SPECIAL BULLETIN | Lifting Operations

1. Lifting Operations
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SPECIAL
BULLETIN
Introduction
A North Sea installation was awaiting the delivery of an urgently
required container and a supply boat was standing off waiting to
offload. The crane normally used for over-side lifting was under
repair and adverse weather was coming in.
Description of plant/process
An installation had two cranes – east and west. All over side
lifts had to be undertaken by the east crane for two reasons;
the prevailing westerly wind and because subsea pipelines run to
and from the installation on the west side. These pipelines have
limited protection from dropped objects. The use of the east
crane for over side lifts is documented in procedures and in the
lifting plans but it is not apparent to the deck crew why the west
crane is not used for over-side lifting.
On the day of the incident, the east crane was under repair and
a supply boat was standing off waiting to offload an ‘urgently
required’ container. Adverse weather was coming in.
A risk assessment was quickly carried out and the decision was
made to use the west crane. A toolbox talk was held and,
although the attendees knew that the east crane was usually
used for loading and unloading supply boats, they could see
nothing wrong with using the west crane. There was an obvious
urgency for the container to come on-board and job went ahead.
Details of the Incident
The crane was lifting one of the last containers weighing 6Te
from the vessel deck. The container was hoisted to a height of
approximately 10m above the sea surface and slewed to clear the
vessel when the load slowed in the hoisting direction and started
to descend uncontrollably. Whilst descending, the operator
returned the control lever to neutral and applied the foot brake.
This had no effect on arresting the load. The load (20’ open top
container) landed on the surface of the sea, started to fill with
water, and submerged to an approximate depth of 10m. The
crane operator left the cab as he described the crane to “shake
violently”. After approximately a minute, the crane stabilised
and the operator returned to the cab to attempt to rescue the
load. The operator managed to get the load to the surface but
could not lift it as the extra weight of the water exceeded the
capability of the crane. The operator reported a burning smell
and halted operations. He engaged the hoist and boom brakes
and mustered as instructed by the OIM.
The crane operator, deck crew and platform riggers installed
secondary rigging to the main hoist line to prevent any possible
slippage.
The onshore Emergency Response Team (ERT) gathered and
developed a rescue plan to recover the load. It was decided that
due to the weather conditions, the quickest and safest method
of rescue was to mobilise a remotely operated vehicle (ROV) to
transfer the load to a dive support vessel crane then cut the crane
pennant to release it from the platform crane. A dive support
vessel was chartered, a toolbox talk was completed and the load
was transferred to the vessel crane. The load was transferred to
a safe area and lowered to the seabed to be recovered at a later
date.
There was the potential that the load could descend, strike and
rupture a live hydrocarbon pipeline. As mitigation against this
threat, the pipeline was de-pressurised and the platform was
partially down-manned to a skeleton crew (one chopper full).
Once the load was recovered to a safe position, the platform
was up-manned.
No personnel were injured during the incident. Damage to the
container contents will be determined once recovered. There was
no physical damage reported to the supply vessel or platform.
Good Practice Guidance
• Lifting operations happen daily and seem routine. But every
lift must have an approved plan that is understood and
followed by all.
• All personnel should be aware of the Major Accident Hazards
surrounding them, particularly those in close proximity and
adjacent to their worksite.
• Maintenance regimes should be detailed, appropriate and
followed. Many maintenance plans have become tick-box
exercises. Maintenance plans should demand accountability
and ownership of the work done with the person undertaking
the maintenance noting the work done and signing the
paperwork. There should be no opportunities to ‘cut and
paste’ or tick boxes. A second person, not involved in
the maintenance work should verify that the work was
undertaken.
• Words such as urgent or routine should not influence our
perception of risk.