ASTM E1974-19

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:E1974 −19
Standard Specification for
Shelter, Electrical Equipment S-250/G
This standard is issued under the fixed designation E1974; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope E631 Terminology of Building Constructions
E1370 Guide for Air Sampling Strategies for Worker and
1.1 This specification covers one type of lightweight field
Workplace Protection
and mobile rigid wall shelter designed for transport by cargo
E1749 Terminology Relating to Rigid Wall Relocatable
truck, fixed or rotary winged aircraft, by rail, and ship,
Shelters
designated as Shelter, Electrical Equipment S-250/G.
E1773 Practice for Sealing RigidWallTactical Shelters with
1.2 The values stated in inch-pound units are to be regarded
Polysulfide Based Sealants
as standard. The values given in parentheses are mathematical
E1800 Specification for Adhesive for Bonding Foam Cored
conversions to SI units that are provided for information only
Sandwich Panels (160°F Elevated Humidity Service),
and are not considered standard.
Type I Panels
1.3 The following safety hazards caveat refers only to the
E1801 Practice forAdhesive Bonding ofAluminum Facings
test methods portion of this specification. This standard does in Foam and Beam Type Shelters
not purport to address the safety concerns, if any, associated
E1851 Test Method for Electromagnetic Shielding Effec-
with its use. It is the responsibility of the user of the standard tiveness of Durable Rigid Wall Relocatable Structures
to establish appropriate safety, health, and environmental
E1925 Specification for Engineering and Design Criteria for
practices and determine the applicability of regulatory limita- Rigid Wall Relocatable Structures
tions prior to use.
2.2 Commercial Standard:
1.4 This international standard was developed in accor-
SAE AMS-W-6858 Welding, Resistance: Spot and Seam
dance with internationally recognized principles on standard-
2.3 Federal Air Regulation (FAR):
ization established in the Decision on Principles for the
FAR 25.853 Compartment Interiors
Development of International Standards, Guides and Recom-
2.4 Military Standards:
mendations issued by the World Trade Organization Technical
MIL-F-14072 Finishes for Ground Based Electronic Equip-
Barriers to Trade (TBT) Committee.
ment
MIL-DTL-55507 Shelter, Electrical Equipment (With or
2. Referenced Documents
Without Equipment), Packaging of
2.1 ASTM Standards:
MIL-STD-252 Wired Equipment, Classification of Visual
C273/C273M Test Method for Shear Properties of Sandwich
and Mechanical Defects
Core Materials
MIL-STD-810 Environmental Engineering Considerations
D1621 Test Method for Compressive Properties of Rigid
and Laboratory Tests
Cellular Plastics
MIL-STD-2219 Fusion Welding forAerospaceApplications
D1622/D1622M Test Method forApparent Density of Rigid
MIL-STD-13231 Marking of Electronic Items
Cellular Plastics 6
2.5 Drawings:
D2842 Test Method for Water Absorption of Rigid Cellular
DL-SM-B-563500 Shelter, Electrical Equipment, S-250/G
Plastics
DL-SM-B-649950 Modification Kit, EMI, MK-1092/G
This specification is under the jurisdiction of ASTM Committee E06 on
Performance of Buildings and is the direct responsibility of Subcommittee E06.53 Available from AMS Publications, SAE International (SAE), 400 Common-
on Materials and Processes for Durable Rigidwall Relocatable Structures. wealth Dr., Warrendale, PA 15096, http://www.sae.org.
Current edition approved July 1, 2019. Published August 2019. Originally Available from Flight Standards Service, Federal Aviation Administration
approved in 1998. Last previous edition approved in 2011 as E1974–11. DOI: (FAA), 800 Independence Ave., SW, Washington, DC 20591, http://www.faa.gov.
10.1520/E1974–19. Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Available from U.S. Army Natick Soldier Systems Center (NSSC), ATTN:
Standards volume information, refer to the standard’s Document Summary page on AMSRD-NSC-CP-CS, General Greene Ave., Natick, MA 01760, http://
the ASTM website. www.army.mil/natick.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1974−19
DL-SM-B-650123 Shelter, Electrical Equipment, S-250/G Voids range from gaps as wide as the space created by a
(Shielded) missing piece of core material to as thin as a break in the
SM-D-208679 Outer Door Assembly continuity of material. Voids may be located solely within one
SM-D-208682 Inner Door Assembly type of material, such as a core material separation; they may
SM-C-435904 Keeper exist between adjacent materials, such as unbonded core
SM-C-435937 Nameplate material; or they may be located between other parts within a
SM-B-563559 Adhesive panel, such as where a piece of material is missing, damaged,
SM-B-563655 Foam, Rigid, Plastic or undersized. Voids may have been created at the time of
SM-D-563754 Diagram, Flatness and Squareness construction such as where a part was omitted; or may be
SM-C-564839 Gasket, Silicone created at a later time, such as a core separation or delaminated
SC-C-595537 Padlock and Key skin.
SC-B-595538 Bonding Procedure
NOTE1—Allotherterminologyrelatedtothisspecificationisdefinedin
SC-B-595539 Cleaning Procedure
Terminology E1749.
