L6 Hatch Covers

Steel Hatch Cover• The more modern type of cargo vessel will be equipped

with one of the many types of steel hatch cover whichare at present on the commercial market.

• The many advantages with this style of cover by faroutweigh the disadvantages.

• They are fast in closing or opening, and the latestversions are so labour-saving that one man could openup all the hatches of a ship in the time it takes to strip asingle conventional hatch.

• Their structure, being of steel, is extremely strong andgenerally forms a flush surface in ’tween deck hatchesproviding ideal conditions for fork lift truck work.

Steel covers may be encountered not just at the weather deck level but throughout a vessel, inclusive of ’tween decks.

Hydraulic operated covers are simple in operation, but should hydraulic fluid leak at any time, cargo damage may result.

The direct pull type must be operated with extreme care, and all safety checks should be observed prior to opening the chain-operated types.

Steel Hatch Cover

Hatch Covers

Lesson 6

Multi Folding Hatch Cover

Sliding Folding

Pontoon

Purpose

• To provide protection from the seas and the weather

• They must be kept securely fastened so that they will not come loose in the severest storm at sea.

Drive System

• Wire rope

• Hydraulic

• Chain

• Rack and pinion

Types of Hatch Cover(Basically 3 types)

• Mechanically operated steel covers, of folding, sliding, rolling, etc. types, fitted with gaskets and clamping devices;

• Steel pontoon covers with tarpaulins and battening devices or with gaskets and cleats;

• Portable covers with tarpaulins and battening devices (usually wooden covers).

Care & Survey of Hatch Coversof Dry Cargo Vessel

IACS

Introduction1. Loss of weathertight integrity continues to be a

constant factor leading to cargo damage which could result in a threat to the safety of the crew, the ship and its cargoes, despite advances in modern shipbuilding technology, construction, navigation and means of preventing ingress of water into hold spaces.

2. We need only to look at cargo insurance claims to recognise the continued prominence of this problem and the vigilance required from crews to ensure that instances of cargoes being spoiled as a result of water ingress through hatch openings are minimised.

Introduction3. Although condensation can cause water to collect in holds,

it is the problem of water entering into cargo holds through the hold openings as a result of badly maintained or damaged closing arrangements that this paper addresses.

4. The Classification Societies are concerned with this problem in particular through the Load Line Convention.

The experience of the Classification Societies confirms the importance of hatch cover weathertightness and the reports of survey - class surveys as well as Load Line surveys –contain frequent references to lack of maintenance of weathertightness of hatch covers.

Introduction5.Where there is any doubt in applying this Guideline,

clarification should be obtained from the individual Classification Society.

• Attention is directed to the separate published Rules of each Society.

• This Guideline is not meant as a substitute for the Society's Rules or the independent judgement and experience of Owners and Survey

Contributing Factors to Leaking Covers

Lack of weathertightness may be attributed to severalcauses, which can be classed within two different types:1. Those which result from the normal use of the hatch

cover system, such asDeformation of the hatch coaming Damage of hatch cover due to impact The normal wear-and-tear of the cleating arrangement, which may be corrected only through extensive repairs or overhauls

Contributing Factors to Leaking Covers

2. Those which result from the lack of proper maintenance:corrosion of plating due to lack of protectionagainst corrosion, lack of adequate lubrication of moving parts, non-replacement of old gaskets, use of cleats and gaskets which do not comply with the standards specified by the hatch cover manufacturer and inappropriate repairs.

What can be done to reduce leakages of hatch covers leakages of hatch covers?

1. The Classification Society Rule requirements for the construction and inspection of hatch covers, cannot, alone, ensure that the hatch covers will be adequate at all times

Improvement in the performance of hatch covers canbe achieved only through an effort by all partiesconcerned, which will involve:• feed back to the manufacturers and Classification

Societies for improvement in original design specifications

• owners, masters and crew in effective maintenance• close and detailed inspections by Classification

Society Surveyors.


2.The hatch covers designers should, perhaps, give less thought to the sophistication of the systems and more to the sturdiness of the equipment, the ease of operation and the convenience of maintenance.

Adequate protection of the steel work should be ensured with high quality coatings, or, alternatively, corrosion-resistant materials should be used.


3.The shipowners and their crews should apply a programme of maintenance to ensure that the steel is not allowed to corrode, gaskets are periodically replaced, movable parts are kept properly lubricated and fittings periodically overhauled.

The crew should also make sure, at each operation of the hatch covers, that the covers are sufficiently clean, especiallyat bearing surfaces, and that the drainage holes are clear.

Since most problems occur at the peripheral and cross-joint gaskets, very strict control of the condition of the components involved must be applied.


• This will involve not only the rubber but the compression bars, the locking devices, the cleating, load bearing surfaces, and the general condition of the coaming top plate.

• In addition, in cases where the hatch panels are moved by hydraulic means then the manufacturer's maintenance procedures must be adhered to in all respects.

