MIL-DTL-11891 REV J Jul 2022.pdf

MIL-DTL-11891J(AT)

19 July 2022

SUPERSEDING

MIL-DTL-11891H(AT)

23 March 2020

DETAIL SPECIFICATION

TRACK SHOE SETS, TRACK SHOE ASSEMBLIES, TRACK SHOE PADS

AND TRACK SHOE BUSHINGS, VEHICULAR: ELASTOMERIZED

AMSC N/A FSC 2530

DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.

INCH-POUND

Comments, suggestions, or questions on this document should be addressed to U.S. Army DEVCOM Ground Vehicle Systems Center, ATTN: Standardization, FCDD-GVS-SAT, MS #268, 6501 E. 11 Mile Road, Warren, MI 48397-5000 or emailed to usarmy.detroit.devcom-gvsc.mbx.standardization@army.mil. Since contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at https://assist.dla.mil.

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mailto:usarmy.detroit.devcom-gvsc.mbx.standardization@army.mil mailto:usarmy.detroit.devcom-gvsc.mbx.standardization@army.mil https://assist.dla.mil/ ii

CONTENTS

PARAGRAPH PAGE

1. SCOPE

1.1 Scope

1.2 Classification

1.3 Track systems

2. APPLICABLE DOCUMENTS

2.1 General

2.2 Government drawings

2.3 Non-Government publications

2.4 Order of precedence

3. REQUIREMENTS

3.1 Qualification

3.1.1 Control plan

3.1.2 Materials

3.1.3 Recycled, recovered, environmentally preferable, or biobased materials

3.1.4 Qualified products list

3.1.5 Approval for the rebuild/overhaul of track components

3.2 Phase I, plant/facilities inspection

3.3 Phase II, establishment of contractor’s control plan and compound characteristics ... 5

3.3.1 Qualification hardware fabrication

3.3.2 Test records and compound identification

3.3.3 Track bushing characteristic tests

3.3.4 Track roadwheel path and ground pad performance tests

3.4 Phase III endurance tests

3.4.1 Bushing endurance

3.4.2 Replaceable pad track system qualification

3.4.3 Integral pad track system qualification

3.5 Production requirements

3.5.1 First article

3.5.2 Workmanship

3.5.3 GC mass spec

3.5.4 Pin/bushing design and construction

4. VERIFICATION

4.1 Classification of inspection

4.2 Inspection conditions

4.3 Qualification inspection

4.3.1 Sampling for qualification inspection

4.3.2 On-vehicle-testing

4.3.3 Qualification approval

4.3.4 Retention of qualification

4.4 First article inspection

4.4.1 First article sample

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iii

4.4.2 First article sample approval

4.4.3 Failure

4.5 Product and process control

4.5.1 Control plan

4.5.2 In-process inspection

4.5.3 Conformance inspection (CI)

4.6 Control tests

4.6.1 Control test samples

4.6.2 Control test failure

4.6.3 Additional specimens

4.7 Methods of inspection

4.7.1 Bushings

4.7.2 Track roadwheel path and ground pad

5. PACKAGING

5.1 Packaging

6. NOTES

6.1 Intended use

6.2 Acquisition requirements

6.3 Definitions

6.3.1 Definition of types

6.3.2 Definition of defects

6.3.3 Definitions for process control

6.3.4 Definitions for rubber products

6.4 Code numbers

6.5 Illustrations

6.6 Testing agencies

6.6.1 Subject term (key word) listing

6.7 Qualification

6.7.1 Extension of qualification

6.8 Track cross reference

6.9 Changes from previous issue

6.10 First article

APPENDIX A BUSHING ENDURANCE TEST PLAN

A.1 SCOPE

A.1.1 Scope

A.2 APPLICABLE DOCUMENTS

A.2.1 General A.2.2 Government documents A.2.2.1 Other Government documents, drawings and publications

A.3 REQUIREMENTS

iv

A.3.1 Test site A.3.2 Hardware requirements A.3.3 Test procedures A.3.3.1 Notification A.3.3.2 Inspection of samples A.3.3.3 Bushing sample insertion A.3.3.4 Bushing sample aging A.3.3.5 Thermogravimetric analysis A.3.3.6 Bushing test machines A.3.3.7 Load profile A.3.3.8 Cyclic compression A.3.3.9 Cyclic torsional deflection load A.3.3.10 Testing duration A.3.3.11 Test machine failure A.3.3.12 Qualification requirements A.3.3.13 Test completion A.3.3.14 Sample disposition A.3.4 Monitoring and certification

APPENDIX B T154 TRACK ON-VEHICLE TEST PLAN

B.1 SCOPE

B.1.1 Scope

B.2 APPLICABLE DOCUMENTS

B.2.1 General B.2.2 Government documents B.2.2.1 Other Government documents, drawings and publications

B.3 REQUIREMENTS

B.3.1 Test program review B.3.2 Test site access B.3.3 Test program scope B.3.4 T154 track design characteristics B.3.5 Test course B.3.6 Operational mode summary B.3.6.1 Climatological conditions B.3.7 Track delivery and storage B.3.8 Contractor hardware requirements B.3.8.1 Sample size B.3.9 Initial inspection/preparation for test B.3.9.1 Inspection of track samples B.3.10 Track identification B.3.10.1 Track assembly marking B.3.10.2 Serial pad marking B.3.10.3 Pad installation and coding v

