RT&L FOCUS AREA(S): General Warfighting Requirements
TECHNOLOGY AREA(S): Materials / Processes; Weapons
OBJECTIVE: Develop a strong, lightweight, lowest price, technically acceptable sunshade capable of blocking 70% of solar radiation and attain Naval Ordnance Safety and Security Activity (NOSSA) authorization for use with the A/E32K-11 Munitions Lifting Assembly (MLA).
DESCRIPTION: The United States Marine Corps (USMC) requires the assembly of munitions in forward operational areas. The following descriptions are detailed in two parts: description of the fielded MLA system followed by the required performance of the Sunshade Cover. The solution desired through this effort is for the Sunshade Cover, but details of the MLA are necessary for developing the solution.
In an effort to satisfy the USMC requirements, the Naval Air Systems Command (NAVAIR) procured the A/E32K-11 MLA; a replacement to the legacy A/E32K-3 Munitions Assembly Conveyor, and similar to the A/E32K-9 Munitions Assembly Conveyor II used by the United States Air Force [Ref 1]. The MLA provides a mobile capability for rapid assembly/disassembly of conventional munitions and a means to load/unload them from/onto munitions trailers. The system can be assembled/disassembled in a day, can be packed into three storage containers, and is C-130 transportable, making it capable of expeditionary missions. The system consists of roller conveyors, two A-frame gantries (each with a pneumatic hoist), four rail conveyors with associated munitions cradles, an Interface Control Board (ICB), and a lighting system. The rail conveyors each measure 10 ft (3 m) in length and are assembled end to end to create a 40 ft (12 m) munition assembly line. The two gantries are positioned at either end of the rail conveyor assembly for lifting bulk munitions from incoming pallets and removing assembled munitions from the rail conveyor to a munitions transport vehicle/trailer. The MLA also incorporates a grounding system comprised of a ground rod conforming to (CID) A-A-55804, Type III, Class B; and ground straps connecting the conveyors, gantries, ICB, etc. [Ref 3].
The MLA requires a durable Sunshade Cover approved for use on the system by NOSSA – the technical authority pertaining to ordnance safety and the NAVSEA OP 5 Ammunition and Explosives Safety Ashore [Ref 5]. Design requirements include, but are not limited to, use of a static dissipative (surface resistivity between 10⁵ Ω/sq and <10⁹ Ω/sq) or conductive (surface resistivity <10⁵ Ω/sq) material capable of discharging to ground. The static dissipative properties of the material used should not be met by use of topically applied treatment; that is, sprayed on the material. The material’s static dissipative properties must remain stable with long-term UV exposure and under varying humidity conditions. If the Sunshade Cover consists of multiple layers, the layers must be electrically integrated such that the surface resistivity measured with one probe on the outside of the material, and the second on the inside of the material, will yield the same results as if both were on the outside of the material. The Sunshade Cover design must not allow point-discharging and/or must bleed off any accumulated charges in a manner that will reduce the buildup of sufficient charge for electrostatic spark discharge (ESD).
The MLA Sunshade Cover must span the width of the two gantries, about 33 ft (10 m), and provide adequate protection from the sun to operators working in the rail conveyor area. The Sunshade Cover must not hinder the MLA system’s stability or operational capability, including the operator’s ability to assemble munitions without Sunshade Cover interference. The Sunshade Cover can, but is not required to, be attached to the MLA and must be capable of easy deployment/storage while the MLA structure remains standing about 16 ft in height (5 m). The Sunshade Cover should block at least 70% of solar radiation and be able to withstand the following environmental conditions:
(a) low Temperature Operating Life (LTOL) with temperatures of -25 °F (-32 °C);
(b) low temperature storage with temperatures of -65 °F (-54 °C);
(c) high Temperature Operating Life (HTOP) with temperatures of 140 °F (60 °C) with a solar load;
(d) high temperature storage with temperatures of 180 °F (82 °C);
(e) 3% to 95% Relative Humidity (RH) (Ref 2);
(f) rain, and/or blowing rain, falling at a rate of 2 in./h (5 cm/h) in winds of 40 mph (64 km/h);
(g) blowing dust in concentrations of 0.3 g/ft³ +/ 0.2 g/ft³ in winds of 35 mph (56 km/h); blowing sand in concentrations of 0.0623 g/ft³ +/ 0.015 g/ft³ in winds of 35 mph (56 km/h);
(h) ice, freezing rain, and/or water delivery with a rate of 25 mm/h with a droplet size of 1.0 mm–1.5 mm; and
(i) salt fog for at least 96 hours [Ref 4].
