Use of Physical Models to Develop Shellfish Excluder Device

Category:

Development of Dredge Components and Equipment

Environmental Dredging

Description:

Model testing provided the following advantages over full-scale testing.

1) Tests were designed by a team consisting of a) a fisheries biologist, b) an engineer

specializing in physical model design and operation, c) an engineer with dredging experience.

2) Fifty configurations were tested before the prototype configuration was selected. The cost of

this process was insignificant compared to doing it on a working dredge.

3) Model was operated with live crabs to evaluate their interaction with the draghead, with and

without the excluder installed.

Reviewer:

C. Woolley

Company / Organization(s):

Access Restricted to U.S. Army Corps of Engineers

Projects Completed:

Excluder model tests

Location:

Scripps NYD Lab

Completion Date:

1995 prototype at Grays Harbor 1997. Prototype at MCR in progress

(1998)

Project Contact:

Portland/Seattle Districts USACE

Project Cost:

~ $60,000 for model testing

Estimated Cost:

$15,000 to fab and install

Comments:

Seattle District current crab mitigation costs at Gray's Harbor up to

$500,000/year. Estimate that use of Excluder will cut that cost by one

half.

Information Sources:

Literature:

Title:

"The Use of Physical Models to Develop a Device to Prevent Entrainment

of Dungeness Crab During Hopper Dredging Operations"

Author:

KW Larson, C. Woolley, J. Powell

Month:

May

Year:

1994

LitType:

Report/Proceedings

Publisher:

WEDA XV

Page:

210

105

Chapter 5 Other Technologies Reviewed