Exhaust system
5
"Wagon-back effect"
As long as we continue to use combustion engines
as sources of power, we will always be faced with
the problem of exhaust emissions. Even though the
level of exhaust emissions from modern combustion
engines has now been minimised, smoke and fumes
are still given off when fuel is burnt.
When we also have a sheer body in motion, another
problem arises. It is the phenomen we call the Wag-
on-back effect".
On a boat with a sheer, broad transom and high su-
perstructure, the result of the "wagon-back effect" is
that the exhaust fumes are drawn up towards the af-
terdeck, dirtying the cockpit and creating unpleasant
conditions for those on board. The problem originates
with what is known as recirculating air. When a boat
moves forward and creates a backward current of air,
an underpressure forms in the boat and the exhaust
fumes are drawn into it.
To avoid such a problem, it is of outmost importance
to design and locate the exhaust outlet properly.
IMPORTANT! Vessel manufacturers should
note that U.S. federal regulations applicable to
U.S. vessels require the installation of an ex-
haust sampling port in the exhaust system that
could be used for connection to an exhaust
emissions measuring device. This applies to
engines certified according to U.S. EPA 40
CFR part 94 regulations.
Where Volvo Penta have not added a sam-
ple port, for example when an inadequate
amount of the exhaust system is supplied to
make such an installation practical, the ves-
sel manufacturer is responsible to ensure that
the required sample port is installed. Failure to
comply with this requirement may constitute
an act that is prohibited under federal law and
may subject the vessel manufacturer to federal
penalties.
Vessel manufacturers should ensure that they
carefully follow instructions concerning an ex-
haust sampling port as required under control-
ling federal regulations. Failure to do so could
be a violation of the prohibited acts set forth
at 40 CFR 94.03, potentially subjecting the
vessel manufacturer to federal penalties, and
could make it unlawful to sell or place the ves-
sel into service.
Instructions to comply with this requirement
can be provided by Volvo Penta upon request.
Summary of Contents for D11 series
Page 1: ...Marine Propulsion Diesel Engines Installation 1 1 D E D5 D16 series ...
Page 2: ......
Page 208: ...206 References to Service Bulletins Group No Date Concerns ...
Page 209: ...207 Notes ...
Page 210: ...208 Notes ...
Page 212: ...7748655 English 11 2007 ...