0027-nd rev 11.2 8-jul-16 guidelines for marine lifting and lowering operations
GUIDELINES FOR MARINE LIFTING & LOWERING OPERATIONS 0027/ND Rev 11 Page 68 of 84 18.11 SPREADER BARS AND SPREADER FRAMES 18.11.1
All lifting equipment such as spreader bars/frames shall be manufactured in accordance with Section
14.
18.11.2
All lifting equipment such as spreader bars/frames shall be certified in accordance with Section 15.
18.11.3
The lift shall be executed within the date validity of the certification of the lifting equipment.
18.11.4
Spreader bars / spreader frames are to be adequately secured against barge motions. Particular
attention should be paid to the securing on tall structures (e.g. high modules, jackets etc.) where high
accelerations will be encountered during transportation.
18.11.5
Where a spreader bar or frame is released from the lifted structure by operation of a hydraulic system,
the hydraulic oil used shall be environmentally friendly and biodegradable.
18.11.6
For spreader bars or frames transported on the barge deck, attention shall be given to ensure that the
rigging is long enough to allow the bar or frame to be rotated into the lift position without fouling the
lifted structure. Attention should be paid to the fact that the lower slings will be slack and the effective
length will be less than the measured length as the sling will form a catenary.
18.11.7
For spreader bars or frames located close to equipment or structures on the lifted object, guides
should be provided to prevent the bars or frames causing damage to the lifted object as the bars or
frames are raised prior to the lift or lowered onto the spreader bar or frame supports after the lift.
Attention should also be paid to the lower slings as these will move as the bar / frame is raised and the
lower slings may also cause the bar / frame to rotate before load is applied into the system.
18.11.8
For spreader bars used subsea which are connected directly to the lifted structure via pins (e.g. a
jacket lower spreader bar) and the pins are released using a remotely activated system (e.g. hydraulic
release), a secondary system shall also be available. Where the secondary system utilises part of the
primary hydraulic system (e.g. an accumulator system using some of the same hydraulic lines as the
primary system), then a tertiary system (independent of the primary or secondary system) shall be
provided. This tertiary system could be by direct pull of a sling connected to the pin by ROV or for
larger pins, by a line from the lift vessel to a pre-installed pulling system incorporating sheaves.
18.11.9
Where a hydraulic accumulator is used to withdraw lifting pins, it must be demonstrated through testing
that there is adequate hydraulic oil and pressure within the accumulator to fully stroke the pins.
18.11.10
For spreader bars / frames connected directly to the lifted object (via lift pins), a support and restraint
system should be incorporated to ensure that the spreader bar does not fall away in an uncontrolled
manner or the spreader frame to drop but allow for a controlled recovery. The support system should
also minimise any vertical movement to ensure that if one pin releases early, the release of the other
pin(s) is not compromised by the rotation of the spreader bar / frame due to the loss of support at the
location where the pin is released. This is particularly important for subsea operations where
corrective action may not be possible.
18.11.11
Where a spreader bar is connected directly to the lifted object (via lift pins), and the lifting operation
required rotation of the spreader bar to upend the structure, it shall be demonstrated that the lift points
will allow the rotation without locking up and there are no items on the spreader bar which will clash
with the lifted object during rotation. Ideally, this should be done through detail checks and a site
rotation test.