5.5 Test results

5.5.1 General

The tests are required to determine the answers to two questions:

.1 whether the bow loading door is reached by the waves; and, if so,
.2 what volume of water would accumulate.

5.5.2 Determination of whether water reaches the bow opening

If, during the constant speed portion of ANY of the test runs required by these guidelines, water is observed or measured as having exceeded the lower edge of the bow opening, then the requirement of the 2000 HSC Code, paragraph 2.2.3.2.2.1 (objective 5.5.1.1) should be deemed NOT to have been satisfied. In the event this is not satisfied, then an exemption may still be possible by further tests to demonstrate compliance with the 2000 HSC Code, paragraph 2.2.3.2.2.2 (objective 5.5.1.2).

5.5.3 Determination of volume of water

From the model tests the accumulated volume of water for each heading angle may be determined by:

.1 direct measurement of the accumulated volume of water by collecting the trapped water on the vehicle deck in a measurement receptacle (preferred method). The water volume collected during each (10 min) test run should be based on the sum of volumes recorded for each successive tank run. For each test case at a given heading angle the volume should be averaged over the volumes of the different test runs (wave realizations) to give a collected volume for a 10 min (full scale) time period; or
.2 determination of the volume by calculation from measurements of water level within the vehicle space, using the method of 5.5.4 below. The position of the solid weight after each run should be positioned to minimize interference with the water height measurement probes.

5.5.4 Calculation of volume of water accumulating on the vehicle deck

5.5.4.1 When the volume of water accumulated on the vehicle deck is estimated from water height sensors, it should be calculated as follows. The mean volume of water during each successive tank run should be determined from the fifteen sensors as defined in 4.1.2.1 to 4.1.2.2. The mean heights of water measured at these locations should be scaled to full scale before calculating the volume of water as follows (where the symbol h’ denotes the water height scaled as described above).

5.5.4.2 Volume of water during tank run i:

Vol_i

A _VD (h’ _FS + 2h’ _FC + h’ _FP + h’ _FMS + 2h’ _FMC + h’ _FMP + h’ _MS + 2h’ _MC + h’ _MP + h’ _AMS + 2h’ _AMC + h’ _AMP + h’ _AS + 2h’ _AC + h’ _AP) / 20 (m³)

Where: A _VD

plan area of vehicle deck capable of being flooded (m² at full scale).

5.5.4.3 The volume of water accumulated during a test run is given by the sum of Vol_i for each successive tank run.

5.5.5 Volume of water to be used in calculating residual stability

The volume of water resulting from the most onerous condition (i.e., heading angle) obtained from 5.5.3.1 or .2 is to be used for calculating the stability properties for demonstrating compliance with the 2000 HSC Code, paragraph 2.2.3.2.2.2.