Leg injury during high pressure water jetting

What happened?

A diver was cleaning a riser with a high pressure (HP) water jet.

During the task, the diver cut their thigh with the water jet.

Why did it happen?

Diver was not properly secured during the cleaning operation.

Length of the HP hose needed for this job was incorrectly calculated. The minimum length of hose required is usually considered to be 1.5 times the maximum anticipated working depth.

Waterjet lance may have been too short. The potential for accidental self-injury during use of HP jetting guns increases as the length of lance (barrel) decreases.

What did they learn?

Before water jetting operations ensure a toolbox talk is held, a full risk assessment is carried out and the length of hose is checked.

The length of the hose should not impact upon the comfort and security of the diver.
Hoses should be tied off at convenient locations to minimise movement caused by pressure supply changes or tidal/current movement.
Hoses should never be tied off to any part of any diving equipment.

Divers should always be comfortably and securely positioned during high pressure water jetting operations, especially during mid-water operations to minimise the likelihood of losing control of the trajectory.

This likelihood is also increased if the retro jet and forward jet on the gun is strongly unbalanced.

Check that guns are appropriately designed, properly balanced, well-maintained, and fit for purpose.

Divers should hold the gun with two hands and use the stop/release trigger before each movement.

Ensure regular communication from the diver to the dive supervisor about the situation at depth.

Remind the dive team of the importance of good communications and consistent observance of safe working practices.

Ask yourself or your crew

How can you check you are properly secured before starting any high-pressure water jetting task?

Are you confident to handle a water gun? What should you do if not?

How do you communicate with other divers/supervisors? What suggestions do you have for improving communication?

What would you do if you saw a fellow diver working in an unsafe manner?

What is the procedure in case of an emergency?

What happened?

A diver was cleaning a riser with a high pressure (HP) water jet.
During the task, the diver cut their thigh with the water jet.
Why did it happen?

Diver was not properly secured during the cleaning operation.
Length of the HP hose needed for this job was incorrectly calculated. The minimum length of hose required is usually considered to be 1.5 times the maximum anticipated working depth.
Waterjet lance may have been too short. The potential for accidental self-injury during use of HP jetting guns increases as the length of lance (barrel) decreases.
What did they learn?
Before water jetting operations ensure a toolbox talk is held, a full risk assessment is carried out and the length of hose is checked.
- The length of the hose should not impact upon the comfort and security of the diver.
- Hoses should be tied off at convenient locations to minimise movement caused by pressure supply changes or tidal/current movement.
- Hoses should never be tied off to any part of any diving equipment.
Divers should always be comfortably and securely positioned during high pressure water jetting operations, especially during mid-water operations to minimise the likelihood of losing control of the trajectory.
- This likelihood is also increased if the retro jet and forward jet on the gun is strongly unbalanced.
Check that guns are appropriately designed, properly balanced, well-maintained, and fit for purpose.
Divers should hold the gun with two hands and use the stop/release trigger before each movement.
Ensure regular communication from the diver to the dive supervisor about the situation at depth.
Remind the dive team of the importance of good communications and consistent observance of safe working practices.
Ask yourself or your crew

How can you check you are properly secured before starting any high-pressure water jetting task?
Are you confident to handle a water gun? What should you do if not?
How do you communicate with other divers/supervisors? What suggestions do you have for improving communication?
What would you do if you saw a fellow diver working in an unsafe manner?
What is the procedure in case of an emergency?