• When hydraulic cleating or securing is arranged, means are to be provided to ensure that the covers remain closed and weathertight in the event of hydraulic failure.


4.The crew should however bear in mind that in extreme cases hatch cover protection may have to be complemented by means of tarpaulins or adhesive tapes.

This is a decision to be made by the Master taking into account the nature of the cargo, expected sea-conditions, uneven load distribution on hatch covers and, above all, previous experience in similar circumstances.

The use of tarpaulins on mechanically operated steel covers must be considered an emergency temporary measure.


5. Containers and cargoes should not be stowed on hatch covers unless they have been designed for such carriage.• Additionally, correct and adequate lashing systems

are to be used at all times when stowing• Cargoes; this is equally important for cargoes

stowed on tween deck covers and that battening down

• Devices are correctly used to the hatch covers at the same time.


6. All securing devices should be checked and tightened by the crew as appropriate especially in case where their ships may be subjected to unusually rough seas.

7.The crew should also make sure that not only the deck cargo, but also the derricks, etc. are properly stowed and secured so that they will not be dislodged in a seaway and cause damage to hatch covers.


8.The appropriate manufacturer's instructions with respect to the safe operation, inspection, maintenance and repair of the type of the hatch cover fitted on the ship should be complied with in all respects.

• To this end a "Record of the Maintenance of Hatch Covers" should also be provided by the Manufacturer together with the operation and maintenance manual to assist owners to carry out the appropriate maintenance.


Hatch Covers & Coamings

guide rails and track wheels;stoppers, etc;wires, chains, tensioners and gypsies;hydraulic system, electrical safety devices, andinterlocks;end and interpanel hinges, pins and stools;ramp profiles, and stowage area;backup structure of wheels, guides and hinges.

Damages to Hatch Covers1 Mechanically operated steel covers are affected by:

• corrosion, which attacks the integrity of the cover itself and which also affects the moving parts (wheels and rails, hinges between panels, cleats and batten screws, etc.)

• deformation caused by faulty handling, shocks from cargo being handled (especially logs and heavy loads), wear-and-tear on gaskets, and overloading with deck cargo

• incorrect maintenance, inadequate maintenance, incorrect repair, lack of adjustment, incorrect operation

• incorrect and inadequate maintenance of the power system of the hatch covers i.e. hydraulic and electric systems and safety devices.

Damages to Hatch Coamings• Hatch coamings are affected by the following factors and

defects:corrosion aggravated by the presence of piping systems, utilising coamings as protection and support, thus preventing normal access to the plating for painting

deformation, both of the plating and of the various supporting members and brackets, mostly due to cargo handling and aggravated by general corrosion

build up of scale, rust, and cargo debris causing the blockage of drains, and the incorrect support of the hatch covers

fret and wear caused by incorrect adjustment of battening devices which in turn causes side plate failures, cracking and stay buckling

Hatch Covers & Coamings

1.Where mechanically-operated steel covers are fitted, checking the satisfactory condition of:

hatch covers (corrosion, cracks, deformations)tightness devices of longitudinal, transverse and intermediate cross junctions (gaskets, gasket lips, compression bars, drainage channels)clamping devices, retaining bars, cleatingchain or rope pulleysguides

Portable Covers or Steel Pontoons

3. Checking of the satisfactory operation of mechanically operated hatch covers:

stowage and securing in open condition;proper fit, locking and efficiency of sealing devices in the closed condition;leakage of cylinders and hydraulic piping;

4. Checking the satisfactory condition of hatch coamings (corrosion, deformations of plating and supporting members and brackets, connection to deck).

General Maintenance• Track ways should be cleaned of loose material

before closing hatches.

• The tension of draw chains should be adjusted as required.

• The wheels, gears, racks and pinions and other moving parts should be kept lubricated.

• The side cleats and cross-joint wedge mechanisms should be kept greased.

Hatch Cover Tightness Testing

• Hose and chalk tests demonstrate whether or not there is contact between the rubber packing and compression bar but give no indication of the actual compression.

• Once at sea, it is often too late to see the shortcomings of this method.

Hatch Cover Tightness TestingUltrasonic Testing

• The principle for ultrasonic testing is remarkably simple.

• An ultrasonic transmitter is placed in the hold (empty or with cargo) and emits ultrasound waves.

• The hatch cover is then closed, fully cleated and battened.

• The ultrasonic detector to listen from the outside and pick up all “leaking” ultrasonic sounds that pass through the sealing arrangements, vents and/or cracks.

• Ultrasonic testing is far more accurate than other testing methods,

• enabling operators and surveyors to pinpoint leaks that are a problem – or are likely to become one.


• When combined with computer systems, ultrasonic testing offers the maritime world a complete tamper-free solution.

• Surveyed data can be memorised for analysis and the data downloaded to PC for fast, reliable and documented reporting


General Maintenance• The hydraulic systems should be checked for leakage,

especially in ‘tween-decks where leaked fluid may damage cargo.

• The drainage channels should be cleaned out and drainage holes checked on weather-deck hatches.