B.3.11 Track shoe installation pattern B.3.12 Load condition B.3.13 Pivoting of vehicles B.3.14 Track tension adjustments B.3.15 Track component replacement B.3.15.1 Hardware torque B.3.16 Torque values B.3.17 Break-In run B.3.17.1 Vehicle operation B.3.17.2 Track cooling B.3.17.3 Visual inspection of track B.3.17.4 Track or pad failures B.3.17.5 Spare track B.3.18 Test procedure B.3.18.1 Fifty mile scenario B.3.18.2 Track switching B.3.19 Inspection and replacement criteria B.3.20 Failure criteria B.3.20.1 Pad sample failure B.3.20.2 Track or pad failures (break-in) B.3.21 Disposition of track test hardware B.3.21.1 Failed track component marking B.3.21.2 Hardware B.3.22 Vehicle disposition B.3.23 Documentation/test reporting/photographic coverage B.3.23.1 Track incidents B.3.24 Final report B.3.25 Photographic coverage B.3.25.1 Applicable information B.3.26 Distribution of reports

APPENDIX C T107 TRACK ON-VEHICLE TEST PLAN

C.1 SCOPE

C.1.1 Scope

C.2 APPLICABLE DOCUMENTS

C.2.1 General C.2.2 Government documents C.2.2.1 Specifications, standards, and handbooks C.2.2.2 Other Government documents, drawings and publications

C.3 REQUIREMENTS

C.3.1 Test program review C.3.2 Test site access C.3.3 Test program scope vi

C.3.4 T107 Track design characteristics C.3.5 Test course C.3.5.1 Operational mode summary C.3.5.2 Climatological conditions C.3.6 Track delivery and storage C.3.7 Contractor hardware requirements C.3.8 Initial inspection/preparation for test C.3.8.1 Track qualification samples C.3.9 Track identification C.3.9.1 Track assembly marking C.3.10 Track shoe installation pattern C.3.11 Load condition C.3.12 Pivoting of vehicles C.3.13 Track tension adjustments C.3.14 Track component replacement C.3.15 Torque values C.3.16 Break-In run C.3.16.1 Vehicle operation C.3.16.2 Track cooling C.3.16.3 Visual inspection C.3.16.4 Track failures C.3.16.5 Spare track C.3.17 Test procedure C.3.17.1 Mission scenarios C.3.17.2 Track switching C.3.18 Inspection and replacement criteria C.3.19 Failure criteria C.3.19.1 Track failure (break-in) C.3.20 Disposition of track test hardware C.3.20.1 Failed track components C.3.20.2 Hardware (failure analysis) C.3.21 Vehicle disposition C.3.22 Documentation/test reporting/photographic coverage C.3.22.1 Track incidents C.3.23 Final report C.3.24 Photographic coverage C.3.24.1 Applicable information C.3.25 Distribution of reports

APPENDIX D T157I PAD ON-VEHICLE TEST PLAN

D.1 SCOPE

D.1.1 Scope

D.2 APPLICABLE DOCUMENTS

D.2.1 General vii

D.2.2 Government documents D.2.2.1 Specifications, standards, and handbooks D.2.2.2 Other Government documents, drawings and publications

D.3 REQUIREMENTS

D.3.1 Test program review D.3.2 Test site access D.3.3 Test program scope D.3.4 T157I design characteristics D.3.5 Test course D.3.6 Operational mode summary D.3.6.1 Fifty mile scenario D.3.7 Climatological conditions D.3.8 Pad delivery and storage D.3.9 Contractor hardware requirements D.3.10 Initial inspection/preparation for test D.3.10.1 Qualification sample inspection D.3.11 Serial marking D.3.12 Pad installation (qualification) D.3.13 Load condition of the vehicle D.3.14 Pivoting of vehicle D.3.15 Track tension adjustments D.3.16 Track component replacement D.3.17 New hardware D.3.17.1 Torque values D.3.18 Break-In run D.3.18.1 Vehicle operation D.3.18.2 Track cooling (break-in) D.3.18.3 Visual inspection (break-in) D.3.18.4 Track pad failure (break-in) D.3.18.5 Spare pads D.3.19 Test procedure D.3.19.1 Track switching D.3.20 Failure criteria D.3.20.1 Pad failure (break-in) D.3.21 Inspection and replacement criteria D.3.21.1 Pad inspection D.3.22 Disposition of pad test hardware D.3.22.1 Failed track pad marking D.3.22.2 Hardware (failure analysis) D.3.23 Vehicle disposition D.3.24 Documentation/test reporting/photographic coverage D.3.24.2 Major track incidents D.3.25 Final report D.3.26 Photographic coverage D.3.26.1 Applicable information viii

D.3.27 Distribution of reports

APPENDIX E T107 TRACK SHOE ELASTOMER AND COMPONENTS FOR USE ON

M88A2 VEHICLES

SCOPE

E.1.1 Scope E.1.2 Classification

APPLICABLE DOCUMENTS

E.2.1 General E.2.2 Government drawings E.2.3 Non-Government publications E.2.4 Order of precedence

REQUIREMENTS

E.3.1 Requirements E.3.2 Phase I, pre-qualification E.3.3 Phase II, plant/facilities inspections E.3.4 Phase III, qualification by on-vehicle endurance testing E.3.5 Phase IV, establishment of contractor’s process control plan and rubber compound characteristics and inspections E.3.5.1 Product and process control plan E.3.5.2 Process parameter controls E.3.5.3 Process parameter selection E.3.5.4 Product characteristic controls E.3.5.5 Product characteristic selection E.3.5.6 Baseline characteristics

VERIFICATION

E.4.1 Classifications of inspections E.4.2 Test records and compound identification E.4.3 Pre-qualification E.4.4 Baseline characteristics E.4.4.1 Roadwheel path and ground pad samples E.4.4.2 Ground pad tests E.4.4.3 Bushing tests E.4.5 First article inspection E.4.5.1 First article sample approval E.4.5.2 Failure E.4.6 Production quality control E.4.6.1 Reduction of production product test frequency through statistical process control…. 101 E.4.6.2 Green component testing E.4.6.3 Finished piece inspection E.4.6.4 Rework (workaway) E.4.6.5 Material weight tolerances ix

