Group Lockout Procedures

Introduction:

Where multiple workers need to work on, or gain access to the same piece of equipment, machinery or electrical system for maintenance, a “group lockout procedure” should be implemented.

The group lockout procedure will ensure that energy sources cannot be restored until all workers have completed their tasks and retreated from the hazardous area.

Scenario:

Many industrial accidents occur as a result of ‘unexpected start-up’. This is where a person is injured or killed as a result of a third party switching equipment back on when the person is still working on the equipment.

Maintenance activity may involve individuals working out of sight of their colleagues. In this situation, injury or death can occur simply because the person restoring the power assumed work was completed simply because no workers were visible on the machine or equipment. A group lockout will negate this risk.

Group lockout can be achieved using a lockout hasp (also sometimes referred to as a multi-lock) where up to six workers are protected. Another method of group lockout involves a group lock box which can involve many workers.

Example 1: Lockout Hasp (Multi-lock)

Figure 1 shows a typical lockout hasp. The jaws pass through the isolation device or lockout device.

Figure 1

It will allow up to 6 individual padlocks to be fitted. The practice of daisy-chaining multi lock hasps should not be undertaken.

Figure 2 shows a different type of hasp attached to an isolating switch. Two padlocks are fitted; a further four padlocks can be added.

Figure 2

 
Example 2. Group Lockout Box.

Figure 3

Figure 4

A variety of group lockout boxes are available which are either portable of wall mounted. Figure 3 shows a portable type and Figure 4 shows a wall mounted group lock box.


Figure 5 illustrates an example of a more complex group lockout involving multiple people.

Figure 5

In this example, access into the mixer vessel is needed via the access hatch. Precautions are essential to ensure that the mixer motor cannot start-up while workers are inside.
By following these steps, the risk of unexpected start-up is negated.

The motor isolator is switched OFF and padlocked by the senior authorised person (SAP).
The following isolation points are locked off:

• Inlet valve
• Outlet valve
• Drain valve

The padlock keys from each of the above lockouts are dropped in the group lock box. The SAP applies a second padlock onto the box lid preventing it from being opened.

Each worker who needs to enter the vessel affixes their own personal padlock to the lid of the group lock box.

It can now be seen that in order to restore power to the motor and open each valve, all padlocks must be removed from the Group Lock Box.

Also, the SAP can carry out a final check of the work carried out, and also validate that no workers remain in the mixing vessel.

This is one example of how a Group Lock Box can be used to protect all workers involved in a lockout procedure.

Total Lockout (Safety) Ltd

http://www.totallockout.com/Lock-Boxes

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