Key Design Principles You Need to Know

Modern warfare relies on advanced technology and interconnected systems. These assemblies serve as vital links between components, enabling the efficient transfer of power and data. Robust military wiring is essential for maintaining dependable communication in high-stakes situations, which supports quick decision-making and rapid responses. The failure of just one cable assembly can lead to significant repercussions, potentially undermining the success and safety of military operations.

It’s little wonder then, that military wire harnesses and cable assemblies are specifically designed and manufactured to meet military specifications (Mil-Spec). To achieve military harness durability, you must use cables, wires, connectors, and components that are approved for military use, adhering to rigorous standards. 

Designing Your Military-Vehicle Wire Harness 

Military-grade cable assemblies are specifically designed to endure the harsh conditions of warfare. They need to be tough, weather-resistant, and shielded against electromagnetic interference (EMI) that can disrupt signal integrity. 

Robust military wiring assemblies also feature durable connectors and high-quality insulation materials, ensuring reliable, long-lasting performance in extreme temperatures and demanding environments. You should also integrate strain relief to protect the assembly from mechanical stress. This will give your application a longer life in demanding environments. In general, design your defense vehicle wiring design to incorporate these points: 

Ruggedization

A military-vehicle wire harness must be ruggedized. This means they’re capable of withstanding extreme weather conditions and resistance to electromagnetic interference (EMI). They’re constructed with high-quality connectors and durable insulation materials to ensure superior performance.

Miniaturization

Mil-Spec wiring is engineered for maximum space and weight efficiency. Smaller wires enable the creation of more compact wire looms and a lighter military-vehicle wiring harness. In military applications, these harnesses are designed to be both durable and high-performing, often using bulkhead connectors that – while smaller in military designs – are made to handle the demanding conditions typical of military environments. The focus on miniaturization helps to optimize the use of space and reduce the overall weight of military vehicles, contributing to improved performance and maneuverability in the field.

Protection From Microwave and Radio Frequence (RF)

Armored vehicle electrical systems often feature Teflon wire coating to protect against RF signals and reduce EMI. The use of gold-plated pins also ensures optimal electrical signal transmission.

Ensuing Military Harness Durability

When designing a military-vehicle wire harness, you must give careful consideration to the materials used, environmental resistance, reliability, connector design, cable management, and compliance with industry standards. These factors are crucial for ensuring durability, performance, and safety in demanding operating conditions.

1. Materials

Conductors: Select high-grade materials like tinned copper or silver-plated copper 

for their superior conductivity, corrosion resistance, and high-temperature tolerance.

Insulation: Choose insulation materials like cross-linked polyethylene (XLPE), fluoropolymers (e.g., PTFE), or silicone, which provide superior resistance to heat, chemicals, and abrasion.

Shielding: Incorporate braided shields, foil wraps, or a combination of both to protect against electromagnetic interference (EMI) and radio frequency interference (RFI).

2. Environmental Resistance

Temperature Extremes: Design harnesses to function in both high and 

low-temperature environments, typically ranging from -55°C to +125°C or higher. 

Moisture and Corrosion Resistance: Use materials and coatings that can withstand exposure to water, salt, fuel, and other corrosive agents. The use of sealed connectors and over-molding techniques can enhance moisture resistance. 

Mechanical Stress: Ensure the harness can endure vibration, shock, and mechanical wear. This involves using strain reliefs, protective sheathing, and robust mounting solutions to prevent damage during operation.

3. Reliability in Harsh Environments

Abrasion Protection: Include external sheathing like braided sleeving, convoluted

tubing, or fabric tape to protect against abrasion from rough surfaces.

Flexibility: Design harnesses with flexible sections that allow for movement without 

stress on the wires, particularly in areas prone to frequent bending or movement.

Redundancy: Implement redundant paths for critical systems, ensuring that a failure 

in one wire or connector does not compromise the entire system.

4. Connector and Terminal Design

Robust Connectors: Use connectors that meet military standards (e.g., MIL-DTL-38999), which offer high resistance to environmental factors and secure locking mechanisms.

Gold-Plated Contacts: Employ gold-plated contacts in connectors to ensure low electrical resistance and prevent corrosion.

Sealed Connections: Design connections with seals to prevent ingress of dust, 

moisture, and contaminants, maintaining the integrity of the electrical connection.

5. Cable Routing and Management 

Strategic Routing: Plan cable routes to avoid sharp edges, heat sources, and 

moving parts that could cause wear or damage.

Secure Mounting: Use clamps, ties, and grommets to secure the harnesses and 

prevent movement during vehicle operation, reducing the risk of wear and tear.

Space Optimization: Optimize the routing and bundling of wires to minimize space 

while ensuring accessibility for maintenance and repair.

6. Standards Compliance

Military Standards: Adhere to relevant military standards, such as MIL-STD-810 for 

environmental testing, MIL-STD-461 for electromagnetic compatibility, and 

MIL-STD-1275 for vehicle power supply requirements.

Quality Control: Implement rigorous testing procedures, including continuity tests, insulation resistance tests, and mechanical stress tests, to ensure each harness meets the required specifications.

7. Modularity and Scalability

Modular Design: Develop modular harness designs that allow for easy upgrades or modifications, accommodating new technologies or mission-specific equipment.

Scalability: Ensure the military-vehicle wire harness can be scaled or adapted to different vehicle models or configurations without significant redesign.

Understanding Mil-Spec Wire and Cable 

Mil-Spec wires are distinct because they have specific designations that set them apart from other types of wiring, like high-temperature or hook-up wires. Similar to CSA and UL standards, Mil-Spec wires must meet strict criteria for your military-vehicle wire harness to be considered compliant.

These wires are used for internal wiring in military vehicles, panels, and other electrical equipment. Applications include bonding moving parts, airframe wiring, point-to-point connections, and antenna installations, where durable shielding is needed.

Mil-Spec wiring is particularly suited for high-temperature and medium-wiring installations, offering excellent performance under mechanical stress and in high-frequency applications. It ensures stable electrical characteristics with minimal power loss.

Today, various Mil-Spec standards help differentiate between cable and wire assemblies. Organizations such as SAE, NEMA, and ANSI group these standards, which can guide your selection of materials and construction methods for specific applications. 

When choosing components for robust military wiring, look for the Mil-Spec designation. 

Keep an Eye on Innovations

Advances in technology are driving innovations in armored vehicle electrical systems. Breakthroughs in materials, design methods, and manufacturing techniques are transforming essential components. For example, the use of advanced, lightweight insulation materials is enabling the creation of more efficient and compact cable assemblies. Enhancements in connector technology – such as miniaturization, increased contact densities, and superior signal integrity – are significantly boosting the performance and dependability of military cables.

The future of military cable assemblies promises significant improvements in data transfer speeds, power handling capabilities, and resistance to extreme environmental conditions. The integration of smart technologies, including embedded sensors for real-time monitoring and diagnostics, is poised to enhance the functionality and maintenance of these vital components. Follow future trends in these developments so that you can improve your defense vehicle wiring design to stay competitive. 

Ask us for a free demo 

Arcadia cloud-based software can streamline your design and manufacturing processes for your military-vehicle harness design – from simplifying your schematics and wire-harness designs to testing interfaces to get your build right the first time. To see how you can improve your efficiency and productivity in this demanding industry, we’re happy to give you a free demonstration. If you have any questions, we’re here to help.