Key points for speed testing of fully enclosed lifeboats

I. Test Conditions (Must be met, otherwise invalid)

• Full Load: Rated crew + all equipment + full fuel + fresh water and food; weight must be met.

• Calm Water/Open Water: Wave height ≤ 0.5m, wind force ≤ 3, no strong current; sufficient water depth, no shallows.

• Integrity and Watertightness: Doors/windows/hatch openings are properly sealed; the fully enclosed structure has no leaks.

• Instrument Calibration: GPS (differential is better), tachometer, timer, and anemometer are valid.

II. Core Standards (Must be met)

• Full Load Calm Water Speed ​​≥ 6 knots

• Towing another fully loaded lifeboat ≥ 2 knots

• Endurance: Continuous sailing at 6 knots ≥ 24 hours

III. Engine Load Test (Required before reaching speed)

• 50% Power (≈80% Rated Speed): 30 minutes, check temperature, oil pressure, vibration, and exhaust.

• 100% Rated Power / Full Speed: Continuous for 4 hours, stable speed, no overheating, no abnormal noise, and no engine stalling.

• Reverse (75% Power): 3 minutes, clutch and reverse operation function normally.

IV. Speed ​​Measurement Procedure (Straight-line Reverse Method, CCS Standard)

• Select a ≥500m straight course, set the GPS start/end point.

• Start the engine at full speed, stabilize the speed for 3–5 minutes, then time the one-way trip.

• Immediately reverse the course and measure again (to eliminate water flow error).

• Repeat 3 round trips and take the average:

• V_average = (V₁ + 2V₂ + V₃) / 4

• Requirement: Average speed ≥ 6 knots.

V. Special Inspection Items for Fully Enclosed Craft

• Fully Enclosed Structure: Doors and windows must not leak air, allow water ingress, or exhibit abnormal deformation at high speeds.

• Exhaust/Ventilation: No backflow, no water ingress, and no oil or gas accumulation in the engine room at full speed.

• Handling Stability: Stable heading, no severe rudder deviation, minimal roll, no bow submersion, and no wave impact.

• Shaft/Propeller: No abnormal vibration, unusual noise, or water leakage.

VI. Towing Test (Mandatory)

• Towing a lifeboat/25-person raft of equivalent weight at a speed ≥ 2 knots at full speed.

VII. Data Recording (All Items Required)

• Boat Number, Date, Location, Sea State (Waves/Wind/Current)

• Full Load Weight, Engine Model/Rated Speed/Actual Speed

• Per Trip: Time, Distance, GPS Speed, Speed, Water Temperature, Oil Pressure

• Average Speed, ≥6 knots; Towing Speed ​​≥2 knots

VIII. Common Mistakes (To be Avoided on-site)

❌ Underloading or Light Load Testing (Results are too high, not accepted by classification societies)

❌ Testing Only One Trip (Large Current Error)

❌ Timing Before Speed ​​Stabilizes (Inaccurate Data)

❌ Sea State Exceeding Standards (Waves > 1m, Strong Winds) - Test Invalid