A21 - Site Visit Questions and Responses.pdf

Ques on #1 – Will there be any opportunity for addi onal work (repairs) to the gates or lock structure?

Answer – No, this contract is for debris and sediment removal only. Repairs will be outside of the scope of the contract.

Ques on #2 – Where to dispose of woody debris at each site?

Answer – The SOW gives mul ple op ons, but if Contractor chooses to dispose onsite, these areas are above high water and acceptable:

LD3 – Beyond the boat ramp parking lot in the woods, downstream of the lock – red dot

LD2 – In the field across the access road – red dot

LD1 – Outside of the lock area fence, in the woods near the boat ramp parking area – red dot

Ques on #3 – How deep is the lock chamber?

Answer – Each lock chamber is 40 feet wide, 30 feet deep, and 200 feet long. Excep on is LD3, which is 300 feet long.

Ques on #4 – What is the bo om of the chamber? Concrete? Timber?

Answer – The bo om of the chamber is mostly concrete, but there are 2 areas where there is mber cribbing as well.

One is an approximate 12” wide sec on extending all the way across the width of the lock where mber cribbing is set down into the concrete floor. This cribbing is above and below the gates where a coffer dam “key” is designed to sit and is around 5 feet upstream and downstream of the area where sediment is to be removed from. In both cases this area is near the transi on from the Yellow work area to the Red as noted on the appendix.

The second is right at the gate “sill” where the gates sit. It’s a small run of white oak that lines the raised concrete area where the gates come together to close.

The intent of this ques on is to figure out how delicate an opera on it may be to use an excavator or something similar to remove debris and sediment. Care should be taken not to damage the cribbing, concrete, or any part of the gates. However, similar equipment has been used in the past with success.

Please see below cross sec on of the upstream part of Lock and Dam 3. Addi onal plans and specs of the locks can be provided upon award if needed by Contractor.

Ques on #5 – Can boats be locked through the locks?

Answer – At #1 and #3, yes, we can lock vessels through. At #2 we cannot due to sediment build-up.

There are NC boat ramps above and below all three lock and dams. Please see NCWRC’s boa ng access area website for a map of ramps on the Cape Fear.

Ques on #6 – Do we have any idea how deep the sediment is behind LD2 upper gates?

Answer – Not for certain, No. Depth finders on the boat indicate at least 3 feet of sediment, likely deeper.