|Real Life Incident |
“It is imperative to keep a check while opening and
closing various tank valves during ab topping up
operation. The tanks which have been topped up,
their valves must be completely shut and the valve
switches should have protective covers. A topping up
operation was carried out on a tanker at Vopak
The duty officer accidentally opened the valve of
3W’s Cargo tank instead of 4W’s Cargo tank. 3W’s
was already topped up to 98%. In few minutes
before mate could realize, the mix-up cargo spilled
on deck from PV valve of 3 Port Cargo Tank. The
operation was suspended and resumed after
transfer of excess oil from No. 3 W’s to buffer tank
It is critical fora mate to check the ullages daily after sailing out from the loading port. The bottom lines of some tankers which run through the tanks have often been found with broken flanges. The inappropriate material used for fabricating nut and bolts in some new ships has been the reason for such cause. As a result of rough weather conditions at sea, often the bottom line is subjected to excessive pressure. This leads to giving-away of nuts and bolts, opening of the flanges, and mixing of separate groups with each other. Due to a difference in head of various tanks, cargo flows from one tank to another by gravity and equalizes. This can prove to be a commercial disaster when carrying 2 different parcels or different grades mix with each other due to material failure.
43. l Marine Insight Cargo Operations for Tanker I 44.