SC-B-595564 Core Material Urethane, Light
SC-B-595565 Core Material Urethane, Heavy
4. Materials Requirements
SM-D-649951 Modification Kit EMI MK-1092/G
4.1 General—The materials and components shall be as
SM-D-649952 Sling Assembly
specified herein and on the applicable drawings. Materials and
SM-D-649953 Shelter, Electrical Equipment S-250/G
components not definitely specified shall be of the quality
SM-C-650082 Skid Assembly
normally used by the manufacturer provided the completed
SM-D-650085 Test Weight Installation
item complies with all the provisions of this specification.
SM-C-650125 Nameplate
SC-D-781228 Door Fixture Construction Tightness Test
4.2 Adhesive—The adhesive used to laminate in accordance
SC-D-781235 Drain, Fixture, Construction Tightness Test
5.2 shall meet the requirements of Specification E1800 and the
SC-D-781236 Test Fixture Installation Construction Tight-
physical properties required by Drawing SM-B-563559 when
ness Test
tested in accordance with 10.1.
SC-B-964240 Nameplate, S-250 Shelter (With Rivnuts)
4.3 Sealer—The sealer, when tested in accordance with
10.1, used to meet the requirements of 5.3, shall have the
3. Terminology
following properties:
3.1 Definitions—For definitions of general terms related to
4.3.1 Sealer Shear, Ambient—The sealer and its bond to the
building construction used in this specification, refer to Termi-
aluminum shall have a minimum average shear strength of
nology E631, and for general terms related to rigid wall
200 psi (1.4 MPa) when tested at 80 6 10 °F (27 6 6 °C).
relocatable shelters, refer to Terminology E1749.
4.3.2 Sealer Shear, Temperature Extreme—The sealer and
3.1.1 delaminations—for purpose of this specification, a
its bond to the aluminum shall have a minimum average shear
delamination is defined as the condition that exists within a
strength of:
shelter section or panel when two surfaces that once were
4.3.2.1 200psi(1.4MPa)whentestedat–65 65 °F(–54 6
bonded together are no longer bonded together. Delaminations
3 °C), and
may occur between any two bonded surfaces; examples in-
4.3.2.2 75 psi (520 kPa) when tested at 200+0–5°F(93
clude: separations between thermal barriers and members,
+0–3°C)
between thermal barriers and skins, between members and
4.3.3 Sealer Shear, Humidity Exposure—The sealer and its
core, or between skins and core. They may be the result of a
bond to the aluminum shall withstand exposure to 95 %
poor quality bond or they could occur due to misuse or severe
relativehumidity 65 %at160 65 °F(71 63 °C)forfourteen
handling of the panels or the shelter after bonding. Test
days. After exposure the sealer shall have a minimum average
requirements of this specification shall not be construed as
shear strength of 75 psi (520 kPa) when tested at 160 65°F
misuseorseverehandlingasthesetermsapplytothedefinition
(71 6 3 °C).
of delaminations.
4.3.4 Sealer Shear, Salt Spray Exposure—The sealer and its
3.1.2 examination—examination consists of simple, gener-
bondtothealuminumshallwithstandexposuretothesaltspray
ally nondestructive determinations of compliance, without the
test, Method 509.4 of MIL-STD-810F using a 20 % NaCl
use of special testing equipment.
solution at 95 6 5 °F (35 6 3 °C) for fourteen days. After
3.1.3 inspection—inspection is the examination or testing,
exposure the sealer shall have a minimum average shear
or both, of supplies to determine compliance with the appli-
strength of 200 psi (1.4 MPa) when tested at 80 6 10 °F (27 6
cable requirements. Sampling an element of inspection.
6 °C).
3.1.4 testing—testing consists of determinations of compli-
4.4 Core Material—The core material shall be a slab type
ance using technical means.
foamed plastic. All three densities shall be used in the shelter.
3.1.5 voids—for the purpose of this specification, a void is Disbursement within the shelter shall be in accordance with
defined as any unauthorized separation or space within a Guide E1370 and the drawings listed on DL-SM-B-563500.
shelter panel or section, that is, any separation or space that is Density, compressive strength, flammability, water absorption,
in conflict with the drawings or other contractual requirements. and shear strength properties shall be in accordance with
E1974−19
Drawings SC-B-595564, SC-B-595565, and SM-B-563655, as and wood parts shall be cleaned in accordance with the
applicable when tested in accordance with 10.2. applicable portions of Practice E1801 and Drawing SC-B-
595538.
5. Construction Requirements
5.5 Welding—Arc and spot welding shall be applied as
5.1 General—Allparts,sub-assemblies,andthefinalassem-
specified by the drawings. No grinding of welds shall be
bly of Shelter, Electrical Equipment, S-250/G shall be con-
required except as specified by the drawings. The purchaser
structed as specified herein and in accordance with the draw-
reserves the right to perform any of the inspections where such
ings listed on DL-SM-B-563500 or DL-SM-B-650123 when
inspections are deemed necessary to ensure supplies and
electromagneticinterferencesuppressionisrequired(see15.2).
services conform to prescribed requirements.
Shelters shall not be fork lifted at anytime during or after
5.5.1 Arc Welding—Inert gas shielded arc welding shall be
construction.
in accordance with MIL-STD-2219.
5.5.2 Spot Welding—Spot welding shall be in accordance
5.2 Lamination—During the laminating (bonding) process
with SAE AMS-W-6858 Class B. Samples of the production
the mating of all panel constituents shall be bonded without
items produced in accordance with the drawings shall be
delaminations, that is, discontinuation in, or separation be-
inspected by the supplier for appearance, external defects,
tween the constituents. Bonding shall be in accordance with
sheet separation, surface identification, and weld location.
