HKIE Professional Assessment - Marine & Naval Architecture Discipline flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Block coefficient CB

CB = ∇/(L·B·T), the ratio of displaced volume to the enclosing rectangular block; typical values range from about 0.55 for fine fast ships to 0.85 for VLCCs.

Deadweight

Deadweight is the difference between loaded displacement and lightship displacement; it includes cargo, fuel, fresh water, ballast, stores and crew, and is expressed in tonnes.

Metacentric height GM

GM = KB + BM − KG, the vertical distance between centre of gravity and transverse metacentre; positive GM gives initial stability and GZ equals GM·sinθ for small angles.

Free surface correction

FSC = Σ(ρ_i·i_i)/(ρ·∇), the virtual rise in KG caused by liquid free surfaces in partly filled tanks; it reduces effective GM and must be deducted in stability calculations.

Angle of loll

A condition of negative initial GM where the ship rests at an angle with GZ equal to zero; it can occur either side of upright and is corrected by lowering KG, not by shifting weight across.

Probabilistic damage stability index

The attained subdivision index A, calculated from survival probabilities of damage cases, must equal or exceed the required index R under SOLAS Chapter II-1 for passenger and dry cargo ships.

ITTC-57 friction line

CF = 0.075/(log10 Re − 2)², the standard skin-friction coefficient correlation used with Reynolds number Re = V·L/ν in the ITTC-78 resistance extrapolation method.

Froude number

Fn = V/√(gL), a dimensionless speed parameter governing wave-making resistance and wave patterns; resistance rises steeply near Fn of about 0.4 to 0.5.

Quasi-propulsive coefficient

ηD = PE/PD, the ratio of effective power to delivered power; it combines open-water efficiency, relative rotative efficiency and hull efficiency (thrust deduction and wake fraction).

Propeller law

For a fixed-pitch propeller, absorbed power varies approximately with the cube of shaft speed and thrust with the square of shaft speed, defining the propeller curve used for engine matching.

Hull girder section modulus

Z = I/y, where I is the second moment of area of the effective longitudinal section about the neutral axis and y is the distance to the extreme fibre; bending stress is M/Z.

Hogging and sagging

Hogging is a wave crest amidships causing deck tension and bottom compression; sagging is a trough amidships causing bottom tension and deck compression; both combine with still-water bending.

Palmgren-Miner rule

Cumulative fatigue damage D = Σ(n_i/N_i), where n_i is the number of cycles at stress range i and N_i the allowable cycles from the S-N curve; failure is predicted when D reaches one.

Plate buckling stress

σcr = k·(π²E/12(1−ν²))·(t/b)², where k depends on edge support and aspect ratio; slender panels buckle below yield and require stiffeners or thicker plate.

Specific fuel consumption

SFOC is fuel mass burned per unit shaft energy, typically 160–175 g/kWh for modern two-stroke engines; it rises significantly below about 50 percent load.

MARPOL Annex VI sulphur limits

The global sulphur cap is 0.50 percent m/m since 2020, reduced to 0.10 percent in Emission Control Areas; compliance is by compliant fuel, scrubber or alternative measures.

EEDI and EEXI

The Energy Efficiency Design Index sets a maximum carbon intensity for new ships; EEXI applies the same concept retroactively to existing ships under MARPOL Annex VI.

Steering gear requirement

SOLAS requires two independent power units; the rudder must move 35 degrees each side and swing from 30 degrees port to 30 degrees starboard in no more than 28 seconds.

Steel grade designation

Normal strength grades A, B, D and E denote increasing Charpy toughness at 0, 0, −20 and −40 degrees Celsius; higher strength grades AH32 to EH40 add yield strength.

Carbon equivalent

CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15; values above about 0.40 indicate reduced weldability and require preheat to avoid hydrogen cracking.

IMO PSPC coating standard

The Performance Standard for Protective Coatings sets surface preparation, coating type and inspection requirements for dedicated seawater ballast tanks, verified at new construction and during surveys.

Special survey interval

Class renewal or special survey is conducted every five years; bottom or docking surveys occur twice in that period with a maximum interval of 36 months between them.

Harmonised System of Survey

The HSSC aligns statutory certificate validity to five years with annual and intermediate survey windows, and permits extension of up to three months only in exceptional circumstances.

Port State Control detention

A foreign-flagged ship may be detained when detainable deficiencies show the ship is unseaworthy; detention is recorded in MoU databases and raises the ship's risk profile.

ISM Code

The International Safety Management Code requires a documented safety management system, a designated person ashore, internal audits, master's review and periodic external verification.

ALARP principle

Risk must be reduced as low as reasonably practicable, balancing the cost of further control against the benefit; it underpins formal safety assessment and marine risk studies.

Formal Safety Assessment

An IMO structured process: hazard identification, risk assessment, risk control options, cost-benefit assessment and recommendations to support rule-making decisions.

Ballast Water Management Convention

The convention requires ships to manage ballast water by exchange (D-1) or treatment (D-2), carry a ballast water management plan and hold an International BWM Certificate.

Emergency generator requirement

SOLAS requires automatic starting within 30 seconds and operation for 18 hours on cargo ships or 36 hours on passenger ships to supply emergency lighting, alarms and essential services.

Unattended machinery space notation

A class notation allowing periodic unmanned operation, requiring alarms, safety shutdowns, fire detection and remote monitoring tested to class rule requirements.

IMO cyber risk management

Resolution MSC.428(98) requires cyber risks to be addressed in the safety management system; IEC 62443 provides the corresponding industrial control system security framework.

HKIE Code of Conduct

Members must act with integrity, uphold the profession's reputation, work only within their competence and declare conflicts of interest; public safety overrides commercial pressure.