Answers_2.DOCX

Questions generated at the site visit

1. What is actual round duct ID size at outside connection to chamber?

ANSWER: Chamber drawing states: HVAC DUCT 30” DIA, .058 THK CORRUGATED STEEL PIPE, TYP 4 PLCS

1. What temperature/humidity variation is allowed when insulated rolling door is opened for firing?

ANSWER: It is understood we will lose WFC conditioning when the firing port door is opened. SMEE is not expected to overcome and maintain conditions within the WFC when the firing port door is opened.

Typical operation involves:

1) temperature soaking the gun as required (barrel sticks out of chamber and is covered by an insulated sock)

2) remove sock

3) loading the weapon

4) opening the clamshell door just enough to give space for recoil, remove sock

5) fire the gun

6) close the clamshell

7) wait for chamber conditions to recover

8) install sock when firing is not imminent

1. What is allowed recovery period?

ANSWER: Test dependent. Most will fire as much and as fast as they can until a temperature lost threshold is reached, requiring a re-soak.

1. How fast does rolling door open and close for firing?

ANSWER: Fast, but that is not a good data point. Firing mission may be 10 minutes between sick removal and gun firing.

1. Will the weapon under test be moved after the door is opened to ensure that the barrel is outside of the chamber, or is the barrel end still inside the chamber at the time of firing?

ANSWER: temperature soaking the gun as required (barrel sticks out of chamber and is covered by an insulated sock)

1. How many rounds are fired over what time period?

ANSWER: Dependent on test parameters. Reference 4.

1. What is diameter of culvert pipe, i.e. the chamber?

ANSWER: Culvert is not a circle.

1. What is the thickness of the metal plate that acts as the chamber liner?

ANSWER: Corrugated pieces are 0.28” thick with overlapping edges bolted together. Firing port quarter sphere is 0.75”thick.

1. What is ceiling height in center of chamber?

ANSWER: Earth floor to ceiling apex is approximately 14’2”.

1. What is earthen floor depth in center of chamber?

ANSWER: Culvert is not a circle. Deepest point is approximately 4’2” below earthen floor.

1. In current design a failure of any kind in either the north or south cascade results in a loss of 50% capacity for both conditioning capacity and air flow. The new requirement in conjunction with suggested concept requires redundancy levels for conditioning at 20% increments. What are the expectations on the airflow side? Two (2) independent 16,000 CFM blowers with independent service access while full operation is maintained or two (2) 8,000 CFM blowers operating in parallel with ability to service only with full shutdown or????? There is nothing in specification covering this issue.

ANSWER: Our intent is that if a module goes offline due to an event such as a compressor failure or loss of coolant, the remaining modules can continue to operate and cool the chamber (ref. 3.2.2.9). Maintaining airflow in this type of situation is dependent on the system architecture and is necessary to meet 3.2.2.9 insofar as a module can be powered off and worked on. There is no specific requirement for airflow redundancy defined Should the design of the system require the airflow to be shut down in order to service a powered off module our conclusion would be that 3.2.2.9 is not met.

If the design is such that airflow reduced when a module is shut down, but the remaining modules continue to operate and effectively cool the chamber our conclusion would likely be that 3.2.2.9 is met. (Note: 3.2.2.9 acknowledges the potential impact of taking a module offline with respect to WFC set-points not being met – reduced airflow could understandably contribute to this condition.)

If the design is such that a module coming off-line would have no impact to the airflow, and the remaining cooling capacity could be used to its fullest to support chamber operations 3.2.2.9 would be satisfied.

1. Is there data which provides current system performance in pulling empty chamber down in temperature from “ambient” (please provide for given data) to -65⁰F?

ANSWER: Yes.

Answer: Anecdotally – On a 70F degree day with empty chamber the current chamber can go from ambient to -60F in 48 hours On a 70F degree day with 60,000 lbs. of steel in chamber the current chamber can go from ambient to -60F in 72 hours.

On a 115F degree day with empty chamber the current chamber can go from ambient to -60F in 60 hours.

On a 115F degree day with 60,000 lbs. of steel in chamber the current chamber can go from ambient to -60F in 84 hours.

