.-Every ship or other vessel carrying petroleum in bulk, other than a ferry permitted to transport tank vehicles under clause (b) of the proviso of sub-rule (1) of rule 33, shall be made of iron or steel well and substantially constructed with scantlings of ample dimensions in proportion to the size of the vessel:Provided that the licensing authority may, in special circumstances, allow use of such ships or other vessels constructed of materials other than iron or steel under such conditions as it may, in consultation with the Chief Controller, specify.