E.4.6.6 Vulcanization time, pressure and temperature E.4.6.7 Failures E.4.7 Conformance inspections E.4.7.1 Sampling for conformance inspection E.4.7.2 Lot formation E.4.7.3 Inspection and defects E.4.7.4 Failures E.4.7.5 Packaging and packing

QUALIFICATION

E.5.1 On-vehicle endurance testing E.5.1.1 Drawings E.5.1.2 Test program review E.5.1.3 Test site access E.5.1.4 Test program scope E.5.1.5 Test course E.5.1.6 Operational mode summary E.5.1.7 Break-In run E.5.1.8 Climatological conditions E.5.1.9 Track delivery and storage E.5.1.10 Contractor hardware requirements E.5.1.11 Initial inspection/preparation for test E.5.1.12 Track qualification samples E.5.1.13 Track identification E.5.1.14 Track assembly marking E.5.1.15 Track shoe installation pattern E.5.1.16 Loading condition E.5.1.17 Pivoting of vehicles E.5.1.18 Track tension adjustments E.5.1.19 Track component replacement E.5.1.20 Hardware torque check E.5.1.21 Torque values E.5.1.22 Vehicle operation E.5.1.23 Track cooling E.5.1.24 Track roadwheel path surface E.5.1.25 Speed change cool down E.5.1.26 Visual inspection E.5.1.27 Track failures E.5.1.28 Spare track E.5.1.29 Mission scenarios E.5.1.30 Track switching E.5.1.31 Inspection and replacement criteria E.5.1.32 Track failure during break-in E.5.1.33 Disposition of track test hardware E.5.1.34 Failed track components E.5.1.35 Hardware failure analysis x

E.5.1.36 Vehicle disposition E.5.1.37 Documentation/test reporting/photographic coverage E.5.1.38 Track incidents E.5.1.39 Final report E.5.1.40 Photographic coverage E.5.1.41 Applicable information E.5.1.42 Distribution of reports E.5.1.43 Materials E.5.1.44 Recycled, recovered, environmentally preferable, or biobased materials E.5.1.45 Qualified products list E.5.1.46 Approval for the rebuild/overhaul of track components E.5.2 Inspections and material property characterization E.5.2.1 Disclaimer regarding material property retention after storage or other aging events E.5.2.2 Sample preparation practices E.5.2.3 Hardness, Shore A durometer E.5.2.4 Tensile properties of elastomeric compounds E.5.2.5 Tear resistance of ground pads E.5.2.6 Bushing endurance E.5.2.7 Specific gravity E.5.2.8 After aging tensile properties E.5.2.9 Differential scanning calorimetry E.5.2.10 Thermogravimetric analysis E.5.2.11 Workmanship inspection E.5.2.12 Product marking E.5.2.13 Track pad and roadwheel path adhesion tests E.5.2.14 Ozone resistance testing E.5.2.15 Pin/bushing design and construction inspection E.5.2.16 Bushing adhesion E.5.2.17 Compression set E.5.2.18 Bushing concentricity

NOTES

E.6.1 Intended use E.6.2 Acquisition requirements E.6.3 Definitions E.6.3.1 Definition of defects E.6.3.2 Definitions for process control E.6.3.3 Preparing activity E.6.3.4 Definitions for rubber products E.6.4 Code numbers E.6.5 Testing agencies E.6.6 First article xi

FIGURE PAGE

1. Style B detachable pad test specimen

2. Type II Shoe test specimen

3. Physical property test sample locations

4. Typical location physical property test samples

5. Blow-Out machine

6. T157I detachable pad test specimen

7. Thermo gun A-1. Bushing load profile A-2. Bushing torsional angle B-1. T154 track hardware illustration B-2. Track shoe marking B-3. "Dead Track Block" bushing check B-4. Roadwheel path rubber inspection criteria B-5. End connector inspection criteria B-6. Center guide inspection criteria C-1. T107 track hardware illustration C-2. Track shoe marking C-3. "Hammer Ring" check test C-4. Track shoe assembly C-5. End connector C-6. Center guide C-7. Typical stages of rubber wear on T107 track D-1. T157I track hardware illustration

TABLE PAGE

I. Applicable track systems II. Bushing property tests III. Roadwheel path and ground pad property tests IV. Bushing adhesion V. Classification of inspection and frequencies (bushings).1 VI. Classification of inspections and frequencies (roadwheel path and ground pad).1 VII. Sampling plan for CI.1, 2 VIII. Classification of defects IX. Extension of qualification X. Track cross reference B-I. T154 track break-in run B-II. T154 track hardware inspection and replacement criteria C-I. T107 road test C-II. T107 break-in run C-III. T107 track hardware inspection and replacement criteria D-I. T157I break-in run D-II. T157I track hardware inspection and replacement criteria E-I. Pre-qualification test properties and minimum required values E-II. Final product roadwheel path and ground pad elastomer material property tests E-III. Final product baseline bushing property tests xii

TABLE PAGE

E-IV. First-article roadwheel path and ground pad elastomer material property tests E-V. First-article bushing property tests E-VI. Green component inspections for bushing, roadwheel path and ground pad elastomer E-VII. Finished piece inspections for roadwheel path and ground pad elastomer E-VIII. Sampling plan for CI E-IX. Conformance inspections for roadwheel path and ground pad components E-X. Conformance inspections for bushing components E-XI. Classification of defects E-XII. Individual components E-XIII. Road test block E-XIV. Break-In requirements E- XV. T107 track hardware inspection and corrective actions criteria

This specification is approved for use by U.S. Army Tank-automotive and Armaments Command, Department of the Army, and is available for use by all Departments and Agencies of the Department of Defense (DoD).

