Recommendations (cont.)

the Beachbuilder did not require a licensed master onboard). This practice, or the

use of some other suitably licensed personnel onboard the dredge (at least for a

limited period of time) in future projects, would provide the same production and

safety benefits.

Ensuring that the dustpan elevation stays as close to design depth as possible

will minimize clogging the pans with clay. Downtime associated with clearing

the pans could be reduced resulting in increased daily production rates.

By optimizing the selection of anchors in order to minimize anchor slippage,

production can be improved in future projects. Such slippage results in a require-

ment for more frequent resetting of the anchors, mandating dredging downtime.

Minimizing this downtime would result in increased daily production rates. The

selection process should involve comparisons between the various anchor charac-

teristics, i.e., holding force per pound of weight and required break out force.

The Beachbuilder used tugs for propulsion during the demonstration. If a

flexible-discharge dustpan dredge is to be used on a project with the types of

requirements reported herein, then the use of sufficiently sized propulsion units

(on a barge for the Beachbuilder or as used in conventional dustpans) could

enhance maneuverability and production. Compared to in-hull propulsion, the

use of tugs introduced a longer time lag between the initial ordering of a given

maneuver and the application of propulsion to achieve that order (due to time

required to communicate the maneuver from dredge to tugs over the radio).

Design of a more efficient propulsion system will require application of naval

architecture principles to account for issues such as horsepower requirements,

geometry of thruster points relative to hull weight and dimensions, etc.

The 2,500-ft-long anchor wire lengths used during the demonstration could

be lengthened or pendants (wire cable extension lengths added to the drum

cables' bitter ends) could be used to optimize the anchoring geometry outside the

channel.

The Beachbuilder has a floating hose connection point on its port mid-ship

side due to the reversing tide (current) conditions it usually works in on the east

coast. It could be advantageous for a flexible-dustpan dredge working in a river

to have a stern connection point to allow the floating hose to play out down-

stream in the current to minimize bending stresses and improve maneuverability.

The feasibility of this suggestion would have to take into account the pumping-

induced reaction forces from the discharge line being applied to the dredge, and

the subsequent impacts on vessel maneuverability.

An installation of a "Y" and associated valves in the shore line would elimi-

nate dredging downtime associated with adding additional pipe in the placement

area. This modification would result in increased production rates and provide a

more even distribution of dredged material lifts in the placement area.

The use of additional hardpoint/submerged line/shore line assemblies would

reduce dredge relocation times.

Chapter 7

Conclusions and Recommendations