Project Equipment

The water depth in the placement area ranged from 4 to 6 ft. The dike, adja-

cent pasture uplands, and wetlands separating the river and the placement area

were approximately 900 ft wide consisting of a rock face adjacent to the river and

the remainder a sandy soil with a maximum elevation approximately 2 to 3 ft

above the river surface. The soil portion of the pasture was vegetated with short

grass, small bushes, and marsh grass adjacent to the open water on the west side.

River vessel traffic during the demonstration project was typical according to the

river pilots. Vessel traffic averaged 20 to 25 deep-draft vessels per 24-hr period.

The passing vessel traffic was not evenly spaced. Several times during the

project, two deep-draft vessels passed abreast in the area of the channel where the

Beachbuilder was working (Photo 1). There were periods of up to 3 hr with no

deep-draft vessel traffic. The deep-draft vessel traffic tended to navigate toward

the outside of the bend, or left descending bank (LDB) side of the channel, while

making their turn into or out of Southwest Pass. Due to cross currents caused by

flows into Pass A Loutre and South Pass, pilots on the deep-draft vessels going

downstream tend to swing the vessels' bows more toward the right descending

bank (RDB) side (thereby occupying more of the channel cross section while

crabbing around the bend entering Southwest Pass) to compensate for the ships'

tendency to be pulled toward the LDB side of the channel (see illustration in

Figure 4).

The U.S. Coast Guard posted a Notice to Mariners about the demonstration.

Shallow-draft vessel traffic consisted of tugs, shrimp boats, work boats, fishing

boats, and pleasure boats. This vessel traffic moved unimpeded both in and out of

the channel during dredging operations. Outside the channel, shallow-draft vessel

traffic moved across the submerged line that ran along the RDB side of the river

up to the shoreline. No count of shallow-draft vessel traffic was maintained

during the project.

Atmospheric conditions during the demonstration project were typical for the

season and recorded in the daily Report of Operations Engineer Form 4267. Day-

time temperatures ranged from the upper 80's to lower 90's (degrees Fahrenheit).

Periodic thundershowers were prevalent in the afternoons. Winds were generally

light to moderate (maximum of 10 knots) with gusts associated with thunder-

showers. Visibility during the demonstration was approximately 10 miles with no

occurrence of significant fog events.

Project Equipment

The dustpan dredge Beachbuilder used for the demonstration project is a

nonself-propelled dredge. The dredge hull is approximately 300 ft long and 75 ft

wide (see Photo 2). The maximum draft of the dredge is approximately 8.5 ft.

The maximum dredging depth of the Beachbuilder is approximately 70 ft with a

ladder length of 104 ft. The dustpan head is 40 ft wide (see Photo 3). The ladder

on the Beachbuilder is equipped with a submerged pump that transfers the sedi-

ment from the head to twin pumps on deck (see Photos 4 and 5). Total pumping

horsepower capability is approximately 9,000 hp (two 3,600-hp dredge pumps

Chapter 2

Project Description