Amendment_4.pdf

3154 Goetz Swing Winch W912BU-19-Q-0008

The purpose of this amendment is to:

1. Answer questions from offerors. Questions that may be of general interest of all

Bidders/Government will appear below. These questions may have been paraphrased or altered to represent several questions regarding the same subject and/or clarify and simplify the question(s). Questions and answers are issued to the Offerors for information purposes only. (Question 19 through 37)

All other terms and conditions remain unchanged.

RFI Responses

Question 19: Did you mean that the first sheave is 27’ from the winch or 27” as defined in your amendment? If 27”, does it move with the wire rope as it pays across the drum? Why is it not shown on the drawing?

Response 19: Answered in Amendment 002, Response 15.

Question 20: The 1.25” diameter wire rope you specify does not technically meet the 3:1 minimum Safety factor required for Winches, are you okay with 2.9:1 or do you want to go to a larger wire rope which may require larger sheaves?

Response 20: Answered in Amendment 002, Response 16.

Question 21: Nothing other than continuous duty, bearing life and Gear box service factor is given for the required design for duty of the winch. However no minimum drum diameter or drum diameter: wire rope ratio is specified. Can you specify a minimum drum diameter for first layer? Can you specify a minimum drum width between the flanges?

Response 21: Answered in Amendment 002, Response 17.

Question 22: Do you have a dimensional drawing of the existing winch. (We ask this because if IHC bids the job, they have an unfair advantage having all the information on the existing winch such as its first layer diameter and the width between the flanges.) Do you have a picture of the existing winch?

Response 22: The Government does not own the rights to the drawings and can therefore not distribute them. See attached pictures of the winches.

Question 23: It is not clear if the 6th layer at 80 fpm or the 1st layer at 50 fpm is the driving design. Did you pick these speeds because that is what you presently have or is there some latitude on the speeds.

Response 23: Winch is to be designed per the solicitation.

Question 24: You state in ”E Gear Reducers” that you want to have the Gear box and the Drum Separate, so that the gearbox can be removed without removing the drum. If there is a Barrel coupling between the input (gear box) side of the drum and the gearbox can you support the drum which this is unbolted allowing the gearbox to be removed or must there be a pillow block supporting the input side of the drum, and a flexible coupling between the pillow block and the gear box?

Response 24: Per the solicitation, the gear box shall be removable without removal of the drum. The gear box shall be removable without the need to provide any additional support to the winch drum.

Question 25: We respectfully ask that the bid date be extended. If you can answer our Feb 20th questions and the additional ones above by Thursday of this week we would be able to supply a proposal by March 8th.

Response 25: Per Amendment 002, bid has been extended to March 11.

Question 26: In section C456, part E gear reducers it says “the gears shall be planetary gears or parallel shaft arrangements”. Is it ok for the reducer to be a helical bevel arrangement?

Response 26: Per the solicitation, the gears shall be planetary or parallel shaft arrangements.

Question 27: On Pg. 6 of the specifications, it says “Each motor shall be designed for a minimum ambient temperature of 50 degrees C.” Should that be maximum temp of 50 degrees C?

Response 27: The specification requirement indicates that each motor shall be able to provide rated output under ambient temperatures as high as 50 degrees C. The rating is to be stamped on the motor nameplate.

RFI 7

Question 28: Where are the line pull amounts coming from (53,250 lbs.)?

Response 28: The original requirement included in the solicitation was 60,000 lbs. Upon receipt of a previous RFI (answered in Amendment 002) indicating that this would present a condition with a factor of safety less than 3:1, the Government reviewed the requirement and reduced it to 53,250 lbs. in order to maintain the factor of safety while exceeding the existing winch line pull.

Question 29: We understand that you want a Brake on the Drum Flange and paragraph D Winch brakes says that that brake will be the holding brake and not to be used for Dynamic Braking. (It would however be a good idea to use this brake for an emergency brake in case of slack cable or overwrap beyond the flanges) Typically Dynamic braking is part of the VFD flux vector system and the energy from the dynamic braking against the full motor torque is dissipated into a resistor bank. If this is the type of Dynamic Braking you want, it would not be in our scope since you are supplying the Avid control which incorporates this feature.

Response 29: Solicitation requires brakes as detailed in the paragraph referenced in this RFI which includes a holding brake (parking brake) and a dynamic brake. The dynamic brake is to be part of the winch assembly and is to be designed to be applied in a condition while the winch is in motion (dynamic). The specification does not require dynamic braking through the

VFD.

Question 30: Are you asking for another electro-mechanical brake such as a motor brake to be used as a second brake to control speed?

Response 30: A holding brake and a dynamic brake shall be provided per the solicitation.

Winch shall be capable of controlling speed through the VFD and motor.

Question 31: You also say that the Dynamic Brake torque shall be greater than or equal to 100% torque of the motor but we are not sure what is meant when you say the dynamic brake have a thermal capacity shall not be less than 15 minutes. If you do not mean similar to motor insulation ratings. (Amount of time brake held off against the spring in an hour) Please explain.

Response 31: The brake shall have the ability to operate in a braking condition for 15 minutes without any adverse impacts to the brake or winch.

Question 32: Are you saying the control will allow the brake to slip, not providing a full closure but a partial closure, and developing pad or shoe heat for 15 minutes. (Like riding your car brakes for 15 minutes while flooring the accelerator?)

Response 32: Please see Response 31.

Question 33: Under 3. Motors and Controllers you mentions which as identified in contract Clause C456, please direct us to which contract document of the solicitation package contains this clause.

Response 33: Contract Clause C456 is included in Solicitation Section C – Descriptions and Specifications.

Question 34: The 1.25" diameter wire rope you specify does not technically meet the 3:1 minimum Safety factor required for Winches, are you okay with 2.9:1 or do you want to go to a larger wire rope which may require larger sheaves?

Response 34: This question was previously addressed in Amendment 0002, Response 16.

Question 35: Nothing other than continuous duty, bearing life and Gear box service factor is given for the required design for duty of the winch. However no minimum drum diameter or drum diameter: wire rope ratio is specified.

a. Can you specify a minimum drum diameter for first layer?

b. Can you specify a minimum drum width between the flanges?

c. Do you have a dimensional drawing of the existing winch?

d. Do you have a picture of the existing winch?

Response 35: The Government does not intend to specify minimum drum diameter or drum width. The winch is required to meet the requirements of the solicitation. Please see Response 22 for items c and d.

Question 36: It is not clear if the 6th layer at 80 fpm or the 1st layer at 50 fpm is the driving design. Did you pick these speeds because that is what you presently have or is there some latitude on the speeds.

Response 36: The line speed requirements were based on the need to maintain or exceed the requirements of the existing winch. The Government does not intend to change the requirements in the Solicitation.

Question 37: You state in "E Gear Reducers" that you want to have the Gear box and the Drum Separate, so that the gearbox can be removed without removing the drum. If there is a Barrel coupling between the input (gear box) side of the drum and the gearbox can you support the drum which this is unbolted allowing the gearbox to be removed or must there be a pillow block supporting the input side of the drum, and a flexible coupling between the pillow block and the gear box?

Response 37: Please see response 24.

(End of amendment)