APPARATUS: THE SHOPS
Fire apparatus safety has significantly evolved over the years, driven by advancements in technology, engineering, and firefighter safety standards.
Early in my fire service career, we rode on the back step and stood in open jump seat areas—neither of which had seat belts. The only secured position was the driver’s seat, equipped with nothing more than a lap belt. Believe it or not, our warning light system consisted of a single rotating beacon on the roof. Looking back on those so-called “good old days,” it’s clear that we operated with minimal regard for safety compared to today’s enhancements.
As my career progressed, so did our focus, shifting toward safety and survival. Today, fire apparatus and crew safety are paramount in emergency response operations. Given the inherently hazardous nature of firefighting, it is crucial that fire apparatus are designed, maintained, and operated with safety as the top priority.
Safety features on fire apparatus play a crucial role in the work of emergency vehicle technicians (EVTs). As an EVT, understanding, maintaining, and troubleshooting these systems is essential to ensuring the safety of both fire personnel and technicians. With evolving standards, advanced electronics, and increasingly complex operating systems, it is imperative that EVTs receive regular training to stay current with the latest fire apparatus technologies.
Repairing and diagnosing issues with safety features on fire apparatus require a systematic approach, specialized knowledge, and adherence to National Fire Protection Association (NFPA) standards.
Following are key points for performing a systematic diagnosis on safety features.
Conduct a visual inspection. Check for damaged wiring, loose connections, or blown fuses in safety-related electrical systems. Inspect hydraulic, air, and mechanical systems for leaks or wear and ensure safety labels and indicators are intact and readable.
Use diagnostic tools by connecting to the onboard diagnostic system (OBD-II or J1939 CAN bus). Use manufacturer-specific diagnostic software. And, perform manual sensor and switch tests (seat belt sensors, door switches, etc.).
Verify electrical and sensor operations. Check for fault codes related to safety features. Use a multimeter to check voltage and continuity in circuits. Do not stick probes in wires—this will lead to bigger issues. Test relays, solenoids, and actuators involved in safety functions.
Be sure to test safety systems in a controlled environment. Perform air brake tests according to NFPA 1910, Standard for the Inspection, Maintenance, Refurbishment, Testing, and Retirement of In-Service Emergency Vehicles and Marine Firefighting Vessels. For lighting and warning systems, verify flash patterns, siren operation, and dashboard indicators. For seat belt and occupant safety systems, check proper engagement and alarms. Finally, for aerial devices and interlocks, confirm proper engagement sequences.
SRS WIRING ON FIRE APPARATUS
When diagnosing and repairing safety systems, it’s crucial to recognize supplemental restraint system (SRS) wiring, as accidental air bag deployment can be dangerous. Look for yellow loom or tape. Many manufacturers use yellow sheathing or tape to mark air bag-related wiring. Air bag system connectors are often yellow for easy identification. In some cases, SRS wiring may be integrated into a broader harness and not distinctly marked.
When handling SRS wiring, always disconnect the battery and wait according to manufacturer guidelines before servicing SRS components. Never probe SRS wiring with a multimeter; this could trigger deployment. Follow manufacturer repair procedures to