1. SCOPE

1.1 Scope. This specification identifies the requirements for qualification and production control of track systems supporting U.S. Military Tracked Vehicles. This specification is intended primarily for the qualification of elastomeric compounds used in the fabrication of track and track components and to ensure that the quality and performance established at qualification is maintained throughout production. The contractor is held fully responsible for the entire assembly/component including all non-elastomeric components and fasteners. The qualified products list (QPL) is divided by individual track components (pads, bushings and roadwheel path/shoe body) listing the contractors qualified to produce the various components, the contractor’s address, and compound identification. The QPL also identifies contractors qualified to assemble the various track components into full assemblies/systems. This includes bushing insertion, pad installation and connecting component (end connectors, center guides) assembly. The track shoe assemblies may be acquired either as sets, assemblies or as individual components (pin bushing assemblies or pads) as specified by the acquiring activity (see 6.1).

1.2 Classification. The track shoe assemblies or components to be procured in accordance with this specification are of the following types and styles:

Type I ................................. Single-pin track shoe Style A ................................... Integral pad Style B.................................... Replaceable pad

Type II ................................ Double-pin track shoe

Style A ................................ .Integral pad Style B.................................. Replaceable pad

Type III ................................ Bushing assemblies

1.3 Track systems. Applicable track systems are designated in table I.

TABLE I. Applicable track systems.

Designation Type/style Technical data package number

T107 (see note 2) II / A 8705914 T107 (see note 3) II / A 12694350 T130E1 I / B 11677988 T132E1 I / B 10934639

T136 II / B 10954051

T138 I / A 10948405 T142 (see note 1) II / B 11645125

T144 II / A 10892811

T150 II / B 12474844

T154 II / B 12268550

T154M (see note 6) II / B 12556910 T157I I / B 12359466 T158LL (see note 4) II / B 12387880 T161 (see note 5) II / B 12496800 T164 I / B 12352500

NOTES:

1. The T142 track block elastomer must be produced in accordance with Drawing 11645127 Block, Track and is exempt from the requirements of this specification except where noted on the drawing.

2. For M88A1 legacy applications only, see Appendix C (not for new procurement).

3. For M88A1 and M88A2 new track procurements, see Appendix E.

4. The T158LL track elastomers must be produced in accordance with Drawings 12348368 Pad

Track Rubberized, 12387878 Block, Track, Rubberized, and 12348382 Pin, Rubberized and is exempt from the requirements of this specification except where noted on the drawing.

5. The T161 track elastomers must be produced in accordance with Drawings 12496785 Pad Assembly Molded Track, 12496792 Block, Assembly Molded Track, and 12496790 Pin, Assembly Molded Track and is exempt from the requirements of this specification except where noted on the drawing.

6. The T154M track elastomers must be produced in accordance with Drawings 12556915 Pad, Track, and 12556913 T154M Pin, Molded and is exempt from the requirements of this specification except where noted on the drawing.

2. APPLICABLE DOCUMENTS

2.1 General. The documents listed in this section are specified in sections 3 and 4 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirement documents cited in sections 3 and 4 of this specification, whether or not they are listed.

2.2 Government drawings. Technical data package (TDP) drawings for the track system or component to be procured will be provided as a part of the invitation for bid.

2.3 Non-Government publications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract.

ASTM INTERNATIONAL

ASTM D395 - Standard Test Methods for

Rubber Property - Compression Set.

ASTM D412 - Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers - Tension.

ASTM D429 - Standard Test Methods for Rubber Property - Adhesion to Rigid Substrates.

ASTM D573 - Standard Test Method for Rubber - Deterioration in an Air Oven.

ASTM D792 - Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement.

ASTM D1149 - Standard Test Methods for Rubber Deterioration – Cracking in an Ozone Controlled Environment.

ASTM D1566 - Standard Terminology Relating to Rubber.

ASTM D2084 - Standard Test Method for Rubber Property -

Vulcanization Using Oscillating Disk Cure Meter.

ASTM D2137 - Standard Test Methods for Rubber Property – Brittleness Point of Flexible Polymers and Coated Fabrics.

ASTM D2240 - Standard Test Method for Rubber Property

– Durometer Hardness.

ASTM D3182 - Standard Practice for Rubber - Materials, Equipment, and Procedures for Mixing Standard Compounds and Preparing Standard Vulcanized Sheets.

ASTM D3183 - Standard Practice for Rubber - Preparation of Pieces for Test Purposes from Products.

ASTM E1131 - Standard Test Method for Compositional Analysis by Thermogravimetry.

(Copies of these documents are available online at www.astm.org.)

2.4 Order of precedence. Unless otherwise noted herein or in the contract, in the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.

http://www.astm.org/

3. REQUIREMENTS

3.1 Qualification. Track shoe assemblies, track shoe pads, and track shoe bushings furnished under this specification shall be products which have been tested and have passed the qualification tests specified herein. The qualification process is divided into three phases as defined in section 3 of this specification: Phase I, Plant/Facilities Inspections; Phase II, Establishment of Contractor's Control Plan and Compound Characteristics; and Phase III, Endurance Tests. The procedures and requirements of these phases must be successfully completed and all requirements met prior to a contractor becoming qualified for listing on the QPL. Section 4 of this specification establishes the quality control requirements based on section 3 as applicable to track all procurement contracts.

3.1.1 Control plan. The contractor shall provide a control plan (see 4.5.1) addressing the requirements of this specification that identifies how the contractor intends to conform to this specification. This plan will require Government approval and will be included as part of the qualification process. This plan shall be submitted to the Quality Assurance Representative (QAR) and Preparing Activity for review and approval. This control plan should be general in nature, identifying the contractor's capability in conforming to the requirements of this specification and should not contain proprietary information. This plan should identify subcontractor control requirements in compliance to this specification as related to rubber.

3.1.2 Materials. The materials used in the production of shoes, pads, bushings and assemblies shall meet the requirements of this specification and be in accordance with the applicable drawings of the track TDPs.

3.1.3 Recycled, recovered, environmentally preferable or biobased materials. Recycled, recovered, environmentally preferable or biobased materials should be used to the maximum extent possible provided that the material meets or exceeds the operational and maintenance requirements, and promotes economically advantageous life cycle costs.

