Test Hold cleaning - preparing a ship for grain
Prior to loading grain, all ships are usually subject to a survey by an approved independent surveyor. The surveyor will require the vessels particulars and details of at least the last three cargoes carried. He will then inspect the holds for cleanliness and infestation, or the presence of any material which could lead to infestation.
When the surveyor is satisfied with the condition of the hold, he will issue the ship with a certificate stating which holds are fit to load grain.Purpose:To ensure cargo holds are prepared to receive the next cargo.
Large claims have arisen when cargo holds have not been cleaned sufficiently to prevent cargo contamination. The requirements for cleaning the holds are dependent upon the previous cargo carried, the next cargo to be carried, charterers' requirements, the requirements of shippers and/or the authorities at the port of loading and the receivers.
It is becoming common practice for receivers to have an inspector at the load port.General
Regardless of the previous cargo, all holds should be thoroughly cleaned by sweeping, scraping and high-pressure sea water washing to remove all previous cargo residues and any loose scale or paint, paying particular attention to any that may be trapped behind beams, ledges, pipe guards, or other fittings in the holds.
If the ship has been carrying DRI (direct reduced iron), the dust created by this particular cargo during loading or discharging, will be carried to all areas of the ships structure and the reaction between iron, oxygen and salt will create an aggressive effect wherever the dust may settle. This is particularly noticeable on painted superstructures. (The IMO Bulk Cargo Code contains guidelines). Whenever salt water washing is used to clean hatches, the relevant holds should always be rinsed with fresh water to minimise the effects of corrosion and to prevent salt contamination of future cargoes. In this respect, arrangements should be made in good time to ensure sufficient fresh water is available for this operation.
Before undertaking a fresh water rinse, the supply line (normally the deck fire main or similar) will need to be flushed through to remove any residual salt water. Accordingly, it is suggested that fresh water rinsing of the holds is left until the end of hold cleaning operations to minimise the amount of fresh water required.