How does a side-rolling, chain-drive “piggy-back” hatch cover work?
A dumb panel with no wheels is lifted by hydraulic lift cylinders fitted to the coaming, a rolling panel is moved underneath it and the dumb panel is lowered onto the rolling panel, which is then driven to one side as the hatch is opened.
The hatches are opened by an arrangement of wires or chains, which stack the hatches one on top of the other at one end of the hatch coaming.
The panels are lifted one on top of the other at one end of the hatch coaming by means of a travelling gantry crane.
A special flexible hinge arrangement allows the first hatch cover to turn through 180° and fold back on top of the second panel; these two then rotate together, coming to rest on top of the third panel and so on.
Which of the following may be considered as key design elements of hatch design? Select all applicable answers:
Why might a chalk test be favoured over other forms of test in certain circumstances?
If loading has already been completed and there are suspicions that a hose test could present a risk to that cargo.
Because it gives a more reliable indication of conditions prevailing when the ship is at sea.
Because it delivers a more even measurement of the seal around the entire hatch coaming.
Because it is the method most favoured by cargo surveyors.
In terms of the sealing of a hatch cover, what are the design requirements? Select all applicable answers:
Why is a chalk test considered to have limited value in establishing the water tightness of a cargo hatch cover?
Because it gives no indication of the amount of seal compression that exists when the ship is actually underway in a seaway.
Because it does not show where the rubber comes into contact with the compression bar.
Because it is out carried out at sea.
Because it is carried out before any cargo is loaded.
Because compression of the seal is marginal.
What controls the geometry of seal compression on hatch covers?
The steel-to-steel contact.
The weight of the hatch cover.
The thickness of the compression bar.
The length of the chains or wires.
The dimensions of the hatch cover.
In terms of the sealing of a hatch cover, what are the design requirements? Select all applicable answers:
Which of the following may be seen as arguments against using hatch sealing tape? Select all applicable answers:
What is “permanent set”?
The groove in the hatch seal face, resulting from the loss of elasticity.
The exact position in which the hatch cover rests when closed.
The limit of good steel on the compression bar down to which steel deterioration may be considered acceptable.
The group of hatch seals which are in continuous contact with the coaming compression bar when the hatch is closed.
The exact angle at which the hatch cover lies when closed.
The distance from the outer edge of a rubber hatch cover seal to the middle of the groove created by the penetration of the compression bar, measured in mm and averaged from readings taken on all four sides of the hatch.
Who performs the statutory annual survey on the hatch covers?
A classification society surveyor.
The company safety manager.
A port-state control inspector.
Which of the following are considered to be the most common forms of hatch cover type? Select all applicable answers:
In a side-opening rack and pinion hatch cover arrangement, what is the function of the “pot lifts”?
To raise a short section of rail to bring the rolling wheels up to the running level.
To deliver power to the rolling wheels.
To drive the continuous wire connecting (and opening) both panels.
To maintain the seal compression.
After defective seals, what is one of the largest causes of serious cargo damage resulting from ingress of water, as highlighted in this module?
Blockage of the drain channels, non-return valves or socks by cargo residues.
Which two areas have been specifically identified in this chapter as being vital to the safe and successful execution of the cargo handling process?
In order to be able to demonstrate “due diligence”, which of the following must there be a comprehensive record of?
As quoted in this chapter, which of the features listed below, render all hatch covers potentially dangerous? Select all applicable answers:
The Hague-Visby Rules require the carrier to properly and carefully load, handle, stow, carry, keep, care for, and discharge the goods carried. The “carefully-to-carry” clause includes which of the following requirements?
That the ship-owner and the master of the ship must understand the nature of the cargo carried and the extent of the precautions necessary to look after it.
That the ship-owner must understand the process of wear and tear resulting from the carriage of cargo and ensure the master pursues a program of regular inspection and maintenance.
That the charterer must understand the nature of the cargo carried and ensure the ship-owner and master of the ship exercise due diligence in its carriage.
That the master of a vessel will exercise due diligence in his responsibilities to the owner of the cargo, the operator of the vessel and to the environment.
Defective hatch covers are particularly associated with vessels of which of the following age brackets?
The annual survey of hatch covers is carried out in compliance with which of the following? Select all applicable answers:
What is the class requirement for a hose test?
Nozzle of 15-18 mm in diameter, water pressure of about 2 bar, the jet of water aimed not more than 1 metre from, and directly at, every part of the sealing areas, moved at not more than 1 metre per 3 seconds, where the hatch covers are closed and cleated.
