Emissions Worldview
BY LARRY PEARSON
The HMS Liberty, shown
in the New York harbor,
will cut emissions by 40
tons per year by repow-
ering with a pair of Tier
2 compliant Cummins
QSK38 engines.
Clearing the Air
Tug repowers prove to be cost-effective answer to cutting emissions, increasing fuel efficiency
In the Port of New York, various
strategies for reducing diesel engine
emissions have been analyzed and
quantified. Yard tractors, locomotives
and towboats were the main producers
of emissions according to a 2006 report
by the Starcrest Consulting Group LLC
for the Port Authority of New York/
New Jersey in the United States.
The report looked at “cold ironing,”
the practice of providing a vessel shore-side electrical power during the time
the vessel is tied up at berth, allowing
auxiliary engines (generators) to be
shut down.
This method of emission control
requires infrastructure to the vessel
docks and modifications to the specific
vessels that will engage in cold ironing.
Because of cost factors and complicated
changes to long-term leasing agreements, cold ironing may not be practical for the Port Authority.
The report looked at other emission
reduction strategies that could be used
throughout the harbor. For the first
time, these other strategies were identi-
fied and quantified.
5. Use of ultra-low sulfur diesel fuel
(USLD) for strategies 1, 2 and 4.
Based on one vessel using cold ironing making nine calls in the harbor per
year, NOx reductions were 3. 1 tons per
year at a cost of US$2.1 million.
If cold ironing is the baseline, many
of the alternatives did as well in NOx
reductions at a fraction of the cost. For
example, locomotives with Tier 2
diesel engines had a NOx reduction of
Larry Pearson is a freelance writer based in
Kenner, Louisiana, U.S.A.
Bollinger rebuilt the 43 m towboat Phyllis including a pair of Tier 2 EMD main engines, new
gears, new Cummins generators and rebuilt main engine and after-cooling systems.
