Your vessel will use its own 50-tonne derrick to lift project cargo from a barge alongside. As Chief Mate, describe the planning required for this heavy lift operation.

A. HEAVY LIFT PLANNING — CM RESPONSIBILITIES: (1) STABILITY CALCULATION (pre-lift): calculate the effect of the 50-tonne lift on stability. Key considerations: (a) When the lift is suspended from the derrick, the weight acts at the derrick head — this can be 20-30m above the keel, dramatically raising the centre of gravity; (b) The "virtual rise in G" (VGM effect): while a weight is suspended, it acts as if at the point of suspension (derrick head). GM is temporarily reduced. Calculate new GM with weight at derrick head; (c) Minimum GM during lift: the loading manual specifies minimum GM for heavy lift operations. Verify compliance; (2) LOAD LINE CHECK: confirm the heavy cargo does not take the vessel below her load line marks; (3) DECK STRENGTH: verify the cargo stowage position deck can carry the weight — both the static load and dynamic loads from vessel motion; (4) DERRICK CERTIFICATE: check the derrick's Safe Working Load (SWL) certificate is current and the proposed lift is within SWL; (5) RIGGING CHECK: inspect all running rigging, blocks, topping lifts, guys, and winches. Do NOT use cracked blocks, worn wire, or uncertified shackles; (6) PERSONNEL BRIEFING: brief the crane operator/derrick crew on the lift plan, communication signals, emergency stop procedures; (7) WEATHER WINDOW: heavy lifts should only be conducted in sea conditions within the equipment's operational limits. Assess wind strength and sea state; (8) MEDICAL READINESS: ensure medic/first aid cover during the lift.

B. Heavy lift stability calculations are only required for lifts exceeding 100 tonnes. A 50-tonne lift on a vessel of 5000 GT or above requires no special stability assessment.

C. The crane/derrick operator takes full legal responsibility for the lift once they begin. The Chief Mate only needs to confirm the cargo weight matches the declared manifest weight.

D. The virtual rise in G from a suspended lift only applies to ship's cranes. Derricks (boom and topping lift) transmit weight directly to the cargo and do not affect GM.

A. CM HEAVY WEATHER PREPARATION — PRE-DEPARTURE: (1) STABILITY CALCULATION: produce final departure stability calculation using the loading computer. Verify: GM exceeds loading manual minimum AND an appropriate margin above minimum for heavy weather (typical recommendation: GM at least 0.5-1.0m above minimum for Force 9+ North Atlantic); check GZ curve meets all intact stability criteria (2008 IS Code); verify trim is within acceptable limits; (2) FLOODING ANGLES: calculate the angle at which the vessel would be at risk of flooding — ventilators, air pipes, or other openings. Ensure this angle has adequate margin above the expected rolling in Force 9; (3) FREE SURFACES: minimise free surfaces in ballast tanks — either top up or press down. Partial tanks create large free surface corrections that reduce effective GM; (4) LASHINGS INSPECTION: physically check all cargo lashings on deck and in holds — direct the bosun and deck gang to retighten any slack lashings. Check hatch covers — all cleats tight, rubber seals intact, cross-joint seals good; (5) DECK FITTINGS: make rounds of the weather deck — secure all portable equipment; check anchor lashings; verify everything on deck is properly secured; (6) BILGES: sound all bilges and ballast tanks — confirm no unexpected water ingress; (7) CREW BRIEFING: brief the watch officers on what speed and heading changes to expect; advise the bosun to keep crew off deck in heavy weather; (8) PASSAGE PLAN REVIEW: review the passage plan with the master — identify alternatives if the weather is worse than forecast.

B. Stability in heavy weather is calculated automatically by the ECDIS loading computer. The Chief Mate only needs to check the final print-out, not independently verify calculations.

C. For a North Atlantic winter passage, the Chief Mate's preparation involves adding extra ballast to maximum capacity regardless of the effect on GM. Maximum ballast always equals safest vessel.

D. Heavy weather preparation is primarily the master's responsibility. The Chief Mate should focus on cargo documentation and hand-over notes rather than stability assessment.

A. CARGO SHIFT — CM INVESTIGATION AND MANAGEMENT: (1) INITIAL ASSESSMENT: 8-degree list unaccounted for by known weights — URGENT. Calculate: with current GM, what weight shift would produce 8 degrees? Formula: d = (W × GG1) / (Δ × GM). This quantifies the possible shift. Stability computer: input the assumed shift and see if it matches observed list; (2) INVESTIGATE CAUSES: (a) Reduce speed and alter course to a more comfortable heading — reduce rolling to minimise further shift; (b) If it is safe to do so, arrange for hold inspection to confirm or identify cargo shift. In Force 9, entry into holds may be impossible safely — wait for a reduction in conditions; (c) Check bilges in all holds — flooding can also cause a list; (d) Check ballast tanks — has a tank emptied or flooded unexpectedly?; (3) CORRECT THE LIST: options to reduce the list: (a) Ballast: pump ballast water to the high side to counteract the list. Use cross-filling of double bottom tanks; (b) Do NOT enter holds to reshift cargo in heavy weather — this is extremely dangerous; (4) STABILITY CALCULATION: recalculate stability with the assumed cargo shift. If GM appears to be reduced significantly — master to consider heading for nearest port of refuge; (5) NOTIFY MASTER: immediately — an 8-degree list is a serious stability situation; (6) MAYDAY READINESS: if list is increasing and stability is deteriorating, prepare for emergency.

B. An 8-degree list can be corrected by transferring fuel oil between port and starboard service tanks. No other investigation is necessary as a list of 8 degrees is within normal operating parameters.

C. Send the bosun's team into the cargo hold immediately to investigate and reshift cargo. Finding the shifted cargo source takes priority over safety considerations in Force 9.

D. Continue passage at full speed. An 8-degree list in heavy weather is caused by dynamic rolling only and will self-correct when the weather improves.