From routine maintenance to breakdown, seafarers work on hazardous machines and equipment every day. Examples of such hazardous equipment could be steam pipelines, diesel generators, turbines, blowers, compressors, auto-start machinery and live circuits.

Every ship is mandated to mitigate risks and hazards from these equipment as they pose a real danger to human life if operated and maintained incorrectly. There is no scarcity of examples where an inadvertent activation of a machine/equipment under maintenance has led to serious injuries and even casualties.

In almost every case, these accidents could have been prevented easily if the equipment had been rendered inoperable or isolated before the crew member started with its maintenance.

This is where lockout tagout procedures (LOTO) become very helpful. Read our guide below for more information on the following.

  • What is the meaning of lockout tagout?
  • 6-step lockout tagout procedure
  • Advantages of lockout tagout
  • Summary
  • FAQ

What is the meaning of lockout tagout?

The term ‘lockout tagout’ refers to a set of safety procedures that enable an operator to effectively isolate dangerous machinery/equipment before starting with their maintenance.

Lockout tagout sample

Lockout refers to ensuring that we have isolated the equipment from the active system and locked it in that position. Tagout refers to the practice of placing tags on the starting positions of equipment. This alerts any crew that is approaching the equipment for operation or maintenance purposes that there is a potential danger.

6-step lockout tagout procedure

The lockout tagout procedure is a standard procedure for carrying out safe and effective maintenance onboard vessels. While the specific steps involved in isolating different machinery change, the core principles remain the same. The lockout/tagout procedure that follows is universal to all machinery onboard. It consists of the following steps:

  1. Preparation
  2. Analysis
  3. Isolation
  4. Lockout/tagout
  5. Residual energy assessment
  6. Senior management verification


Preparation for major maintenance tasks must begin as early as possible. On the scheduled day, the task must be discussed with the full staff during the toolbox meeting.

They must be made aware of what machines will be under maintenance for what duration and about the standby equipment in use. If the job is being performed by the deck side, the engine side officials must also be kept informed and vice versa.


The responsible officer must visit the maintenance site and analyze all the hazardous energy sources that need isolation. These could be mechanical, electrical, hydraulic, pneumatic, chemical or thermal.

If there are multiple energy sources in the equipment under maintenance, they must all be evaluated on how they can be reliably de-energized. The officer must also analyze the hazards associated with the multiple sources and prepare means for their control.


Isolation refers to the effective interruption or removal of an energy source from machinery. For electrical equipment, the breaker is disconnected. For the main engine, any of the interlocks such as the turning gear can be engaged to prevent an unintended start.

Electrical breaker isolation
Electrical breaker isolation

A filter cleaning on a hot oil pipe can be done by isolating the filter using a standby line. If there are multiple energy sources, they must all be isolated.

Lockout tagout

This is the most important step in LOTO safety. In this step, we ensure that no one except the crew performing repairs can reactivate the equipment deliberately or inadvertently

For this step, the officer must use the equipment in the lockout tagout kit to physically lock and tag the starting equipment.

The kit has lockout tagout devices such as circuit breaker lockouts, cable lockouts, gate and ball valve lockouts, hasps, padlocks, warning tapes, and other useful equipment that must be fixed onto machinery starting points to restrict their operation.

After locking the equipment, the officers place tags such as ‘Do not start’, ‘Do not operate’, ‘Locked out equipment’ at these starting points. These tags provide additional information such as the name of the person placing the tag, the senior officer-in-charge, the date of maintenance, and any additional remarks. The tags are placed at all the locations where the equipment can be started from.

Common LOTO tags
Common LOTO tags

Residual energy assessment

Many machines continue to hold a part of the energy that was present in the system even after de-energization. This energy is known as stored or residual energy. The residual energy must be released and the equipment must be depressurized completely prior to starting maintenance. Proceeding without de-energizing the system could lead to serious injuries.

The stored energy could be in the form of residual electrical charge, heat, compressed air, hydraulic liquid, steam, chemical, stored mechanical energy (spring), etc. In every machine, there are safe methods to release this energy. For example, you could bleed out a pressurized liquid or vent out air, steam and fumes. The responsible person must release the stored energy in a safe manner before moving on to the next step.

Senior management verification

In the case of lockout tagout procedures being performed by junior officers, the senior officers must verify the same before work is started. They must physically go and ensure that all the steps have been performed satisfactorily.

One way to do this is to use a work permit system. The work cannot start unless the crew member receives a work permit signed by the senior management (and even the superintendent for major overhauls). This permit must then be prominently visible at the work site for the entire duration of the job.

Advantages of lockout tagout

The LOTO safety procedure provides advantages on many fronts provided it is implemented effectively. A half-hearted implementation is just not enough. We usually apply these procedures to machines that have auto-start functionality or those that can start from multiple locations. An effective LOTO strategy provides the following advantages:

  • Crew safety
  • Easy implementation
  • Correct use of machines

Crew safety

Crew safety is the foremost concern on any vessel. Every vessel is striving towards a zero incidence goal. To that end, they are investing in many safety procedures. But few are as effective as LOTO safety procedures. It is an excellent (and often necessary) method to safeguard workers against serious injuries when working on or around dangerous equipment.

Many other safety procedures in use do not deliver as much value. LOTO addresses a very critical safety hazard that can cause death or disability. Whenever companies have applied it on ships, number of major and minor incidents have reduced significantly.

Easy implementation

When compared with other methods, the LOTO safety program is much easier to apply. It also costs much less. It provides a set framework that officers can put into action almost immediately upon receiving a LOTO kit. LOTO training is also fast and straightforward which even onsigners can pick up competently.

Correct use of machines

Besides providing safety to operators, LOTO ensures that a machine works as per design. Starting a machine when under maintenance can, in many cases, cause permanent damage to it. The safeguards may not be in place, parts may be loose and auxiliary equipment such as coolant pumps may be off during maintenance.


Lockout tagout procedures are an essential part of any maintenance routine even if some view it as inconvenient, time-consuming and burdensome. In the long term, it ensures an efficient, incident-free operation.

Over the past few decades, it has helped prevent many casualties and an even greater number of injuries.When officers apply it diligently, it can benefit the crew member, equipment and the environment. However, regular training of new recruits, as well as veteran seafarers, is crucial to take full advantage of LOTO.

Frequently Asked Questions:

What is the LOTOTO procedure?

The LOTOTO procedure is an extension of the LOTO procedure. It stands for Lock Out, Tag Out, Try Out. This step ensures that the isolation controls were effective. After isolating the system, the controls should not be able to start the machine or release any more hazardous energy.

After operating the controls, the responsible officer must check if the action re-energized the system. If there are multiple energy sources, we must check for each of them.

Such verification ensures that even if someone were to start the machine inadvertently, it would not start. Although, one of the duties of the individual responsible for the isolation is to notify everyone the isolation will affect. This step should prevent the inadvertent starting as it is, but verification with LOTOTO adds an extra layer of protection.