Nozzle of 10-15 mm in diameter, water pressure of about 3 bar, the jet of water aimed not more than 1 metre from, and directly at, every part of the sealing areas, moved at not more than 1 metre per 10 seconds, where the hatch covers are closed but not cleated.
Nozzle of 20-24 mm in diameter, water pressure of about 1,5 bar, the jet of water aimed not more than 1,5 metres from, and directly at, every part of the sealing areas, moved at not more than 1 metre per 5 seconds on the cross-joints and 1 metre per 3 seconds on the peripheral joints, where the hatch covers are closed and cleated.
Article III, rule 1 of the Hague-Visby Rules requires the carrier to fulfil which of the following conditions? Select all applicable answers:
In which of the following operational conditions would an extruded hollow section seal commonly be used?
On side-rolling cover fitted to a bulk-carrier.
For oil cargoes on an OBO vessel.
Where the vessel trades in Arctic conditions.
On vessel with large open hatchways, where coaming movement will be a problem.
Which of the following are suggested in this chapter as examples of relatively low cost preventative measures that may prevent expensive cargo claims? Select all applicable answers:
In additional to ensuring that cleats are properly applied, which of the following are checks that would be made as the hatches were being secured after closure? Select all applicable answers:
In a four-panel arrangement, the cylinders are operated once the cleats are all released, causing the first, or “leading” pair of panels to peak. At this time, what is happening to the second pair of panels?
The wheels of the “trailing pair” roll up onto their trackways.
They are also “peaking” in parallel.
Nothing is happening to the second pair of panels. They are totally independent.
The third panel is raised at 45° and the fourth is about to begin elevating.
What obligation is there on the ship-owner, in respect of the carriage of goods by sea?
To exercise due diligence to make the ship seaworthy.
To carry goods in the most expeditious manner, irrespective of risk.
To be seen to comply with the prevailing regulations when audited or inspected.
To carry a copy of the Hague-Visby rules on board.
Which of the following is the definition of “steel-to-steel geometry” as explained in this module?
The hatch cover is designed such that when it rests, with steel-to-steel contact between the side plate or the support pads and the coaming, the geometric relationship between the compression bar and the seal rubber is exactly right.
The hatch coamings are designed such that when the hatch cover rests on the seal, with continuous and even contact between the compression bar and the seal rubber along the length of the hold opening perimeter, the geometric relationship between the support pads and the coaming is exactly right.
The tolerances during manufacture of hatch covers are less than 0,01 % of the side plate thickness.
If coaming movements are expected to be significant, what type of seal will the designer commonly consider fitting?
A seal comprising of a sponge core with outer skin.
Which are the types of test commonly employed to determine the water tightness of hatches or other openings? Select all applicable answers:
When de-ballasting is about to start, why is it necessary to have the vents on water-ballast hatches open?
If they are closed, the tank may collapse under vacuum.
Because it is a requirement on the safety checklist.
Because it makes cleaning easier.
If they are closed, they may be forgotten when the ship goes to sea.
Where would you find information on routine maintenance, operation and safety issues related to hatch covers, including the greasing program for various components, notes on the care of wire ropes and fittings and details of the hydraulic system?
The operating and maintenance manual.
The classification society handbook.
What normally determines the size of lift-away (pontoon) covers on container ships?
That they are capable of being lifted by shore-side container gantry cranes.
That they are capable of supporting a minimum four-stack of 40′ containers.
That they are fitted with an adequate number of anti-lift bolts to resist anticipated upward forces generated by stacks of containers as identified in the ship’s cargo handling manual.
That the longitudinal length of any one hatch cover does not exceed 0,25 of the registered length of the vessel on which it is fitted and the width is not more than 0,85 of the moulded breadth.
In which of the following operational conditions would a seal with a sponge core with an outer skin made of nitrile rubber commonly be used?
For oil cargoes on an OBO vessel.
Where there are very heavy hatch covers.
On side-rolling cover fitted to a bulk-carrier.
On vessel with large open hatchways, where coaming movement will be a problem.
Which of the following age brackets are particularly associated with defective hatch covers?
What will an inspection prior to discharge primarily establish?
Whether the measures taken in sealing the hatch after loading were successful.
Whether there is any damage to the hatch cover panels.
Whether there is any damage to the trackway.
Whether the hatch was closed properly.
