MCA Certificate of Competency Ship Construction and Seaworthiness Questions and Answers Flashcards

According to SOLAS Chapter II-1, what is the primary function of a ship's forward collision bulkhead?

Answer: To provide a watertight boundary against flooding in the event of a bow collision.

The foremost transverse watertight bulkhead is the collision bulkhead. Its primary purpose, as mandated by SOLAS, is to limit the extent of flooding into the rest of the vessel if the bow and forepeak tank are breached in a head-on collision. While it contributes to overall strength, its main role is damage stability.

A vessel is loaded with heavy cargo concentrated in the midships holds, with the fore and aft holds remaining empty. The vessel is currently in still water. Which type of longitudinal stress is most likely to be affecting the hull girder?

Answer: Sagging

Sagging occurs when the middle of the ship bends downwards. This happens when there is more weight in the midships area and more buoyancy at the ends, or when the vessel is supported by a wave crest at the bow and stern with a trough amidships. In this scenario, the concentration of cargo weight amidships causes the hull to sag.

A UK-flagged vessel's Load Line mark (Plimsoll line) is being inspected. Which marking indicates the maximum permissible draught in the Summer seasonal zone for saltwater?

Answer: The horizontal line passing through the centre of the disc

The main load line mark is a disc with a horizontal line passing through its centre. The upper edge of this central horizontal line corresponds to the Summer load line ('S') in saltwater. 'W' is for Winter, 'T' is for Tropical, and 'F' is for Fresh Water.

What is a primary advantage of using a semi-balanced rudder compared to a fully unbalanced rudder?

Answer: It requires less torque from the steering gear to operate.

A semi-balanced rudder has a portion of its blade area forward of the turning axis (rudder stock). When the rudder is turned, the water pressure on this forward portion helps to push the rudder further, counteracting some of the force on the after portion. This reduces the overall torque required from the steering gear to achieve the desired angle.

A box-shaped vessel, initially on an even keel, suffers a breach and completely floods an empty, watertight midship compartment. Assuming the vessel's weight does not change, what is the immediate effect on the vessel's trim?

Answer: The vessel will remain on an even keel, but its mean draught will increase.

When a midship compartment is bilged, the loss of buoyancy is symmetrical about the vessel's longitudinal centre of flotation (LCF). The vessel will sink deeper into the water (increase its draught) to regain the lost buoyancy, but because the effect is symmetrical, there will be no change in trim. The vessel will settle bodily in the water on an even keel.

Which of the following is a key objective of the renewal survey for a Cargo Ship Safety Construction Certificate, as required by UK regulations implementing SOLAS?

Answer: To conduct a thorough examination of the ship's hull, machinery, and electrical installations.

The Cargo Ship Safety Construction Certificate renewal survey is a comprehensive inspection of the vessel's physical condition. It focuses on ensuring that the hull structure, main and auxiliary machinery, boilers, pressure vessels, and electrical systems are in a satisfactory condition and fit for service for the next five-year period. Radio and safety equipment are covered by the Safety Equipment and Safety Radio certificates, respectively.