as these lubricants generally tend to react with the packing rubber’s surface and cause
damage. Abrasive residues will settle in the grease and cause rapid deterioration of therubber. Only in specific cases, and when explicitly recommended by the manufacturers,
special types of grease (usually silicon grease) can be applied.
When replacing packing rubber, it should be remembered that size is not the only criterion that should be observed. Issues like design compression, weight/metre, mean compression force and installation and preservation requirements should be considered.
Whilst it may be tempting to try “speeding up” replacement of the rubber by lightly
inserting the rubber in the retaining channel and closing the panel to push the rubber further into the retaining channel, practice has shown that this does not work and this repair
method should be discouraged.
During inspections, it is important to check packing rubbers for following defects which
may aﬀect the sealing eﬃciency such as:◎ Overcompression andpermanent set (imprint)◎ Physical damage◎ Discontinuity ofthe sealing

Overcompression and permanent set (imprint)
which can be caused by improper adjustmentof the steel to steel contact or ageing.
Physical damage such as cuts, abrasion,
deformation,...
Discontinuity of the sealing, meaning thatthe line of contact should not be interrupted
as a result from gaps, missing pieces, steps
between adjacent lengths of rubber (usually
after partial replacement), damages,…

◎ Oﬀ centre imprint

Oﬀ centre imprint as result from misalignment,
flaws in the design, installation, fitting,….

25

◎ Cleanliness of the sealing

surface

Impurities such as cargo remnants, rust, etc
should be removed as they might aﬀect sealing and test results or cause irrevocable damage to the packing rubber.

③ Bearing pads
In order to keep the packing rubber at the required design compression, steel to steel
contact between the panel and hatch coaming is necessary. This is usually provided by
the bearing pads (also called Fz stoppers) which consist of a support pad on the hatch
cover and a landing pad on the hatch coaming. Apart from the straightforward steel-tosteel type bearing pads, diﬀerent designs with diﬀerent materials for the mating halves
are available on the market.

Support Pad

Landing Pad
Photograph 10 Support Pad & Landing Pad

Bearing pads will wear down in function of type, age and loads that are acting uponthem. According as bearing pads wear down, the compression of the packing rubber will
increase and therefore the wear process should be regularly monitored by checking theskirt clearance which can easily be measured with a ruler or feeler gauge. Information
regarding the skirt clearance and max. allowed wear on the bearing pads can be found in
the manual and will usually be in range of 2-3mm. Some mating surface designs include
wear rings or marks that indicate the bearing pad wear.

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Photograph 11

Checking skirt

clearance with feeler gauge

Figure 4

Bearing pad wear will result inovercompression of the packing rubber.

Bearing pads play a crucial role in the sealing process and inspections should focus on:◎ WearWear in way of the landing pads (resulting is
reduced skirt clearance).

◎ Lack of contact

Lack of contact between the support andlanding pads.

◎ Structural integrity◎ Type of steel◎ Cleanliness and freemovement

Structural integrity of the bearing pads, coaming and deck structure so that the weatherloads and stresses that are acting on thehatch covers can safely be transferred towards the deckstructure.
Correct steel for the landing (mild steel) andsupport pads (hardox).
Cleanliness and free movement between thelanding and support pads (even/smooth surfaces). Greasing of the bearing pad surfaces
is usually not recommended (check with manual) and may even accelerate weardown incase dust and abrasive residues settle in thegrease.

27

Older hatch cover designs may not have bearing pads installed in which case the steel tosteel contact will be achieved through direct contact of the hatch cover side plating withthe hatch coaming. In such cases, wear and damages in way of the panel/coaming interface (lower part of the hatch side plating and coaming table surface) should be checkedfor damages such as corrosion , grooving, thinning, deformations,….

Photograph 12
Steel to steel achieved by contact
between panel side plating andcoaming table. Grooving andthrough corrosion in way of panel/coaming interface

Bearing pads are relatively easy and quick to repair but adjustment of bearing pads isbeyond the capacity of the ship’s crew and should preferably be done by qualified repair
personnel.

