After last week's analysis of the dramatic purchase of Solstad's fleet of 37 platform supply vessels (PSVs) by Tidewater, this week's column deals with a drillship suffering a mooring failure – not whilst drilling on location, thankfully, but alongside at an American ship repair facility. Nobody was hurt, but the incident serves as a reminder that safety standards across the shipping industry have to be enforced.
The industry is locked in a cycle of the same type of incident occurring over and over, and nobody is taking action to prevent recurrence until there is a fatality or a serious material loss. Indeed, the example of enclosed space fatalities suggests that even a dozen completely preventable deaths a year is insufficient to drag the industry from its willfully blind torpor.
Every day, thousands of vessels tie up alongside in harbours all around the world using bollards and mooring bitts. Inevitably, they are marked with the safe working load, the mooring line is slung around the bollard, and all is well – until it is not okay.
The recent National Transportation Safety Board (NTSB) report into the collision caused by the break-away of the drillship Valaris DS-16 at the ST Engineering Halter Marine and Offshore shipyard in Pascagoula, Mississippi, in March last year reminds us that serious accidents can have mundane causes.
In this case, US$5 million of damage was caused as two expensive ships with nearly two hundred people on board collided in a violent squall in the middle of the night.
On March 12, 2022, the Valaris drillship was at the shipyard in the Gulf of Mexico for reactivation work, tied up alongside the quay to six bollards, and had 164 crew and drilling personnel on board as the unit prepared for a new contract. The rig master had received forecasts of strong winds and had verified that the strength and direction forecast were below the limitations of the vessel's mooring analysis.
However, deckhands were instructed to check the mooring lines every hour from the dock, and, as the winds increased, they were instructed to remain on the dockside to monitor how the lines were being loaded, the NTSB found.
It was not a nice job in the middle of the night in a howling gale and pouring rain, but still an application of good seamanship.
Unfortunately, just after the midnight change of watchkeepers, the captain was awoken in his cabin by the dreadful sound of what he believed was a mooring line snapping, and he felt a shudder run across the vessel. He rushed to the bridge and found the watchkeeping officer there trying to call his stateroom.
The bollard forward of DS-16, bollard number six – which secured the drillship's four bow lines and the two stern lines of the semi-submersible moored beside her on the quay – had broken at its base. The 40-knot wind was blowing the bow of DS-16 into the channel. The two deckhands who were monitoring the mooring lines from the dock watched helplessly from the quayside.
The NTSB report recounts how, as the bow of the vessel began to peel away from the pier, the remaining mooring lines parted one by one, twang, twang, twang, as they became overloaded in series.
The 229-metre-long drillship began to drift into the channel in an east-southeast direction. The captain sounded the general alarm to alert the crew, and hailed nearby tugs for assistance. DS-16 sounded multiple blasts on the ship's whistle to attract the attention of any vessels in the immediate area of the danger, and the master warned the drillship's crew to prepare for the possibility of collision with the ships moored on the opposite side of the channel at the Chevron facility.
The chief mate radioed nearby vessels on VHF channel 16 and advised of the drillship's breakaway and uncontrolled movement. At 00:25 local time, the deck crew of the rig released its port anchor, a manoeuvre they had conducted a drill on when the warning of high winds was received. Everyone on board was mustered, and the radio operator confirmed that all persons were accounted for.
At about 00:35, the rig's port anchor dug into the seabed. A few minutes later, the DS-16 crew lowered the starboard anchor. This slowed the vessel's movement, but it was still heading towards Chevron dock number six, where the 190-metre LOA bulk carrier Akti was moored, waiting to complete loading petroleum coke.
Several tugs arrived to assist DS-16, and began pushing against the drifting drillship, attempting to arrest her motion. According to the captain's report to the NTSB, after the drillship's anchors fetched up, DS-16 stopped drifting, but the tugs were not able to completely stop the vessel's stern from moving towards Akti.
The rig master alerted the bulker of the impending collision via VHF radio. Then the worst happened – a sickening grinding of steel. At 00:41, the starboard side of DS-16 made contact with the starboard side of the moored Akti. The rig came to rest alongside the cargo vessel.
Crewmembers inspected their respective vessels for damage, sounded all tanks, and made required casualty notifications. There were thankfully no injuries reported on board either vessel, or amongst those on the quayside, and there was no pollution reported, either. Divers found no damage to the underwater portion of the vessels' hulls during an underwater inspection. DS-16 remained alongside Akti until the drillship could be safely moved back to the ST Engineering facility later that afternoon.
The total damage resulting from the breakaway was estimated at US$5 million, more than 80 per cent of which was inflicted upon DS-16.
"DS-16 sustained damage to the riser handling system, deck fittings, transfer hose-reel system, walkways and platforms, and other equipment on board," the NTSB report continued. "A bulwark panel was deformed on the starboard side, and insets on the side shell plating and port stern were also noted."
The cost of replacing the broken bollard was US$20,000.
The cause of the incident is clear. After the incident, the four mooring lines that had been used to secure the rig to bollard number six were found to be intact. However, all other lines used to tie up the vessel had parted when the breaking load was placed on them by the failure of the bollard.
Valaris had performed a mooring analysis, as you would expect when placing a US$300 million asset with a displacement of 69,900 tonnes alongside.
The bollards at which DS-16 had moored were originally fabricated in 1997. Each of the bollards used by the rig was stenciled with its corresponding number and "300T," indicating an assumed safe working load (SWL) of 300 tons (272 tonnes). The NTSB found that there were no policies or procedures addressing the frequency of inspections for the shipyard's bollards by ST Engineering, nor were there any statutory requirements for inspections.
In other words, the 300-ton SWL was a purely hypothetical figure.