1. Please confirm there is no time requirement to implement low temperature cooling after running MIL-STD Method 507.6-IX (Aggravated Cycle) ANSWER: Transition from a hot-humid to a cold test phase is typically preceded by a “dry out” period where the chamber is operated hot & dry as needed to eliminate as much moisture from the air and soil as is reasonable. Whenever possible cold testing precedes a hot-humid test phase.

1. Are “ALL” the data points listed in para. 3.2.2.4 actually required for “ALL” the systems being provided to comply with new 20% staging requirement?

ANSWER: The SMEE is considered one “system”. 3.2.2.4 needs to be met for the SMEE system as a whole. Reference answer to • 3.2.2.4 (below) for additional clarification.

1. Since the above data requirements were not listed for the ACC Option, assume they are not required.

ANSWER: Reference SMEE Specification 3.4.2. ACC Control and Instrumentation Meets requirements specified for the SMEE Control and Instrumentation unless otherwise specified. Therefore 3.2.2.4 is applicable to the ACC.

1. During sight visit, it was observed that only on thermocouple was used to manage surface temperature limit requirement on six (6) defrost heaters. Is this acceptable? Was not able to observe installation of main heater banks, was this same methodology used there also?

ANSWER: The design and control of the current system was such that one thermocouple was sufficient to collect the necessary surface temperature data for the defrost heater observed during the site visit (ref. SMEE Specifications, Figure A-8). The design of the proposed system will determine if one thermocouple on each defrost heater is sufficient to ensure the system meets performance and safety requirements set forth in the SMEE specification.

Each Skid currently has 3 main heating elements, all connected to a 100A 208V 3PH breaker (A total of 6 main heaters and 200amps for both skids combined). Each of these heaters has an associated thermocouple. The design of the proposed system will determine if one thermocouple on each defrost heater is sufficient to ensure the system meets performance and safety requirements set forth in the SMEE specification.

1. Why are all heaters listed in specification operating on 208 volts and is this a requirement?

ANSWER: This is how the system was built and delivered. There is no requirement heating and defrost systems operate at 208 volts. The design of the proposed system and the available power currently on-site (ref. 3.1.2) will determine the operating voltages of heaters. The system must meet the performance and safety requirements set forth in the SMEE specification.

1. There is no 208 volt power supply listed so if this is required for heaters, is a transformer also required as part of the new installation?

Answer: The design of the proposed system and the available power currently on-site (ref. 3.1.2) will determine the operating voltages of heaters and other equipment. The proposed design will need to integrate any necessary equipment to convert existing, available power to the design requirements.

1. The specification calls out that the current system has two (2) 400 amp, 480 Volt and one (1) 600 amp, 480 volt supplies. Will these be subdivided due to potentially having more, smaller systems?

Answer: The Government shall provide the existing slab with the existing conduit stubs and currently installed power cables. Reference the included drawing. If the proposed design requires changes to the slab, stubs, currently installed conduit, etc. the proposal must clearly address this in scope and cost.

First set of previously submitted questions / Concerns

· 1.2 Background: It is stated that the chamber test area includes an ”earthen” floor. How has humidity been managed in the past considering high humidity would potentially turn this to “mud” and following this reaching the ultimate low RH conditions become virtually impossible as the “earth” has an unlimited supply of moisture. Is this floor sealed in some manner?

Answer: Reference answers to 10. and 13. Chamber design drawings and construction photographs show the floor sealed as described below:

1) Natural soil graded to shape of “CMPA” (chamber culvert).

2) 6” foam in-place insulation 3lbs/in3

3) 6” compacted sand graded to shape of “CMPA”

4) CMPA with waterproof membrane

5) A floor drain system is installed

· 1.2 Background: Also relating to the 13,000 cu. ft. test chamber, what if any information is available concerning the heat leak through walls and points of access. Other than the reference to it being covered initially with foam (no thickness given) and backfilled with earth, we know nothing. Are there dimension relating to the culver/chamber and more information in the insulation, doors etc. so as to make some accurate analysis of the potential heat loads we need to design for.

