Introduction

Energy is defined as the ability to do work. Total energy includes potential and kinetic energy or a combination of the two. Uncontrolled energy can be hazardous and has the potential to cause injury or death.

Hazardous energy (any energy that could cause harm to a worker and/or damage to equipment) can take various forms, including: 

Kinetic energy of moving mechanical parts. Potential energy stored in vessels, tanks, hydraulic (fluid) or pneumatic (air) systems, and springs, including gravitational energy and suspended weight, which can be released as hazardous kinetic energy. Electrical energy from generated electrical power or stored in electrical storage devices such as capacitors or batteries. Thermal energy including both high and low temperatures (i.e., from steam) and resulting from mechanical work, radiation, chemical reaction, or electrical resistance. Chemical (flammable or reactive) and nuclear energy (radioactive or fissile materials).

The control of hazardous energy is important to prevent injuries from inadvertent start-up or the activation of equipment and energy during installation, maintenance, service, repair or other types of work. The type and source of the energy must be recognized for its potential to cause harm to personnel and/or damage to equipment. The most common form of energy is electrical, but mechanical, hydraulic, pneumatic, chemical, gravitational, and thermal energy can also be dangerous. These other energy sources may be directly associated with the electrical energy for a particular piece of equipment and therefore must also be controlled to prevent the equipment or machine from moving. The key to the control of hazardous energy is the recognition of applicable hazardous energy sources, the type and magnitude of the energy available in the workplace, and the methods and means necessary for energy isolation and control.

This section of the Naval Safety Center Acquisition Safety website concentrates on the challenges of electrical shock, electrical arc flash, electrical arc blast, and other hazardous energy sources in the shipboard environment. Another focus is the importance of planning in the ship design phase to minimize or eliminate these hazards. Incorporating hazardous energy system safety in the early stages of design is important to the acquisition process. Exposure to hazardous energy can be eliminated or at least reduced by designing, arranging, and installing equipment, cabling, electrical panels, distribution circuits, pipeline systems and valves, and control systems to achieve safe maintenance and repair operations and to ensure the safest environment during operating, combat, standby, and emergency modes. An electrical hazard analysis, including shock and arc flash, must be an integral part of the design and installation phases of a project. The shock hazard analysis and the arc flash hazard analysis must be performed in order to identify the voltage level and the arc flash incident energy values for potential exposure, safe work practices, and personal protective equipment (PPE) required to operate and work safely on the equipment, during and after commissioning. Click here to view the whole article including Resources.