hydrodynamic model uses a repetitive process that modifies flows in response to changed
topography caused by the channel and the passage of a vessel through that channel. Thus,
channel depth and width effects on the vessel can be examined. Forces causing ship
motion are both environmental and mariner-controlled. Environmental forces include:
current, bank effects, wind, and waves. Mariner-controlled forces include: rudder angle,
propeller revolution, tugs, and bow and stern thrusters.
Results from the simulator studies of channel alignment can provide substantial savings
through design, evaluation, maintenance, or construction costs, or through avoidance of
unforeseen expenses. The ship/tow simulator gives pilots the opportunity to test a channel
before it is built, thus the customers get their channels evaluated for safety in advance.
Also the channel is optimized for size, which will conserve construction costs and will
provide the safest affordable channel to construct and maintain. Navigational changes can
also be adjusted to avoid real estate problems or conflict with environmentally sensitive
areas or to avoid high relocation costs such as water supply lines that could present a
The Brownsville Ship Channel in Brownsville, Texas, was completed in 1995. Results
from the simulator study reduced the original .8 million estimate by approximately
million. The primary savings were from study results, which reduced the recommended
width of the 24-km (15-mile) Laguna Madre Reach from 90 m (300 ft) to 75 m (250 ft).
Dennis Webb, CEERD-HC-ND, e-mail: Dennis.W.Webb@erdc.usace.army.mil Phone:
Point of Contact