0 Purpose
The purpose of these interim guidelines is to assist Administrations and recognized
organizations in verifying that ships complying with EEDI requirements set out in
regulations on energy efficiency for ships have sufficient installed propulsion
power to maintain the manoeuvrability in adverse conditions, as specified in regulation 21.5 of chapter 4 of MARPOL Annex VI.
1 Definition
1.1 "Adverse conditions" mean sea conditions with the following parameters:
| Significant wave height hs, m
|
Peak
wave period TP, s
|
Mean
wind speed Vw, m/s
|
| 5.5
|
7.0 to
15.0
|
19.0
|
JONSWAP sea spectrum with the peak parameter of 3.3 is to be considered for coastal
waters.
1.2 The following adverse condition should be applied to ships defined by the
following threshold values of ship size.
| Ship length,
m
|
Significant wave height hs, m
|
Peak
wave period TP, s
|
Mean
wind speed Vw, m/s
|
| Less than
200
|
4.0
|
7.0 to
15.0
|
15.7
|
| 200 ≤
Lpp ≤ 250
|
Parameters linearly interpolated
depending on ship's length
|
| More than
Lpp = 250
|
Refer to paragraph 1.1
|
2.1 These guidelines should be applied in the case of all new ships of types as
listed in table 1 of the appendix required to comply with regulations on energy
efficiency for ships according to regulation 21 of MARPOL Annex VI.
2.2 Notwithstanding the above, these guidelines should not be applied to ships with
non-conventional propulsion systems, such as pod propulsion.
2.3 These guidelines are intended for ships in unrestricted navigation; for other
cases, the Administration should determine appropriate guidelines, taking the
operational area and relevant restrictions into account.
3 Assessment procedure
3.1 The assessment can be carried out at two different levels as listed below:
3.2 The ship should be considered to have sufficient power to maintain the
manoeuvrability in adverse conditions if it fulfils one of these assessment levels.
4 Assessment level 1 – minimum power lines assessment
4.1 If the ship under consideration has installed power not less than the power
defined by the minimum power line for the specific ship type, the ship should be
considered to have sufficient power to maintain manoeuvrability in adverse
conditions.
4.2 The minimum power lines for the different types of ships are provided
in the appendix.
5 Assessment level 2 – simplified assessment
5.1 The methodology for the simplified assessment is provided in the appendix.
5.2 If the ship under consideration fulfils the requirements as defined in the
simplified assessment, the ship should be considered to have sufficient power to
maintain manoeuvrability in adverse conditions.
6 Documentation
Test documentation should include at least, but not be limited to, a:
-
.1 description of the ship's main particulars;
-
.2 description of the ship's relevant manoeuvring and propulsion systems;
-
.3 description of the assessment level used and results; and
-
.4 description of the test method(s) used with references, if
applicable.