Attachment 1_Q and A HHFWG Inspection_0001.pdf

# Questions Responses

Would it be possible for someone from the bureau to supply pictures of the location of the hydraulic cylinder and stem rack area (EL.

3560.50), as well as, the general area where the anchor points will be installed?

It is assumed that this question refers to the Transfer Structure for temporary storage of the hoist and stem set as shown on drawing 447- 100-60181. See the Q.1 photos for information. Unfortunately, the wall where the anchor points are to be installed is barely visible in profile due to the POV of the camera.

Does the BOR have all the picking brackets and support brackets shown on as-built drawings 447-D-1035 and 447-D-1039 or do we need to provide some or all of them?

447-D-1035 shows details of the hoist support frame that is an integrated part of the hoist assembly as shown in 447-D-1033 & 447-D-1060.

447-D-1039 shows details of the stems and some internal components of the cylinder head.

Refer to 447-D-1061 for dimensional information of lifting and handling equipment and spec section 51 00 10 for corresponding photographic evidence of this equipment stored at Hungry Horse. The Contractor may use this lifting and handling equipment as part of their lifting plan.

It looks like special spreader beam(s) will need to be engineered and fabricated for tandem crane picks. Has the BOR used tandem cranes in the past and if so are there spreader beams available?

The gantry crane main hoist has not been used in many years and it not currently load tested for use, which is why the Government has decided to go the route of Contractor mobile cranes. The Government has not used tandem cranes in the past and spreader beams are not available.

4 Can we work multiple shifts and weekends?

Pending Construction Engineer Group (CEG) availability as work is outside and shouldn't have impact on HHFO personnel. Outage requests or HH personnel-needed assistance will have to be scheduled.

5 The drawings state the gate assembly weighs 114-tons. Does the BOR have weights of just the gate and individual components?

The drawings do not publish the individual weights and the main hoist of the gantry crane is not equipped with a load cell, so a record of weights is not available. The 114 US Tons is a calculated estimate of the heaviest antcipated lift of the system, taking into account that the main hoist of the gantry crane is rated for 125 US Tons.

The specifications mention that we need to power-wash the stems and gate leaf and not let the water go down the road drains. Does the existing paint contains lead or other heavy metals? I assume we will need a vac truck to remove the water and properly dispose of the water.

The existing coating is most likely coal-tar enamel and the original coating. The intent of the power-washing is to remove organics so the condition of the coating can be observed and measurements taken. It is not the intent of the powerwashing to remove coating. Once organics are removed from the surfaces, they are considered waste and must be collected and properly disposed of by an effective means.

7 How much traffic does the bridge typically have in August?

The following are estimates: Visitor Center visitation numbers for 2019, 2018 and 2017 were 47,848, 37,427 and 30,712 respectively, for an average of about 39,000 per year. Assuming 4 persons per vehicle and that each vehicle drove across the dam to view the far side, that provides for 9,750 vehicles for the year.

The VC is basically open June through September, so conservatively dividing this number by 4 provides for 24,000 vehicles per month.

24,000 divided by 30 days in a month provides for 800 vehicles per day

This does not account for logging trucks, boat trailers, kayakers, campers, hikers, wood cutters, outfitters/stock trailers, USFS, etc. that do not stop at the VC, so you could probably add another 50 or so per day.

A daily estimate of traffic across the day may be 850 or more.

The "Interruption of Service" period is scheduled 8/2/21 thru 8/13/21. Note 1 of Drawing 447-100-60182 (Mobile Crane & Traffic Plan) states "In the event that the gantry crane is not available for removal of the fixed wheel gate, this drawing provides a plan for..."

8.a.

During this time, will ALL power be completely out for the duration of the 2 week period; or just the local power to the specific unit being removed and inspected..??

This project has been scheduled to take place during the regularly scheduled generating unit maintenance. Some or all of the remaining generating units may be operational.

8.b. During this time, will the Gantry Crane be available for use for Leaf/Stem Section removal/reassembly..?? The gantry crane will not be available as noted in 3.

8.c. If the Gantry crane will be available for use during the project, will the government supply an operator..?? The gantry crane will not be available as noted in 3.

9 Is 114 tons (as noted in Note 1 of 447-100-60182) the approx weight of Leaf, Stems, Lifting Cylinder, etc. (Heaviest Lift Anticipated)..??

Based on available information, the 114 US tons estimate is the heaviest anticipated 'dry' lift of the combined hoist, stems, and gate. The main hoist of the gantry crane is rated for 125 US Tons, so it may be reasonable to assume that additional hoisting resistance from water and tracking in the gate guides could see load spikes that were considered in the gantry crane design.

140R1021B0001 Hungry Horse Fixed Wheel Gate Inspection Post Site Visit Q & A

Drawing 447-100-60182 depicts a good Mobile Crane & Traffic plan. Being that this inspection has been performed previously, what size of mobile cranes were used in the past, if they were needed..??

Mobile cranes have not been used in the past. Drawing -60182 was created with market research data obtained from DOC Hoist/Snell Crane to support project feasibility should it be determined that mobile cranes would be the preferred choice moving forward. The drawing was finalized in a more general sense as not only pertinent to the upcoming project, but as a resource for potential mobile crane use in the future.

What crane companies has the Dam Facility used before (that they are comfortable with) or that are on the bidders list or aware of this project..??

The Government has no preference or "comfort level" with any previous crane companies. It is unknown who is aware of the project.

12 Per (35 22 53 2.01-B-1) Furnish of Hydraulic Oil; What is type of oil..?? What is anticipated Amount Requested (5 gal, 55 gal, etc.)..??

12.a.

The four hoists share the same accumulator tank. It is anticipated that most of oil will be retained in the system as the remaining three hoists shall remain operational during the project. Some oil may need to be drained and disposed of during disconnection and isolation activities of the hoist. Any reduction of oil in the system shall be replaced with new oil by the Contractor to maintain operation of the remaining three hoists and to 'top-off' the system at the conclusion of the project.

12.b.

For amount, on-site mechanics like to "keep it low with sufficient oil for all fwg's to operate. The tank has a sight glass with amount line where they normally keep it"

12.c.

For type, "The Texaco Rando HD 32 hydraulic oil...is an adequate oil to use in the hydraulic system...this is a hydraulic oil with anti-wear additives making it suitable for all types of hydraulic pumps and for pressures over 1000 psi"

Q&A Responses