Practice E1801 and SC-B-595538. Both sides of all panels
5.5.2.1 Test specimens shall be used to represent the manu-
prior to assembly into shelter form and all shelters shall be
facturing practice. Three single-spot shear specimens shall be
acoustically interrogated for delaminations using a tap hammer
usedforcheckingpurposes.Threesingleshearspecimensshall
fabricated in accordance with Fig. 1. The shelter may be
be tested for ultimate strength and variation in shear strength.
considered acceptable if it contains less than twelve distinctly
5.5.2.2 Failure of a test specimen or samples of a welded
individual delaminations or unbond type voids, provided none
item shall be cause for rejection of the production quantity the
is greater than 2 in. (50 mm) across measured in any direction,
specimen or sample represents.
and provided the shelter meets all other requirements.
5.6 Riveting—No more than one rivet/rivnut in ten and no
5.3 Seal—All inner and outer skins, joints, edges, and
more than two adjacent rivets/rivnuts shall exhibit any of the
hardware shall be sealed in a manner that will prevent
defects specified below, when inspected as specified in 10.6.
collection and retention of water and provide a barrier against
5.6.1 Looseness—There shall be no evidence of looseness
the entrance of water into any panel or the interior of the
parallel to the plane of the mating surface due to oversized
shelter. Unless otherwise specified on the shelter drawings, all
holes or looseness perpendicular to the plane of the mating
exterior rivets, rivnuts, screws, and bolts shall be dipped in
surfaces due to rivets/rivnuts not being tightly seated.
sealer prior to installation and the heads of rivets shall be
5.6.2 Heads—Rivet and rivnut heads shall not be cut,
covered with sealant after installation. (See Practice E1773).
marred, chipped, eccentric, distorted, or otherwise mutilated.
5.4 Cleaning—All metal parts shall be cleaned at that stage
Countersunkrivetsandrivnutsshallnotprojectaboveorbelow
of assembly indicated on the applicable drawing listed on
the mating surface more than 15 % of the netting material
DL-SM-B-563500 or DL-SM-B-650123, by a process in ac-
thickness.
cordancewithPracticeE1773andDrawingSC-B-595539oras
5.6.3 Mating Surface and Materials—The mating surface
specified in the applicable portion of MIL-F-14072. All foam
shall not be marred or indented due to rivet or rivnut
installation, nor shall there be any distortion or warpage of the
mating materials. There shall be no foreign material between
riveted surfaces.
5.7 Hardware—All locks, latches, hinges, hinge pins,
fasteners, bolts lifting and towing eyes, steps and other shelter
hardware shall be made corrosion resistant in accordance with
the applicable drawings listed on DL-SM-B-563500 or DL-
SM-B-650123. The hardware shall be subjected to the test of
10.7 and shall show no evidence of corrosion or damage which
in any way impairs the specified performance of the individual
part.
5.7.1 Padlocks and Keys—All padlocks and keys shall be in
accordance with SC-C-595537 and shall be interchangeable to
the extent determined by 10.10.
5.8 Finish Protective—Protective finishes shall be in accor-
NOTE 1—Material—Aluminum 6061–T6 or equivalent.
dance with the applicable drawings listed on DL-SM-B-
NOTE 2—Tolerance—6 ⁄32 (1 mm).
FIG. 1Tap Hammer 563500 or DL-SM-B-650123 and shall be free of the defects
E1974−19
cited in the classification of visual finish defects of MIL-F- at 100 % relative humidity (with condensation) for 4 h when
14072 when inspected as specified in 10.8 and 10.12. tested as specified in 10.7.
5.9 Marking—Member centerline, punch marks,
6.3 Temperature—Thesheltershallbecapableofwithstand-
nameplates, instruction and data plates, and other markings
ing the following operating temperatures when tested as
shall be in accordance with MIL-STD-13231 and the appli-
specified in 10.14:
cable drawings listed on DL-SM-B-563500 or DL-SM-B-
6.3.1 Operating Temperature—Exposuretoanambienttem-
650123. Marking shall be inspected as specified in 10.9 and
perature in the range of –65 to 125 °F (–54 to 52 °C) plus a
10.12.
solar load such that the outside skin reaches a minimum
temperature of 195 °F (90 °C); exposure at any one time not to
5.10 Interchangeability—Like units, subassemblies, assem-
exceed 75 h at the low temperature extreme and4hatthe high
blies and replaceable parts shall be physically and functionally
temperature extreme.
interchangeable without modification of such items or of the
shelter. Dimensions shall be within the limits specified on the 6.3.2 Non-Operating Temperature—Exposure to an ambient
temperature in the range of –80 to 160 °F (–62 to 71 °C);
applicable drawings listed on DL-SM-B-563500 or DL-SM-B-
650123. Reliance shall not be placed on any unspecified exposure at any one time not to exceed 24 h at the low
temperature extreme and4hatthe high temperature extreme.
dimension, rating, characteristic, etc. Individual items shall not
be hand picked for fit or performance. To determine compli-
6.4 Heat Transfer—The thermal characteristics of the shel-
ance with this requirement the items listed in 10.10 shall be
ter shall be such that the overall coefficient of heat transfer of
measured and shall be in accordance with the dimensions and
thesheltershallnotexceed0.50BTUsperhourpersquarefoot
tolerances specified on the applicable drawings.
