1 When it becomes necessary to replace an engine
to which regulation 13 of MARPOL Annex VI applies in principle (power
output of more than 130 kW) the non-identical replacement engine shall
comply with the standards set forth in paragraph 5.1.1 of the respective
regulation (Tier III) when operating in an area designated under regulation
13.6 of MARPOL Annex VI if the replacement takes place on or after
1 January 2016 unless:
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.1 a replacement engine of similar rating complying
with Tier III is not commercially available; or
-
.2 the replacement engine, in order to be brought
into Tier III compliance, needs to be equipped with a NOx reducing
device which due to:
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.1 size cannot be installed in the limited space
available on board; or
-
.2 extensive heat release could have adverse impact
on the ships structure, sheeting, and/or equipment whilst additional
ventilation and/or insulation of the engine-room/compartment will
not be possible.
2 In making the determination that a Tier III
engine is not a feasible replacement engine for a ship, it should
be necessary to evaluate not just engine dimensions and weight but
may also include other pertinent ship characteristics. These pertinent
characteristics could include:
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.1 downstream ship components such as drive shafts,
reduction gears, cooling systems, exhaust and ventilation systems,
and propeller shafts;
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.2 electrical systems for diesel generators (indirect
drive engines); and
-
.3 such other ancillary systems and ship equipment
that would affect the choice of an engine.
3 Restrictions should also be considered concerning
engine adjustment/matching needed to meet boundary conditions and
performance data necessary for SCR operation at all relevant mode
points.
4 If the replacement engine is part of a multi-engine
(twin-engine) arrangement and it is replacing an engine that is not
a Tier III compliant engine due to it having been installed prior
to the Tier III implementation date, a need to match a replacement
engine within a multi-engine arrangement should be part of the criteria
to be considered. In such cases, if it were decided to exempt a replacement
engine in multi-engine arrangements it must be clear that is where
engines are installed as matched pairs (or more) as propulsion engines
and that matching is necessary to ensure comparable manoeuvring/drive
response rather than where multiple engines are installed such as
in the case of generators.
5 A replacement engine that meets the Tier III
limit should be installed provided it does not incur an increase in
the ship's electrical demand beyond the installed capacity.
6 In no case should modification to the ship's
structure be allowed which weakens its structural stability below
the acceptable level.
7 The Administration should consider how far the
shipowner's specification of the device will determine whether a non-identical
replacement engine is not required to meet the Tier III limit (for
example, by requiring an excessive urea storage capacity – relative
to bunker capacity – or that the SCR device is not to increase
engine weight/volume by more than an unjustifiably low percentage).
8 There may be differences between a Tier III
and a Tier II engine that should not affect the determination
of whether a non-identical replacement engine should not be required
to meet the Tier III limit, such as:
9 The shipowner should provide evidence to the
Administration that a Tier III engine cannot be installed and should
report specifically what prevents a Tier III compliant engine from
being installed, taking into account the provisions of these guidelines.
The shipowner should document the search for compliant Tier III engines
and explain why the closest available engine with respect to size
or performance is not appropriate for the ship. The search should
include engines produced by manufacturers other than the original
engine's manufacturer. This documentation, duly endorsed by the Administration,
should be kept with the replacement engine's EIAPP Certificate.