3.1.4 Qualified products list. Type I and type II track shoe assemblies, track shoe sets, track shoe pads, and type III bushings furnished under this specification shall be products which are qualified for listing on the applicable qualified products list at the time set for opening of bids.

Qualification for all systems/components includes the contractor’s plan, all materials, processes, tests, facilities, and assembly, as applicable, of these systems or components. The contractor is responsible for the entire component/assembly being submitted for qualification and subsequent production including all metal parts and fasteners.

3.1.5 Approval for the rebuild/overhaul of track components. Contractors/military depots which desire to obtain approval for the rebuild of track or track components covered by this specification must utilize this specification in conjunction with the current Depot Maintenance Work Requirement (DMWR) for single pin and double pin track used on military vehicles. This specification should be used to specify requirements for rubber and rubber processing. The DMWR should address the quality of the rebuilt/overhaul metal components.

3.2 Phase I, plant/facilities inspection. Defense Standardization and Specification Program

SD-6, “Provisions Governing Qualification (Qualified Products Lists)” and DOD 4120.24, “Defense Standardization Program Policies and Procedures”, authorizes the preparing activity or its authorized agent to conduct plant/facility inspections prior to the start of any qualification testing.

Subcontractors that provide uncured rubber for processing by the contractor requesting qualification shall be subjected to the same inspection and test requirements on that portion of the product/process that is within the subcontractor's purview.

3.3 Phase II, establishment of contractor’s control plan and compound characteristics.

Prior to the start of qualification hardware fabrication, the contractor shall establish a Process Fingerprint Plan (see table II and table III, and 4.5.2.4) that describes the entire process used to produce the qualification hardware. This plan shall identify the target values and ranges (limits/tolerances) the contractor expects during qualification hardware fabrication. This plan shall address all the requirements of this specification and adequately describe the process and product supplied for qualification. This plan shall bear the signatures of the Government QAR and an authorized representative of the contractor. This plan shall remain at the contractor's facility but be made available for review by the preparing activity or its authorized agent. This information shall not be disclosed in whole or in part for any purpose other than to evaluate the product submitted for qualification testing.

TABLE II. Bushing property tests.

Test requirements ASTM Specification paragraph Tolerance(see note 1)

Specified gravity D792 3.3.3.2 ±0.020 Hardness D2240 3.3.3.3 ±5 pts Tensile strength D412 3.3.3.4 ±16% Tensile strength (aged) D573 3.3.3.5 ±30% (Change) Ultimate elongation D412 3.3.3.4 ±15% Ultimate elongation (aged) D573 3.3.3.5 ±40% (Change) Tensile stress (modules) @ 200% strain D412 3.3.3.4 ±17%

Thermogravimetric analysis E1131 3.3.3.6 3.3.3.6 Vulcanization using oscillating disk cure meter D2084 3.3.3.7 3.3.3.7

Adhesion D429 3.3.3.8 3.5.4.2 Compression set D395 3.3.3.9 ±0% Brittleness point of flexible polymers D2137 3.3.3.10 ACPT/REJ

GC mass spec None 3.3.3.11 3.5.3

NOTE:

1. The contractor shall provide all test results of all lots of elastomeric materials used in the preparation of all qualification hardware when tested to the requirements of this table. During production, the contractor will be required to maintain the production values within the tolerances specified in this table.

3.3.1 Qualification hardware fabrication. The fabrication of the qualification hardware shall be in accordance with the approved Process Fingerprint Plan (see 3.3). All testing must be conducted in the presence of a government inspector or its authorized agent, signed off for conformance to the requirements and dated. This plan and test data generated during the fabrication of elastomeric components for qualification will be used by the Government as a measure of conformance/performance in future production contracts (see 3.4.1.2) and will remain proprietary to the contractor. All records/test results of all lots of elastomeric materials used in the preparation of all qualification hardware shall be made available to the Government QAR upon request. This information shall not be disclosed in whole or in part for any purpose other than to evaluate the product submitted for qualification testing. The Government reserves the right to conduct these tests at any time to ensure compounds in production are in conformance to the data established during qualification.

3.3.2 Test records and compound identification. All test records must contain at a minimum, the compound identification and source, test results, test facility identification, dates of tests, and name of tester. These records must be signed and dated by the Government QAR or authorized agent. The contractor will identify the method to be used during qualification and utilize the same method during subsequent production testing. Compound numbers must be identified to the component being qualified, for example bushing compound xxxxx, ground pad compound yyyyy and roadwheel path compound zzzzz, and fully identified on the applicable test records/data sheets. Any record, data sheet or certification lacking proper identification, or one that does not contain clear and concise information will not be considered in compliance to these requirements and rejected.

3.3.3 Track bushing characteristic tests. Table II has been established in order to identify the compound performance characteristics/properties being provided for qualification for future reference and production control purposes, pending successful qualification. Table II identifies the requirements for establishing the characteristics of the bushing compound(s). These tests will be performed during the fabrication of the T130E1 long bushings (P/N 11678029) required for qualification and in accordance with the requirements established in Appendix A.

3.3.3.1 Specimen preparation. Specimens shall be prepared in accordance with the applicable ASTM and shall be of an equivalent state of cure to that of the bushings submitted for endurance testing. The following tests will be performed on samples taken at the final mixing of the compound (see 4.3.1.1) and be of an equivalent state of cure as bushings submitted for qualification: specific gravity, hardness, tensile strength, elongation, tensile stress, aged properties, brittleness point, cure meter, thermogravimetric analysis (TGA), load deflection, compression set and G/C mass spec. The following tests shall be performed on vulcanized samples: hardness, adhesion, and bushing endurance (see 4.3.1.2).