Answer: Chamber design drawings and construction photographs show 6” 3 lbs/in3 foam insulation used on external surfaces of the CMPA prior to being covered with earthen backfill. Doors and wall members are internally filled with 1.8 lbs/in3 foam insulation.

· 3.1.4: What is the magnitude of “shock and over pressure” induced by cannon firing that needs to be considered?

Answer: Limited data for the SMEE installation site is available. In short the best guidance we can provide is to ensure the system is designed in such a manner to dampen vibration and shocks as necessary for sensitive items mounted to the SMEE skids. Vibration and shock isolators should be used as necessary in addition to flexible sections and strain reliefs on lines and cables. Current equipment modules are emplaced as shown in the SMEE Specification. Proposed designs may include additional protections as determined by the contractor.

For proposals failing to account for and describe shock mitigation on critical or sensitive components; strain and flex on coolant lines, cables, or piping our conclusion would probably be that 3.1.4 is not met.

Pressures will vary depending on location of equipment.

At the SE corner of the firing chamber: 2.0 psi At the SMEE Pad near the N. Cascade coil cabinet: 0.2psi

Rough Order of Magnitude for A and B duration: 2.9ms and 80ms respectively.

*Does not account for seismic shock – only the pressure wave.

· 3.1.7: The definition of “Outdoors” used here would pertain to piping not enclosed within any mechanical equipment enclosures. True or false?

Answer: True.

· 3.2: Need more information on potential loads involved. i.e. chamber wall materials, insulation and construction. Doors and type of sealing. All information relevant to identifying heat loads both dead and live required to size refrigeration systems.

Answer: Reference answers to 10, 13, • 1.2.

· 3.2.1.3: See comment above RE ability to reach low RH conditions.

Answer: Reference answers to 10, 13, • 1.2.

· 3.2.1.4: Please clarify term “static chamber”. Does this mean empty chamber only or does it include the static load referenced in 3.2?

Answer: Non cyclic, steady state chamber temperature.

· 3.2.2.1: Please clarify!

Answer: SMEE operation will occur from the control room. Controls equipment is expected to be connected to the YPG ICAN (ref. SMEE Specification 3.2.2.10). In the event the ICAN is down, local control from the control room shall continue normally.

· 3.2.2.4: In so much as the new system concept will include as many as 7 cascade systems (14 compressors) as compared to current system of only four compressors, are all of the items listed really required. For example, based on concept illustration in para. 3.2.3.2, each module would have two compressors, 2 or 3 evaporator fans, 4-6 condenser fans. That’s potentially 9 x 7 modules, or 63 motors to which we would be monitoring amp draw. This does not include motors required for main conditioned air circulation. Similar argument in the case of other item listed. When dealing with only two systems as is current design, not too big of an issue. The IO required for the list as applicable to proposed design becomes quite significant. Please review and clarify.

Answer: The design of the proposed system will impact IO required to meet 3.2.2.4. However, the concern is noted, and we recognize the requirement as written could be interpreted in the described manner. The current system reports total amperage draw for each discreet bank of condenser fans: High Temp, North High Stage, and South High Stage. A proposed system reporting amperage draws for discreet banks of condenser fans (quantity determined by design) would be acceptable. The actual number of evaporator fans required is dependent on system design (ref. answer to 11.)

· 3.2.3.4: Currently there are two sets of supply and return ducts between conditioning systems and WFC. Will this same configuration also be necessary between the SMEE “Mixing Box” concept and the WFC? Are the same point of connect to be used? If so, what size are they currently. If not, whose responsibility to install new ones appropriate to interface with new design if it is single in design. Considering the new approach emphasizes redundancy, would think that connection to current interfaces would be most appropriate.

Answer: The Government shall provide the connection points to use as determined by the proposed design. The proposed design needs to interface with the chamber as-is.

· 3.2.8.3: Is it also permissible to design each of the modules to function as either cascade cooling systems or as single stage systems for high temperature and humidity. We have done this many times before and this approach offers a greater degree of redundancy as well as capacity in the humidity and nominal temperature modes.

