What is the scantling draft of the vessel ?

1. Using of recirculation water during cleaning, could cause the water become a static acumulator and when you use this water via butterworth system, there will be a mist in the cargo tank which will be like the clouds with static acumulator.

2.If you will use chemicals during cleaning, it must be closed system and tank atmospher should be checked.Most of chemical has toxicty and flammable even very low.You should treat the tank like toxic cargo and flammable cargo after cleaning.Gas measuruments should be done before entry.

Mega Harley
Mega Harley

1. What is the danger assosiated with the use of recirculated water during cleaning operations?

2.What is the danger assosiated with the use of tank cleaning chemicals/agents during cleaning operations?

Scantling draft is the maximum draft at which the ship can withstand all the loads safely. In other words, it is the draft at which the strength of the ship is built.
It may or may not be equal the tropical draft (Maximum to a ship can load as per load lines).
Let us say a ship's maximum depth is 15 meters. Its tropical draft is 12 meters. Let us say based on the strength of the ship, we calculate to how much draft this ship can be loaded and still the stresses on the ship will be in safe zone. Let us say we find this draft as 13 meters.
Off course we cannot load upto 13 meters. This is because as per load line convention we can only load upto 12 meters. But if it is safe to load upto 13 meters draft, why we are allowed to load only upto 12 meters. This is because load line drafts are not based  on the draft that we can load. Rather it is based on the minimum freeboard we need to have at all conditions.