General average is expected to be declared imminently after the container ship Dali struck and brought down part of the Francis Scott Key Bridge in Baltimore.

When general average is declared, cargo and vessel interests share in the cost of a casualty, but the sums involved can take years to establish, particularly for a boxship with multiple interests.

The 9,962-teu Dali (built 2015) struck the bridge on 26 March, less than an hour after it left its berth at the Port of Baltimore. Investigators are currently focused on potential problems with electrical equipment on the vessel.

Cargo claims consultant WK Webster said late Thursday that general average “may have been declared” but it is understood that an announcement will come imminently and possibly on Friday.

WK Webster said it had instructed an expert marine surveyor to investigate the cause of the bridge strike for a possible challenge to general average claims by cargo interests.

Repair costs for the ship are estimated to be at least $28m, with salvage costs likely to top $19.5m, according to court papers filed by the owners and operators on 1 April.

The filings were part of a court move by the owner and manager of the ship to limit their liability. Six people died in the accident and costs are likely to run into the billions of dollars.

Shipowner Grace Ocean and manager Synergy Marine, both based in Singapore, lodged a petition in a federal court in Baltimore to cap legal exposure at nearly $43.7m — although the figure is a provisional estimate that the companies’ lawyers plan to update.

Insurance payouts for the Baltimore bridge collapse will be among the biggest ever seen in shipping, said Lloyd’s chief executive John Neal. Barclays analysts estimated that insurers face claims of as much as $3bn.

The Dali, chartered by AP Moller-Maersk, was carrying 4,659 containers at the time of the incident.

The first containers were lifted from the ship last weekend and 38 were removed by Thursday, according to the joint command centre for the operation.

The wreckage of the bridge and roadway lies across the bows of the ship and needed to be removed before the Grace Ocean-owned ship could be relocated in the coming days.

Moving the vessel and clearing the debris will allow for the shipping channel to be fully reopened. Temporary channels have allowed 69 vessels to transit since the accident.

“There has been incredible progress this week towards our goal to open the limited access deep draught channel,” said Colonel Estee Pinchasin of the US Army Corps of Engineers.