per degree Fahrenheit (2.9 Watts per square metre per degree
5.11 Facsimiles—When specified (see 15.2), the contractor Kelvin) when tested accordance with 10.15.
shall provide facsimiles of the nameplate and all data and
instruction plates required by DL-SM-B-563500 and DL-SM-
7. Structural Integrity Requirements
B-650123. Each facsimile shall be in accordance with its
7.1 General—The shelter shall be capable of complying
drawing and shall include any and all information required to
with the requirements of 7.2 – 7.6.When a payload is required,
be inserted, except shelter serial number.Artwork shall be of a
1900 lb (860 kg) in accordance with Drawing SM-D-650085
quality at least comparable to the drawings.
shall be used. The requirements of 5.13 are applicable to all
5.12 Shelter Weight—When inspected as specified in 10.12
tests.
and10.13,thegrossweightoftheshelter,excludingtheliftand
7.2 Transportability—The shelter, with payload, shall be
tie-down device, (Drawing SM-D-649952) shall be as follows:
capable of being picked up by a crane, transported while
5.12.1 770 6 20 lb (350 6 9 kg) without Mod Kit, EMI,
suspended from the crane, and lowered to any predetermined
MK-1092/G, and
point on the ground. The shelter shall also be capable of being
5.12.2 782 6 20 lb (355 6 9 kg) with Mod Kit, EMI,
transported as follows:
MK-1092/G installed.
7.2.1 Rail Transport—The shelter, with payload, shall be
5.12.3 Records—Records shall be maintained of Serial
capable of being transported by railroad. Compliance with
numbersandactualweightofsheltersandshallindicateifEMI
10.16 shall constitute compliance with this requirement.
Kit MK-1092/G is installed.
7.2.2 Lift Transport Simulated—The shelter, with payload,
5.13 Service Integrity—Unless otherwise specified, tests
shall be capable of being suspended by its lifting eyes and
specifiedhereinshallnotresultinanydiscontinuityinthebond
exposed to 3.5 g’s acceleration. Compliance with 10.17 shall
between the aluminum, foam, or wood thermal barriers, or all
constitute compliance with this requirement.
ofthese(thatis,adelamination),orinanybulking,splitting,or
7.3 Drop—The shelter, with payload, shall be capable of
any other deformation or structural weakening, or both of the
being dropped as specified in 10.18. Every shelter subjected to
shelter.Thesealof5.3shallremainintact.Alldimensionsshall
drop tests shall be shipped only to a depot and shall have its
remain in accordance with the drawings listed on DL-SM-B-
nameplate “S-250 Shelter” (with rivnuts) in accordance with
563500 or DL-SM-B-650123. Brackets, lugs, flanges, inserts,
Drawing SC-B-964240 attached with rivets over the shelter
bolts, and any other mounting arrangement shall securely
nameplate,DrawingSM-C-435937(SM-C-650125ifshielded)
retain test loads, doors, and hardware.Any deformation of any
priortoshipment.Shippingdocumentannotated(FORDEPOT
mounting arrangement resulting from any specified test shall
USE ONLY).
bewithindrawingtolerancesandshallnotcausedegradationof
its retaining ability or of specified shelter performance.
7.4 Towing Simulated—The shelter, with payload, shall
withstand a force of a least 2000 lb (900 kg) applied to each of
6. Environmental Requirements
the skid assemblies, and their attachment to the shelter, as
specified in 10.19.
6.1 General—The shelter shall be capable of meeting the
following environmental test requirements with no harmful
7.5 Lifting and Towing Eye Assembly—Each lifting and
effect to any finish or performance capability (see 5.13).
towing eye assembly, as attached to the shelter, shall withstand
6.2 Moisture Resistance—The shelter shall withstand daily a minimum load of 5000 lb (2270 kg) applied in accordance
exposureofupto97 %relativehumidityfor20handexposure with 10.20.
E1974−19
7.6 Steps, Roof Access—Each of the two recessed folding through the impact area and examined. Impact shall not result
steps installed to provide access to the shelter roof shall in rupture to either skin. No delaminations between skin and
withstand a load of 400 lb (180 kg) applied in accordance with core or crushing of core is allowed outside a 3 in. (75 mm)
10.21. radius from the center of impact.
9.4 Fabrication and Assembly—Samples (see 10.1.1) shall
8. Tightness Requirements
be assembled using parts, materials (and their amounts), and
8.1 General—The shelter shall be capable of complying
processes that will be employed in production, be fabricated
with the following:
and assembled in accordance with the specification, and meet
8.2 Torque, Door Latches—Torques shall be measured as all requirements specified herein.
specified on Drawings SM-D-649951 and SM-D-649953 and
9.5 Workmanship—The shelter shall be manufactured with
shall be as specified in 10.22.
the degree of workmanship normally considered appropriate
8.3 Electromagnetic Interference (EMI) Shielding—The for each of the areas listed under 5.0 (see 10.12).
shelter shall be capable of being shielded from electromagnetic
interference (EMI) by the installation of Modification Kit,
10. Tests Required
electromagnetic interference, MK-1092/G in accordance with
10.1 Coupon Samples—Fabricate coupon samples for both
DL-SM-B-649950 and with no other modification. Shielding
adhesive and sealer tests in accordance with the physical
shall provide a minimum attenuation of radiated and induced
properties paragraph of Drawing SM-B-563559. Ten coupons
EMI fields as specified in Specification E1925 within the
are required for each of the five conditions for first article
frequency range of 100 kHz to 10 Ghz when tested in
samples. Five coupons are required for each of the test
accordance with 10.23. Should a shelter subjected to the EMI
conditions for production inspection.
