By Cleanship Marine Services · Published · last updated · 6 min read
How to prepare cargo holds for grain: a grain-clean checklist that passes survey
Grain is the cargo that most often decides whether a hold-cleaning job was good enough. It's food, it's inspected by people whose job is to say no, and in some countries the inspection is run by government authorities who don't negotiate. Most ships that fail a grain survey didn't do too little work. They did the work in the wrong order, or ran out of time before the drying stage.
This guide covers how to prepare holds for grain, how long to allow, and the checklist we'd run before letting a surveyor anywhere near the hatch.
What "grain clean" means for the surveyor
The working definition most charterparties lean on comes from P&I guidance: holds clean, swept, washed with fresh water, free from insects, odour, previous cargo residue, lashing material, loose rust scale and paint flakes, then dried and well ventilated. The US Department of Agriculture puts it from the other side: stowage areas must be clean, dry, free of infestation, rodents, toxic substances and foreign odour, and otherwise fit to carry grain.
So the surveyor is checking five things, roughly in this order of how often they fail ships:
- Residue of the previous cargo, especially in places you can't see from the tank top
- Loose rust and paint that could fall into the cargo
- Moisture: wet bilges, damp patches, sweating steel
- Odour
- Insects and infestation, including in the bilge wells and on hatch cover rubbers
If you want the background on how grain clean compares with the other standards, see our guide to hold cleanliness standards.
How many days should you allow for grain-clean preparation?
There's no honest single number, because the answer depends almost entirely on the previous cargo. A hold coming out of another grain cargo might need little more than sweeping, a wash and a fresh water rinse. The same hold coming out of petcoke or coal needs chemical cleaning, high-pressure work on the upper structure and a lot more drying time.
As a planning approach, work backwards from the inspection:
- Drying: at least a day after the final rinse in good weather. More in humid conditions.
- Fresh water rinse: a few hours per hold, but only once everything else is finished.
- Washing and chemical work: the variable part. Allow most time here after dirty cargoes.
- Sweeping and residue removal: start during discharge if you can.
If the numbers don't fit inside the ballast leg or the port stay, that's the moment to bring in extra hands, not after the first failed survey. A riding crew working on passage is often the way to make the maths work.
Step by step: preparing holds for grain
Follow the general cargo hold cleaning procedure, with these grain-specific points layered on top.
Remove every trace of previous cargo. Not just the tank top. Grain surveyors look at hopper tops, frame brackets, ladder rungs and platforms, pipe guards, the top of the hatch coaming and the underside of the hatch covers. A handful of coal dust on a bracket at 12 metres will fail the hold.
Remove loose rust and flaking paint. Hard rust that won't move under a scraper is usually tolerated. Anything that flakes or lifts must go. If there's a lot of it, this becomes a scaling job, not a cleaning job, and needs planning in its own right.
Get rid of chlorides. Finish every wash with fresh water. Salt residues pull moisture out of the air and can make a hold look damp days after it was dry.
Clean and prepare the bilge wells. Remove all residue, clean the strainer plates, test the bilge suctions, then cover the wells as the shipper or charterer requires. Burlap (hessian) fitted over the bilge plate and sealed at the edges is a common requirement for grain, to stop the cargo getting into the bilge system while letting water drain.
Check the hatch covers. Rubbers, cross-joints, drain channels and compression bars. Old cargo trapped in a hatch rubber is a classic fail, and so is a hatch cover that leaks in the first shower after loading. Many operators run an ultrasonic or hose test before a grain voyage.
Deal with odour. Ventilate thoroughly. If the previous cargo was strong-smelling (some fertilisers, fishmeal, some ores), plan extra ventilation time and, if necessary, a deodorising wash compatible with food cargoes.
Check for insects. Look in corners, behind ladders and in bilge wells. Residue from a previous grain or agricultural cargo is where infestation lives.
Dry everything. Tank top, hopper sides, bilge wells and the underside of the hatch covers. Mop and squeegee, don't just wait.
The Chief Officer's pre-inspection checklist
Run this in every hold before calling the surveyor. Use a strong torch, a scraper and a white rag.