After the collision, ultrasonic thickness tests were performed on the remaining bollards where DS-16 had been moored. These tests found that there was serious wastage in the lower portion of several bollards, including number six.
A measurement of the remaining base of the number six bollard showed that the steel wall thickness was less than 63 mm on the side farthest from the edge of the quay — an apparent reduction in thickness of about 128 mm, as the original bollard design drawings showed a wall thickness of 190 mm. Over the quarter-century since the bollard was built, two thirds of it had rotted away!
Additionally, the NTSB noted that several other bollards showed signs of external corrosion and wastage. Steel wires and chains were looped around the bases of bollards from which pier fenders hung, and these had caused chafing and wear (See above.).
The bollards had been modified from the original design, with additional "horns" (for which there were no engineering records) added to them to accommodate more mooring lines. These modifications increased the overall height of the bollards from just over 60 cm to anywhere from about 120 cm to 210 cm. The additional horns for mooring lines were added well above the height of the horns on the original design.
Earlier this month, my fellow Baird Maritime columnist Alan Loynd went in search of common sense in shipping (here). None of it was evident when the mooring bollards at ST Engineering in Mississippi were modified.
Basic physics tells us that as the height of a bollard (or its horns) increases, the horizontal or up-leading pull on the upper portion of the bollard significantly increases the moment of force applied to the base of the bollard. Therefore, bollard number six — and likely many of the other bollards used to secure DS-16's mooring lines — was incapable of sustaining the working loads from its original design.
This was an accident that had been waiting to happen for many years. A wind gust of 40 knots is strong, but it is not exactly a hurricane force.
Surely, this would be a simple open and shut case of "Test and inspect your bollards, shipyards, and harbour owners"?
No, because that is exactly what the US Coast Guard told harbour facilities to do in a safety alert issued in 2018. And obviously, because this was "just a safety alert," nobody did anything, certainly not at Pascagoula, and probably not anywhere else, either.
"There have been a number of shore side marine bollard failures whereby moored vessels were cast adrift," the coast guard alert began. "In some cases, this resulted in damage to the involved vessel as well as other nearby vessels and shore side structures."
This is exactly what happened in March 2022 to Valaris DS-16.
It is exactly what happened in New Zealand in 2017, when the cruise ship Seabourn Encore broke away from its wharf and collided with a cement carrier in the port of Timaru of February 12 of that year.
The Transport Accident Investigation Commission (TAIC) report cited failures by the port operator as "the safe working loads of the bollards on Number One Wharf were unknown and therefore it was not possible to determine whether the mooring plan for any ship was safe."
It is also exactly what another NTSB accident report found happened at BAE Systems' shipyard in Mobile, Alabama, on April 3, 2013, when a bollard failure caused the breakaway of the cruise ship Carnival Triumph from its moorings. Carnival Triumph subsequently collided with the dredger Wheeler and towing vessel Noon Wednesday. The NTSB report found that incident caused US$3 million of damage and caused one fatality. The bollards "were known by BAE Systems to be in poor condition with an undetermined mooring load capability," the report continued.
The cause of these problems is clear, as the coast guard states that in the US, "neither the Coast Guard nor the Occupational Safety and Health Administration (OSHA) has regulatory oversight over these items."
The European Commission transport commissioner Violeta Bulc admitted that the EU had the same problem, in a written answer to a British European Parliament Member. Jude Kirton-Darling had requested more information on the safety of mooring equipment in ports in 2016, asking whether the commission intended to make the testing of bollards mandatory.
Ms Bulc replied that it did not, and that "no generally applicable industry standards regarding the development of safer mooring arrangements exist or are currently in preparation."
And where nobody has regulatory oversight, guess what? Nobody cares!
"Abnormal loads are oftentimes caused by excessive winds acting against the sail area of vessels which can be substantial for certain types of vessels such as container and cruise ships," the US Coast Guard warned in the 2018 circular. "Forces developed by winds acting against a vessel's hull rise exponentially as the wind speed increases and, as a result, are often extreme…
"The coast guard strongly recommends that facility owners and operators take steps to develop a routine inspection program for bollards and other mooring equipment" (coastguard highlight).
Strong recommendations mean nothing in shipping. Only the force of fines and other regulatory penalties focuses minds.
How long will it be until we read about another – and likely worse – incident involving bollard failure?
Finally, please read this brief but gruesome 2001 International Marine Contractors Association (IMCA) accident report of the serious injury to a rigging supervisor on a pipelay barge when the bollard on a cargo barge alongside failed and bounced on the deck, smashing the supervisor's safety helmet and head. It reminds us that the physical inspection of bollards is a problem that has been with us for generations.
"On investigation," the IMCA concluded, "the steel quality of the bollard in the weld area was questioned. A qualified third party was to inspect the other bollards for evidence of fatigue and steel hardening."
But guess what? Another IMCA report from 2019 shows the failure of a bollard on a cargo barge due to corrosion of bolts.
"This particular bollard," the report concluded, "rated 25T SWL, was not fit to perform its designed purpose and hold any weight. The condition survey for the barge did include inspection of all mooring bollard, but not the bow centre bollard, which was not designed or planned for use."
Cue Lonnie Gordon. This song should be an anthem for the entire marine industry: "Happening all over again, I was such a fool to think that you would ever change your way…"
Background reading
Specifications of Valaris DS-16 are found here.
Our campaign on liftboat safety is another area where safety problems recur time and again, and flag states and class appear simply not to care enough to take meaningful action.
Between 2019 and 2022, Rightship found that there were 31 fatal incidents that happened in enclosed spaces on ships, resulting in 39 lives lost completely unnecessarily. It makes grim reading.