While the use of man baskets mounted on cranes is common to the utility transmission construction industry, it will surprise many that OSHA has clearly established their premise that cranes are designed to lift loads – not people – and that hoisting personnel with a crane is inherently more dangerous than using equipment designed to lift personnel. For this reason, it is important that safety planners and crews understand OSHA's intentions for crane-mounted baskets and the issues associated with their use. The crane and derrick standard regulates lifting of personnel, both in a crane-mounted basket and on a suspended platform. OSHA has directly stated that it considers a crane-suspended basket the same as a crane boom tip-mounted basket for the reason stated above (29 CFR 1926.1400 Subpart CC Preamble, page 48035).
In 29 CFR 1926.1431(a), OSHA defines exceptions that must be established to use a crane-mounted basket as follows: “The use of equipment to hoist employees is prohibited except where the employer demonstrates that the erection, use, and dismantling of conventional means of reaching the work area, such as a personnel hoist, ladder, stairway, aerial lift, elevating work platform, or scaffold, would be more hazardous, or is not possible because of the project's structural design or worksite conditions.”
OSHA has further demonstrated their intent at limiting crane-mounted basket use by fining employers and stopping work where they determine that employers fail to demonstrate need for accepted use of crane-mounted baskets.
Issues Reaching the Work
In tower access, crane-mounted baskets are necessary for reaching heights unobtainable by elevator buckets. The use of crane-mounted baskets adds an element of safety over the option of climbing lattice or wood and, other than helicopters, is the only means of access for most concrete or steel pole structures. Still, access from a basket has its limitations because of space and reach. The most frequent issue with regulators is when workers find it necessary to step onto the toeboard, midrail or even top rail of the basket to reach the work point. Stepping off the floor of the basket is a violation covered by two standards:
• 1926.453(b)(2)(iv): “Employees shall always stand firmly on the floor of the basket, and shall not sit or climb on the edge of the basket or use planks, ladders, or other devices for a work position.”
• 1926.1431(k)(2)(ii): “Platform occupants must not stand, sit on, or work from the top or intermediate rail or toeboard, or use any other means/device to raise their working height.”
De Minimis Exceptions
Almost everyone reading this article who uses crane-mounted baskets – or even bucket trucks – will say that there are times when you simply have to step off the floor to reach the work and using a basket is intrinsically safer than climbing or transferring to the structure. They might also argue that since they have to step off the floor, they still have fall protection so they can't fall. For these reasons they might assume they can argue for a de minimis violation of the feet-on-the-floor rule.
The issue with feet on the floor is the employee waist above the rail. In that position, they are more likely to fall or be bounced from the basket. The issue is not whether or not the worker has fall protection, but whether or not they are more likely to fall or be thrown from the basket with their feet off the floor than they would be if their feet were on the floor. Being thrown from the basket means the employee is likely to impact the structure, wire, insulators or rigging. Employers who assume they can expect a de minimis exception for violating the feet-off-the-floor rule simply because they are using fall protection should be very careful to properly understand the criteria for de minimis. Having fall protection is not necessarily the means to that exception.
Fall Protection, Prevention and Arrest
OSHA has issued clear rules for fall protection requirements. Even though we are talking about crane-mounted baskets in this instance, these rules apply to bucket trucks, too. Fall prevention requires short lanyards so that an occupant cannot be pulled or thrown from the basket and can be attached to either a belt or full body harness. Fall arrest requires stopping a fall as well as preventing injury from striking a surface below. Fall arrest rigging is more common to the utility industry largely because it uses a longer lanyard necessary to reach the work from the basket. Fall arrest systems must begin arrest of a fall within 6 feet and fall arrest lanyards must be attached to a full body harness. The issue with some lanyards, especially deceleration lanyards, is that they are too long – 8 to 12 feet – when fully deployed. Falling from a basket or bucket close to the cradle can result in striking a truck below. Aloft, a deployed lanyard can result in striking an insulator, a pole, crossarms or a wire below the basket.
OSHA has cited employers for failing to have fall protection when employees falling from a basket hit conductors or other surfaces even if the employee did not fall to the ground. I am aware of at least one such instance where OSHA entered into an agreement with an employer who adopted the use of retractable lanyards in place of fixed or decelerating lanyards as part of a settlement over a citation for failure to have fall protection. Many employers now meet basket/bucket fall protection requirements using retractable lanyards. A retractable lanyard only deploys enough lanyard to allow the employee to reach the work position. It locks up in a fall within inches as opposed to 6 feet, making it less likely that an employee will strike an object below the basket in a fall. I have not seen it in use, but I am aware there is also a new bucket rim-mounted anchorage strap that allows both reach and use of short fall prevention lanyards.
Operator and Upper Basket Controls
OSHA requires that operators have basket controls if the basket is primarily on-site for lifting of personnel. During a site inspection, the OSHA compliance officer is expected to ask about the use of the crane. If the crane is on-site purely for the purpose of basket access to the work site, it is required to be equipped with upper controls. If the crane is used for both lifting and as a man basket, upper controls are not required. It is imperative that a compliance officer understands that the crane is on-site for both lifting and man basket access to the work area. If the basket is controlled by an operator at lower controls, the operator may not leave the controls while the basket is occupied.
Proof and Trial Lifts
A proof test is required any time a basket is installed on a crane. The basket must be uniformly loaded to 125 percent of the basket rated load. The load test must be held for five minutes. After the test, a competent person must inspect the basket to ensure its safety. Proof testing is required once after each basket installation. In the proof test requirements for a cable-suspended basket, the weighted basket must be lowered to a test position and held by the hoist brake for five minutes. Hydraulic booms do not have hoist brakes and most regulatory agencies interviewed accept a calibrated dynamometer with appropriate slings and anchorage for proof testing a crane-mounted basket.
Trial lifts are required for each setup location. After the crane is set up, the basket is loaded to its expected working load. The basket is then run through the path to the work area before it is allowed to be occupied. Even if the day’s work will take place at several structures and each setup will be exactly the same, there must be a trial lift for every setup no matter how similar the operations are. In the preamble to the crane and derrick standard (FR Vol. 75, No. 152, 8/9/2010, page 48038), OSHA has clearly defined its intent that an independent trial lift be performed for every setup.
Finally, here are a few other requirements worth mentioning that are relatively self-explanatory:
• A proof and trial lift may be conducted simultaneously with proof test weight applied.
• A person may not safety-off to a structure and the basket at the same time.
• An operator using controls from a basket must be qualified, but is not required under the standard to be third-party certified unless he is the person who sets up the crane for operation.
• Loads may not be lifted on the hoist while the basket is occupied.
• Materials and equipment in an occupied basket must be secured against movement while the basket is in motion.
• Baskets may not be used for the sole purpose of transport of tools or equipment except during trial lifts.
• The platform user's manual must be in the platform or on the equipment during operation.
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