④ Locators
Besides the bearing pads, the locators (sliding positioners) will ensure that the panels areproperly guided and positioned when being closed. This means that the packing rubber
in way of panel intersections is properly compressed up to the manufacturers’ design
compression and that panels are properly aligned and centered.
Locators will also operate against small clearances and should be correctly installed andmaintained to avoid excessive clearances.
In order to correct for wear in way of the locators, more recent designs include replaceable and adjustable locator pads (with shim plates).

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Photograph 13

Photograph 14 Measuring clearance

Locator with adjustable padsof locator with tapered feeler gauge.

Together with the bearing pads, the locators are important for achieving tightness andtherefore regular inspection is required. Inspectors should especially be looking for thefollowing:◎ Wear and excessive clearance

Wear and excessive clearance (usually
2-3m max) as excessive wear will directly
compromise sealing eﬃciency.

◎ Structural integrity

Structural integrity to ensure that the locator parts and coaming structure can withstand loads and stresses.

⑤ Stoppers
Once properly closed in port (static condition), panels should remain in their correct
sealing position throughout the voyage whilst the ship will be in a dynamic condition atsea. Relative movements will tend to distort the panel arrangement, alignment and geometry but in order to prevent forces that are acting on the hull girder to be transferred
directly into the panels, some limited movement should be allowed.

29

Photograph 15

Panel stopper arrangement

Therefore, stoppers (sometimes also called rolling or pitching stoppers depending on
their working direction (longitudinal (Fx) or transversal (Fy)) will be installed withsmall clearances. Depending on the loads and design of the hatch cover panels, stoppers
may come in diﬀerent shapes and sizes. Items to look out for during inspections are:◎ Excessive wear/clearance

Excessive wear/clearance as with excessive
clearances control over the movement of
the panels will be lost which would result indamage or accelerated wear of other parts.

◎ Structural integrity

Structural integrity as damages or advanced
corrosion and wastage will affect the stopper capacity.

⑥ Securing systems
Under the ICLL, it is required that hatch panels can be properly secured to the ship. Thisis necessary to prevent panels from being pushed oﬀ or blown away and leave the hatch
and hold exposed to the elements.
Securing of the hatch panels will generally be done manually with the well-known quick
acting cleats or holding down devices (the latter usually seen on board of very large

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container carriers), or by means of automated systems (self auto-wedge closing systems,
hydraulic cleating systems,…). The type of cleat system to be installed will depend
amongst others on the number of crew available for preparing the hatch covers for sea assome cleating systems are more time consuming to open/close as others.

Photograph 16 Quick acting cleat parts

It is important to note that cleats are fitted to hold the panel down when the ship is atsea but not to obtain a tighter seal. In order to accommodate for the relative movements,
cleats have to be “flexibly” mounted, hence the rubber washers which are generally used
for this purpose.
Crew should also be aware that in cases of leaks being found during tests, extra tightening of the securing cleats will not help in achieving a better or tighter seal as the steel
to steel contact (bearing pads) will prevent panels to be pulled further down. Excessive
tightening will only restrict cleat movements and lead to deformations or even failure of
the panel side plating, coaming table and cleat parts which eventually would leave thepanels unsecured and the ship at risk.

31

In order to ensure that cleats are fit for duty, they should regularly be inspected for:◎ Structural integrity

Cleats connect the panel with the hatch coaming
table and as such, strength related issues suchas corrosion, deformations and thinning (reductionof cross-sectional thickness) of the diﬀerent partsof the cleating system, as well as the coaming
table and panel side plating should be checked.

◎ Total number

As the required holding power can only beachieved when all cleats are in place, missing (anddamaged) cleats should be replaced.

◎ Flexibility

The rubber washers should be in good condition(not overpainted, no additional steel of rubber
washers fitted).

◎ Alignment

If cleats are crooked or misaligned their holding
power will be aﬀected.

◎ Adjustment

Cleats allow for adjustment of wear in the hatch
cover (bearing pad) system and should be tightened to the correct tension.

Where cross wedges are installed, attention should be paid to proper installation andadjustment (no building up with shim plates) as well as deformation (bent or “banana
shapes” wedges) and overtightening should be avoided.

