Struck By Fact Sheet MODULE DESCRIPTION This module provides information that will enable you to recognize common struck-by hazards at construction worksites. OBJECTIVES Upon completion of this module, you should be able to: Identify common struck-by hazards Describe types of struck-by hazards Protect yourself from struck-by hazards Recognize employer requirements to protect workers from struck-by hazards. In This Document Definition Statistics Flying Objects Nail Guns Falling Objects Power Lines Crane Operators Crane Personnel Summary MODULE OUTLINE 1. What Is a Struck By Hazard Definition of Struck By Hazards Flying: Thrown, hurled, or being propelled across space. It can include instances when a piece of material separates from a tool, machine or other equipment, striking a worker, resulting in injuries or fatality. Falling: Source of injury is from an object traveling from one elevation to a lower level, including instances where the injured person is crushed, pinned, or caught under an object. Swinging: Materials are mechanically lifted, they have the potential to move and strike workers. Rolling: An object which is moving or sliding on the same level at which the worker is located. Impact: Used to describe the injuries caused by a struck event Forcible Contact: Another word for impact. Caught-in or between hazards: Often mistaken for a struck-by event. Crushing Injury: An injury which is not associated with a struck-by event.
2. Struck By Hazards Stats 3. What are the common types of struck-by hazards in construction? (Struck by flying object)
Accident Prevention Recommendations: Institute a program for frequent and regular inspections of job site, materials, and equipment by a competent person(s) Require employees expose to the potential hazards associated with flying nails to use appropriate personal protective equipment. Train employees using powder-actuated tools in safe operation of the particular tool. Train employees on operating power actuated tools to avoid firing into easily penetrated materials. 4. Nail Gun Safety (Struck by flying object) Nail guns are popular for a reason. They get the job done in a blink of an eye. But that rapid-fire action can work against you. In a split second, a nail gun can enter your finger, your hand, or worse. Nail gun injuries are much more common than people think. Most injuries involve puncture wounds to hands or fingers, but serious, even fatal, injuries are also associated with the use of these tools. Most nail gun injuries happen --through accidental or unintended firing, often associated with recoil of the tool after firing. --from ricocheting nails --a nail going through the work surface --airborne nails --by-passed safety features --unsafe work practices --holding finger on contract trigger. Nail guns have two trigger types: --A contact trip trigger which allows it to fire anytime the trigger is held and the nose of the gun presses into a surface. This trigger type allows for bump or bounce nailing by just holding the finger trigger and moving the head repeatedly onto the surface. --A sequential trigger which requires the nose to be in contact with the surface but will not fire unless the sequential trigger is pulled. A sequential trigger helps avoid inadvertent discharge. These two finger triggers look exactly alike! Use extreme caution and know which trigger you are activating. A contact trip trigger carries twice the risk of the sequential trigger and is associated with accidental firing the most. 5. What are the common types of struck-by hazards in construction? (Struck by flying object) It is important to remember that flying hazards come in many different forms. In one case a worker was removing a frozen bolt from the track of a caterpillar front-end loader and was
struck-by the bolt which entered his forehead. In another case where a worker was freeing a pump component under pressure and was impaled by the pump component. And another worker was killed when a blast of compressed air from a gas pipeline struck him. A compressor was started to fill the pipeline with compressed air in an effort to push out a "pig." when the pipeline suddenly cleared, the employee was still in the way and was killed. The area should have been cleared before the compressor was started. vices do not always work, nor do they always read correctly. 6. What are the common types of struck-by hazards in construction? (Struck By falling object) Struck-by falling objects hazards occur when a source falls from a higher elevation to a lower level. This hazard includes instances where the injured person is crushed, pinned, or caught under a falling object. Struck-by falling object does not include collapsing material or structures. One example is what happened when a worker was tearing down a transmission structure using a digger-derrick when a pole broke and struck him on the head. Another example is when a worker was struck-by a load of wall panels that fell off his truck. Or when four workers were injured when rebuilding a bridge that was washed out by floods, the crane boom cable broke and the boom fell on them. Or the worker who was engaged in cutting an 8,000-lb boiler in sections with a cutting torch. The section being cut fell off allowing the remaining section weighing 5,000 pounds to flip over onto its bottom and land on the worker. Or even the rigger who attached a load to the block hook of a wheel mounted crane. The crane operator was positioned in the cab and waiting for the hand signal to make the lift. During this process, the jib of the crane fell from its stowed position on the boom and struck the worker. The worker died later at the scene. It was discovered that the pin used to secure the jib to the boom was missing, allowing the jib to be displaced. The crane was not inspected prior to use 7. Power Line Precautions Power lines are the most dangerous among crane accidents. OSHA standards require that you stay at least 10 feet away from power lines when operating a crane. When crane work requires being near power lines, all electrical distribution and transmission lines must be de-energized and visibly grounded at every point of work.
They also must be grounded and de-energized where insulating barriers, not attached to the crane, have been erected to prevent physical contact with the power line. Equipment or machines shall operate near power lines only when in compliance with the following requirements: For lines rated 50 kv. or below, minimum clearance shall be 10 feet between the lines and any part of the crane or load. For lines rated over 50 kv., minimum clearance shall be 10 feet between the lines and any part of the crane or load, plus 0.4 inches for each 1 kv., or twice the length of the line insulator, but never less than 10 feet. In transit with no load and the boom lowered, the equipment clearance shall be a minimum of 4 feet for voltages less than 50 kv.; 10 feet for voltages over 50kV., up to and including 345 kv.; and 16 feet for voltages up to and including 750 kv. A person shall be designated to observe clearance of the equipment and give a timely warning for all operations where it is difficult for the operator to maintain the desired clearance by visual means. When judging the distance of a power line, the operator to judge can be easily tricked due to the distance and slack of the power line. A good way to practice is to measure out the clearance distance and install visual barriers for the operator and other personnel to use. 8. Crane Operator Requirements Crane operators must be qualified on specific crane types and have on-the-job training. They are required to pass a practical operating examination, which is limited to the specific type of equipment they can operate. Operators are required to meet these physical qualifications: Have vision of at least 20/30 Snellen in one eye, and 20/50 in the other, with or without glasses Be able to distinguish red, green, and yellow, regardless of the position of the colors, if color differentiation is required for operation Must have adequate hearing, with or without hearing aids, for the specific operation Disqualifications are due to a history of epilepsy or of a disabling heart condition. 9. Cranes should only be operated by the following personnel: Designated operators Learners under the direct supervision of a designated operator Maintenance and test personnel, when it is necessary in the performance of their duties Inspectors Only the specified personnel are allowed to enter a crane cab, with the exception of persons such as oilers and supervisors, whose duties require them to do so; and then only in the performance of their duties and with the knowledge of the operator or another appointed person.
Hand signals are very important to know when working on the jobsite. It is a requirement that a poster be posted at the jobsite with an illustration of the hand signals that every operator and personnel working with or around cranes must know. Hand signals for crane and derrick operators should be those set by the American National Standard Institute customized for the type of crane in use. 10. Summary Now that you have completed this module, you should be able to: Recognize the major causes of crane accidents Describe the pre-planning that is required before using a crane State the main precautions that need to be taken when working near power lines Understand the importance of operator and personnel requirements.