The discharge pipe on the Beachbuilder was attached to flexible floating hose

small offices, an electrical room, and a pilot house. There are no crew's quarters

on the dredge. The pilot house contains the leverman station (see Photo 9) and

computer monitors showing equipment gauges, dredge position relative to the

work area, and dustpan head elevation (see Photo 10). Project hydrographic sur-

vey data are uploaded to a proprietary computer program that develops an area

contour plot. The contour plot is integrated with a navigation program that

includes real-time Differential Global Positioning System (DGPS) signal input

and outputs a visual image of the dredge location with respect to the channel

limits and elevation contours, all of which are displayed on a computer monitor.

A continually updated image of the dredge track is also displayed. The dustpan

head elevation (corrected for the river stage) and position are shown relative to

the channel profile. This system provides the leverman a real-time display of

dredge location and dustpan head elevation relative to the required area of opera-

tion. The survey data and resultant contour plot are updated at least once a day.

The discharge pipe on the Beachbuilder was attached to flexible floating

hose (see Photo 11) that allowed the dredge to move across and up and down the

channel. The maximum floating hose line length was made up of 47 30-ft sec-

tions for a total length of 1,410 ft (see Photo 12). This length of pipeline allowed

the dredge to move across the full width of the channel and up and down the

channel approximately 1,500 ft. This particular line length was selected to allow

maximum lateral and longitudinal dredge mobility in the channel and also to

minimize the hydrodynamic drag forces acting on the line especially as it was

deployed more perpendicular to the current flow. Each section had an inside

diameter of 30 in. (750 mm) and a bladder on the outside with sufficient buoy-

ancy to float the hose when filled with dredged material. An anchor barge (or

skidder) and a small tug were used to hold the floating hose in position to reduce

the stress on the hose connections due to the strong current (see Photo 13). The

floating hose was connected to a hard point. The hard point is an anchored

floating adapter used to connect the floating hose to the submerged line. The hard

point was anchored by a 10,000-lb Danforth anchor and was moved and re-

anchored as required to allow the dredge to work in specific reaches. In moving

the hard point, steel pipe was added or subtracted to the submerged line side of

the hard point to reach the new anchor point.

The steel pipe ran submerged on the bottom of the river (called submerged

line) from the hard point to the dike. The total length of submerged line ranged

from 4,320 to 7,920 ft during the project based on the hard point location. The

shore line steel pipe ran across the dike, pasture, and existing wetlands into the

designated placement area. As the placed dredged material built up above the

surface of the water in the marsh area, additional shore line was added to extend

the placement further into the designated placement area (see Photo 14). Two

hydraulic backhoes mounted on swamp tracks (swamp buggies) were used to

move the pipe and build temporary dikes to direct discharge flow (see Photo 15).

Other than the use of these temporary dikes to direct discharge flow, no other

containment dikes were used in the placement process.

A variety of support equipment was used during the demonstration project.

The tug Delta Eagle (3,000 hp; see Photo 16) was originally connected to the

stern of the Beachbuilder to simulate the self-propelled characteristics of a

conventional dustpan dredge. Due to the swift current and problems with the

Chapter 2

Project Description