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Photograph 17“Banana shaped” cross wedge with striker plate built up⑦ Drain systems
When relative movements are exceeding the packing rubber’s design compression, water will pass through the sealing arrangement and collect in the drain channels which
will eventually evacuate the incoming water out on deck. As such, drain systems (bothin way of the cross joints (“A”) as well as on the hatch coaming (“B”)) are the last barrier to water ingress into the hold.

A

B
Photograph 18

Drain systems

33

Drain systems consist of a drain channel, drain hole in the coaming table and a drainpipe fitted with a non-return valve. The non-return valve will prevent water from outside
to enter into the hold (in case of heavy weather).

5. Float(Ball)
1. Drain pipe
4. Fins
3. Fire cap

2. Drain valve

Photograph 19

Drain systems: Principle ‑ non-return valve

Drain valves should always be open and free but the non-return valve should be closedwith the fire cap in case of CO² release (fire) or fumigation. Only in case the valves
should become damaged during the voyage and if insuﬃcient spare valves are available,
the use of a piece of firehose, long enough to bend back on itself to prevent water ondeck from entering the drainage system, can be considered as a temporary solution.
Whilst checking drain systems, inspectors should focus on the following points:

34◎ Structural integrity

Structural integrity of drain channels incross joints and on the coaming (corrosion, damage,…).

◎ Type of drain valve

Original type of drain valve fitted.

◎ Condition of the drain system

Drain system (drain channel, drain hole,drainpipe and drain valve) free and unobstructed.

P&I Loss Prevention Bulletin

Vol.53◎ Fire caps

Fire caps provided and available in a clearly identified space (e.g.
CO² station).

Whilst loading or discharging bulk cargo, it can be considered to plug the drain hole toprevent cargo from blocking the drain holes and valves, but attention should be paid toremoving the plug prior to closing the hatch covers.

⑧ Compression bars
In order to achieve aweathertight seal, packing rubbers act against a
packing rubber mating
surface, often referred toas the compression bar.

A

B

Depending on the type ofrubber installed, this caneither be a raised com-

Photograph 20 Compression bars

pression bar (with rounded sealing surface for normal type flex or sponge core seals – Photograph “A”) or a flat
steel mating surface (which can be the steel coaming plating itself or a stainless steel
strip welded onto the coaming table for the CAT or sliding profile seals - photograph"B"). The flat steel mating surfaces are easy to install, maintain and clean and have norestrictions in movement. Nowadays, the raised type compression bars will generally bemade of stainless steel.

35

Compression bars should usually be checked for some important issues.
◎ Structural condition

As packing rubber pressure and loads (meancompression force and relative movements) areconsiderable, compression bars should be structurally intact and strong to withstand the repeated forces acting on them.

Straightness of the compression bars is important as unevenness will result in irregular compression.

◎ Straightness

Smoothness of the compression bar sealing
surface will prevent abrasion of, and damage
to, the packing rubber surface. Corrosion, cuts,
remnants of previous cargo etc… should be
identified and addressed.

◎ Smoothness⑨ Operating systems
Modern hatch panels are generally heavy pieces of equipment that require mechanicalpower to be opened/closed and their operation is not without risk. Electro-hydraulicoperated systems are still commonplace but more recently electric driven systems arebeing installed as well.
From a safety point of view, it is recommended to operate hatch covers with an operator
who is in charge of the controls and a supervisor who ensures that no one is passing in
way of the moving hatch covers. Hatch covers should always be operated by properly
trained personnel.
Strictly speaking, opening and closing mechanisms are not related to the sealing andsecuring arrangements but they are necessary to open and close the panels for cargo operations.

