Tug towing pennant failure while assisting a berthing
operation in Southampton resulted in damage to the wheelhouse windows of tug Svitzer
Mercurius (IMO 9695523) and injuries to its crew, a report from the UK
Marine Accident Investigation Branch (MAIB) has found.
At 12:31 local time on December 22nd 2019 the
starboard forward towline pennant on board the tug Svitzer Mercurius parted and
snapped back while the vessel was acting as stern tug to ultra-large container
ship CMA CGM Marco Polo (IMO 9454436) as it berthed in Southampton,
England.
The towline and pennant recoiled back toward the tug,
breaking one of its forward wheelhouse windows and damaging several others.
Five of the seven-man crew, who were standing in the
wheelhouse, were sprayed with glass fragments from the broken toughened glass
window and suffered multiple minor lacerations. Fortunately they were all
wearing either glasses or sunglasses and no eye injuries occurred.
Svitzer Mercurius had recently changed ownership and had
joined Svitzer’s Southampton operations from the Netherlands. It continued to
operate with its Dutch crew, who were contracted to provide familiarization
training to Svitzer crews over a three-month handover period.
Svitzer tug masters provided local port knowledge. The
towline pennant was found to have failed at approximately 52% of its original
minimum breaking load. Close examination of the pennant indicated that it had
previously sustained high shock loads and cyclic load damage to its
load-bearing core.
However, due to its jacketed construction, the core was
difficult to examine.
Svitzer representatives visited the vessel several times
before the tug started work in Southampton, and an independent survey of the
tug and its equipment had been carried out. Neither identified existing wear
and damage to the pennant nor its unsuitability for further work. The
wheelhouse windows also met specific international standards as part of classification
society requirements for ‘green seas’ loading. Those standards did not require
resistance to solid body impact such as a recoiling towline.
However, in 2018, the tug manufacturer Damen Shipyards
Group had introduced an impact-resistant window glass on its new tugs as
standard equipment, having recognized the snapback hazard and potential for
serious crew injuries.
The tug’s classification society, Det Norske Veritas, has
been recommended to take the findings of this investigation to the
International Association of Classification Societies to develop a unified
requirement to minimise, in the event of impact from a recoiling towline, the
risk of injury from broken window glass to personnel within tug wheelhouses.
A recommendation has also been made to the tug operator,
Svitzer Marine Limited, to review the risk to wheelhouse crews across its feet
posed by towline snapback and, where it is assessed to be high, evaluate the
viability of introducing laminated glass for wheelhouse windows.
2014-built, UK-flagged, 447 gt Svitzer Mercurius is owned
by Svitzer Europe Holding BV of Ijmuiden, Netherlands. It is managed by Svitzer
Marine Ltd of Middlesbrough, UK. It is entered with Skuld (Skuld Energy
Business Unit) on behalf of Svitzer AS. As of January 5th the vessel
was underway near Southampton, UK, no other named destination.
2012-built, Bahamas-flagged, 176,546 gt CMA CGM Marco
Polo is owned by Shin Doun /Mi-Das Line of Imabari, Japan. It is managed
by CMA CGM of Marseille, France. It is entered with North on behalf of Mi-Das
Line SA Shin Doun Kisen Co Ltd, As of January 3rd it was en route
from Port Klang, Malaysia, to Colombo, Sri Lanka.
