Structural Features with Regard to Keel, Side Shell and Decks Flashcards
what is a hatchways and coamings structure? and what are they for?
-Hatchways and coamings on a ship or boat are structures used for access and protection.
-The hatchway is an opening in the deck of a ship, providing access to different compartments or cargo spaces.
-The coaming is the raised border or frame around the hatchway, designed to prevent water from entering the compartment below. This is especially important in rough seas or bad weather
-The coaming effectively acts as a barrier to keep the interior of the vessel dry and safe.
Explain how the strength is reduced due to hatch openings and what measures can be put into place to compensate
Hatch Openings Reduce Strength
Interrupt Structural Continuity: Hatch openings in a ship’s deck interrupt the continuous structure, reducing the overall strength and rigidity of the deck.
Stress Concentration: These openings create areas of stress concentration, as the load that would have been distributed across a continuous deck is now focused around the edges of the hatch.
Measures to Compensate for Reduced Strength
- Reinforcing Coamings: Strengthening the hatch coamings (raised borders around the hatch) to distribute stresses and add rigidity.
-Regular Inspections: Ensuring regular maintenance and inspection to identify and address any structural weaknesses early on.
What are pillars used for?
-Pillars on a ship are vertical columns used as structural supports. They transfer loads between decks, helping to secure and strengthen the entire structure of the ship.
-Key disadvantage is that they can take up space, potentially limiting the effective use of the area where they are placed.
what are bulwarks
-Bulwarks are the solid side of the ship above the deck on areas exposed to the weather. Placed at the extremities
-Bulwarks are designed to protect vents, other deck fittings and personnel working in the areas exposed to the weather.
on the deck, what is put in place to prevent large amounts of water being retained on it?
To prevent this from happening gaps known as freeing ports are utilised
-The scuppers are drains which prevent water being retained on deck to the level of the fishplate.
-Fishplate at the extremities of the deck(can retain liquids goin over bord and prevent pollution)
how does a bilge keel work?
Bilge keels work by increasing the water resistance on the sides of the hull as the ship rolls, which creates a counteracting force that reduces the intensity of the rolling motion, leading to a more stable and comfortable journey.
why can bilge keels be easily damaged?
Bilge keels stick out from the bottom of the ship. Because of their position, they can easily hit things in the water or the seabed, especially in shallow or rocky areas. This can cause them to get damaged or broken.
what is the purpose of hatch covers?
To cover the openings on a ship’s deck, keeping the inside dry and safe from water
what measures are in place to prevent water ingress?
- Tight seals around hatch covers.
- Regular checks and maintenance.
- Proper closing and securing of the covers.
What is the purpose of the quick acting cleat and the compression bar?
Quick Acting Cleat: Helps to quickly and securely lock the hatch cover.
Compression Bar: Helps to create a tight seal when the hatch cover is closed, preventing water from getting in.
Why do we need to maintain hatch covers?
To ensure they seal properly, preventing water from entering the ship and protecting the cargo and the ship’s interior
what are weathertight door and what is their purpose?
-Purpose is to stop water from flooding into the accommodation and other spaces.
-Steel doors with rubber seals achieve this combined with steel dogs, which pull in the door on all sides to ensure that the rubber seals are compressed against the raised door frame.
what do open bracket floors do
open bracket floors provide support between solid floors using brackets at the centerline girders and at the margins.
what are plate floors?
A plate floor is an side to side constructional member which is found in the double bottom of a ship. The plate floor is positioned from the centerline outward towards the margin plate.
what are watertight doors?
Watertight doors are usually located below the waterline and are critical in maintaining the vessel’s integrity in case of underwater damage. They are built to withstand high-pressure differences and are an integral part of a ship’s subdivision and damage control systems.