test fail to pass, another shelter from the same lot shall be
10.1.1 Comparability of Fabrication and Cure—Fabricate
subjected to the EMI test.
samples and cure using materials, processes, and conditions
8.4 Construction Tightness—The shelter shall be airtight to
compatible with those used on panels or shelters, or both,
the extent that it shall be capable of achieving and maintaining
including:
a pressurized state without leakage when tested in accordance
10.1.1.1 Surface conditions of and method of preparing
with 10.24.
materials to be bonded,
10.1.1.2 Same batch and type of material,
8.5 Watertightness—The shelter shall be watertight when
10.1.1.3 Duration of, temperature, and pressure during cure,
tested in accordance with 10.25. Shelter weight after testing
10.1.1.4 Minimum cure time before handling, and
shall be as specified in 5.12 after allowing 2 lb (1 kg) for the
test weight mounting hardware of Drawing SM-D-650085, if 10.1.1.5 Time elapsed between application of adhesive to
applicable. the first item (coupon or panel) in a lot to the application of
pressure to the lot of items. Verify two or more part mixes of
8.6 Fording—The shelter, without the use of special fording
adhesive or sealer, or both, as being in accordance with the
kits, shall be capable of being immersed in water to a depth of
manufacturer’s recommendations before shear tests and range
30 in. (760 mm), as measured from the bottom of the shelter
on coupons. Calibrate automatic dispensing machines, when
skids, with no failure of the seal specified in 5.3 or damage to
used to mix or deliver, or both, two or more part adhesive or
the structure when tested and inspected as specified in 10.26.
sealer, or both, at least once every 4 h. Cure sealer coupons at
Shelter weight after testing shall be as specified in 5.12 after
ambient temperature and the lap joint shall be under a pressure
allowing 2 lb (1 kg) for the test weight mounting hardware of
of approximately 5 psi (34 kPa).
Drawing SM-D-650085 if applicable.
10.1.2 Shear Strength Tests—Test coupons after being sub-
8.7 Light Tightness—No direct rays of light shall be visible
jected to the specified exposure, if applicable, and at the
through or around the air inlet louver assembly, as installed in
specified temperature. Stabilize the temperature of the coupons
the shelter and with the weather cover fully open, when tested
at the specified level and measure by a thermocouple attached
in accordance with 10.27.
tothecouponsoverthelapjoint.Thethermocoupleshallnotbe
attached on that side of the lap joint closest to the heat or cold
9. Other Requirements
source nor shall the method of attachment impair the applica-
9.1 First Article—When specified (see 15.2), a sample shall
tion or measurement of the shear force in any way. Apply the
be subjected to first article inspection (see 15.3) in accordance
shear force to destruction with the rate of application constant
with 11.1.
at less than or equal to 1 in./min (25 mm/min). Any noncom-
pliance with 4.2 for adhesive and 4.3 for sealer shall constitute
9.2 Lift and Tie Down Device—A combination lift and tie
down device (sling) conforming to Drawing SM-D-649952 failure of this test.
shall be provided as part of each shelter. Each leg of the device
10.2 Core Material Tests—Subject core material samples to
shall be capable of exceeding a tensile load of 9500 lb (4300
the following tests: for each test a set of five specimens is
kg) as specified on the drawing and shall fail before slippage
required for each type or grade of core material used in the
occurs at the sling sleeves when tested as specified in 10.28.
shelter. Fabricate specimens from actual shelter core material
9.3 Impact Panel—The shelter panels shall withstand the pieces randomly selected from production core material parts.
test of 10.29. After the test, the panel shall be cross sectioned Specimen dimensions shall be within 60.015 in (60.40 mm).
E1974−19
Except for flammability, compliance with 4.4 shall be deter- allowed to fall against the panel. A hammer blow on a
mined by the average of the specimen results, with the lowest laminated area produces a solid or firm or ringing sound
result no less than 90 % of the required value. Failure to meet whereas a delaminated area produces a deadened or hollow or
the requirements of 4.4 shall constitute failure of this test. metallic slap sound. Use the flat end of the hammer for tapping
10.2.1 Apparent Density, Core Material—Test five
into corners. The extent of interrogation of each side of each
specimens, each 2 by 3 by 3 in. (50 by 75 by 75 mm) in panel shall be at least four hammer impacts per square foot of
accordance with Test Method D1622/D1622M.
panel area between members and at least four hammer impacts
10.2.2 Compressive Strength, Core Material—Test five per square foot over members on the interior side of the panel.
specimens each 2 by 3 by 3 in. (50 by 75 by 75 mm) in
Once a suspect area has been located, interrogate said area in
accordance with Procedure A of Test Method D1621, with the detail by at least one hammer impact per inch in all directions.
load applied to the 3 by 3 in. (75 by 75 mm) faces.
