U.S. Department of Labor
Process: Hot Work
Hazard: Burns and Shocks
In shipbuilding and repair, burns are among the most prevalent injuries to workers performing hot work. These burn injuries most often occur when hot sparks or molten slag become trapped in footwear or clothing. Another common cause of burns, especially in inexperienced workers, is contact with heated surfaces that remain hot long after hot work has been completed. Burn injuries to workers passing under staging, platforms or deck grating where hot work is being performed above also occur.
Most shipyards restrict welding or burning jobs to workers who have completed a comprehensive training or apprenticeship program and are deemed to be proficient and safe to perform this work. In this interest, some shipyards operate their own welding schools to assure quality work, and safe operations. This training will typically follow the standards for the training and qualification of welders as established by the American Welding Society. The safety component of the training includes instruction in the types of welding hazards, personal protective equipment, fire safety, electrical hazards, fumes and ventilation. Training also covers welding and other types of hot work. Shipyard policy and procedures governing hot work permits and performing hot work in confined spaces, as well as other special requirements are also covered. Shipyards that do not operate welding schools may avail themselves of safety and health training which may be offered by insurance carriers, state and federal agencies, or one of the many commercial training resources that can be located on the Internet. Contractors who are working in the shipyard should also be made aware of, and be required to adhere to the same rules and follow the same procedures as shipyard workers performing hot work.
It is important that all employees who work near, or pass through or under areas where hot work is being performed, be aware of the potential hazards associated with this work. Employee orientation programs and periodic safety talks or bulletins are used in shipyards to provide workers with this information. Shipyard operations often require that workers perform many different jobs in close proximity to one another,and care must be taken to prevent workers from coming into contact with surfaces that have recently had, or are having hot work performed on them. Flame resistant blankets or pads are often used for this purpose. Some yards require workers that have completed hot work to mark surfaces as "hot" and indicate the time before leaving the area.
Personal protective equipment (PPE) consisting of hood, face shield, or goggles with appropriate filter lenses (as discussed in the eye protection section), leathers, protective sleeves, and flame resistant gauntlet type gloves are essential. Hard hats with fasteners for attaching welding hoods or face shields should be available for use in areas where protective helmets are required. Skullcaps of leather or flame resistant fabric will provide protection against head burns and may be worn under the hard hat. Also needed are long sleeve coveralls or a long sleeve cotton shirt with a close fitting collar to keep out sparks and slag. When long trousers are worn instead of coveralls they should not have cuffs, that might catch and hold hot materials. Shirts and trousers should be made of cotton or a flame resistant material; synthetic fibers such as nylon or polyester will burn and melt to form a hot plastic mass that adheres to the skin and may cause a more serious burn injury.
For personnel performing hot work, protective footwear should be of the high top or work boot variety as this will help prevent burn injuries from sparks or molten slag entering the shoe. Hard rubber soles will provide insulation for workers performing arc welding or cutting. For overhead work, capes and sleeves should be worn. Some workers like to wear a cotton bandana around the neck to prevent sparks and slag from going down the shirt collar.
Proper job set up and preparation will also help to prevent burn injuries. Removing combustible materials from the work area prior to the start of hot work will prevent hot sparks or slag from starting fires. A suitable fire extinguisher should be available at or near the work location. Further, ensuring that the work area is free of flammable dust or gas is also important as part of job set up. When flammable gas welding, gas cutting or brazing is to be performed in an enclosed or confined space the worker must understand and adhere to all rules and procedures for preventing flammable atmospheres from developing in the workspace. When hot work is to be performed on structural voids such as stanchions, rudders, railings or bilge keels, inspection and testing to ensure that no flammable or explosive atmosphere exists within the void must be performed. Whenever possible, overhead welding or burning should be avoided and workers should position themselves away from falling slag. Additionally, workers should avoid performing hot work directly over other employees or in heavy traffic areas. When this is unavoidable, signs can be posted to warn of the hazard from falling sparks and slag, traffic patterns can be temporarily altered, or a worker can be stationed to warn others.
The nature of shipbuilding and repair work requires that many arc-welding operations be performed out doors in all kinds of weather. Arc welding is also performed in tight and awkward locations in confined and enclosed spaces aboard a vessel. This work is often performed using portable welding equipment that is frequently moved from place to place and subject to rough handling and use. These circumstances necessitate extreme caution to avoid electrical shocks. Though the shock itself may cause injury, a worker's reflexive reaction to even a small electrical shock may cause the worker to suffer a more serious accident such as a fall.
In arc-or-stick welding, the open circuit voltage that exists between the electrode holder and the ground during the "off arc" or "no load" period presents a potential hazard to the worker. The worker can become exposed to this voltage when setting up work, changing working position, or changing welding electrodes.
The insulation on welding electrode holders is sometimes damaged from rough use and from moving welding equipment through tight spaces aboard vessels. Contact with skin or damp clothing by the bare metal exposed when this occurs can result in a shock. Similarly, welding leads and cables can become cut or nicked from rough handling and use, exposing the bare metal of the conductor. Leads, cables and electrode holders should be inspected prior to work and more frequently in rough use situations. When working in tight and confined spaces, care should be taken to prevent hot sparks and slag from falling onto and damaging welding leads.
When working a substantial distance from the welding unit, cables should be suspended on S-hooks or overhead supports whenever possible. Damaged leads or cables should be immediately removed from service. Many shipyards require that damaged equipment be "tagged" and taken out of service to ensure that it is not used until properly repaired or disposed of.
Shipyard safety and health professionals tend to agree that changing electrodes with bare hands, wet gloves or while standing on a wet, or grounded surface is probably the leading cause of electrical shock to shipyard welders. In hot weather or when working in a hot location, electrode contact with perspiration soaked clothing has also been the cause of electrical shock.
Proper grounding to assure that electrical current flows from the arc and back to welding machine is extremely important. When the work is not properly grounded the worker may become part of the ground path and receive an electrical shock. One hundred percent grounding and/or ground fault circuit interrupters are the surest means of preventing electrical shock. Often in shipyards, welding is performed on a number of components, plates, or sub assemblies that may be set up in a staging area, or on an outdoor platen. When a single welding machine is used to do this work, the work pieces should be bonded together with a cable of sufficient current carrying capacity to assure an adequate ground return is maintained as the worker moves from one work piece to another.
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