Attachment 1 - Specifications.pdf

Attachment 1 – Specifications

Oyster Broodstock Repository Raft

USDA-ARS Pacific Shellfish Research Unit (PSRU) (Newport, OR)

Equipment need: An oyster broodstock repository raft to grow shellfish produced by the USDA ARS PSRU. A design-build-install service is required for this repository raft including all cages that will be used to grow oysters on the raft.

Dimensions: approx. 40 feet by 30-35 feet. The length of the available dock is 60 feet with 4 steel pilings.

Attachment points: Three or four steel pilings that anchor the Hatfield Marine Science Center (HMSC) pumphouse dock. The pilings are 20 feet apart from each other. The use of pile guide attachment is required for this raft.

Physical description: A floating mussel raft like structure that is made from corrosion resistant metal (marine grade aluminum), and which is capable of holding 170 oyster cage stacks. The HMSC dock is approx. 2 miles from open ocean and has full salinity seawater (approx. 33 ppt) nearly continuously. As such corrosion is a major concern at this site.

Gantry crane(s) must be installed that are capable of lifting at least one cage stack, then travelling towards the dock or a built in work station where cages can be placed onto the deck for processing. Each cage stack holds 6 SEAPA cages with 600-1000 animals per stack (estimated maximum weight 600-1000 pounds per stack, including biofouling).

Electricity for gantry cranes is available in the HMSC pumphouse, approximately 75 feet from the middle of the raft site.

Bridle attachments on the repository must be secure such that the rope bridle does not come loose and fall into the water during severe weather, wind and wave events. The SEAPA cage stacks measure approximately 4.5 feet tall, 2.2 feet long and 1.33 feet wide. To provide adequate lifting space USDA estimates that each stack needs 30 inches of length (4 inch bu er between cage stacks) between bridle attachments on a single cross member.

The cross members are estimated to require 24 inches of width between them (8 inch bu er between cages), except for cross members next to floatation pontoons, where 18 inches is likely required.

The use of fiberglass reinforced polymer (FRP) walkways or other non-slip surfaces on the raft is required to increase worker safety. Railings or other grab bars that sta working on the raft can use to steady themselves are required for safety.

Oyster cages are included in this requirement and have two (2) di erent specifications due to di erent needs of di erent aged animals. 1) For young animals (less than 1 year), 3 mm mesh plastic cages in 15 liter volume are needed that can be stacked and nested on top of one another. Two hundred 3mm mesh cages are needed. 2) For age 1+ animals 12mm mesh plastic 25 liter volume cages are needed that can be stacked and nested on top of one another. Eight hundred 12mm mesh cages are needed.

Below is a crudely drawn aerial representation of the raft. Dark blue are floatation pontoons, brown are cross members where cage stacks hang from, with light blue sections representing walkways.

Dock 60’ long 20’ between pilings

Gangway landing