The components comprising the MLA sunshade system should have a minimal footprint when not in use to enable storage in the MLA systems existing storage containers or a small standalone storage container. Material should be shown to resist fungus growth or deterioration. The Sunshade Cover must be field repairable to the greatest extent possible. Periodic maintenance and testing requirements must be minimal to none.
PHASE I: Develop a design for a sunshade cover. Demonstrate the feasibility of the proposed concept in meeting the requirements through analysis and lab demonstrations. Provide one or multiple conceptual designs of an A/E32K-11 MLA Sunshade Cover. The Phase I effort will include prototype plans to be developed under Phase II.
PHASE II: Design and develop a prototype sunshade cover for the A/E32K-11 MLA. Demonstrate use and wear over time to determine any degradation. Provide an estimate of per-unit cost with backup cost data, including parts/manufacturing. Provide a top-level failure analysis and service life estimate. Demonstrate the static dissipative or conductive nature of material using best industry practices. Facilitate and receive NOSSA approval for use of prototype with A/E32K-11 MLA system. Demonstrate that the use of the prototype does not negatively impact use of the A/E32K-11 MLA system. Provide a top-level assessment of whether the cover would pass requirements detailed in Reference 3, and when tested in accordance with the following information: (a) HTOL in 505.7 solar radiation with (procedure) I (cycling and heating effects) of 140 °F (60 °C) ambient air, (b) high temperature storage in 501.7 solar radiation with (procedure) I (storage) of 180 °F (82 °C) maximum; (c) LTOL in 502.7 solar radiation with (procedure) II (operational) in -25 °F (-32 °C) minimum; (d) low temperature (storage) in 502.7 solar radiation with (procedure) I (storage) in -65 °F (-54 °C) minimum; (e) rain in 506.6 solar radiation with (procedure) I (rain and blowing rain); (f) icing/freezing rain in 521.4 solar radiation with (procedure) I glazed ice of 13 mm thick; (g) humidity in 507.6 solar radiation; (h) sand and dust in 510.7 solar radiation with (procedure) I (blowing dust) and (procedure) II (blowing sand) in Air Velocity of 35 mph (56 km/h); and (i) salt fog for 96 Hours [Ref 4].
PHASE III DUAL USE APPLICATIONS: Transition the MLA sunshade for use on the A/E32K-11 MLA. Support United States Government testing and fielding of developed solution. The technology could be used for improved solar protection and material coverage in dusty/explosive environments (e.g., mining, refineries, oil rigs).
- Rowe, C. “MEOC and AAMOC students assemble munitions lifting assembly during WTI 2-18. DVIDS.” Defense Visual Information Distribution Service, March 14, 2018. https://www.dvidshub.net/image/4236612/meoc-and-aamoc-students-assemble-munitions-lifting-assembly-during-wti-2-18
- “MIL-STD-810H, Department of Defense test method standard: environmental engineering considerations and laboratory tests.” Department of Defense, January 31, 2019. http://everyspec.com/MIL-STD/MIL-STD-0800-0899/MIL_STD_810H_55998/
- “Commercial item description (CID) rods, ground (with attachments) A-A-55804, (Type III, Class B.).” Defense Logistics Agency, Defense Supply Center Richmond, May 30, 2002. http://everyspec.com/COMML_ITEM_DESC/A-A-55000_A-A-55999/A-A-55804A_42558/
- “ASTM B117-19 Standard Practice for Operating Salt Spray (Fog) Apparatus.” ASTM International, 2019. https://doi.org/10.1520/B0117-19
- NAVSEA OP 5 VOLUME 3. AMMUNITION AND EXPLOSIVES SAFETY ASHORE FOR CONTINGENCIES, COMBAT OPERATIONS, MILITARY OPERATIONS OTHER THAN WAR, AND ASSOCIATED TRAINING.
Additional information: Request can be made to Naval Surface Warfare Center Indian Head Explosive Ordnance Disposal Technology Division Detachment Picatinny, G13 Naval PHST Division Bldg. 458, Whittemore Ave. Picatinny Arsenal, NJ 07806-5000: POC: Martin F. Orozco, firstname.lastname@example.org, 973-724-5925 OR Explosives Safety Technical Manuals (ESTM) data is also available on the secure Naval Ordnance Safety and Security Activity (NOSSA) website at: https://nossa.dc3n.navy.mil/nrws3/Home.aspx. You must register for access to the website in order to view the electronic library.