HKIE Professional Assessment - Marine & Naval Architecture Discipline cheat sheet

Principal dimensions: LOA (length overall), LBP (length between perpendiculars), B (moulded breadth), D (moulded depth), T (draught); LBP is the reference length for most hydrostatic and strength ratios.

Block coefficient CB = ∇/(L·B·T); typical values: 0.50–0.60 fine (container/fast ferry), 0.70–0.75 general cargo, 0.80–0.85 VLCC/bulk carrier.

Midship section coefficient CM = AM/(B·T); prismatic coefficient CP = CB/CM; waterplane coefficient CWP = AW/(L·B).

Fineness affects resistance: low CP (0.55–0.65) favours high Froude number; high CP (0.75–0.82) favours low-speed displacement hulls.

Deadweight (DWT) = displacement − lightship; includes cargo, fuel, fresh water, ballast, stores and crew. Displacement = lightship + DWT.

Freeboard is assigned from the International Convention on Load Lines (1966/88 Protocol); minimum freeboard depends on length, type (A/B), superstructure and sheer.

Design spiral: mission requirements → dimensions/coefficients → lines → powering → structure → stability/subdivision → cost; iterate until convergence.

Tonnage: GT = K1·V (V = total enclosed volume, K1 = 0.2 + 0.02·log10 V); 1969 Tonnage Convention governs GT/NT, distinct from displacement.

Archimedes: buoyancy force = ρ·g·∇ = weight; equilibrium floating body displaces its own mass of water.

KB for box = T/2; for triangular section = 2T/3; BM = I/∇ where I is waterplane second moment about centreline (box: I = L·B³/12).

Metacentric height GM = KB + BM − KG; GZ = GM·sinθ for small angles (valid up to ~10°); use GZ curve beyond that.

Free surface effect: FSC = Σ(ρ_i·i_i)/(ρ·∇); corrected GM = GM_solid − FSC.

IMO IS Code 2008 intact stability criteria: area under GZ to 30° ≥ 0.055 m·rad; to 40° (or flooding angle) ≥ 0.09 m·rad; to 40° minus to 30° ≥ 0.03 m·rad; GZmax ≥ 0.20 m at ≥ 30°; angle of GZmax ≥ 25°; GM0 ≥ 0.15 m.

Weather criterion (severe wind and rolling): b ≥ a, where a and b are the wind heeling lever and the residual dynamic stability area lever.

Damage stability: SOLAS Ch. II-1 subdivision and damage stability; probabilistic index A ≥ R (required subdivision index) for passenger and dry cargo ships; deterministic two-compartment standard for tankers under MARPOL I.

Angle of loll: negative GM with GZ = 0 at upright; vessel lists to either side; correct by reducing free surface and lowering KG, not by shifting weight across.

Inclining experiment: GM = (w·d)/(W·tanθ) using a known shifting weight w at transverse distance d; performed at lightship, used to verify KG.

Total resistance RT = RF (friction) + RR (residuary, dominated by wave-making) + RA (air and appendage allowance); ITTC-78 method is the standard extrapolation procedure.

Friction: CF = 0.075/(log10 Re − 2)² (ITTC-57); Re = V·L/ν; ν ≈ 1.19×10⁻⁶ m²/s for seawater at 15 °C.

Froude number Fn = V/√(gL); wave resistance rises steeply near Fn ≈ 0.4–0.5 (hump); planing craft operate above Fn ≈ 0.7.

Admiralty coefficient: P = Δ^(2/3)·V³/C; useful for scaling power estimates between similar hulls.

Effective power PE = RT·V; delivered power PD = 2π·n·Q; quasi-propulsive coefficient ηD = PE/PD = ηO·ηR·ηH (open-water, relative rotative, hull efficiency).

Hull efficiency ηH = (1 − t)/(1 − w); thrust deduction t and wake fraction w are determined by self-propulsion tests or empirical data.

Propeller law: P ∝ n³, T ∝ n² for fixed pitch; propeller curve used to match engine layout and select design point.

Seakeeping: response amplitude operator (RAO) gives motion per unit wave amplitude; natural roll period T = 2π·k/√(g·GM) - large GM gives short, stiff roll.