When considering the strength of a hatch cover, what kind of loads must it be able to withstand? Select all applicable answers:
In additional to ensuring that cleats are properly applied, which of the following are checks that would be made as the hatches were being secured after closure? Select all applicable answers:
Which of the following figure in the top ten reasons for cargo damage based on water damage, as listed in this chapter?
If personnel are in, or could be in the vicinity of a hatch cover, what should you do before you open or close it?
Use all available means of communication to notify them that a hatch cover movement is about to take place.
Nothing – it is for them to take due care.
Ask them to leave the area.
Walk all around the hatch cover, so that you can complete the “inspection” section of the safety checklist.
Which of the following is a description of the purpose of locators?
To keep the seals and the hatch cover in the correct alignment with the compression bar and coaming, yet still provide enough clearance to avoid the hatch covers picking up main hull forces when the ship is moving at sea.
To maintain the precise extent of penetration of the hatch cover seal rubber by the compression bar on the coaming and prevent the ingress of water into the hold.
To mechanically engage wedges on the hatch cover with matching wedges on the coaming, firmly holding the hatch cover in place once closed.
To prevent corrosion and wear on the support pads.
For four panel hatch covers, two types of mechanism have been described for lifting the “trailing pair”. Which are they?
What general rule does this program suggest designers of hatch covers, those who maintain them and those who operate them should direct their efforts towards?
Defending the thin line where the compression bar and the seal rubber meet.
Minimizing the time delays due to opening and closing of hatch covers.
Ensuring seals must be resilient or elastic enough to make up for hull and coaming deformations.
That intervals between replacement of hatch seals are maximised.
Which of the following must there be a comprehensive record of, in order to be able to demonstrate “due diligence”?
Which of the following do industry statistics indicate as being the cause of a high proportion of reported cargo-worthiness defects?
Hatch covers, their seals and securing arrangements.
Cargo handling cranes, wires and control systems.
Untypical weather conditions.
Which of the following are common patterns of peripheral cleat? Select all applicable answers:
In terms of the safety of a hatch cover, what are the appropriate considerations? Select all applicable answers:
Which of the following is checked at an annual survey? Select all applicable answers:
What type of hatch cover is frequently fitted with an indirect cross-joint cleating arrangement, where wedge-shaped battening devices attached to the covers engage in coaming sockets, causing the panels to be forced together as they are lowered onto the coaming?
Four panel folding covers.
Under standard operating conditions and with proper handling, what might the expected life expectancy of a rubber hatch seal be (as quoted in this program)?
What is the name given to the restrained devices fitted to hatch covers to absorb longitudinal and athwart ships forces that will be experienced due to the motion of the ship when at sea?
Which of the following may be considered as key design elements of hatch design? Select all applicable answers:
Which of the following, as highlighted in this module, are known to regularly block drainage channels and non-return valves? Select all applicable answers:
Which of the following have the longer working life?
You are carrying out maintenance on number 3 hatch cover. The permanent set has reached half the design compression in places and there are signs of wear. You have cut out two metres of bad seal along the port side. What length of rubber will you actually cut to insert in its place?
Which of the following is the definition of “weather tightness”, as given in this program?
That in any sea condition water will not penetrate into the ship.
That in normal sea conditions, any water ingress past the hatch seals can be suitably controlled without the application of additional defensive measures.
That a minimal amount of water will penetrate if the hatch is impacted by excessively heavy weather conditions.
As identified in the applicable reading drawn from the IACS empirical scale for hatch cover thickness, based on distance from the bow of the ship.
If a ship’s hatches have been properly maintained and closed securely and properly, but are found to have leaked in abnormally severe weather, which of the following may form evidence that may be submitted in defence of a cargo claim? Select all applicable answers:
What is the minimum length of any piece of rubber seal inserted during a repair, as recommended in this module?
Which of the following figure in the top ten reasons for cargo damage based on water damage, as listed in this chapter?
How should the use of hatch sealing tape and other sealants generally be viewed?
They must never be seen as an acceptable alternative to good and thorough maintenance or proper repairs.
They should always be used in case the hatch cover and seal are defective.
They provide a cheap solution to minor defects.
They provide an adequate solution to major weather tightness problems over a short length of voyage.