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During inspection, attention should be focused on following items:◎ Opening/closing speed◎ Abnormal noise◎ Proper greasing ofmoving parts◎ Oil leakage◎ Damages anddeformations◎ Safety items

Opening/closing speed (depending on type andmanual specs).
Abnormal noise and sounds as well as vibrations
during panel operation are indications of problems.
Proper greasing of moving parts such as wheels,
hinges will facilitate proper operation and extend
in-service life of bearings.
Oil leakage from hydraulic systems (deck piping,hydraulic power pack, cylinders) will result in lossof oil, slippery surfaces and can cause pollution.
Damages and deformations to deck, coaming
and panel plating will affect strength, structural
integrity and may jeopardize proper operations
and entail safety hazards.
Safety items, such as safety latches to secure
panels in open position or EMY stops should bein good condition and operational.

Hydraulic systems operate at very high pressures(up to 250 bar) and any impurities in the oil will
have a devastating “shotgun” eﬀect on the component parts of the power pack, valves etc. Impurities
can also be drawn into the system via leak sites andcylinders. Leaks, regardless of their size, should
be repaired immediately and it is recommended toprotect hydraulic cylinders from contact with cargo
remnants and dust with protective sleeves.

Photograph 21
Protective sleeve for cylinders

37

Piping should be thoroughly flushed after repairs to remove debris and oil, even if newly
supplied, should be properly filtered before use.
Crew is to be familiar with the emergency closing procedures (EMY power packs, wire
operated systems, …) in order to reduce delays in operation and/or prevent cargo in theholds from becoming wet.
When chains or wires (incl. associated gypsies and pulleys) are used for opening andclosing of the hatch covers, they should be checked for strength, wear and diminution,
damage, proper tension, elongation. In case the hatch cover system consists of pontoons
which are lifted by crane, it is important to check the strength of the lifting points on thepanels and conspicuous marking of same is recommended.

Photograph 22 Pontoon covers on container vessel properly marked/indicated38

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Chap.

05

MARINE TAPE:
A blessing or a curse?

Most of the wetting damage claims as a result from hatch cover leakage are commercial
related, rather than statutory related. In cases where cargo has sustained wetting damage,it is often assumed that the ship/owners failed to exercise due diligence in making hatch
covers weathertight. Within the context of hatch covers, due diligence requires the master/owners to carry out a normal and reasonable inspection to ensure that the hatch covers are in good condition. In case defects are noted, it is expected that necessary steps
are taken to correct the situation. It is important that corrective actions are made in linewith good industry standards and maker’s guidelines.
Very often, when being faced with unsatisfactory test results, various sealants such as
marine sealing tape, expansion foam etc are used to cover the leaky spots, which is notin line with the due diligence principle. The use of extra sealants allows claimants toassume that the master/shipowner was aware of the tightness issues and decided not to
repair the problem in a proper way and decided to opt for the cheapest and quickest solution that would allow him to start the voyage and meet with commercial deadlines. By
doing so the Master and shipowner would fail in their duty to provide a seaworthy andcargoworthy ship and look after the safety of the ship, crew and cargo by not complying
with the due diligence requirements.

39

Photograph 23 Marine tape

Photograph 24 Expansion foam

It is however, a fact that many charterers or shippers are asking Masters to apply sealing
tape after loading and by doing so they put the Master in a diﬃcult position. On the one
hand, Masters have the duty to cooperate with charterers and comply with reasonable
requests that do not aﬀect the ship’s safety, but on the other hand, masters are (or shouldbe) aware of the fact that applying marine sealing tape might put them in a diﬃcult position in case the cargo should sustain wetting damage during the voyage. In such cases,
masters and owners should ensure that they can prove that, before applying the sealingtape, the hatch covers were weathertight, i.e. passed an ultrasonic (or hose) test as well
as a visual inspection which confirmed that all hatch cover parts are in a well maintained
and good condition. In such case it might be recommended to call in the assistance ofa surveyor to carry out the hatch cover test and inspection. Results of these inspections
will be considered as a third party confirmation that all is in order and would provide
good evidence in case of a claim. In case defects are found during such an inspection,
they should be addressed in a proper way prior to applying the sealants. Finally, making a note in the ship’s logbook stating that the hatch covers were tested, inspected andfound in order (and making reference to the test/inspection report), and that the sealing
tape was applied at the explicit request of charterers or shippers would be further proofof a professional approach towards the use of marine sealing tape.
One thing that is also often overlooked in case it is decided to apply marine sealing tape(various types are currently on the market), is that this sealing tape adheres strongly tothe hatch panel surface (it is even recommended to heat the panel surface/tape to ensure

