Vessel Quotas and Operating Requirements Vessel Quotas and ...

The basic equations used for the calculation of emissions are:
EMISSIONS ,VCC,MODE = (EF)(LF MODE ) × (HP) × LF MODE × TIME
where:
VCC - vessel class (cruise ship, or tour, charter, or private vessel)
EF - emissions factor
LF -mode specific load factor
HP I- maximum Horsepower
Load Factor and Power calculations are provided in table D-2, and the calculations of emissions
rates in lbs/hr are provided in table D-3.
For this evaluation, it was assumed that the cruise ships would operate in the park for 9 hours per
use day, and that tour vessels would operate in the park for 13 hours per use day (based upon
2001 average—See Tables D-4 and D-5). Charter and private vessels are assumed to operate for
9.5 hours per use day, based upon generic assumptions established by The Energy and
Environmental Analysis 2000 Report because there was no specific operation time data available.
Time-in-mode for assumptions are adjusted for alternatives 4, 5, and 6, where speed restrictions
would require cruise ships to maintain a slow cruise. It was assumed that the cruise ships would
therefore take twice as long to enter and leave the bay, and therefore the total time for cruise ships
under alternatives 4, 5, and 6 would be 13 hours. Other vessels would not be subject to the speed
restrictions. NPS staff and vessel operator observations were used to determine average time at
each speed classification (time-in-mode), assuming that the majority of time would be spent at
normal cruise, with some time spent at a slow cruise and maneuvering (see table D-6).
Use day data for 2001 was collected for cruise ships, tour vessels, charter vessels, and private
vessels, and it was used to determine baseline annual emissions. This data is summarized in tables
D-4, D-5, D-7, and D-8.
In the development of projected emissions, annual use day quotas were used to determine number
of in-season use days for all vessels, and off-season entries for cruise ships and tour vessels. Offseason
vessel use days for charter and private vessels were assumed to be the same as the
baseline. Daily emission and annual emissions were calculated differently in this evaluation.
Daily emissions were calculated assuming that the vessel use of Glacier Bay is at the maximum
quota of 2 cruise ships, 3 tour vessels, 6 charter vessels, and 25 private vessels, adjusted as
required for each alternative. The total provides a worst-case evaluation of daily emissions in the
park on a given day, and under these conditions. Annual emissions include all emissions emitted
during the calendar year, January to December, and were determined using annual seasonal
quotas and 2001 use data as described above.
Baseline emissions and 2001 operating data are provided in tables D-7 and D-8. Use-day quotas
and calculations for alternatives 1, 2, 3, 4, 5, and 6 are provided in tables , D-9, D-11, D-13,
D-15, D-17, and D-19, respectively. Load factors are adjusted to account for speed reductions for
alternatives 4, 5, and 6. Estimated daily and annual emissions for alternatives 1, 2, 3, 4, 5, and 6
are summarized in tables D-10, D-12, D-14, D-16, D-18, and D-20, respectively.
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