The delamination boundaries shall be marked as the point of
10.2.3 Flammability—Determine flame resistance of the
acoustic change (deadening) plus ⁄2 in. (13 mm). Failure to
five specimens, each ⁄2 by 2 by 6 in. (13 by 50 by 150 mm),
meet the requirements of 5.2 shall constitute failure of this test.
in accordance with Appendix F of FAR 25.853. The average
10.3.1 Disposition of Delaminated Panels—Reject all de-
extinguishtimeshallnotexceed15sandaverageburndistance
laminated panels found before assembly into shelter form.
shall not exceed 6 in. (150 mm).
Limit the number of rejected panels per calendar month to 5 %
10.2.4 WaterAbsorption—Testthreespecimens,each6by6
of all panels fabricated during that entire calendar month.
by 3 in. (150 by 150 by 75 mm) in accordance with Test
Rejectedpanelsinexcessofthisamount,eventhoughrepaired,
Method D2842 with the following changes: weigh each speci-
shall not be accepted without the written approval from the
men as it is first submerged; the weighing jig shall also be
purchaser.
weighed at this time; for the final weight, the specimens must
10.3.2 Disposition of Shelters Containing Delaminated
be weighed and removed from the water in reverse order, the
Panels—Reject all shelters found to contain delaminated pan-
water absorption shall be calculated as follows (see Table 1):
els.Limitthenumberofrejectedshelterspercalendarmonthto
2 2 2
lb water/ft 5 W 2 W 2 W 2 W /A 32.048 lb/ft /g/cm (1)
~ ! ~ !
2a 1a 2 3 1.0 % of the total contract quantity with the total no more than
5 % of the total contract quantity. A shelter shall not contain
where:
more than two repaired panels regardless of when it was
W = initial submerged weight of jig and samples (gm)
1a
repaired, that is, before or after use in the shelter. Shelters not
W = initial submerged weight of jig (gm),
2a
complying with these limitations shall only be accepted by
W = final submerged weight of jig (gm),
written approval of the purchaser. Maintain a record of the
W = final submerged weight of jig and samples (gm), and
shelters containing a repaired panel, including which panel,
A = specimen surface area (cm ).
location, and extent, and report as required elsewhere in the
1 1
10.2.5 Shear Strength—Test five specimens, each ⁄2 by 1 ⁄2
contract.
by 6 in. (13 by 38 by 150 mm) in accordance withTest Method
10.3.3 Condition of Shelter Exterior Skins—The exterior
C273/C273M, except that the load shall be applied at a
skin of the shelter panels may contain dents between structural
constant rate such that the maximum load will occur in one
members provided the skin is not punctured and provided the
minute or more.
maximum depth of the dent does not exceed ⁄16 in. (1.5 mm)
10.3 Delamination Testing and Repair—Individual panels
and no more than one shelter in ten contains one dent not
and shelters shall be tested for delaminations by use of the tap
exceeding ⁄8 in. (3 mm) in depth.
hammer (see Fig. 1).Accomplish detection by tapping with the
10.3.4 Delamination Repair:
sphericalendwithaforceequaltothatproducedwhenthehead
10.3.4.1 Document repair procedures for delaminations.
is raised approximately 1 in. (25 mm) above the panel and
The contractor may utilize a procedure only after receiving
approval from the purchaser designated in the contract. The
TABLE 1 First Article Specimens
contractor should be aware and fully understand, however that
Requirements Test
Inspection Quantity
should the purchaser later determine that the procedure is
Subsection Subsection
Adhesive 50 coupons 4.2 10.1 objectionable or inadequate, or its implementation does not
Sealer 50 coupons 4.3 10.1
fulfill its intended purpose, the purchaser may require that its
Core material:
usebediscontinuedandanotherconsultationbeheldtoresolve
Density 5 for every grade or 4.4 10.2.1
type the inadequacy.
Compressive strength 5 for every grade or 4.4 10.2.2
10.3.4.2 The maximum area of any single delamination and
type
Flammability 5 for every grade or 4.4 10.2.3 the maximum number of single delaminations per panel
type
allowedisstatedin5.2.Multipledelaminationsonapanelshall
Water absorption 3 for every grade or 4.4 10.2.4
be separated by a structural member in order for that panel to
type of urethane
Shear strength 5 for every grade or 4.4 10.2.5 be considered eligible for repair.Adelamination on the interior
type
side of a panel and another delamination on the exterior side of
Lift and tie down device 1 complete 9.2 10.28
the same panel and with both delaminations being between the
Impact panel 1 for every type core 9.3 10.29
same two members shall not be considered separated.
E1974−19
TABLE 2 Dimensional Inspection
10.4 Cleaning Inspection—Inspection of the cleaning pro-
cess shall be in accordance with Practice E1773 and SC-B- Inspection Drawing Flatness Required
A
595539. Any noncompliance shall require re-cleaning of the Frame flatness Within 0.03 in.
Torque required:
parts processed since the last acceptable inspection.
Door handle torque SM-D-649953 Small door 10 ft-lb (14 j)
Large door 15 ft-lb (20 j)
10.5 Welding Inspection—Visually inspect arc welding in
Door handle torque SM-D-649951 Small door 20 ft-lb (27 j)
accordance with the requirements of maintenance sampling for
(Shielded shelter) Large door 25 ft-lb (34 j)
production in accordance with MIL-STD-2219. For resistance
Deviation allowed:
B, C D
Shelter flatness SM-D-563754 3 out of 36
welding, fabrication and inspection of production specimens
B, C E, F
Shelter squareness SM-D-563754 6 out of 36
and inspection of production parts shall be in accordance with
A
Flatness of doors and openings at gasket and contact surfaces. This shall be
SAE AMS-W-6858. Failure to meet the requirements of 5.5,
inspected by checking the flatness of the four sides and the flatness at the corners
with sub-paragraphs, shall constitute failure of this test.
using a straight edge. JO-Blocks, dial indicator height gauge or surface plate, or
both. Flatness shall be within 0.030 in. (1 mm) total.
