Preparation of a cargo hold to load grain is not just a question of sweeping, cleaning or washing down the hold. There are a sort of matters to consider, and failing or not approval the holds in a survey after vessel berthed alongside can result in a substantial looses and headaches!

I will try to write down something that I have experienced in those 35 years working as surveyor and probably will help somebody to avoid looses and many headaches.

The beginning of holds approval is monitoring discharge operation and be sure that grabs and bulldozers are not causing any damage in the tank top, hoppers, air/sound pipes, water ingress sensors and bilges, because grain cargo is very sensitive for water or oil leaking, insects or foreign matters.

Some surveyors are very exigent and requests the holds cleaning as hospital or butchery, some others are not and if you don't know how will be the surveyor`s requirements, you for sure must know how should be the holds condition to load grain cargoes.

The quality of the grains, as per Brazilian or China or American`s rules, has an acceptable margin of impurities, but such impurities refer to the grain process
of production (foreign matter, heat, burned, mouldy, broken beams, greenish beams) and not foreign matter of previous cargoes as coal, petcoke, iron ore,
fertilizers, cement, sulphur, cooper concentrate, ect.

Sometimes, working as Owner`s P&I attending surveyor I have questioned a surveyor working for the shipper and shows him that such condition of a cargo hold do not reflects in the final quality of the grain cargo; see below exemple:

Considering that: A cargo hold designed to load 10.000 mt of soya beams, the attending surveyor inspected the hold and requests additional cleaning because
he found some small lumps of coal inside the hold, what do do!!

If we divide the weight of small lumps of coal (2kgs) by 10.000.000 kgs (capacity of cargo hold) the result will be 0,0000002kgs or 0,0002grams or 0,00002% of the cargo that should be loaded in the hold.

Many lawyers will consider the result of above calculation insignificant, but only one lawyer allegation says that such 2kgs of coal should kill a population!! and what to do!!

The best way is to avoid such lumps of coal during hold inspection and there is only one way to avoid one lawyer allegation.

Master, chief officer and crew have to commitment assume in the hold inspection taking the consideration that there is only one way to avoid looses and headaches for his owners or charterers and it depends only their engagement, most of times, they are not involved because charterers contract a shore cleaning company and the survey should be done by an independent surveyor, but if crew must be involved.

Holds approval start from the beginning, coordinating last discharging operation to avoid damages, testing ballast tanks and bilges by pressure and visual inspection and all the cleaning method should be the same;

Cleaning steps:
Ask terminal to remove as much as possible the cargo from holds, if possible swept or bring down all residues of cargo from behind shell frames, corners, wedges, flanges, stairs, pipes, etc.
Collect all cargo residues while in the terminal to avoid extra works by crew using ship`s crane, barrels and hand buckets!!
Visual inspection of cargo residues while berthed in the port.

Washing steps:
Removing all cargo residues from arest, wedges, flanges, corners, behind pipes, stairs, frames;
Scrapping down rusty and paint scales areas;
Salt water wash by high pressure;
Application of chemicals and brush to remove oil and cargo impregnated in the walls/bulkheads;
salt water washed again;
Visual inspection to check actual condition and if any additional cleaning need;
Final rinzed with fresh water;

It is recommended that all ballast tanks be fully and pressurized to check for leaking;
Bilge valves tested;
Water ingress tested;
All holds must be dry and free of moisture or water pools