what is the meaning Both to blame collision clause in maritime law and shipping law?

Clause in a bill of lading or charter- party which stipulates that, in the event of
a collision between two ships where both are at fault, the owners of the cargo
must indemnify the carrying ship against any amount paid by the carrying ship
to the non- carrying ship for damage to that cargo. This clause arises because,
under American law, a cargo owner is not able to make any recovery from
the carrier for damage resulting from negligent navigation but may instead
sue the non- carrying ship which, in turn, seeks recovery from the carrying
ship in proportion to its fault. This would render a carrier indirectly liable for
a loss for which he is not directly liable to the cargo owner. The clause has,
however, been held to be invalid in the American courts when incorporated
into a contract with a common carrier.
The clause in BIMCO’s Gencon charter- party reads as follows:
“If the Vessel comes into collision with another vessel as a result of the negligence of the other
vessel and any act, neglect or default of the Master, Mariner, Pilot or the servants of the Owners
in the navigation or in the management of the Vessel, the owners of the cargo carried hereunder
indemnify the Owners against all loss or liability to the other or non- carrying vessel or her owners
in so far as such loss or liability represents loss of, or damage to, or any claim whatsoever of the
owners of said cargo, paid or payable by the other or non- carrying vessel or her owners to the
owners of said cargo and set- off, recouped or recovered by the other or non- carrying vessel or her
owners as part of their claim against the carrying Vessel or the Owners. The foregoing provisions
shall also apply where the owners, operators or those in charge of any vessel or vessels or objects
other than, or in addition to, the colliding vessels or objects are at fault in respect of a collision
or contact.”