Locks and Tags Enable Safer Machine Interventions

Editor: Ahlam Rais

A large number of workplace accidents is connected with industrial machine maintenance. Because of this, a serious safety programme should include processes to increase the safety of interventions on machines. A tested way to reduce workplace accidents during maintenance, is the use of Lockout/Tagout.

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Lockout/Tagout devices are engineered to block specific energy sources in the ‘off’-position.
Lockout/Tagout devices are engineered to block specific energy sources in the ‘off’-position.
(Source: Brady Corporation)

The Lockout/Tagout procedure prevents injuries connected with maintenance such as fractures, lacerations, amputations, burns and shocks. It is a planned safety procedure which involves the isolation and inoperability of the energy supply of industrial machinery during maintenance.

The procedures vary in different companies, but they usually have the same building blocks, states the firm. These include a written policy including prescribed operating sequences and a definition of roles and responsibilities; padlocks and unique keys adapted to the working environment; and dedicated devices to block energy sources in the ‘off’-position, adds the company.

Written Policy and Procedures

Central in any safety programme is the written, company wide policy. In many companies this is a 20 page document. But it can grow quite easily to 200 pages in large multinationals. The Lockout/Tagout procedure is usually signed by the Health & Safety Manager, Production Manager and top executives within the company.

Added to the policy should be detailed, step-by-step descriptions of how to lock out various energy sources per machine present in the company. The company suggests to visualise every energy control point that needs to be locked out, and to offer distinct steps in a clear layout for optimal procedure communication.

Equally important as isolating machinery from its energy supply before maintenance starts, is informing employees on how to safely reactivate machinery when maintenance is done. Steps could include making sure the work is completed, cleaning up all tools and work-aids, checking guards and controls and notifying employees the locks are being removed, explains the company.

3 Roles to Identify

According to the firm, every employee plays one out of three roles in any Lockout/Tagout programme:

-Authorised employees are the only ones who can lock out equipment. These employees need rigorous training in the procedure. They need to know where the energy sources are for every machine they service, how to isolate them safely, and how to do their job without risk.

-Affected employees, whose work can potentially be affected by the programme. They need to be very aware of the importance of the procedure and they need to know what to do if their machinery is locked out.

-Next to affected employees, there will always be employees whose work could never be affected by the programme. It is, however, important to inform them about the significance of the procedure to make sure they refrain from tampering with any locks.

Training and/or communication for these employee categories, is of major importance for the quality of the Lockout/Tagout procedure in any company.

The Right Lock is the Key to Safety

When the procedure is written, it is time to source the tools to support the programme. Choosing the right padlock for the working environment is an important step. These locks are in place to prevent employees from inadvertently re-energising machinery and putting their maintenance workers at risk, states the firm.

The working environment determines which padlock to use. In electrical applications non-conductive padlocks are the best choice. According to the company, for electrical panels, lightweight padlocks are preferred. Aluminium padlocks have superior durability in humid or in outside environments. Colour-coded padlocks help recognising who locked out an energy source when multiple maintenance teams are active.

Every padlock can have a unique key, making it impossible to open a second lock with the same key. Unique keys guard an important principle: only the individual who placed the lock, can remove it. The use of a master key or grandmaster key should always be a last resort and must be described in the procedure.

Dedicated Lockout Devices

Dedicated lockout devices exist for every type of energy control point, including handles, push buttons, valves or other mechanisms that allow energy to flow to a machine. According to the company, when applied correctly, a Lockout/Tagout device will block an energy source in the ‘off’-position, making it impossible to re-energise machinery without removing the padlock, or padlocks, on the lockout device.

To decide which devices one would need for a succesful programme, one needs to map all energy control points present in one’s company. It is very important not to miss any energy control points, because if they are not locked out, servicing a machine will never be safe, explains the firm.

Time for Action!

If you are faced with a number of maintenance accidents, or increasing risks and near misses during maintenance, the firm believes that it is time to seriously consider the programme. The procedure will help the customer reduce workplace accidents, reduce lost working hours due to recovery from injury, and reduce litigation risks for one’s company, opines the company.

A great way to start a programme, is inviting a specialist to perform an audit in order to map all energy control points present in one’s company, explains the firm. When these are identified, selecting the right lockout devices and locks becomes easy. A list of tools will, in turn, help to write clear and dedicated step-by-step lockout procedures.