22.—(1) The master of any vessel carrying or which has recently carried a liquid dangerous substance in bulk shall ensure that none of the following operations are commenced–
(a)the discharge from the vessel’s tanks of ballast or slops contaminated with any dangerous substance;
(b)the cleaning or ventilation of any tank which was last used to carry a dangerous substance; or
(c)the pumping overside of bilges contaminated with any dangerous substance,
unless the conditions specified in paragraph (3) have been complied with.
(2) The master of any vessel carrying or which has recently carried any flammable liquid in bulk shall ensure that none of the following operations is commenced–
(a)the gas freeing of any tank which was last used to carry the substance;
(b)the cleaning of any such tank with water, steam, detergents or other chemicals;
(c)the purging of any such tank with an inert gas; or
(d)the washing of a tank with crude oil during unloading,
unless the conditions specified in paragraph (3) have been complied with.
(3) The conditions referred to in paragraphs (1) and (2) are as follows–
(a)where the vessel is at a berth–
(i)the berth operator has given his permission, and
(ii)the harbour master has given his permission (which may relate to any or all of the following, namely, named vessels, named berths or specified operations), or has been notified and has not objected on grounds of safety; or
(b)where the vessel is not at a berth, the harbour master has given his permission.