OS 35 wreck to be cut in two as part of removal plan
The operation to remove the wreck of the OS 35 will involve cutting the hull into two pieces and placing them onto a semi-submersible heavylift vessel to be taken to a shipyard for scrapping.
Details of the plan were revealed on Friday by John Ghio, the Captain of the Port, during a briefing to journalists alongside the Gibraltar Port Authority’s independent salvage advisor Eric Houtteman.
The removal operation has as its top priority safety and minimising the risk of environmental pollution, and should be completed well within the May 30, 2023, timeline set by the port.
The technical proposal was approved by the GPA following an exhaustive review of the plan with TMC Marine, the company handling the tender for the removal operation on behalf of the insurers and owners of the OS 35.
The agreement clears the way for TMC Marine to award the contract to its preferred bidder, the Dutch company Koole Contractors, and for the mobilisation of specialised barges and vessels required for the removal operation.
The first phase, which is likely to commence before the end of the year, will involve using a crane barge to empty the ship of its cargo of steel bars, which will be processed and recycled.
The vessel will then be cut into two pieces, one smaller foreword section and a larger after section.
Crucially, the cut will be made in the area of the foreword cargo tanks to ensure that empty fuel tanks that may contain oily residue remain intact and undisturbed.
The foreword section, where the damage was sustained when the OS 35 collided with an LNG carrier while sailing out of the Bay of Gibraltar, will be lifted onto the heavylift vessel using chains.
The aft section, which retains buoyancy, will be towed a short distance from the coastline to allow sufficient draught for the semi-submersible vessel to sink below the wreck and lift it out of the sea ready for onward transportation.
The plan is subject to multiple variables – not least the impact of adverse weather - and could yet change.
But the hope is that the wreck will be transported to an EU-approved ship recycling yard – Koole Contractors operates one in Amsterdam – for scrapping, and in line with the Basel Convention on the transboundary movement of hazardous goods.
No details were released of the cost of the operation, which is covered by the OS 35’s insurers.
Mr Ghio said the GPA was satisfied that the proposal was “eminently deliverable” and would be completed within the timescale envisaged by the port.
If all goes well, it will mean the wreck being removed in its entirety with minimal pollution from oily waste or debris.
For the past two months, salvors have been working to strip the inside of the sunken ship of all material and fittings.
“It’s as close to bare metal on the inside as it gets,” he said.
The decision to approve the wreck removal plan is a key landmark in the response to the OS 35 casualty.
Prior to taking the decision, the GPA briefed Spain’s maritime authorities, which have been working closely with Gibraltar in the response to the incident.
Mr Ghio said Spain had been offered the opportunity to “cast an eye” over the proposal in case it had anything to add, with no objections being raised.
“This critical milestone is an important step in ensuring that the removal of the wreck is completed within the timeframe established by the Gibraltar Port Authority in the wreck removal notice,” he said.
“It also confirms that the methodology and efficiency of the works envisaged are deliverable at the same time as being fully compatible with the strictest measures for the protection of the environment.”