2.3.1 For those engines which have not been adjusted
or modified relative to the original specification of the manufacturer,
the provision of a valid EIAPP Certificate should suffice to demonstrate
compliance with the applicable NOx limits.
2.3.2 After installation on board, it shall be
determined to what extent an engine has been subjected to further
adjustments and/or modifications which could affect the NOx emission.
Therefore, the engine, after installation on board, but prior to issuance
of the IAPP Certificate, shall be inspected for modifications and
be approved using the on-board NOx verification procedures
and one of the methods described in 2.1.2.
2.3.3 There are engines which, after pre-certification,
need final adjustment or modification for performance optimization.
In such a case, the engine group concept could be used to ensure that
the engine still complies with the limits.
2.3.4 The shipowner shall have the option of direct
measurement of NOx emissions during engine operation. Such
data may take the form of spot checks logged with other engine operating
data on a regular basis and over the full range of engine operation
or may result from continuous monitoring and data storage. Data must
be current (taken within the last 30 days) and must have been acquired
using the test procedures cited in this NOx Technical Code.
These monitoring records shall be kept on board for three months for
verification purposes by the Parties to the Protocol of 1997. Data
shall also be corrected for ambient conditions and fuel specification,
and measuring equipment must be checked for correct calibration and
operation, in accordance with the procedures specified by the measurement
equipment manufacturer in the engine's technical file. Where exhaust
gas after-treatment devices are fitted which influence the NOx emissions,
the measuring point(s) must be located downstream of such devices.
2.3.5 To demonstrate compliance by the direct
measurement method, sufficient data shall be collected to calculate
the weighted average NOx emissions in accordance with this
Code.
2.3.6 Every marine diesel engine installed on
board a ship shall be provided with a technical file. The technical
file shall be prepared by the engine manufacturer and approved by
the Administration, and required to accompany an engine throughout
its life on board ships. The technical file shall contain information
as specified in 2.4.1.
2.3.7 Where an after-treatment device is installed
and needed to comply with the NOx limits, one of the options
providing a ready means for verifying compliance with regulation 13 of Annex VI is direct
NOx measurement and monitoring in accordance with 2.3.4.
However, depending on the technical possibilities of the device used,
subject to the approval of the Administration, other relevant parameters
could be monitored.
2.3.8 Where, for the purpose of achieving NOx compliance,
an additional substance is introduced, such as ammonia, urea, steam,
water, fuel additives, etc., a means of monitoring the consumption
of such substance shall be provided. The technical file shall provide
sufficient information to allow a ready means of demonstrating that
the consumption of such additional substances is consistent with achieving
compliance with the applicable NOx limit.
2.3.9 If any adjustments or modifications are
made to any engine after its pre-certification, a full record of such
adjustments or modifications shall be recorded in the engine's record
book of engine parameters.
2.3.10 If all of the engines installed on board
are verified to remain within the parameters, components, and adjustable
features recorded in the technical file, the engines should be accepted
as performing within the NOx limits specified in regulation 13 of Annex VI. In this
case, with respect to this Code, an IAPP Certificate should then be
issued to the ship.
2.3.11 If any adjustment or modification is made
which is outside the approved limits documented in the technical file,
the IAPP Certificate may be issued only if the overall NOx emission
performance is verified to be within the required limits by: a direct
on-board NOx monitoring, as approved by the Administration;
a simplified on-board NOx measurement; or, reference to
the test-bed testing for the relevant engine group approval showing
that the adjustments or modifications do not exceed the NOx emissions
limits.
2.3.12 The Administration may, at its own discretion,
abbreviate or reduce all parts of the survey on board, in accordance
with this Code, to an engine which has been issued an EIAPP Certificate.
However, the entire survey on board must be completed for at least
one cylinder and/or one engine in an engine family or engine group,
or spare part, if applicable, and the abbreviation may be made only
if all the other cylinders and/or engines or spare parts are expected
to perform in the same manner as the surveyed engine and/or cylinder
or spare part.
2.3.13 Flow charts providing guidance for compliance
with the requirements of an initial, periodical and intermediate surveys
for certification of marine diesel engines installed on board of ships
are provided in figures 2 and 3 of appendix 2 of this Code.