3.3.3.2 Specific gravity. Specific gravity tests will be performed on the bushing compounds subject to qualification test in accordance with ASTM D792. Specific gravity tests will be performed on 3 samples from each compound submitted for qualification and all results will be provided to the Government. Samples shall be taken from unvulcanized compounds at the final mixing stage (see 4.7.1.1).

3.3.3.3 Hardness – durometer. Hardness tests will be performed on laboratory specimens from bushing compounds subject to qualification in accordance with ASTM D2240. Hardness tests shall be conducted on 3 samples each of the unvulcanized compounds taken from the final mixing stage as well as 3 samples of the vulcanized finished components. All data generated as the results of these two tests shall be reported to the Government. The production tolerance for hardness will be ±5 from the average value established at qualification (see 4.7.1.2).

3.3.3.4 Physical properties of bushing compounds. Physical property tests will be conducted on each compound submitted for bushing qualification in accordance with ASTM D412.

All test results will be reported to the Government. For production of qualified bushing compounds, the adjusted value established following qualification tests (3.4.1.2), shall be held to the following tolerances: ±16% for tensile strength, ±15% ultimate elongation, ±17% for 200% modulus (see 4.7.1.3, 4.7.1.5, and 4.7.1.7).

3.3.3.5 Aged physical properties. Aged physical property tests will be performed on specimens taken from bushing compounds in accordance with ASTM D573. Accelerated aging shall be conducted for 166±2 hours at 158±3.6 °F or 70 to 72 hours at 212±3.6 °F. All test results will be reported to the Government. The tolerance for the percent change of unaged tensile strength to aged tensile strength will not exceed 30 percent during production. The tolerance for the percent change of the unaged elongation to the aged elongation will not exceed 40 percent during production (see 4.7.1.4 and 4.7.1.6).

3.3.3.6 Thermogravimetric analysis. This test will be performed in accordance with

ASTM E1131 during qualification to establish requirements for future reference during process control. All test results will be reported to the Government. The ranges for TGA are as follows (see 4.7.1.8):

a. Plasticizer + Residue: ±3%

b. Polymer: ±5%

c. Filler: ±5%

3.3.3.7 Vulcanization using oscillating disk cure meter. A curing characteristics curve

(trace) shall be obtained as outlined in ASTM D2084 on the bushing compound being submitted for qualification. The traces will be provided to the Government. The following tolerances will be used in production when compared to the charts representing traces of compounds used for fabrication of components for qualification. Parameter definitions shall be according to ASTM D2084. Alternative test methods and parameter may be used but must be identified in the control plan and approved by the Preparing Activity (see 4.7.1.9).

a. Minimum torque (M): ±2 pound-inch (lb-in) [±0.23 Newton-meter (N-m)]

b. Maximum torque (M): ±4 lb-in (±0.45 N-m)

c. Time to 60 percent of M: T(60) ± 0.4 minutes

d. Time to reach 5 lb-in (0.57 N-m) above minimum torque: ±0.4 minutes

3.3.3.8 Bushing adhesion test. Testing apparatus shall conform to ASTM D429, method

B. A hub and spindle assembly is required for mounting the bushing insert (P/N 87565l9) that shall permit full rotation about a fixed axis. Three complete bushing assemblies (P/N 11678029) shall be selected as the test samples and be of an equivalent state of cure to that of the bushings submitted for endurance test. Testing shall be conducted on the outer rings of the bushing assembly (see 4.7.1.10).

3.3.3.8.1 Sample preparation. The bushings shall be prepared for testing by cutting the rubber rings transversely down to the metal insert and separating circumferentially for a distance sufficient to permit a firm grip by the free end of the power-actuated clamp. Injection molded bushings shall be cut on the sprue side (injection side) to ensure discontinuity (non-knit) of the elastomer is checked.

3.3.3.8.2 Procedure. The bushing shall be mounted on the pin in the hub and spindle assembly with the free end of the rubber firmly gripped by the machine clamp. The machine shall be started and the rubber pulled circumferentially from the sleeve/insert. In the event the elastomer is about to tear off, specimens should be cut back to the metal. Force measurements shall be recorded and observations made throughout the test to determine the minimum load required to separate the rubber from the metal/adhesive interface or from the rubber itself.

3.3.3.8.3 Acceptance. Successful adhesions will be those that result in a separation in the rubber (rubber tear) without evidence of separation in the rubber-to-metal interface. The bond between metal and all bonding agents/cements shall be higher than the bushing rubber so that separation during adhesion occurs only in the rubber. The load required to separate the rings from the pin shall be not less than that shown in 3.5.4.2. For T130El bushing qualification, a minimum of 29 pounds per inch of width is required. The elastomer pulled off the sleeve and that remaining shall be examined for any defects including cracks, blisters, or porosity. Discontinuity (non-knit) of the elastomer resulting in any indication of separation of the elastomer shall be cause for rejection.

All test results shall be reported to the Government.

3.3.3.9 Compression set. The bushing laboratory specimen shall be subjected to the compression set test of method B of ASTM D395 for 22±0.5 hours at a temperature of 158±3.6 °F using type 1 specimens. Five specimens shall be tested with the average results reported in accordance with ASTM D395. The compression set shall not exceed 25 percent and all data shall be reported to the Government (see 4.7.1.11).

3.3.3.10 Brittleness point of flexible polymers. The specimens and test method shall be in accordance with ASTM D2137. Specimens shall be type B of method A and tested at a temperature of -40±3.6 °F in accordance with method A of ASTM D2137. Five specimens shall be tested and inspected showing no evidence of cracks, fissures, or pinholes. In the event one specimen fails, an additional five specimens shall be prepared and tested. Failure of two or more of the initial five specimens, or any of the last five specimens, shall be cause for rejection. Test results shall be reported to the Government (see 4.7.1.12).

