Multiple Lockout Device
A multiple lockout device is a mechanical accessory, such as a multi-lock hasp, lock box interface, or cable/chain system, designed to allow many individually keyed personal locks to be attached to a single lock point or key-securing point. This enables multiple workers to control a common energy-isolating device or group lockout system, ensuring each worker maintains personal control over their own lockout protection.
On a shop floor, multiple lockout devices are used in three main scenarios. First, a multi-lock hasp is attached to a single disconnect switch, allowing several workers to each apply their personal padlock, preventing re-energization until all locks are removed. Second, in group lockout for large lines, two qualified workers lock out all energy-isolating devices and place keys in a lock box; a hasp on the box lets each additional worker attach their personal lock, ensuring no key access until all locks are removed. Third, cable/chain/bar systems route through multiple disconnects, secured by one personal lock, effectively locking all devices. These systems require written procedures, risk assessments, and training per WorkSafeBC and CSA Z460 standards.
- Treating multiple lockout devices as shared locks by using one lock with multiple keys or master keys, violating the requirement for each worker to have a unique key and personal control.
- Improper installation of cable/bar/chain systems, such as using thin or flexible cables that allow partial movement of switches, or makeshift materials like rope, leading to incomplete isolation.
- Missing or weak written group lockout procedures and risk assessments, including no posted procedure at the work site, unclear designation of qualified workers, and failure to document failure modes for cable systems.
How does a multiple lockout device interact with WorkSafeBC’s definition of a Control System Isolating Device (CSID)?
A multiple lockout device does not function as a CSID itself. Instead, it secures the CSID or energy-isolating device, ensuring it stays in a position that prevents risk of injury. The CSID provides the primary safety function, while the multiple lockout device is a mechanical safeguard preventing unauthorized change of state under group conditions.
What performance and design characteristics must a multiple lockout device meet under WorkSafeBC/CSA?
It must have mechanical strength to resist deformation or breakage under foreseeable forces, with fittings requiring tools for removal. It must physically prevent operation of the energy-isolating device, accommodate the required number of personal locks without compromising security, and be specifically referenced in written lockout procedures and training.
In group lockout, how is safety ensured when some workers remove their locks before others?
Each worker applies their personal lock to the key-securing system via a multiple lockout device. When a worker finishes, they remove their own lock, indicating they are clear. Safety is preserved because keys to primary locks remain inaccessible until all personal locks are removed and two qualified workers remove their locks from the key-securing system, preventing partial re-energization.