Added resistance in waves increases required power; voluntary speed loss and sea margin (typically 15–25%) are included in the power prediction.

Primary hull girder loads: still-water bending moment (SWBM) plus wave-induced bending moment (VWBM); hogging (deck tension) and sagging (bottom tension) are the two cases.

Section modulus Z = I/y; hull girder bending stress σ = M/Z must stay below permissible values, typically ~175 N/mm² for mild steel in still water plus wave.

Shear stress τ = Q·S/(I·t); maximum near neutral axis at side shell and longitudinal bulkheads.

Classification society rules (IACS UR S7, S11, S18) set minimum thickness t = t0 + k·(scantling reduction for corrosion) with t0 tied to length and frame spacing; IACS Common Structural Rules apply to bulk carriers and oil tankers.

Plate buckling stress σcr = k·(π²E/12(1−ν²))·(t/b)²; stiffeners raise k and limit panel width; check both plate and stiffener buckling.

Fatigue: S-N approach with hot-spot stress and Palmgren–Miner cumulative damage D = Σ(ni/Ni) ≤ 1; typical design life 20–25 years.

Longitudinal strength members: deck, bottom shell, inner bottom, hopper/upper wing tanks; transverse frames resist local loads and provide buckling restraint.

Structural idealisation: effective breadth of attached plating, shear lag at hatch openings, and stress concentration at bracket toes and openings drive detail design.

Two-stroke slow-speed diesel (60–120 rpm) drives fixed-pitch propeller directly; four-stroke medium/high-speed engines drive via gearbox or alternator.

Specific fuel consumption: modern two-stroke ≈ 160–175 g/kWh; four-stroke ≈ 175–195 g/kWh; SFOC rises sharply below 50% load.

Brake mean effective pressure BMEP = (P·60·nR)/(Vd·n); typical BMEP 18–22 bar for two-stroke, 20–28 bar for four-stroke.

Turbocharging raises charge air density; scavenging (uniflow for two-stroke) and intercooling control thermal load and NOx.

MARPOL Annex VI Tier III NOx applies in Emission Control Areas for new ships; Tier II globally. SOx cap 0.50% m/m global from 2020, 0.10% in ECAs; scrubber or compliant fuel required.

EEDI/EEXI and CII (AER/CG) are IMO carbon-intensity measures under MARPOL Annex VI; SEEMP Part III requires a ship operational carbon intensity plan.

Auxiliary systems: fuel treatment (purifiers, viscosity control to ~10–15 cSt at injection), lube oil, cooling (central/sea water), compressed air for starting, and exhaust gas economiser for steam.

Steering gear: SOLAS II-1 requires two independent power units; rudder movement 35° each side, 30°→30° in ≤28 s at rated speed.

Shafting: intermediate and tail shaft with stern tube bearing; alignment check via jack-up or sag/gap method; torsional vibration analysis mandatory for new installations.

Steel grades: normal strength A, B, D, E (increasing toughness); higher strength AH32–EH40, with grade tied to thickness and location per classification rules.

Welded block construction: hull divided into blocks, pre-outfitted, then erected in dock; dimensional tolerance and weld distortion control are key production issues.

Weld types: butt welds (full penetration) in shell and strength members, fillet welds for stiffeners; NDT by RT, UT, MT and PT per IACS and class requirements.

Corrosion protection: coatings per IMO PSPC (Performance Standard for Protective Coatings) for ballast tanks; sacrificial anodes and impressed current cathodic protection for hull.

Aluminium, FRP and high-strength steel are used in fast craft; galvanic isolation is required where dissimilar metals meet.

Launching and docking: longitudinal/end launching, side launching, floating dock or slipway; block weight and centre of gravity must be checked against stability during launch.

Sea trials: speed/power trial, manoeuvring (turning circle, zig-zag, crash stop per IMO Res. MSC.137(76)), endurance and vibration/noise measurement.

Quality control: material certificates (EN 10204 3.1/3.2), welder qualification to ISO 9606, WPS/WPQR per ISO 15614.

Classification societies are IACS members (e.g. ABS, BV, CCS, DNV, KR, LR, NK, RINA); they set and verify class rules but are not flag-state authorities.