3.3.3.11 GC mass spec. The Government may perform spot inspections for the purpose of obtaining samples for pyrolysis-gas chromatography/mass spectrometry analysis. Up to five samples may be taken at any time during a production contract. Samples will be taken from end item cured parts. The initial part of the method will thermally desorb the additives, which are then analyzed by gas chromatography/mass spectrometry. Following desorption of the additives, the remaining sample will be pyrolyzed and analyzed by gas chromatography/mass spectrometry. A baseline scan will be performed on the material submitted for qualification. Future results will be compared with the baseline to determine that there are no new peaks appearing, no ingredients missing and no substitutions in subsequent production runs (see 4.7.1.13).

3.3.4 Track roadwheel path and ground pad performance tests. All material property tests indicated in table III for the track roadwheel path and ground side pads (integral and replaceable) shall be conducted in accordance with the referenced ASTM's, the Process Fingerprint Plan (see 3.3) and in accordance with the requirements of this specification. The following tests will be performed on qualification samples taken on unvulcanized samples at the final mixing of the compound (see 4.3.1.3) and be of an equivalent state of cure as compounds being submitted for qualification: specific gravity, hardness, tensile strength, elongation, tensile stress, aged properties, brittleness point, cure meter; ozone resistance, TGA, GC mass spec. The following tests will be performed on qualification samples taken on vulcanized samples: hardness, tensile strength, elongation, tensile stress, aged properties, ozone resistance, adhesion, and blow-out (see 4.3.1.4).

3.3.4.1 Specific gravity. Specific gravity tests will be performed on the pad (integral and replaceable) and roadwheel path compounds subject to qualification test in accordance with ASTM D792. Specific gravity tests will be performed on a minimum of 3 samples from each compound submitted for qualification and all results provided to the Government. Samples shall be taken from unvulcanized compounds at the final mixing stage (see 4.7.2.1).

3.3.4.2 Hardness – durometer. Hardness tests will be performed on laboratory specimens of pads (integral and replaceable) and roadwheel path compounds subject to qualification in accordance with ASTM D2240. As a minimum, hardness tests shall be conducted on 3 samples each of the unvulcanized compounds taken from the final mixing stage as well as 3 samples of the finished components. The results of all tests shall be provided to the Government (see 4.7.2.2).

3.3.4.3 Physical properties of pad and roadwheel path compounds. Physical property tests, as a minimum, will be conducted on specimens taken from each compound used in the pads (integral and replaceable) and roadwheel path in accordance with ASTM D412, table III, and figure 1 through figure 4. The three specimens for the style B (Tl54) ground pad shall be taken as shown in figure 1. The three specimens for the style B (T154) roadwheel path shall be taken as shown in figure 2. The three specimens for the style A (Tl07) ground pad shall be taken as shown in figure 3. The three specimens for the style A (Tl07) roadwheel path shall be taken as shown in figure 4. The three specimens for the style B (T157I) ground pad shall be taken as shown in figure 6. All test results will be reported to the Government. The production tolerance for the physical property tests based on the average values established during qualification tests will be ±15% for tensile strength, ±15% ultimate elongation, and ±15% for 200% modulus (see 4.7.2.3, 4.7.2.5, and 4.7.2.7).

TABLE III. Roadwheel path and ground pad property tests.

Test requirement ASTM test method

Specification paragraph Tolerance (see note)

Specific gravity D792 3.3.4.1 ±0.020 Hardness D2240 3.3.4.2 ±5 pts

Tensile strength D412 3.3.4.3 ±15% Tensile strength (aged) D573 3.3.4.4 ±30% (Change)

Ultimate elongation D412 3.3.4.3 ±15% Ultimate elongation

(aged) D573 3.3.4.4 ±40% (Change)

Tensile stress (modulus) @ 200% strain D412 3.3.4.3 ±15%

Thermogravimetric analysis E1131 3.3.4.5 3.3.4.5

Vulcanization using oscillating disk cure meter

D2084

3.3.4.6

3.3.4.6

Adhesion style A & B ground side pads D429 3.3.4.7 ±0%

Adhesion type I & II (roadwheel path) D429 3.3.4.7 ±0%

Ozone resistance D1149 3.3.4.8 ACPT/REJ Ozone resistance None 3.3.4.9 ACPT/REJ

Brittleness point of flexible polymers D2137 3.3.4.10 ACPT/REJ

GC mass spec None 3.3.4.11 3.5.3 Blowout test style A None 3.3.4.12 ACPT/REJ

NOTE: The contractor shall provide all test results of all lots of elastomeric materials used in the preparation of all qualification hardware when tested to the requirements of this table. During production, the contractor will be required to maintain the production values within the tolerances specified in this table.

3.3.4.4 After age physical properties. Physical property tests, as a minimum, will be conducted on 3 aged specimens taken from each compound used in the pads (integral and replaceable) and roadwheel path in accordance with ASTM D573, table III, and figure 1 through figure 4. Three specimens for each test are required and all results will be reported to the Government. Accelerated aging shall be conducted for 166±2 hours at 158±3.60 °F or 70 to 72 hours at 212±3.60 °F. The production tolerance for the percent change of unaged tensile strength (see 3.3.4.3) to aged tensile strength will not exceed ±30 percent. The tolerance for the percent change of the unaged elongation (see 3.3.4.3) to the aged elongation will not exceed ±40 percent (see 4.7.2.4 and 4.7.2.6).

3.3.4.5 Thermogravimetric analysis. This test will be performed in accordance with ASTM E1131 during qualification to establish requirements for future reference during production.