10.6 Riveting Inspection—Examine riveted joints or rivnuts
B
Method of measurement and tolerances with tools and gauges used shall be
for tightness, the joined parts for damage, and for the rivet/
subjected to approval by the purchaser technical activity designated in the
contract.
rivnut heads to be properly seated and tight against their
C
The purchaser technical activity designated in the contract shall be notified by
bearing surfaces. Replace rivets/rivnuts not meeting the re-
the contractor 15 days before this inspection is to be performed.
D
quirements of 5.6 with properly installed rivets/rivnuts and Four deviations out of the 36 interior measurements on any one sample shall be
cause for rejection of the shelter.
then reinspect as specified above.
E
Seven deviations out of the 36 interior measurements on any one sample shall
be cause for rejection of the shelter.
10.7 Moisture Resistance Test—Subject the shelter with
F
More than two deviations in any one corner of the shelter be cause for rejection
doors open to the moisture resistance test of MIL-STD-810E,
of the shelter.
Method 507.3, Procedure II.After cycling has been completed,
thereshallbenoevidenceofdelamination,cracking,corrosion,
or deterioration to any part of the shelter and there shall be no
malfunction of doors, latches, hinges, or any other hardware.
10.12 Visual and Mechanical Inspection—Examine equip-
Failure to meet the requirements of 5.7 and 6.2 shall constitute ment for the requirements of construction (see Section 5).
failure of this test.
Comply with the item requirements listed in MIL-STD-252,
Type 4, 5, 7, 8, 9 and 11 defects only. Further, classify a shelter
10.8 Finish Inspection—Inspect finish in accordance with
weight above the required maximum (see 5.12) as a major
the quality assurance provisions of MIL-F-14072 including
defect.
paint adhesion, and 10.12 of this specification. Failure to meet
the requirements of 5.8 shall constitute failure of this test.
10.13 ShelterWeightTest—Determinecompliancewith5.12
by weighing on a platform beam or dial indicator scale. The
10.9 Marking Inspection—Visually inspect marking to de-
platform of the scale shall be of sufficient extent so as to allow
termine compliance with 5.9. Failure to meet the requirements
the placement of the entire shelter on it. The beam or indicator
of 5.9 shall constitute failure of this test.
shall have 1 lb (60.5 kg) or less graduations. The scale shall
10.10 Interchangeability Inspection—Gauge or measure the
have an accuracy of at least 61lb(60.5 kg) or one-sixth of
dimensions listed below to determine compliance with the
1 % of full scale reading, whichever is smaller. Calibrate the
physical interchangeability requirements of 5.10. When a
scale at least twice per month using standard weights traceable
dimension is not within specified or design limits, it shall be
to the National Institute for Standards and Technology. Failure
considered a defect:
to meet the requirements of 5.12 shall constitute failure of this
10.10.1 Dimension of doors and door openings,
test.
10.10.2 Mounting dimensions of hinges and latches,
10.14 Temperature Test—Place the shelter, with both doors
10.10.3 Size and mounting dimensions of skids,
and the louver cover closed and with the drain hole closed in
10.10.4 Size and mounting dimensions of towing eyes,
a manner acceptable to the purchaser in a temperature con-
10.10.5 Size and mounting dimensions of lifting eyes,
trolled room and subjected to the tests of 10.24.1 and 10.24.2.
10.10.6 Dimensions of drain and drain plug, and
Measure air temperature by ten thermocouples located in
10.10.7 Check padlocks and keys for proper operation.
accordance with Fig. 2. Outside thermocouples shall be pro-
Keys (four) shall be checked against at least three different
vided with radiation shields of aluminum foil between the
padlocks.
thermocouple and radiation surface. Air circulation shall not
10.11 Dimensional Inspection—Inspect the shelters and
exceedavelocityof7milesperhour(11kg/h)at3in.(75mm)
panels for conformance with the drawings in the following
away from any shelter surface. Conduct inspection to deter-
areas (see Footnotes A and B of Table 2):
mine compliance with 5.13 after completion of each test.
10.11.1 Items listed in Table 2,
10.14.1 Operating Temperature—Stabilize the air tempera-
10.11.2 Interior and exterior dimensions,
ture inside and outside the shelter at 120 to 125 °F (49 to
10.11.3 Location and visibility of punch marks for mount- 52 °C)foraperiodof5min,duringwhichtimecheckthedoors
ing members. Verify location at the individual panel stage of
and latches for ease of operation and freedom from binding.
fabrication, and Then subject the exterior of the shelter roof panel to an
10.11.4 Verify locations of holes on painted interior shelter additionalsimulatedsolarloadappliedasrapidlyaspossibleto
panel surfaces at the shelter assembled stage of fabrication. produce a temperature of 195 °F (90 °C) (minimum) on the
E1974−19
outsideskinoftheroofpanelasmeasuredby12thermocouples
located in accordance with Fig. 3. Obtain the simulated solar
load using at least 28 lamps, type 1000T3, 230 volts. Arrange
the lamps in four rows of seven lamps each and operate within
10 %ofratedvoltage.Maintainthe120to125° F(49to52 °C)
ambient air temperature plus the roof solar load for a period of
4 h at which time remove the solar load and increase the air
temperature both inside and outside the shelter to 160–0+
5°F(71–0+3°C)(as measured by the ten thermocouples of
Fig. 2) as rapidly as possible and maintain for 5 min. Then
completely remove the shelter from the heated chamber to an
ambient temperature between 60 and 85 °F (16 and 29 °C).