Statutory certificates are issued by flag state or recognised organisation (RO): Safety Construction, Safety Equipment, Safety Radio, Load Line, IOPP, ISM, ISPS, MLC.

Survey types: initial, annual, intermediate, special (class renewal, 5-year cycle), bottom/docking survey (twice in 5 years, max interval 36 months), and occasional surveys.

Harmonised System of Survey and Certification (HSSC) aligns certificate validity to 5 years with annual/intermediate windows; certificate extensions limited to 3 months in exceptional cases.

Port State Control (PSC): Paris MoU, Tokyo MoU, USCG; detention for detainable deficiencies; targeting based on flag/ship risk profile.

ISM Code requires SMS with documented procedures, designated person ashore (DPA), internal audits and master's review; ISPS Code sets port/ship security levels 1–3.

Condition surveys and thickness measurement are used for ageing ships; class may impose condition of class (CC) or recommendation with deadlines.

Recognised Organisation Code (RO Code, IMO Res. A.739(18) as amended) governs delegation of statutory surveys to class.

SOLAS: Chapter II-1 (subdivision/machinery), II-2 (fire), III (LSA), IV (radio GMDSS), V (safety of navigation), IX (ISM), XI-1/XI-2 (special measures, ISPS).

MARPOL Annexes: I oil, II NLS, III harmful substances in packaged form, IV sewage, V garbage, VI air pollution; each has its own certificate and record book.

Formal Safety Assessment (FSA) per IMO: hazard identification → risk assessment → risk control options → cost-benefit → recommendations.

ALARP principle: risk reduced as low as reasonably practicable; used in HAZID, HAZOP and QRA for marine operations.

Ballast Water Management Convention: D-1 exchange or D-2 treatment; BWM Plan and International BWM Certificate required.

Oil pollution: OPA 90 in US waters requires COFR, vessel response plans and double hull; IMO conventions require SOPEP/SMPEP.

Life-saving appliances: SOLAS III and LSA Code; lifeboat capacity 100% each side (cargo ships), immersion suits, EPIRB, SART, and GMDSS Sea Areas A1–A4.

Emergency response: muster list, fire and abandon-ship drills monthly (cargo) or weekly (passenger); enclosed space entry procedures per IMO Res. A.1050(27).

Ship power systems: 440 V/60 Hz or 380–400 V/50 Hz three-phase AC; 220 V for lighting; 24 V DC for control and emergency.

Generator sizing based on load analysis; IEC 60092 governs electrical installations in ships; class rules define short-circuit and protection coordination.

Emergency generator: SOLAS II-1 requires 30 s automatic start and 18 h (cargo) or 36 h (passenger) operation for emergency loads.

Earthing: hull return generally prohibited except for specific cases (IMO/IEC); insulated distribution for essential services and tankers.

Automation: UMS (unattended machinery space) notation requires alarms, safety systems and fire detection; bridge and engine-room alarm systems per class rules.

Integrated bridge systems and ECDIS: IMO performance standards (Res. MSC.232(82)); paper chart backup required unless dual ECDIS fitted.

Cyber risk: IMO Res. MSC.428(98) requires cyber risk management in the SMS from 2021; IEC 62443 applies to industrial control systems.

Programmable electronic systems (PES) require fail-safe design, redundancy for safety-critical functions and periodic testing per class.

HKIE Code of Conduct: members shall uphold the dignity and reputation of the profession, act with integrity, and not misrepresent competence or qualifications.

Duty to public safety and health overrides commercial pressure; engineers must report unsafe conditions to the appropriate authority.

Confidentiality applies to client information, but disclosure is permitted when required by law or when public safety is at risk.

Conflict of interest must be declared in writing; members shall not accept benefits that could improperly influence professional judgement.

Continuing Professional Development (CPD): HKIE expects a minimum of 45 hours per year (or equivalent) for maintaining competence.

Professional assessment: candidates must demonstrate competence across the discipline, ethical judgement and communication; referees verify experience.

Sustainability and environmental responsibility are professional obligations; engineers should apply best available techniques and consider lifecycle impacts.

