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HKIE Professional Assessment - Marine & Naval Architecture Discipline study materials
HKIE Professional Assessment - Marine & Naval Architecture Discipline study resources

HKIE Professional Assessment - Marine & Naval Architecture Discipline: Ship Design and Naval Architecture Fundamentals

HKIE Professional Assessment - Marine & Naval Architecture Discipline · Work through your exam, one topic at a time.

All guide sections

Ship Design and Naval Architecture Fundamentals

What this domain tests

This section checks whether you can convert a stated mission (deadweight, cargo capacity, speed, route, draft limit) into a coherent set of principal dimensions and form coefficients, and then defend the compromises. Expect definitional precision, coefficient arithmetic, and questions on how regulatory instruments constrain the design spiral.

Core definitions

  • LOA, LBP, B (moulded), D (moulded depth to the freeboard deck), T (design draft). Displacement is computed from moulded dimensions below the waterline.
  • Block coefficient C_B = displacement volume / (L x B x T); prismatic C_P = volume / (midship area x L); midship C_M = A_M / (B x T); waterplane C_W = A_W / (L x B). Identity: C_B = C_P x C_M.
  • Early-stage approximations: C_W is roughly (2/3)C_B + 1/3; displacement = density x L x B x T x C_B, with seawater at 1.025 t/m3.
  • Lightweight + deadweight = displacement. GT and NT are dimensionless volumes under the 1969 Tonnage Convention, not masses.

Constraints that shape the design

Freeboard under LL 1966; subdivision and damage stability under SOLAS Chapter II-1; intact stability under the 2008 IS Code; tonnage; EEDI/EEXI/CII; cargo intake; air draft; berth and dry-dock limits; noise and vibration. The design spiral iterates these until displacement converges, so a change in one coefficient propagates everywhere.

Worked example

A ship has LBP 120 m, B 20 m, T 8 m, C_B 0.70, in seawater of 1.025 t/m3. Volume = 120 x 20 x 8 x 0.70 = 13,440 m3. Displacement = 13,440 x 1.025 = 13,776 t. If lightweight is estimated at 4,200 t, deadweight = 9,576 t. A 5% design margin adds about 689 t of displacement, which must be bought with extra draft or beam; before accepting, re-check the freeboard, the damage stability result and the berth draft limit.

Traps that cost marks

Using LOA where the coefficient is defined on LBP; mixing moulded and extreme breadth; quoting a C_B without stating the draft it belongs to; treating GT as a weight; using 1.000 t/m3 for seawater; ignoring how a design margin cascades into freeboard and stability.