Safe, Successful Commercial Diving
by E.R. Cross
Each year hundreds of recreational divers will make the decision to become commercial divers. Most will start their careers by attending a commercial diving school. For this reason, recreational divers should know what diving schools teach. Also, they should be aware of future trends in diving technology. Divers should know both the kinds of jobs and the equipment they might have to use. Schools should be evaluated to see if they have the technology equal to that of the present and possible future. For informed divers the transition from recreational to commercial will be successful.
In this and in some future Technifacts, I will review the areas of work in the commercial diving industry and some of the tools and equipment divers have to use to safely and successfully complete their assigned tasks. Obviously, the most important of these are life support and related equipment.
LIFE SUPPORT EQUIPMENT
Life support equipment includes that which provides a breathing gas. It also includes lifelines, communication systems and heating equipment. It should be noted that life support equipment for a commercial diver is far more extensive and complex than that of a recreational diver. The reasons for this are the complexity and potential hazards of the work site and the demands of the jobs.
Under some stringent safety conditions, Occupation, Safety and Health Administration (OSHA) regulations permit limited use of scuba in commercial diving. However, many contractors are members of the Association of Diving Contractors (ADC) and do not use scuba.
Most commercial diving work is performed by divers using several kinds of helmets and related equipment and with what have become known as bandmask rigs. Either can use compressed air or a mix of gases as a breathing medium. Both types of equipment can be surface supplied or self-contained. The depth and duration of the dive and the expected job demands will usually dictate the kind of equipment and breathing gas used.
Owing to several aspects of the work involved, commercial diving has been divided into several classifications. Within these classifications there may be specialty diving and work qualifications. The two major areas of work;therefore the main classifications;are offshore diving and inland diving. There are several others that employ fewer divers.
Offshore diving usually refers to the offshore oil industry. There is some diving, however, that is not oil related and is done far offshore. However, in this Technifacts, offshore diving will refer to the oil industry and the various phases of diving devoted to it.
The offshore oil industry started in 1947 when a well was drilled off the Louisiana coast in 18 feet of water. By the late 1950s, oil had been found in much deeper water off California. Diving has always been critical to the continually expanding industry. Chevron will soon start producing oil from nearly 2,600 feet of water in the Gulf of Mexico. In 1996, almost 60 years after the first offshore well was drilled, Exxon is challenging the oil industry with a well planned for 4,880 feet, also in the Gulf of Mexico. It truly will be a 21st century well. Also planned for the next century is a dual underwater pipeline across the Arabian Sea between the countries of Oman and India. It will reach depths of 11,483 feet at a pressure of 5,100 psi.
Our present technology does not permit divers to work at the great pressures of the above depths. I believe suited divers should not be subjected to the unknown risks such deep diving will carry. However, diver operated equipment will likely be used on most deep water jobs.
From the first offshore well in 18 feet of water to the present, there have been many changes in diving technology. However, nearly all underwater work was done using various surface supplied diving equipment. Later, the use of saturation diving permitted longer, deeper work by divers. Knowledge that makes all prevalent forms of diving relatively safe has been researched and tested. Equipment has also kept pace with oil industry requirements.
Primarily because of concern about the safety of aging infrastructures of dam and bridge systems, inland diving has become an important aspect of commercial diving. In the United States the government has mandated annual dam and bridge inspections. In most cases, this involves inland divers using helmet or bandmask equipment. In some of these structures, diving to greater depths has required mixed gas or saturation diving equipment and techniques.
Inland diving also includes inspection, maintenance and construction of many harbor installations such as piers, marine railways and boat and ship moorings. Nearly all hull inspections, cleaning, minor repairs and propeller servicing are accomplished by inland divers. Near shore underwater work on pipelines, moorings and related tasks is usually done by inland divers. Inland diving is as diverse and demanding as offshore work.
Safe, successful and rewarding commercial diving involves much more than proper training, equipment and good diving techniques. When divers work with others on private or public property, legal responsibility, liability and insurance must be faced. In the months ahead, Technifacts will periodically review various aspects of commercial diving in detail. Primarily, the information will be designed so recreational divers can relate this aspect of diving to their own;or potential;qualifications.
SKIN DIVER readers who have specific questions about any aspect of commercial diving are invited to write to E. R. Cross, c/o Technifacts, SKIN DIVER Magazine, 6420 Wilshire Boulevard, Los Angeles, CA 90048-5515. Whether you are interested in your qualifications as a scuba diver or the additional training you may need to go commercial, Technifacts may be able to help in your decisions. Also, Technifacts can provide information about the equipment you will use in commercial diving, job skills that may be required or a potential future in any phase of diving. Before going commercial, know where you are going.