Signing and sealing engineering documents implies personal accountability for the work; delegation does not transfer responsibility.

Displacement Δ = ρ·g·∇; in seawater ρ ≈ 1.025 t/m³, so Δ (tonnes) ≈ 1.025 × ∇ (m³).

Lightship includes hull, machinery, outfit and fixed ballast; deadweight covers all variable loads.

Length between perpendiculars (LBP) is used for Froude scaling, class rule length and tonnage calculations.

Camber, sheer and rise of floor affect deck drainage and reserve buoyancy; moulded dimensions exclude shell plating thickness.

Small-angle stability: GZ = GM·sinθ; righting moment = Δ·g·GZ.

GZ curve area and range of positive stability are the primary intact stability measures.

Permeability μ affects floodable length; floodable length curve derived from the margin line (3 in below bulkhead deck).

Bulkhead spacing and number of compartments determine the damage stability standard.

ITTC-57 friction line: CF = 0.075/(log10 Re − 2)²; form factor (1+k) applied to CF in the ITTC-78 method.

Propeller open-water characteristics: KT = T/(ρn²D⁴), KQ = Q/(ρn²D⁵), ηO = (KT/KQ)·(J/2π), advance ratio J = V/(nD).

Cavitation limits blade loading; expanded area ratio and blade section chosen to avoid cavitation at design condition.

Roll damping dominated by bilge keels, anti-roll tanks and fin stabilisers; added mass in roll is significant.

Hull girder idealisation: effective longitudinal members contribute to section modulus; openings reduce effectiveness.

Wave bending moment per IACS UR S11: hogging and sagging envelopes as functions of L and CB.

Local loads: still-water pressure ρgh, wave pressure per class rules, deck cargo loads and tank pressures.

Buckling check: plate slenderness β = (b/t)·√(σy/E); stocky plates yield, slender plates buckle.

Engine layout diagram: limits of torque-rich and torque-poor operation; propeller curve must lie within the allowable range.

Auxiliary boiler and exhaust gas economiser supply steam for fuel heating and accommodation.

Fuel changeover procedure required for ECA entry; viscosity and temperature control must be managed to avoid thermal shock.

MARPOL Annex VI requires bunker delivery notes and sampling points; sulphur content records retained for 3 years.

Steel properties: yield ~235 N/mm² (AH32: 315 N/mm²), tensile 400–520 N/mm²; elongation and Charpy impact toughness specified by grade.

Weldability: carbon equivalent CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15; CE > 0.40 requires preheat.

Post-weld heat treatment and stress relief for thick sections and critical joints.

Dimensional control: laser tracking, total station and 3D scanning used to verify block alignment.

Class notation examples: ✠A1, ✠A2, AMS, ACCU, Ice Class, ESP (Enhanced Survey Programme for tankers/bulkers).

Enhanced Survey Programme (ESP) per IACS UR Z10 for oil tankers and bulk carriers; close-up survey and thickness measurement at defined ages.

ISM audits: initial, intermediate (between 2nd and 3rd anniversary) and renewal (5 years).

Statutory certificates must be on board and valid; PSC may detain for expired or missing certificates.

Risk matrix: likelihood × consequence; risk accepted, reduced, transferred or avoided; ALARP demonstration required.

HAZID and HAZOP are structured hazard identification techniques applied to new designs and modifications.

Garbage management per MARPOL Annex V: discharge restrictions by category and distance from land.

Oil record book entries and SOPEP drills are PSC inspection focal points.

Short-circuit coordination: discrimination between main switchboard and distribution boards ensures only faulty circuit trips.

Battery backup for emergency lighting, radio and alarm systems; UPS for automation and navigation.

Insulation resistance monitoring required; minimum values per IEC 60092 (e.g. 1 MΩ at 500 V DC test).

Explosion protection: Ex d, Ex e, Ex i classifications for hazardous zones on tankers per IEC 60079.

Competence boundaries: engineers shall only undertake work within their competence and seek specialist advice where needed.

Records and reports must be accurate and not misleading; falsification is a disciplinary matter.

Whistleblowing protections and reporting channels for safety or ethical concerns.

Professional indemnity and liability: engineers remain accountable for design decisions even when employed by a company.