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P&I Loss Prevention Bulletin

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proper adhesion, especially in cold weather). Upon completion of the voyage, the tapewill be removed, but generally during this removal process paint becomes detached,leaving the panel surface unprotected and exposed to the elements with corrosive action
setting in if not dealt with quickly and in a proper manner. Maintenance of the areas withcoating breakdown is time consuming, especially when the sealing tape is applied on all
hatch covers, and will deviate attention from other (and perhaps more necessary) shipboard maintenance tasks. When owners are convinced that their hatch covers are in goodcondition and able to prove this, it is better to reconsider the charterers’ request to apply
marine sealing tape and/or to include in the C/P that no sealing tape will be applied.
With regards to the fumigation issue, it should be noted that hatch covers are built andtype approved to be weathertight, not gastight. In order to reduce the risk of fumigation
gas escaping (which is a threat to people and will reduce fumigation eﬃciency) sealants
can be used, but in that case it is not used for masking defects but rather to improve fumigation safety and eﬃciency.
However, and before applying the sealing tape, hath covers are normally tested and inspected and only when they are in good shape and weathertight, the sealing tape can beapplied in order to enhance gastightness.
Many ship owners are saying indeed that they apply sealing tape as “extra” precaution
but unfortunately investigations generally reveal that the hatch covers were not weathertight at the outset of the voyage in the first place so that the sealing tape cannot be
considered as an “extra security” but rather as a shortcut to avoid expenses for necessary
repairs and maintenance in case hatch covers leak (which is not in line with the due diligence principle).
Always remember that there will be relative movements between the panels as well as
between the panels and the ship (especially in heavy weather) which might cause thesealing tape to become damaged, detached and loose.

41

EVIDENCE IN
06 CASE OF CLAIMS
Chap.

In the unfortunate event that a claim is filed against the ship, and in order to help the
P&I club and legal people to defend the owner’s interests, it will be up to the master andowners to prove that they have done whatever is necessary in order to make the hatch
covers weathertight. This can be done by providing relevant documents such as:

Work schedules
Maintenance logs & test reports
Work speciﬁcations
Standing instructions
Reports and correspondence
Logbook entries
Hatch patentee manual
Holding valid (relevant) certiﬁcates
Evidence of planning voyage & weather reports
Proof of operating the ship in a good/seamanlike manner
during the voyage (C/C, RPM, etc.)

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Chap.

07 HATCH COVER TESTINGThe ICLL states that “The arrangements shall ensure that the tightness can be maintained in any sea conditions, and for this purpose tests for tightness shall be required at
the initial survey and may be required at periodical surveys and at annual inspections or
at more frequent intervals”.
There are diﬀerent methods for testing hatch covers and in a number of cases it may be
useful or recommended to combine diﬀerent methods in order to get an as good impression as possible about the hatch cover condition. The most commonly used testing methods are listed below:●

Ultrasonic test●

Hose test●

Light inﬁltration●

Chalk/grease test (for normal or sliding-type rubbers)●

Smoke test●

Pressure decay(It is beyond the scope of this article to explain each of the above testing methods in detail, but
further information can be found in class regulations or by contacting the author of the article).

It should be noted that the above testing methods mainly provide information about thesealing system only. Weathertightness requires not only confirmation that hatch covers
are tight, but also that the structural integrity and securing related issues are in order.
Tightness can only be achieved and maintained during the voyage on condition that allcomponent parts are in good condition which can only be confirmed after a detailed visualinspection by qualified and knowledgeable persons. Concluding that hatch covers are weathertight on basis of an ultrasonic test alone is dangerous and might lead to cargo claims.

43

Chap.

08 MAIN PROBLEMS FOUND
Experience has revealed that, when testing and inspecting hatch covers, the following
typical or frequently seen mistakes are identified below.