- Tank top clean, dry, no residue in corners or along welds
- Lower hoppers clean; no residue on stools or in the hopper-to-tank-top corners
- Side frames and brackets clean on all faces, including the upper side of each bracket
- Upper hopper tank sloping plates clean, no dust lying on them
- Transverse bulkheads and corrugations clean top to bottom
- Ladders, rungs, platforms and handrails free of residue
- Pipe guards, sounding pipes, air pipes and their guards clean on top
- Underside of hatch covers and hatch girders clean
- Hatch coaming tops, drain channels and rubbers clean and intact
- No loose rust scale or flaking paint (tested with a scraper)
- No odour of the previous cargo
- No insects or signs of infestation
- Bilge wells clean, dry, suctions tested and covered as required
- Lights working (surveyors notice)
- Photographs taken of each hold for the record
If you find a problem, fix it and re-check. The pre-inspection exists to catch the things you'd rather find yourself.
Where ships usually fail a grain survey
The same few locations come up again and again:
- Top of frame brackets and the upper side of stiffeners. Dust lands there during discharge and nobody sees it from below.
- Hopper tank tops. The sloping plate is easy to wash and easy to miss.
- Under the hatch covers. Cargo dust and loose paint sit on the girders and fall when the covers open.
- Bilge wells. Residue, water and smell in the one place everyone cleans last.
- Ladders. Every rung is a little shelf.
We've written separately about why a hold that looks clean still fails inspection. It's worth reading before your next grain fixture.
Country-specific strictness
Some load ports are well known for strict grain inspections: Australia, the United States and Canada are the usual examples. Skuld's guidance includes a case where a ship cleaned to what was described as "normal grain standard" before arriving in Australia, failed because of small rust patches, and had to undertake an expensive re-clean. If you're loading grain at a strict port, clean to the strictest reasonable interpretation and remove loose rust even where another inspector might let it go.
If the hold fails anyway
Get the surveyor's findings in writing, hold by hold, location by location. Photograph what they point at. Fix exactly what was listed, plus anything similar you find nearby, and call them back. Keep a clear timeline. It matters later if there's an argument about off-hire.
If the failure is in places your crew physically can't reach, such as the upper frames on a large bulker, a rope access team can often clear the findings far faster than rigging staging. Get in touch with the vessel's position and the surveyor's report and we'll tell you honestly what it'll take.
Sources & further reading
Frequently asked questions
What does grain clean mean?
Holds that are clean, swept and washed with fresh water, free from insects, odour, residue of previous cargo, lashing material and loose rust or paint, then dried and ventilated so they're ready for the shipper's and surveyor's inspection.
How long does grain-clean preparation take?
It depends on the previous cargo. After a clean cargo it may take a day or two for a whole ship. After petcoke, coal or other staining cargoes it can take several days, with most of the time spent on washing, chemical treatment and drying.
Why are bilge wells covered with burlap for grain?
Burlap (hessian) over the bilge strainer plate lets water drain into the well while stopping grain from entering and blocking the bilge system. Shippers and charterers often require it, so check the voyage instructions.
Is some rust acceptable in a grain clean hold?
Hard, tightly adhering rust is usually accepted. Loose scale and flaking paint that could fall into the cargo are not. Inspectors in some countries apply stricter limits, so remove anything that lifts under a scraper.
What do grain surveyors check in a cargo hold?
Previous cargo residue, loose rust and paint, moisture, odour and insects. They concentrate on hard-to-clean areas: frame brackets, hopper tops, ladders, hatch cover undersides and the bilge wells.
- grain clean holds
- prepare cargo holds for grain
- grain clean checklist
- grain survey cargo hold
- hold preparation for grain
- USDA stowage examination
- grain hold inspection
Related articles
- Inspection & standardsHospital clean, grain clean, normal clean, shovel clean, load on top: hold cleanliness standards explainedWhat hospital clean, grain clean, normal clean, shovel clean and load on top actually mean, who decides which one applies, and what happens when a hold fails.
- Cargo-specific cleaningPetcoke hold cleaning: why it's so hard to remove and how to get holds back to grain cleanWhy petroleum coke sticks to cargo holds, which chemicals work, how to clean petcoke from frames and brackets, and a realistic petcoke-to-grain hold cleaning procedure.
- Hold cleaningHow to clean a bulk carrier cargo hold: the full procedure, step by stepA practical bulk carrier hold cleaning procedure — from planning and dry sweeping to washing, chemicals, fresh water rinse, drying and the pre-inspection — in the order that actually works.