Answer: The proposed design is not incompatible with 3.2.3.2. “The proposed configuration of these modules, and how they supply conditioned air to the WFC may differ from Figure 1 and will be determined by the Offeror.” However, the strategy could cause difficulty meeting 3.2.5.2 and 3.2.6.3 – although conceivably possible to do without conflicting these two sections. Our concern would be that a failure with a low-temperature module configured in this manner would automatically result in an inability to perform high temperature testing (assuming the High Temperature Cooling Equipment is used for temperature and humidity control during non-low temperature testing). The proposed system would need to effectively address this risk (ref 3.2.2.9).

· 3.2.9: Does this mean that for your testing purposes, no dry air is required below -25⁰F?

Answer: Make up (dry) air may be supplied to the chamber temperature test range (‐65°F to 165°F). The requirement is that makeup air be conditioned between -25F and +120F as required. Mixing of make-up air with the return air is acceptable to meet the make-up air temperatures of -25F to +120F.

Currently makeup air is introduced into the chamber though the Make Up Air Unit (ref. SMEE Specifications APPENDIX A). It is then mixed with the return air before being supplied to the chamber.

4.1.4: Considering magnitude of project, request min. 72 weeks ARO

· 22 weeks ARO completed design drawings

· 54 weeks ARO pre-delivery inspection

· 68 weeks ARO installation and shake-down complete

· 72 weeks ARO Training and acceptance testing complete Answer: Potential offerors are encouraged to submit proposals, and identify if a requirement is partially met or the requirement is met in a different way. Proposals will be evaluated based on technical merit and SMEE performance requirements.

· 4.2.1: Kick-Off 8 weeks ARO Answer: Site visit to confirm site layout and infrastructure to occur early in the process.

The most critical need in information to determine thermal cooling/heating capacities. The information provided on page A-4 of Appendix A is insufficient to determine required capacity for new system. Please contact me if there are question regarding the above requests.

Second set of previously submitted questions /concerns Reference Appendix A: I believe that this is information only regarding the current system and does not necessarily imply requirements for new system.

Answer: Correct – design of the new system is expected to be significantly different than the current one. Data regarding the existing equipment is provided as a reference only.

· Cascade Cooling

· Reading between the lines, total air flow to “Weapons Firing Chamber” (WFC) is 16,000 CFM with both north and south cascades running simultaneously. Running independently, each could provide 8000 CFM and roughly 50% cooling capacity to the WFC. Please confirm this logic.

Answer: Reference answer to 11.

· Why are heaters 208Volts?

Answer: Reference answer to 17.

· High Temperature Cooling

· Is Combustion Air and Make-up Air?

Answer: Reference answer to • 3.2.9.

· A Munters HC9000 Dehumidifier/Dryer is referenced. This unit has a flow range of 4500 to 12,000 CFM, which does not correlate with any of the values given, i.e. 500 CFM “Make-up” or 2,500 CFM “Combustion” air. Please clarify relative to current requirement. Solicitation specifications Para 3.2.9 states 800 CFM Make-up air which we interpret as Combustion air based on description in paragraph. This follows the requirement for a desiccant de-humidifier. Is 800 CFM the maximum requirement for either de-humidification and Make-up Combustion air?

Answer: Data regarding the existing equipment is provided as a reference only. Current system routes return air though the dehumidifier. This airflow is returned to the return air supply entering the modules.

· This current skid has its own 8,000-9,250 Blower?

The dehumidifier does not utilize its own fan to circulate the chamber return air.

Will there ever be a one-on-one meeting with end user(s) to discuss details at a high level prior to providing a formal quotation. Based on my 50 years of experience, the limitations of this type of question an answer communication on a requirement of this magnitude will lead to disaster for one or the both of us.

A site visit was announced and executed per the FBO posting. The Contractor’s proposal to include sufficient conceptual configurations, and design theory to permit evaluation of the proposal. The Technical team is anticipating and able to work closely and actively with the contracted vendor to ensure successful delivery of the SMEE. The design review process exists not only for the Government to determine project status, but also as a means for the vendor to solicit and receive feedback from the Government.

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