Common mistakes● Insuﬃcient knowledge about hatch covers, not allowing for goodinspections and proper, understandable reporting●

Overestimating the capability of the shipʼs crew for repairs(maintenance & adjustment)●

Omitting to call in specialists (remember that being able toprove that repairs were carried out by a specialist team will
help in proving due diligence)●

Overlooking the importance of involving class when shipboard
repairs are carried out on hatch covers●

Improper/temporary repairs by crew●

Missing manual/drawings●

No proper and detailed on-board instructions for maintenance●No maintenance ﬁles on board (i.e. PMS) to document maintenance and repairs●

Hatch covers not included in SMS and PMS● No understanding of the due diligence principle and requirements●
44

Insuﬃcient spare parts

P&I Loss Prevention Bulletin

Vol.53

Weather tightness mistakes●

Ignoring discard/replacement criteria (over-compression)●

Replace rubber packing without addressing steel to steel
contact issues●

Installation of backing strips everywhere, even on top of rubber packing●

Mix of new and old rubber●

Using old rubber (from shipboard stock and ignoring shelf life)●

Use of small pieces and ﬁlling-in of gaps●

Improper maintenance of seals and rubber channel (painting)

Mechanical mistakes●

Abnormal sounds/vibration during operation ignored●

No greasing, no greasing plan●

Onboard repairs instead of landing panels ashore●

Ignoring safety issues (heavy and moving equipment)

Hydraulic mistakes●

Cleaning ﬁlters instead of changing●

Improper ﬁltering● Closing covers without pump●Changing of pipes without ﬂushing●

Valve positions during voyage●

Ignoring leaks & pollution risk●

Ignoring high pressure risk

45

Chap.

09

CONCLUSION

Hatch cover maintenance and operation requires a thorough understanding of basic principles together with type specific issues and requirements. Experience and claims showthat hatch cover problems still remain one of the predominant causes for claims and accidents on board vessels.
Whilst hatch cover claims are generally associated with wetting damage, it should not be
overlooked that incorrect maintenance or operation may involve loss of life and limb or
pollution. Moreover, claims for wet damaged cargo, pollution or accidents and injuries
will always have an adverse impact on the owner’s business model.
To avoid hatch cover related claims, owners should consider setting up dedicated training and familiarization programmes related to occupational safety, operation and inspection. Relevant and type specific hatch cover checklists should be made and their use
implemented.

TRAINING
Assistance and help with developing training strategies andchecklists can be obtained from the author of this article.
IMCS Training Academy

46

Mr. Walter Vervloesem (FNI)

URL

https://imcs-training.eu

E-mailtraining@imcs.be

P&I Loss Prevention Bulletin

Vol.53

JAPAN P& I CLUB
Websitewww.piclub.or.jp/en/

Principal Office (Tokyo)

2-15-14, Nihonbashi-Ningyocho Chuo-ku, Tokyo 103-0013, Japan
Phone: 81-3-3662-7272 Fax: 81-3-3662-7107

Kobe Branch

6th Floor Shosen-Mitsui Bldg. 5, Kaigandori Chuo-ku, Kobe, Hyogo 650-0024,
Japan
Phone: 81-78-321-6886 Fax: 81-78-332-6519

Fukuoka Branch

3rd Floor Hakata-Ekimae Center Bldg., 1-14-16 Hakata Ekimae, Hakata-ku,
Fukuoka, Fukuoka 812-0011, Japan
Phone: 81-92-260-8945 Fax: 81-92-482-2500

Imabari Branch

5th Floor Imabari-Kitahoraicho Building, 2-2-1 Kitahoraicho, Imabari, Ehime
794-0028, Japan
Phone: 81-898-33-1117 Fax: 81-898-33-1251

Singapore Branch

80 Robinson Road #14-01 Singapore 068898
Phone: 65-6224-6451 Fax: 65-6224-1476

Japan P&I Club (UK) Services Ltd

5th Floor, 38 Lombard Street, London, U.K., EC3V 9BS
Phone: 44-20-7929-3633 Fax: 44-20-7929-7557

Edited by Loss Prevention and Ship Inspection Dept. Japan P&I Club