• Check that compression bars are making complete contact with sealing gaskets.

• Weather tightness may be checked by hose-testing the covers before loading.

Inspection of hatch covers are carried out when the hatch cover are opened or are otherwise accessible on each voyage cycle, but need not be inspected more frequently than once per month:

1. Hatch cover panels, including side plates, and stiffener attachments of opened covers for visible corrosion, cracks or deformation

2. Sealing arrangements of perimeter and cross joints (gaskets, flexible seals on combination carriers, gasket lips, compression bars, drainage channels and non-return valves) for condition and permanent deformation

3. Clamping devices, retaining bars and cleating for wastage, adjustment, and condition of rubber components

4. Closed cover locating devices for distortion and attachment5. Chain or wire rope pulleys;

6. Guides7. Guide rails and track wheels8. Stoppers9. Wires, chains, tensioners and gypsies10. Hydraulic system, electrical safety devices and

interlocks11. End and inter-panel hinges, pins and stools where fitted

As part of this inspection, the coamings with their plating, stiffeners and brackets shall be checked at eachhatchway for visible corrosion, cracks and deformation,especially of the coaming tops and corners, adjacentdeck plating and brackets.

Rubber Gasket

• Flexible seals• Wide rubber gasket located around the

periphery of each panel of the hatch cover• Gasket 2” wide and pressed against a narrow

blade of steel located on the opposing faces meeting the gasket.

General Guidance for Hatch Surveys

1.The Surveyor should make his presence on board known to the Master, or his representative, before starting the survey.

2. Surveyors are reminded that they should at all times observe local port/terminal and ship’s safety regulations.

• In the absence of such regulations the Surveyor shall carry out the survey following best safety practices.

3. Surveyors should always request to be accompanied by a ship's officer during their survey and also allow Owner’s representatives to accompany them, if requested.

4. Mounted and labelled conventional colour photographs (originals only) of deficiencies and general aspects of the ship are required.

5. Surveyors should make a detailed examination of the ship and question the ship's staff


6. The Club requires a weathertightness check of the hatch covers. The method of checking must be reported. The preferred method of testing is by ultra-sound. The equipment should be Class approved (e.g. manufactured by SDT/MacGREGOR) and the operator certificated to use it.

If Class approved equipment is not available other typesmay be used.• However, the type used must always be reported.• Where ultra-sound testing is not possible then a water

hose test (to class requirements) should be used,but NOT if some cargo is already in the hold.

• Where no other test method is practical, a chalk test should be performed.


7. Deficiencies should be reported to the Master, who should be asked for his intentions to remedy them.

8. The Surveyor should inform the Master that the Club requires that hold openings be made weathertight prior to the application of any additional sealing methods (e.g. sealing tape, foam, cement or non-class approved systems).

9. Preliminary advice, detailing the deficiencies and the Master’s intentions to remedy them, must be prepared and promptly forwarded to the Club and the Owner. • The Master should sign this advice and also be given a

copy.


10. The Surveyor should re-attend to verifyremedial action and weathertightness

• Updated reports are to be sent accordingly.


Opening Single Pull Macgregor Steel Hatch Cover

1. Release the side securing lugs, ensuring that they are correctly stowed in flush position with the track.

2. Clear away any hatch top wedges between hatch sections.

3. Rig the check wire to the lug of the leading hatch section and turn up the bight of the wire on to cleats or bitts.

4. Rig the bull wire so as to provide a direct pull to the winch from the leading edge of the hatch cover.

5. Complete all work on top of the hatch covers. Check that the track ways are clear of all obstructions, such as pieces of dunnage etc.

Plan View

6. Turn down the eccentric wheels by use of bar levers, or by using the jacks under the hatch cover sections.

7. Check that the locking pins are securely replaced in the eccentric wheels once the wheels have been turned down to the track, in such a manner that they will not slip out when the wheel rotates or when the hatch is in the vertical stowed position.

8. Ensure that all personnel are aware that the hatch cover is about to open, and that the stowage bay for the covers is empty and clear to allow correct stowage of the sections.


9. Have a man standby to ease the check wire about the bitts, and, just before hauling on the bull-wire, remove the locking pins at the ends of the leading hatch section.

10. Heave away easily on the bull-wire once the locking pins are removed, taking the weight of the leading hatch section.

11. Ease out on the check wire as the bull-wire heaves the hatch open.


12. Once all hatch sections are in the stowed verticalposition, the bull-wire should not be removed untilthe securing chains from a fixed point are in positionto hold back the hatch sections in the stowage bay area.

13. Clear away the check wire, coiling it down to one sideof the hatch. Do not attempt to detach the check wirefrom the lug of the leading edge of the hatch.


Single pull Macgregor steel hatch covers in the stowed upright position, showing fore and aft ends of two separate hatches.

Chain pull steel hatch covers in the stowed upright position

Side rolling covers (right). Rack and pinion drive, with hydraulic lifting and cleating.

L6 Hatch Covers

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