Near-miss: Flooding of a diver’s helmet

A member has reported a near-miss that occurred during diving operations. A diver’s helmet – a Kirby Morgan Superlite 17B – flooded during the dive. Fortunately the diver was only at a depth of 3m at the time, a secondary retention system was fitted and the diver was able to reach the surface without further problems.

The initial investigation found that the helmet had become free of the neck dam yoke at the rear and that the rear hinge tab was separated from the helmet alignment sleeve. Normally, correct alignment of the helmet and neck dam yoke would be characterised by the helmet alignment sleeve being passed through the rear hinge tab. In this instance, the helmet was still connected at the front and was retained on the diver’s head via the harness upper link assembly ‘earrings’ attached to the diver’s harness.

The investigation found that the helmet came free because the helmet had not been correctly aligned with the neck dam yoke when the diver was being readied for the water. It concluded that this should have been easily spotted, pointing to the need for review of the final checks conducted immediately prior to the dive commencing.

The company has recommended the following actions:

• diving supervisors must re-examine their diver dressing process and checks to establish if both self-checks and cross-checks are firmly established and being followed by divers and deck crew;
• diver equipment checks must be verbally communicated between the diver in question, the person dressing the diver and the diving supervisor. These checks should be logged within the dive logs;
• divers should be reminded that they are responsible for safety checks of their own equipment, as far as possible. A competent person (normally another diver) must physically check that the hat is installed correctly on the neck dam prior to the diver entering the water.

The manufacturer of the helmet, Kirby Morgan Dive Systems, Inc. has provided the following safety information for proper dress-in procedures, as per its manual for this equipment:

1. “Prior to diving with any diving helmet, a competent person must ensure that the mechanisms that lock the helmet on the diver’s head, as well as all other helmet functions, are adjusted properly and operating correctly, per the manufacturer’s manual. These checks should be logged in the helmet logbook.
2. Because it is impossible for the diver to see whether the helmet has been latched on correctly, or whether his other equipment has been properly configured, it is essential that a competent person (an experienced tender or another diver) assists the diver in dressing in.
3. The diving supervisor is responsible for ensuring the diver is dressed correctly prior to entering the water. These final checks are normally carried out by a competent tender or another diver and should be logged in the diving operations (supervisor’s) logbook.
4. Once the diver has entered the water, but before he proceeds with the work of the dive, it is the responsibility of the supervisor to ensure that all in-water checks for the diver’s life support equipment are carried out. These checks should be logged in the diving operations (supervisor’s) logbook.”

The manufacturer has also now informed IMCA that it has developed a yoke strap, KMDSI part #505-134 and yoke strap guide, KMDSI part #505-138, which can be retrofitted to all Kirby Morgan Superlite 17A/B helmets. These are now standard issue on all Superlite 17 helmets. These items will help prevent separation of the yoke from the helmet, when properly installed and used. IMCA is also aware that a number of IMCA diving contractor members have provided alternative systems on such helmets which prevent the helmet becoming detached from the diver even in the event of the helmet and neck clamp assembly becoming separated. KDMSI has noted “However, these items are not a substitute for proper maintenance of KMDSI helmets, or proper pre-dive inspection of the equipment by the dive, tender and the diving supervisor”.