and hopped on board through the door.
Lessons learned
• Side/pilot doors should be kept closed when not in use.
• Open side doors that are soon to be used should be attended by ship’s crew trained in their duties. They should be strongly advised to let no one attempt a boarding or disembarkation
without a proper gangway in place. A sign should be installed on the safety chain to reinforce the interdiction.
• Even experienced mariners and surveyors can be tempted to skirt safety rules for the sake of expediency. Never be intimidated by the rank or title of a visitor and stick to your vessel’s procedures.
Thread mismatch causes misfire: MARS 201720
A ship’s officer was tasked to recharge a compressed air bottle from the lifeboat. During charging, the union/adaptor connection between the compressor and the air bottle disconnected and blew away. Pressure in the bottle at the time was about 100 bar; the maximum designed pressure of the air bottle is 200 bar. Luckily, no-one was injured.
The company investigation found that the specification of the union/adapter used on board was a different specification from the original.
The male part of the union was a taper thread while the female part was a straight type. A proper fit would have matched fittings; taper with taper or straight with straight.
Lessons learned
• Air compressors create high pressures so accidents involving them can have serious consequences. Training and familiarity with the equipment is needed before use.
• Always inspect compressor fittings carefully before connecting; sometimes mismatched parts can be mistakenly used.
