Specifications needed for the net pens_1.docx

Specifications needed for the net pens

A single net pen structure consisting of two pens (minimum 1500 sq ft surface area each) and walkways, work areas and anchors is required. The structure is to be deployed in a lake system that experiences winter ice flows. It requires a flotation system that supports the pens as well as a walkway (minimum 4 ft wide) that surrounds both pens entirely. The support structure will be made of non-toxic, non-rusting materials, with a longevity of service of up to 30 years. It will include appropriate engineering to provide support to the walkway and anchor attachments. The walkway itself will be made of non-slip materials or design. A removable pipe railing 42 inches tall will be included around the interior of the walkway and will be able to resist the weight of the pens and additional biomass that is accumulated during the time in water.

The entire net pen structure (including walkways and pens) will be constructed to be submersible to a depth of at least 10 ft. This will also include a mechanism to retrieve the entire structure from submersion when needed.

The structure will be anchored with appropriate anchors (e.g. 1,000 – 1,500 lbs. marine anchors) and associated hardware to be deployed in depths of up to 35 feet. Hardware must include anchors, all anchoring attachments, chains, shackles, high visibility marine bouys (minimum of 8 approximately 36 in x 52 in) and mooring light. The anchoring system will also include necessary lines and associated floats to mark anchor location and provide a means to adjust anchor location when needed.

In addition, a working platform (approximately 10 ft x 24 ft) is needed. The platform must be of similar non-toxic, non-rusting, and non-slip materials as the net pen structure. It must include appropriate attachment points to tie off to the net pen structure as well as attach boat bumpers.

The pens (n = 2) will be constructed of 6 mm mesh black knotless nylon netting with a removable top netting panel installed with a commercial grade marine zipper. Pens will be at least 1,500 sq ft surface area (e.g. 39 ft x 39 ft) and will extend 20 ft deep with ability to adjust to fluctuating water levels. It will use the same mesh throughout and will include an attached chain (at least ¼ inch) around the bottom perimeter to keep the net submerged. It will also include webbing or rope loops in the corners and in the middle along the inside bottom to act as attachment points for retrieving the bottom of the net. Bird net will also be provided in two sections to cover each of the pens. The netting will consist of 1.5” x 1.5” 380/27 ply black twisted knotted polyethylene square mesh with a machine sewn rope border. Each section will be approximately 45 ft x 45 ft.

Services provided must include on site assembly of the structure, including structure assembly and deployment, anchor assembly and deployment, net install, bird net install, working platform deployment, and adjustment to ensure proper functioning of the ballast system for submersion.