1240LU24Q0059QandAs8272024.pdf

1240LU24Q0059

Little Rock Creek Trail Bridge Replacement

Darby Ranger District, Bitterroot National Forest

Questions and Answers As of 8/27/2024

8/23/2024

1. Is the hike in from the trailhead 3 miles to the bridge with no option for workers to access the bridge site via ATV/motorcycle? The only access to the bridge site being either on foot or by helicopter with motorized vehicles allowed at the bridge site for construction.

Answer: No access by ATV or motorbike. This trail is open to bicycles. Do not plan boat access; during the fall, the reservoir is drawn low, and likely cannot get a boat to the site. Getting a boat close, would then require one to walk through thick mud and sediment to stable ground.

2. Would all helicopter utilization be the contractor's responsibility to hire, organize, and then submit a plan to the CO for approval?

Answer: Yes

3. Would the trail be closed for the full 60 day allotted period of work from 09/15/25 to 11/14/25? I saw in the supplemental specifications pg.28 section 156.05 on temporary closures it lists a max of 2 days of consecutive closure but no minimum number of consecutive open days.

Answer: The trail is open for hikers the entire time, other than temporary closures. Temporary closures will be when flying materials, and possible other activities that pose a safety concern. At the bridge location, the trail will be closed during construction. Hikers can choose to ford the stream if they choose.

4. The note on sheet 1/6 on the Regional Standard Drawings R6-STD-963-10 states “* See Little Rock Creek Trail Bridge Replacement plans for substructure and trail details. Any discrepancies between these drawings and the Little Rock Creek Trail Bridge Replacement plans shall be clarified with the CO prior to implementation.” Can you tell me which set of drawings controls for construction? There are discrepancies (in the questions below) between the RS drawings and the DJ&A Construction plans.

Answer: Regional Specifications control for the superstructure (including treated sill), and the DJ&A Little Rock Creek Trail Bridge Replacement plans control for substructure and trail details.

5. RS drawings show three rows of diaphragms, DJ&A drawings show four rows.

Answer: 5 Rows of diaphragms. Per the triangle symbol for the 40’ span, the requirement is to install diaphragms at third pts of span and within a distance of the depth from the abutments.

6. RS drawings show a 3-1/8” wide diaphragm @ sht. -02b, and a 5-1/8” wide at sht -03a, please confirm desired diaphragm width.

Answer: Diaphragm width is 3-1/8”

7. RS drawings indicate a maximum clear with for the design at 7’-0”, however the Planning Sheet indicates a 7’-9” clear-width, while DJ&A drawings show a minimum of 8’-0” min clear width on sht.

6/9. This determines the number of stringers, please confirm the desired clear-width as well as the total number of stringers required and the dimensions as 5-1/8”x24x41’, AYC.

Answer: 8’ clear width is required. That will require 5 (five) 5-1/8”x24”x41” stringers at 1’-10” spacing. The Typical Section on sheet 6 of Little Rock Creek Trail Bridge Replacement plans are correct. Planning sheet has been updated to indicate an 8’ clear width and is incorporated into Solicitation 1240LU24Q0059 via Amendment 001.

8. Sheet -03a of the RS drawings are un-readable at the “Materials” section, at least on my downloaded copy. It appears to give options for the sill and decking materials, however I can’t read it clearly, could you please resend that page?

Answer: Updated sheets are included in the updated RS drawings and incorporated into Solicitation 1240LU24Q0059 via Amendment 001.

9. Follow the planning sheet as far as what is allowed to be treated and what is not?

Answer: Correct. The planning sheet has correct designations for treatment, as does Table B.1 Schedule of Items.

8/27/2024

10. Can you provide historic water level elevation of the lake in Sept/ October?

Answer: The Bitterroot NF does not operate Lake Como Dam and Reservoir. This dam is operated by The Bitter Root Irrigation District. Historic Reservoir levels can be obtained from the Bitter Root Irrigation District.

11. Is it acceptable to use the lake for access to the work site if the water level is acceptable?

Answer: Yes, it would be acceptable. It is anticipated that by September/October that water levels will be quite a distance from the project site and there will be large “mud flats” to traverse to access solid ground from reservoir. Any ground disturbance to access the project site from the reservoir shall be restored.

12. Can you provide a Landing Zone (LZ) and a staging area?

Answer: The staging area for the project is on the south side of Lake Como Dam in the truck/boat trailer parking area (Lat/Long 46.060536, -114.234214) (see attached illustration, below). The truck/boat trailer parking area will be closed to the public for the contractor to stage equipment and materials, prep/pick up/drop off sling loads. The Government will not be providing fencing. There is no designated staging area at the project site.

13. Can hydraulic equipment be mobilized to the site to support the heavy lifting of the beams, rocks, etc?

Answer: Yes, mechanized and hydraulic equipment is permissible at the project site but will need to be transported via helicopter.