A large steel structure fitted over a hatch opening to prevent the ingress of water into the cargo hold. It may also be the supporting structure for deck cargo.
How does the folding pair works hatch cover?
The folding pair is operated by hydraulic cylinders acting directly on the end hinge arms, which are connected at stools on the deck. When the cylinders push the end panel up from the closed position, the cover folds and the second panel, fitted with wheels, rolls on rails to a stowage position.
How do you test a hatch cover for leakage?
Testing of vessel’s hatch covers for weathertightness can be performed by different methods. The most common ones are hose tests and UST. Weathertightness can also be checked by light test, chalk test, air test and putty or moulding test.
What are the drawbacks of water test in hatch covers?
The limitation or drawbacks of this test is that it requires two persons and hatch cover to be tested must be empty. The leakage if very minimal cannot be identified by naked eye and cannot be performed in sub zero or cold weather. 2.
What are the most common leak detection tests for hatch covers?
One of the key areas for loss prevention in the scope of the Club’s Condition Surveys is the testing of hatch covers for watertight integrity. The most common methods of leak detection are water hose test and ultrasonic test.
What are the 5 different types of hatch cover?
Types Of Hatch Covers
- Lifting type.
- Rolling type.
- Folding type.
- Sliding type.
- Roll stowing type.
What part in the hatch cover that is among the weakest part of the hatch covers?
Retaining channels – The gasket retaining channels are among the weakest construction parts of the hatch covers.
How does your hatch cover help your ship regardless of their different types?
A weathertight cover is a cover designed to prevent the passage of water into the ship in any sea condition. Hatch covers are constructed to be weathertight, which means that, in any transient condition, water will not penetrate into the ship through the covers.
What does hatch work mean?
Filters. (art) Crosshatching; ornamentation using a crosshatch pattern. Look at the hatchwork around the edges! noun. (uncountable, shipping) The apparatus around the hatches of a vessel, particularly the cargo hatch.
What part of the ship is hatch located?
A cargo hatch or deck hatch or hatchway is type of door used on ships and boats to cover the opening to the cargo hold or other lower part of the ship. To make the cargo hold waterproof, most cargo holds have cargo hatch.
What are the basic procedures in maintaining cargo hatch covers?
GENERAL MAINTENANCE AND ROUTINES
- Before closing the hatch covers, ensure that the hatch coamings and double drainage channels are swept clean of any cargo debris. …
- Whilst cleaning, check for any damage to the coaming area, paying particular attention to the compression bars, wheels, wheel tracks and landing pads.
Which packing is used for side rolling and folding hatch covers?
- Mostly used on side rolling and folding hatch covers.
- Consists of a solid skin with a sponge rubber core.
- Standard compression: 12mm.
- Produced to guarantee long life time.
How will you ascertain the weather tightness test for hatch covers?
Water hose tests are used to determine weather tightness of hatch covers. If correctly performed, hose testing will show hatch joints that leak.
What are the methods of testing hatch cover?
Various methods can be used to test a vessel’s hatch covers such as light test, chalk test, air test, putty tests, moulding tests, hose tests and ultrasonic tests (UST).
What is piggy back hatch cover?
TTS has developed a highly-automated hatch cover system to meet the cargo access needs of bulk carriers whose design requires the hatch opening to be up to 80 per cent of a ship’s width but without any stowing space in either direction.
What is sliding hatch cover?
The sliding hatch covers for tween decks can be fitted on both general cargo ships and in refrigerated cargo ships, especially where the decks are non-insulated. The panels slide, one under the other, as the hatch opens and they stow slightly sloping.
What is twin deck in ship?
Tweendeckers are general cargo ships with two or sometimes three decks. … Cargo such as bales, bags, or drums can be stacked in the tweendeck space, atop the tweendeck. Beneath the tweendeck is the hold space, used for general cargo.
What method would you use to test the rubber seal on a weathertight hatch?
TESTING TO VERIFY HATCH COVERS ARE WEATHERTIGHT
Hose tests should be carried out in the calm, still waters of a port. Another test method is ultrasonic testing and it is strongly advised that this is conducted at routine intervals in order to demonstrate the weathertight integrity of the vessel’s hatches.
Why inspection of hatch cover is important prior before leaving the berth or port?
Before leaving port, the crew should inspect the hatch covers to ensure they are in a weathertight condition. … The crew can ensure that the paint is intact, which will give good protection against corrosion. Corrosion on the hatch cover might cause a hole in the steel construction.
What is hose test?
With hydrostatic testing you fill up the hose with a medium, such as water, and take it to a pre-specified test pressure and hold it for a period of time. During this pressure phase the hose is monitored and inspected to make sure the hose can withstand the pressure.
Why does the hatch cover testing is very important?
Ensuring a ship’s hatch covers are weathertight is an essential aspect of exercising due diligence to make a ship cargoworthy that may not be covered by routine classification society inspections. This requires an appropriate method of testing to enable any potential problems or defects to be identified and resolved.
What is difference between watertight and weathertight of the hatch cover?
In practical terms, the difference between weathertight and watertight is that a weatertight fitting shall withstand water pressure from the outside (be watertight from outside), whilst a watertight fitting shall withstand water pressure from both sides.
What is broken stowage?
Broken stowage is lost cargo space in the holds of a vessel due to the contour of the hull and/or the shape of the cargo. Dunnage, ladders, and stanchions are example of broken stowage. Broken stowage is shown as a percentage figure which is estimation of the space that will be lost.