Which of the following are acknowledged challenges to the ship’s officers and crew, in terms of maintenance of their hatch covers and associated fittings? Select all applicable answers:
Which of the following are among the critical hatch cover spares to be carried on board, as recommended in this program? Select all applicable answers:
Prior to closing hatch covers, which of the following should be standard safety checks? Select all applicable answers:
A prime cause of early failure of hatch seals is over-compression caused by corrosion or breakdown of the steel-to-steel contact. Cleats are then frequently over-tightened in an attempt to compensate. But what types of failure does this action commonly result in? Select all applicable answers:
What technique do automatic cleats employ to hold the hatch firmly in place once closed?
Wedges on the hatch cover engaging mechanically in matching wedges on the coaming.
They slide across like a wedge bolts.
They are applied and tightened using hydraulic cylinders to provide the force.
They are dropped into place and then tightened up with a spanner.
Who are best placed to continuously monitor the operational condition of hatch covers and sealing arrangements on board?
The ship’s officers and crew.
The company superintendent.
How is a chalk test carried out?
Chalk is spread on the compression bar and the hatch is then closed; when it is re-opened, the seal is examined for the absence of chalk at any point, which indicates a lack of contact.
Chalk is spread on the compression bar and the hatch is then closed; when it is re-opened, the seal is examined for the presence of chalk at any point, which indicates a lack of contact.
Chalk is spread on the hatch cover seal and the hatch is then closed; when it is re-opened, the seal is examined for traces of cargo in the chalk, which indicates a leak.
Chalk is spread on the compression bar and the hatch is then closed and sealed; water is applied by hose; when the hatch is re-opened, any leak will be indicated by blue discoloration of the chalk where water has penetrated.
What are the two main aspects to the maintenance of hatch covers in service, as identified in this program?
In which of the following operational conditions would a solid rubber seal commonly be used? Select all applicable answers:
Which of the following is a description of the function of periphery cleats around a hatch cover?
They provide vertical restraint, stopping the panel lifting, while permitting some relative movement between the coaming and the cover.
They provide horizontal restraint, control the cross-joint seal compression and ensure the edges of the hatch cover panels at the cross joint remain firmly pressed or held together and that the cross joint seal rubber remains properly compressed.
They provide transverse restraint, restricting the horizontal movement of the panel, ensuring that the compression bar remains within the groove in the hatch seal.
What is the unique different design feature in a side-rolling, chain-drive “piggy-back” hatch cover arrangement?
A dumb panel with no wheels is lifted by hydraulic lift cylinders fitted to the coaming, a rolling panel is moved underneath it and the dumb panel is lowered onto the rolling panel, which is then driven to one side as the hatch is opened.
No direct hydraulic power is used and the hatches are opened by an arrangement of wires or chains.
The panels are lifted one on top of the other at one end of the hatch coaming by means of a travelling gantry crane.
A special flexible hinge arrangement allows the hatch cover to turn through 180° and fold back on top of an adjacent panel.
In order to understand the basic principle behind hatch cover design, how must the hatch be considered?
As a dynamic (mobile) object on the coaming.
As a static object on the coaming.
As a rigid object on the coaming.
As an open area continually exposed to salt water.
Before attempting to open the hatch covers, what should happen to all cross-joint cleats and wedges?
They should be disengaged.
They should be examined for signs of wear or failure.
When replacing the straight pieces of a hatch seal, what is the recommended additional percentage to be allowed when cutting?
None, it should be cut to the exact length required.
In additional to those items that would normally be covered at an annual survey, which of the following is checked at a 5-year special survey? Select all applicable answers:
If it is assumed that the covers have been properly installed, which of the following lead to the majority of the problems of accelerated wear of hatch seals? Select all applicable answers:
In terms of strength, what kind of loads must a hatch cover be able to withstand? Select all applicable answers:
Which of the following can be seen as potential limitations of a hose test? Select all applicable answers:
In determining when a hatch cover seal has reached the point when it needs to be replaced, what general “rule of thumb” is commonly applied?
When permanent set reaches half the design compression.
When permanent set reaches full design compression.
When a groove is seen in the seal.
After not less than 9 months and not more than 15 months service.
When impact damage or localized corrosion is found on the top of the compression bar.
When it appears as a recommendation following a Class survey.
What is the minimum length of any straight piece of rubber seal inserted during a repair, as recommended in this module?
You have just replaced the seal on number 2 hatch. What should you do now?
Measure the seal compression and record it.
Secure the lid as tightly as possible and leave it closed until arrival; in the next port.
Measure the groove in the seal in the forward corners of the hatch.
Compare the appearance of the new seal to that of the old seal.