NOTE 2—The length and position of the thermocouple’s wires shall
permit complete removal. Open the shelter drain hole prior to shelter
removal.
10.14.2 Storage Test—Subject the shelter alternately to
Method 501.4 and Method 502.4 of MIL-STD-810EF, except
perform three cycles of each test (high temperature and low
temperature). The cycles shall range from 160 °F (71 °C) for
the high temperature tests and –80 °F (–62 °C) for low tem-
peraturetests(asmeasuredbythetenthermocouplesofFig.2).
NOTE 1—A = Outside T.C.s approximately 10 in. (250 mm) from
In addition, all doors and latches shall operate freely without
corners.
binding at either temperature extreme.
NOTE 2—B = Inside T.C.s as shown
FIG. 2Thermocouple Location on Sidewalls 10.15 Heat Transfer Test—Placetheshelterinatemperature
controlled room that is at a constant temperature of –40 + 5 °F
A
(–40 + 3 °C) outside the shelter. The walls and ceiling of the
TABLE 3 Sequence of First Article Inspection
chamber shall be a minimum distance of 2 ⁄2 ft (750 mm) from
Inspection Requirements Test
Subsection Subsection
the walls and ceiling of the shelter. Place a 3KW electric coil
Cleaning 5.4 10.4
open frame heater at the center of the shelter floor. Place a
Welding 5.5 10.5
multi-speed 10 or 12 in. (250 or 300 mm) diameter fan 6 in.
Lamination 5.2 10.3
(150 mm) in the back of the heater such as to direct air through
Interchangeability 5.10 10.10
Riveting 5.6 10.6
the heater toward the front of the shelter at an inclined angle of
Construction tightness 8.4 10.24
15 degrees. Maintain a stabilized temperature inside the shelter
Finish 5.8 10.8
Marking 5.9 10.9 of not less than 100 °F (38 °C) above the outside. Air circula-
Dimensional (in accordance with 5.1 10.11
tion shall not exceed a velocity of seven miles per hour (11
stated drawing
kg/h) at 3 in. (75 mm) away from any shelter surface. Stabilize
Visual and mechanical 5.1 10.12
Shelter weight 5.12 10.13 electrical power input and temperatures when the inside and
Door latch torque 8.2 10.22 1
outside groups of thermocouples each vary less than 2 ⁄2 °F
B
Moisture resistance 6.2 10.7
(1.5 °C) while maintaining the minimum differential of 100 °F
Temperature 6.3 10.14
Heat transfer 6.4 10.15
(38 °C) located in accordance with Fig. 2. Temperature and
Rail transport 7.2.1 10.16
electrical power input stabilization for at least 30 min. In the
C
Drops 7.3 10.18
D, E
stabilized condition the electrical power input will equal the
Construction tightness 8.4 10.24
Towing, simulated 7.4 10.19 heat loss. Do not change the rpm of the fan. The power input
Lifting and towing eye pulls 7.5 10.20
to the fan and heater shall be constant during the stabilization
Lift transport, simulated 7.2.2 10.17
period and measured by an ammeter, voltmeter, and wattmeter
Steps, roof access 7.6 10.21
Light tightness 8.7 10.27 in the electrical circuit. Use the power input, the average inside
EMI shielding 8.3 10.23
and outside temperature, and the inside surface area of the
Watertightness 8.5 10.25
shelter in calculating the overall coefficient of heat transfer,
Fording 8.6 10.26
Door latch torque (second time) 8.2 10.22
that shall be no greater than that specified in 6.4. Failure to
A
meet the requirements of 6.4 shall constitute failure of this test.
First article sample testing and shelter testing shall not begin until at least seven
days after the sealer application, including application of touch-up sealer.
B
NOTE 3—To avoid a large pressure differential between the inside and
First article specimen testing shall be completed no later than the end of this test
(see 11.1.1). This inspection shall not begin until at least seven days after final outside of the shelter, a form of pressure relief should be incorporated into
finish application including touch-up paint. the drain hole.
C
See Note 10 of Table 7.
D 10.16 Rail Transport, Impact Test—Load the shelter with a
For correlation data purposes only. CTT (construction tightness test) results are
not to be used as accept/reject criteria for the drop test.
1900 lb (860 kg) load in accordance with Drawing SM-D-
E
Door portion and gasket portion only.
650085 and load on a railroad flat car. Perform the test in
Commercially available from several sources.
E1974−19
NOTE 1—Tolerance 6 ⁄2 in. (13 mm).
FIG. 3Thermocouple Location of Roof
accordance with MIL-STD-810F Procedure VII. Impact test 10.18.1 Flat Drop—Lift the entire shelter 18 in. (460 mm)
the shelter and position in both the longitudinal and lateral anddroponce.Initialcontactshallbealongtheentirelengthof
directions on the flat car. Rail transportability tests shall be both skids.
performed for impacts at
...