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Bulk carrier hatch cover maintenance standards
To ensure against the entry of sea water, rain or spray, all weather deck and hull openings (hatches, doors and ramps etc.) should be tightly secured and always maintained in good order.
Battening down hatch covers with manual cleats can be a long job in a large ship with a small crew. Often done at night, in inclement weather, and in circumstances in which the crew may not be as attentive to their duties as they should be, cleats can be left undone, eccentric wheels not turned up, multiple panels incorrectly aligned and cross joint wedges not hammered up. Permanent local damage to gaskets with consequent leakage may also occur during battening down as a result of obstructions such as lashing wires or cargo residues left on hatch coamings or between panels.
When water penetrates a hatch seal, it is collected in a drainage channel and discharged clear of the hatchway. Water may spill over onto the cargo in the hold below if these channels are allowed to become blocked or restricted.
Below article outline issues related to cargo claims and tests to be carrie out on board to detect any leaks- importance of hatch cover maintenance and program that are required to be maintained on board to avoid insurance claims
Fig: Side rolling steel hatch cover
As per IMO /MSC/Circ.1071 Ship owners and operators are recommended to maintain a record of maintenance, and component replacement, to facilitate statutory surveys by the Administration.
All major repairs should be undertaken only after consultation with the hatch cover manufacturer and with the approval of the Administration. Hatch cover maintenance plans should form part of a ships safety management system as referred to in the ISM Code.
Although the PMS has an ongoing system both for renewals and maintenance regime, it is recommended that vessels maintain a simple checklist as per makers instructions is advisable to be maintained on board and the checklist should cover the below items.
After Each cargo operation
- Clean the coaming tops and remove any debris or equipment
- Clear drain line holes and valves of debris
- Drain valve caps should be attached by chain, but not screwed on. They must be ready in case of a fire in the hold or when carrying out fumigation operations
- Grooves and worn landing pads can be built up with welding and ground down, as required, giving a permanent repair
- Check and clean the surface of the seals and take special care if the cargo is dusty or gritty
- After discharge check hold internals, including ladders, sounding pipes, backetrs and inner coaming surface for mechanical damage
- Check hydraulic system for leaks, especially coupling, valve blocks and flexible hoses
- Check forrust streaks on the inside of the coaming which would indicate a leaking hatch cover, then take any necessery remedial action. Clean off the old rust streaks and stains.
Routine maintenance - three monthly
- Grease wheel spindles, cleat spindles, hinge pins and hydraulic cylinder protective sheaths
- Check hinge pins for wear and reapir as necessary. Worn hinge pins can casue slewing of panels and leaking cross joint cleats
- Grease cleat wedges, drive chain sprockets, toothed racksand cylinder spherical bearings
- Check and adjust drive and towing chain adjusters
- Check rubber seals for elasticity, mechanical damage or permanent deformation
- Hatch covers usually make steel ¨Cto steel contact when a compression bar indents rubber seals by 12-16 mm, check makers manual for exact compression
- When the hatch covers are opened the rubber should almost retain its original shape, although new rubber will invariable suffer a 1-2 mm permanent set after the first operation
- Once the permanent indentation reaches 70% of the designed compression the hatch cover is likely to leak.
- Do not grease the rubber packing or seals unless proceeding into cold wetaher when glycerine based grease can be used.
9 Monthly or Annual checks
- Check qunatity and condition of spares carried on board
- The rubber packings and adhesive have a limited shelf life and normally should be date stamped when purchased
- Check hydraulic system oil by analysis
- Check safety locking devices and hydraulicsystem cutouts
Quick acting cleat
Dos and Donts
- Always rectify steel to steel faults first
- Keep chains and cleats correctly adjusted
- Attach locking pins and chains to doors and hatch covers in open position
- Keep coaming tops and double drainage channels in good order
- Keep hatch covers and clean coaming tops and double drainage channels after loading bulk cargo through the grain or cement hatches
- Always kee[ wheels, hinges and chain tension equipmet well greased
- Do not enter a hold with suspect atmosphere
- Do not remove ball valve from drain valves
- Do not allow grooves to form in coaming tops in way of the side panels
- Do not leave loose cleats when proceeding to sea
- Do not screw down cleats beyond normal tension
Related information on ships structural arrangements:
Mechanical steel hatch covers arrangement and watertight integrity onboard a bulk carrier
Ships structural problem because of corrosion & metal fatigues - related countermeasures
Classification Society Establishes Design Standards For Bulk Carriers
High rate of corrosion at sea and preventing methods
Corrosion prevention methods for bulk carrier
Maintenance procedure for mechanical steel hatch covers
Steel hatch cover maintaining watertightness - Classification society guideline
Structural standards & strengthening of bulk carriers
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Operation of sea going bulk carriers involved numerous hazards . Careful planning and exercising due caution for all critical shipboard matters are important . This site is a quick reference to international shipping community with guidance and information on the loading and discharging of modern bulk carriers so as to remain within the limitations as specified by the classification society.
It is vital to reduce the likelihood of over-stressing the ship's structure and also complying with all essential safety measures for a safe passage at sea. Our detail pages contain various bulk carrier related topics that might be useful for people working on board and those who working ashore in the terminal. For any remarks please Contact us
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