Results of the TGA will be provided to the Government. The ranges for TGA are as follows (see 4.7.2.8):

a. Plasticizer + Residue: ±3%

b. Polymer: ±5%

c. Filler: ±5%

3.3.4.6 Test measurements with oscillating disk cure meter. A curing characteristics curve (trace) shall be obtained as outlined in ASTM D2084 on the compounds used in the pad (integral and replaceable) and roadwheel path of the track being submitted for qualification. The traces will be provided to the Government. The following tolerances will be used in production when compared to the charts representing traces of compounds used for fabrication of components for qualification. Parameter definitions shall be according to ASTM D2084. Alternative test methods and parameters may be used but must be identified in the control plan and approved by the Preparing Activity (see 4.7.2.9).

a. Minimum torque (M): ±2 lb-in (0.23 N-m)

b. Maximum torque (M): ±4 lb-in (0.45 N-m)

c. Time to 60 percent of M: T(60) ±0.4 minutes

d. Time to reach 5 lb-in (0.57 N-m) above minimum torque: ±0.4 minutes

3.3.4.7 Track pad and roadwheel path adhesion test. Adhesion tests will be conducted on the finished products of the track systems being submitted for qualification. As a minimum, two representative samples of the ground pad (integral and replaceable) and two representative samples of the roadwheel path elastomer are required for the adhesion tests. One test specimen from each component shall be prepared for test in accordance with 3.3.4.7.1 using the test apparatus of ASTM D429, method B (see 4.7.2.10).

3.3.4.7.1 Sample preparation. The samples shall be prepared in the location as shown in figure 1 through figure 4. The elastomer shall be cut down to the base metal along two parallel lines, leaving an elastomer strip 1±1/16 inch in width, 1/2 to 1 inch in thickness, with length extending in the direction of maximum adhesive area. The elastomeric thickness shall be as uniform as practical of the thickness shown in the respective figures for the component under test. When necessary, the portion of the elastomer remaining outside of the 1-inch wide section of the cut strip shall be removed from the metal base to avoid any edge constraint during the test. The elastomer shall be stripped from the metal using a sharp knife for a sufficient distance to permit firm gripping of the tab in the grip of the test machine head.

3.3.4.7.2 Procedure. The metal base of the specimen shall be mounted to one head of the testing machine using care in centering and adjustment so that the tension shall be uniformly distributed across the strip width. The machine shall then be started and, when the applied force causes the elastomer to begin separating from the metal, the recorder shall be started. Force shall continue to be applied and recorded continuously throughout the test. The point of separation of the elastomer from the metal shall be observed carefully throughout the test. In the event that tearing up into the elastomer occurs, the specimen should be cut back to the metal without stopping the machine.

3.3.4.7.3 Acceptance. The roadwheel path adhesion shall not be less than 60 pounds per inch of width and the pad adhesion shall not be less than 120 pounds per inch of width. Successful adhesions will be those that result in a separation in the rubber (rubber tear) without evidence of separation in the rubber-to-metal interface. The bond between metal and all bonding agents/cements shall be higher than the component compound so that separation during adhesion tests occurs only in the rubber. The elastomer pulled off the metal plate/shoe body and that remaining shall be examined for any defects including cracks, blisters, or porosity. Discontinuity (non-knit) of the elastomer resulting in any indication of separation of the elastomer shall be cause for rejection. All data generated during this test will be provided to the Government.

3.3.4.8 Ozone resistance. Prepare specimens in accordance with Method B, Procedure B2 of ASTM D1149. The specimens shall be smoothly finished in accordance with ASTM D3182 and ASTM D3183 and obtained from either of the following (see 4.7.2.11):

a. Three samples each shall be taken from each compound used on the track roadwheel path and ground pad (integral and replaceable) and shall not include any outer surface.

b. Samples may be taken from each uncured compound production molding blanks, prepared in the form of ASTM tensile slabs, and certified as being of an equivalent state of cure as the production molded component (roadwheel path stock and ground pad).

3.3.4.8.1 Procedure. Specimens shall be tested in accordance with ASTM D1149 and mounted in accordance with Method B, Procedure B2 of ASTM D1149, except the length of the clamping strips shall be such as to facilitate placement within the ozone chamber. Specimens shall then be placed in the chamber and exposed for 7 days at a temperature of 104±3.6 °F having a partial pressure of ozone of 50 millipascals. The specimens shall show no evidence of cracks when inspected at seven power magnification. Test results will be reported to the Government.

3.3.4.9 Optional ozone test procedure. As an option, the following procedures may be used in place of the above to accommodate the ozone test requirement (see 4.7.2.11).

3.3.4.9.1 Specimen preparation. The size of the specimens shall be in accordance with Method B, Procedure B2 of ASTM D1149, except the thickness shall be 0.080±0.005 inch.

Specimens shall be obtained from either of the following:

a. Three specimens shall be taken from the track block chevron and shall not include any outer surface.

b. Three specimens shall be taken from production molding blanks of uncured rubber compounds, being used to rubberize track components, prepared in the form of tensile slabs and certified as being of an equivalent state of cure as the production molding.

3.3.4.9.2 Procedure. The specimen shall be tested in accordance with Method B, Procedure B2 of ASTM D1149, except the length of the clamping strips shall be such as to facilitate placement within the ozone chamber. Specimens shall then be placed in the chamber and exposed for 7 days at a temperature of 100±2 °F in an air-ozone mixture containing 50±5 parts by volume of ozone per hundred million parts of air. The specimen surfaces shall be finished smoothly and of uniform thickness in accordance with part C of ASTM D3182. The rubber materials shall have no evidence of cracks when inspected at 7 power magnification at the end of 7 days.

3.3.4.10 Brittleness point of flexible polymers. The specimens and test method shall be in accordance with ASTM D2137. Specimens shall be type B of method A and tested at a temperature of -40±3.6 °F in accordance with method A of ASTM D2137. Five specimens shall be tested and inspected showing no evidence of cracks, fissures, or pinholes. In the event one specimen fails, an additional five specimens shall be prepared and tested. Failure of two or more of the initial five specimens, or any of the last five specimens, shall be cause for rejection. Test results shall be reported to the Government (see 4.7.2.12).

3.3.4.11 GC mass spec. The Government may perform spot inspections for the purpose of obtaining samples for…