SABINE-NECHES WATERWAY (SNWW) CHANNEL IMPROVEMENT PROJECT FEASIBILITY STUDY

used for the analysis presented in the Economic Appendix. Also shown are the times included
in this sensitivity prepared for IEPR. The times used in the Appendix are shown on the left side
of the tables and the sensitivity times are on the right. The times used in the Appendix suggest
that multiple shuttles would be loaded simultaneously and innovations over the 2010-2069
future could result in this occurrence; however, this was found not to be realistic for existing or
future conditions. The offshore times on the left are reasonable given standard unloading time.
For instance using a standard unloading rate of 5,250 tons per hour, it would take 60 hours to
unload a 325,000 DWT tanker ((325,000 * 0.97 capacity)/(5,250 short tons per hour). The
basis for including this sensitivity is due to concerns are that analytical assumptions based on
optimal offshore turnaround time, optimal scheduling of shuttle arrivals, and perhaps lower than
realistic vessel operating cost (the Corps’ FY08 tanker vessel operating costs were 17 percent
lower than the FY07 release) result in criteria that is unrealistically conservative for this aspect
of the analysis. The sensitivity was found to be representative of actual conditions. In
comparison, the times used for the base are not realistic.
TABLE 4J
Mother Vessel Combined Time Offloading and Waiting Between Shuttles
Mother Vessel Hours Offshore
Mother Vessel Offshore Hours
Component ( Lightering )
Lightening Lightering Lightening (S )
Minimum (hrs) 8 8 60 24
Most Likely (hrs) 12 12 60 * 31 *
Maximum (hrs) 36 36 168 120
Hours Used for
Calculation 12 12 96 ** 30 **
*The most likely time for the mother vessel for lightering is based on a 325,000 DWT tanker, a
cargo to short ton ratio of 0.97, and an unloading rate of 5,250 short tons per hour. The most
likely time for the mother vessel for lightening is based on a 165,000 DWT tanker, a cargo to
short ton ratio of 0.97, and an unloading rate of 5,250 short tons per hour. The hours used for
calculation are based on a @risk triangular distribution using the minimum, most likely, and
maximum values shown. The maximum values used as input into the @risk distribution are
t d t f th li ht i
An additional component modified for this sensitivity was to separate Venezuela from Brazil.
While shipments of crude oil from Brazil to SNWW are presently less than 1 percent, future
expectations are that this will change. The Appendix analysis included Venezuela and Brazil as
one region. Table 4K displays the transportation costs from the Appendix (Table 111) and the
resulting effect on total project benefits as shown in Table 141 of the Appendix. Table 4L
displays the transportation cost with Brazil separated out from Venezuela. Table 4M displays
the results of using the routing shown in Table 4L and the mother vessel sensitivity based times
from Table 4J (i.e. 96 hours offshore for the lightering mother vessel and 30 hours offshore for
the lightening mother vessels)
The concerns about commodity growth rates are addressed in response to comment 6.
Addendum SNWW External Peer Review Report 37 Battelle
June 16. 2010