(a)the petroleum shall be carried-(i)in 200 litres capacity steel barrels, the screw bungs of such barrels being well fitting and sealed; or(ii)in 200 litres capacity sealed steel drums, not more than three tiers of which may be carried on any single vessel; or(iii)in 10 litres capacity sealed tins, not more than six tiers of which may be carried on any single vessel; or
