“MY BIG HOO”
INCLINING EXPERIMENT
PROCEDURAL MANUAL
Rev Description Date Reviewed and Approved:
A First Issue 20. Jun.23 Earl Brenio Naval Architect Consultant
AMADEUS MARINE LTS
Issue: 1
Rev: A
Inclining Experiment
Procedural Manual Date: 20.JUN.2023
INCLINING EXPERIMENT – MY BIG HOO Page 1 of 3
Purpose and Scope
Determine the lightship displacement, LCG and metacentric height of the vessel by
conduct of a practical inclining experiment, draft mark measurement and ship condition check.
The purpose of this document covers only for towing stability the vessel from Mariveles Freeport zone
to Subic Freeport zone, Philippines.
Upon the completion of the vessel the yard intended to conduct the final Inclining experiment.
Responsibilities
The inclining experiment will be performed by yard and witnessed by the Classification
Society Surveyor and Flag Administration Surveyor.
The Owner’s Representative should also be invited to attend, although their
attendance is not essential.
Any other labour required for manoeuvring of weights or other duties should be
assessed and organized for the experiment.
1. Action
1.1. Environmental and General Conditions
1.2. In general the wind velocity during the test should not exceed 10 knots.
1.3. The vessel must be free floating; ie mooring lines must be slack during draft and pendulum
readings. Water depth, location and time of the test are to be indicated.
1.4. Gangways, cranes etc are to be in stowed position.
1.5. As few cables, hoses etc as possible should be connected to the shore. Those that are
connected should be slack.
1.6. The loading condition during the test is to be specified.
2. Draft Measurements
2.1 Draft measurements should be recorded immediately prior to or after the test.
2.2 Draft measurements should be performed using a throttled transparent plastic tube, for
dampening wavelets, where available.
3. Seawater Density
3.1 A hydrometer for water sampling in the vicinity of the vessel is required to determine the
specific gravity of the seawater.
AMADEUS MARINE LTS
Issue: 1
Rev: A
Inclining Experiment
Procedural Manual Date: 20.JUN.2023
INCLINING EXPERIMENT – MY BIG HOO Page 2 of 3
4. Tanks
4.1 Tanks should in principle be either empty or full; ie as few tanks as possible shall be
partly filled. Full tanks should be pressed up and checked through air pipes or by sounding.
4.2 All empty tanks and void spaces should be visually inspected before and after the test.
4.3 Tanks should be manually sounded.
4.4 Normally no consumption of fresh water will be allowed during the test.
4.5 No movement of liquid onboard is allowed until the test is completed.
4.6 Cross-flooding pipes should be closed to eliminate any possibility of cross flow between
tanks.
4.7 Bilge water and water on deck should be removed
5. Foreign Weights
5.1 Minimum number of personnel is to be onboard during the test. Persons are to remain in the
same position during inclining and pendulum readings.
5.2 Deadweight is to be reduced to a practical minimum.
5.3 A detailed schedule of remaining items of stores etc should be prepared; samples of multiple
items should be weighed as a check, as should large items, which are difficult to estimate.
5.4 Loose weights (which may roll or slide) should be secured or removed from the vessel.
5.5 List of foreign weights (weights that are not part of the lightweight) including position of their
centre of gravity is to be prepared.
5.6 Foreign weights include:
5.6.1 Liquids in tanks
5.6.2 Stores, provisions, personnel etc.
5.6.3 Temporary equipment and weights
5.6.4 Inclining weights
5.6.5 Any other variable weights
6. List of Tools
6.1 Draft mark gauge
6.2 Water collecting tube and bucket
6.3 Hydrometer
6.4 Dinghy with oars
6.5 Tape measure(s)
6.6 2 x pendulums
6.7 2 x water trays
6.8 Inclining weights as required
7. Inclining Weights
7.1 At least 4 solid weights (or 4 groups of solid weights) shall be used to incline the vessel.
7.2 The physical dimensions (L x B x H) of each weight are to be given.
AMADEUS MARINE LTS
Issue: 1
Rev: A
Inclining Experiment
Procedural Manual Date: 20.JUN.2023
INCLINING EXPERIMENT – MY BIG HOO Page 3 of 3
7.3 Sufficient weight must be provided to incline at least 1 degree each side, but not more than 4
degrees. Heel angle must also be checked to ensure that there is in the water.
7.4 The intended positioning of weights onboard must be checked for structural strength & possible
deck finish damage. Weight movements should generally be trim will take place.
7.5 Total weights 8 tonnes. Location of weight between frame 3 and 16. Those weights must bear means
of identification. The expected angle of heel is between 1.3° and 2.6° and total readings will be eight.
8. Pendulums
8.1 Two pendulums, should be used to measure the inclination. Where practical the experiment should
aim to achieve a maximum pendulum deflection of 100mm to 150mm
8.2 Protected positions should be provided for the pendulums and the measuring personnel. The
pendulum position is one at aft approx. frame H and one at fore approx. frame 81.
8.3 The length of the pendulums shall be checked by the surveyor prior to the test. The pendulum
length is 6 meters.
9. Inclination Procedure
9.1 The inclining weights on port side should be shifted systematically from port to starboard and back
again. The procedure is to be repeated for the starboard.
9.2 Onboard cranes should be returned to their stowed position after each shift of weights, if used.
9.3 Exact location of moved weights and pendulum readings shall be recorded for each shift.
9.4 At least 6 shifts of weights and corresponding readings should be performed. Except for the upright
positions (0-positions), the shifts should give even distribution of points on the inclining diagram
(movement vs angle).
9.5 The shift of weights must take place transversely at the same height, or else a correction is to be
made for the change in VCG.
9.6 The accumulated inclining moment and the corresponding inclining angle after each shift are to be
recorded. Any unexpected readings should be investigated immediately, before continuing the test.
10. Calculation of Lightweight Data
The following lists should be endorsed by the attending surveyor during the test before they are used in
the Inclining Test Report:
10.1 Weights to be deducted (foreign weights & tank soundings)
10.2 Weights to be added (missing weights)
10.3 Weights to be relocated
The final GM value is to be calculated based on accumulated inclining moments and angles with a
correction for any free surface moment in slack tanks.
