II. H - Questions and Answers Amend 0002.pdf

Question 1:

Requirement 4.2.1 - Each puller subassembly shall provide a minimum working load of no less than 60,000 pounds tension. 15-1176-S02 Tension Test Facility, Section 1.2. Scope states “The maximum tension for the facility is 30,000 pounds”, which conflicts with this requirement of this paragraph.

Answer 1:

While standard operation (detailed in 15-1176-S02) of the Tension Test Facility has a maximum working load of 30,000 pounds tension, the maximum working load of the facility is 60,000 pounds tension. The intent was for the end two sections (larger material and strength) to test to 60,000 pounds. If you are taking an exception to the requirement, please provide rationale.

Question 2:

Also, the existing Ball Screw Nut 50X10R has maximum dynamic load rating of 14860 lbs (66.1 kN). Two per subassembly yields a maximum dynamic load of 29720 lbs per subassembly.

Answer 2:

If you are taking an exception to the requirement, please provide rationale and OQE for exception. Define dynamic load for this rating?

Question 3:

Requirement 4.2.3 - Capable of advancing or retracting the drive head at a variable rate between

0.01 inches per second and 1.0 inches per second. Is there any requirement for cycling or high acceleration? If so what is the maximum frequency and amplitude, or acceleration required?

Answer 3:

There is no requirement for “quick” cycling or high acceleration. Typical cycling scenarios go from 50 pounds to a nominal tension and repeat. Typically if the head rate is set correctly the rise and fall time are on the order of seconds or minutes.

Question 4:

Requirement 4.2.4 - Capable of measuring drive head position data to +/- 0.001 inches.

The existing system does not include a method of directly reading drive head position (e.g.

LVDT or string pot). Drive head position can be calculated from servo motor encoder data, gearing ratio, pulley dimensions and ball screw pitch with a resolution of +/- .001 inch indicated.

This reading will not account for backlash in ball nut and gearing, or deformation ball screw and frame.

Answer 4:

The existing system uses servo drives and encoders to measure position.

Question 5:

Requirement 4.2.5 - Capable of measuring tension data via a load cell and indicator to an accuracy (including linearity) of less than +/- 0.15% over the full scale. Since load cell tension data is transmitted digitally (RS232 or RS485), the accuracy of the measured tension data will be that of the existing components. The specifications for the existing Honeywell Model RF load cell and SC Series instrumentation do not seem to meet the requirements of this paragraph.

Answer 5:

The upgrade of load cells and indicators is not permissible due to METCAL Program requirements. Revision to 4.2.5, if any, will be provided in a subsequent amendment.

Question 6:

Requirement 4.2.7 Designed to withstand the shock and vibration associated with catastrophic failure of UUTs at 60,000 pounds and at full extension up to 200 times over the life of the system. What is the maximum “full extension” expected?

Answer 6:

Full extension is the extremes of the head travel, i.e. the position at the south most end of drive head travel and the north most end of drive head travel.

Question 7:

Requirement 4.3.6 - Allow both puller subassemblies to be controlled independently or concurrently. When operated concurrently, is a single UUT being loaded by both drive heads together?

Answer 7:

The requirement for using both heads comes into play when the stretch of the UUT exceeds the extension length of one of the units. In that case, one head would be driven to near full extension then the other head would pull the final amount. The non-moving drive head could be locked but must hold the tension provided by the other head.

Question 8:

Requirement 4.4.1 - The Control Console shall be compatible with Windows 10 (or newer) operating system. The PC is indicated in section 2.0 as “one (1) HP 420 Z3 Windows 10 computer provided by the Government. “ Will the PC have a standard Windows 10 image, or will it be a government-secured Windows image? Can the PC be shipped to vendor for use during system development? How many monitors will the PC have; three are preferred?

Answer 8:

As indicated in the second paragraph of section 2.0, one computer will be provided for software installation. This computer will not be shipped to a vendor facility for use during system development. The Government anticipates that vendors already have a proven tensioning software that will be installed onto the computer. The Government will provide monitors for the computer. The Government currently anticipates reusing three monitors in the control room.

Question 9:

Requirement 4.3.9 - Be designed with appropriate guards and other electrical features to promote safe operation with minimal risk to personnel. Guidance for this requirement can be found in GFI 15-1176-S02, Standard Operating Procedure for the Tension Test Facility. Section 2.0 states “This document provides the requirements for the replacement of the control equipment and control console (red boxes, figure 1).” Machine guarding would seem to fall outside the scope of this upgrade, although interfacing electrically with existing E-Stops, limit switches etc. would be included.

Answer 9:

Equipment installed (motor, motor controller, and pulley system) will have to be guarded. The Government’s expectation is for the vendor to ensure all current safety measures are either maintained or improved by their designed system.

Question 10:

In the attached documents MIL-T-28800E page 2 Paragraph 1.2.2 Class 1,2,3,4 to 7. What class will the enclose box need to follow? Are there any specific tests on that enclosure box?

Answer 10:

MIL-T-28800 has been superseded by MIL-PRF-28800.

Question 11:

Are you looking for a line-by-line response to each specification or an overall synopsis of the proposed solution?

Answer 11:

Per the RFQ, offerors shall provide responses to each of the factors listed to allow the Government to make a best value assessment of the offeror’s capability.

Offerors shall provide total price to complete the requirement under CLIN 0001, inclusive of installation and, if applicable, any FOB shipping costs.

Item Number Description Quantity/Unit Total Price CLIN 0001 Towed Systems Prototyping and Test Facility

Upgrades per Specification Document.

1 Lot