The thought of an OSHA Compliance Office visiting a construction site may make some cringe.
OSHA released a ‘directive for enforcing requirements of the Cranes and Derricks in Construction standard.’ The purpose of the directive is to give OSHA personnel a basis on how to conduct their inspections at construction sites when equipment covered by Subpart CC are present.
The items outlined below are just the minimum a Compliance Office follows during their inspection. The officer can include items in the inspection from other applicable requirements if the reason for the inspection is a fatality, compliant/referral inspection, or if a hazardous condition is present.
- Are ground conditions adequate, including support/foundation, matting, cribbing, blocking, etc?
- Is there visibly apparent need for repairs of equipment?
- Are nearby power lines energized; what is the voltage; what is the crane’s working area; and what are the encroachment prevention procedures?
- Is a signal person used and do they have documentation of qualification, electronic or physical?
- Is the qualified signal person the one communicating with the operator?
- Are lift plans being followed, if used?
- If hoisting personnel, who determined it was necessary?
- Are meetings being conducting for working near power lines, A/D work or hoisting?
- Is all available rigging equipment compliant?
- Are load charts and OEM manual’s available for the specific equipment used?
- Is the operator qualified, trained and competent?
- Are equipment and wire rope inspections being conducted; by whom; and are they qualified?
- Are safety devices and operational aids functioning?
- Are there any visual deficiencies of hoisting equipment, components and load line?
- How is weight of load determined?
- Are qualified riggers being used for A/D work and when in the fall zone?
- Who is the A/D Director and are they present?
- Are oilers and mechanics qualified; are they communicating with the operator; and are...
This Flat Top Luffing Tower Crane can go from horizontal with a 55 meter radius to a minimum radius of three meters in only 90 seconds. The luffing speed is varied by the load sensing hydraulic luffing cylinder.
This near vertical feature is particularly beneficial on crowded job sites. With the jib in this vertical position, the out-of-service radius is less than 10 meters.
It has 12 tonnes lift capacity when dual reeved at 55 meters, and 6 tonnes capacity at 55 meters when single reeved.
Read more about Wolffkran’s 166B on Vertikal.net.
See also, Tower Crane Collision.
Sidewalks are built for pedestrian traffic, not to support the weight of an aerial lift. The wheels of this aerial lift exert hundreds of pounds per square inch of weight on the ground beneath it.
This operator chose to operate the aerial lift on a sidewalk which also contains service covers. Obviously, these service covers are rated less than the sidewalk. The operator drove over the sidewalk cover causing it to crumble and ultimately triggering the toppling of this aerial lift.
The condition of the occupants of this aerial lift is unknown; however, the most common cause of fatalities in aerial lift accidents is turnover.
Handling a load with one forklift may not be complicated, but handling a load with two forklifts can be very complicated. This job required two forklifts and a scissor lift working together in close proximity to each other. It would seem simple enough to unhook and lower this dragster to the floor, but the forklifts don’t work in unison. The difference in the lowering speed of each forklift could cause the dragster to fall from the forks.
The task would require the forklifts to be positioned under the dragster in a manner that would prevent damaging as well as balancing the vehicle. At the direction of a signalperson, the forklifts would raise the dragster to take the weight of the hangers. Then, it would be disconnected. Finally, the signal person would observe and control the descent of each forklift.
See Forklift Foul-Up to see what can happen when things go wrong.
Run for cover! There is a crane in my neighborhood setting roof trusses.
Seriously, there are dozens of crane accidents on YouTube. It seems as if most cranes end up on the roof of the house they were meant to build or reach over.
I think, there are two main reasons for all the videos of crane accidents on YouTube: One is that cranes are interesting to watch, and if they are in a public setting someone is going to take a picture or video of it. The other is that most residential contractors won’t pay for a professional crane company. Instead, they use a taxi rental company, or even worse, they rent a crane from a tool rental company and operate it themselves.
When working in residential areas, there is also the problem of where to setup. Yards, streets, sidewalks, and driveways don’t have the capacity to support a crane. And, of course, you’d have to setup in the street because you can’t mess up an owner’s yard causing the operator to reach over the house to set a pool or spa. Before you know it, the crane runs out of capacity and ends up in someone’s living room.
If you happen to be a spectator, just remember to keep a safe distance!
Synthetic round, grommet or endless slings are stronger and even lighter than other slings given their rated capacity.
There are two reasons for this. Not weaving the synthetic fibers, but instead, forming a loop of loose fibers that nest together without overlapping, eliminates cutting of internal fibers. Endless slings are inherently twice as strong when used in vertical and basket hitches as compared to their single legged counterparts. Round slings are covered with a non-load bearing sleeve which protects the loops of loose fibers.
Some theatrical round slings, identified by a black sleeve, take this idea one step further by replacing fibers with steel wires that would normally be used to make wire rope.
Manufacturers, like Lift-it, are making round sling assemblies with hardware already included. They may add a hook or link to a single sling or make multi-leg bridles with hooks and links. In order to accomplish this, slings must be manufactured around the hardware.
Our Rigging Equipment Inspector training program includes inspection of synthetic rope slings.
An impatient worker jumps the gun and accidentally rams his forklift into a shelving unit in a Russian Vodka warehouse. The shelving unit toppled onto him as well as another forklift in operation. As the shelving collapsed another shelf was hit and a domino effect echoed throughout the warehouse.
One of the forklift operators walked away from the incident unscathed, the other operator suffered a foot injury.
Collisions are always a potential hazard when there are more than one tower crane on the job site with overlapping coverage. There are anti-collision devices that will attempt to prevent accidents from occurring, but standard operational safety should be the primary source in avoiding collisions.
It is believed that this collision occurred because the Jost hydraulic crane was out of service with its jib raised in the path of the flat-top saddle jib tower crane. The operator sustained head injuries in the collision.
October 2010, Edison Electrical Institute (EEI) provided to OSHA clarification of digger derrick work in the electric-utility industry. EEI explained that when a digger derrick is used to install a pole, it is typical that the same digger derrick is used to install pad-mount transformers as part of the same power system as the poles. The Cranes and Derricks Standard was written to exclude the pole work but not the pad-mounted transformer installation. This would require digger derrick operators to obtain certification if using the digger derrick when installing pad-mounted transformers.
After review of EEI’s documentation, OSHA broadened the digger derrick exemption in November 2012 by publishing the direct final rule and a companion proposed rule. Only one comment was received and OSHA determined it to be a “significant adverse comment” and issued a withdrawl of the broadened exemption in Feb. 2013.
The commenter was concerned that the proposed rule exempted riggers and signalperson from working with digger derricks, therefore decreasing worker safety. After further investigation OSHA agreed that the commenter did not provide adequate information. The commenter noted 7 incidents where they believed having riggers and signalpersons present would have prevented the incidents. OSHA determined that the incidents did not relate to pad-mounted transformer installation and therefore issued the purposed rule in June 2013.
Whether it is a quick in and out or a complete construction project, self-erecting tower cranes are a serious option filling a niche between telescoping and lattice boom cranes. Because they are efficient to transport and erect easily, they compete with lattice boom cranes for reach when heavy capacity is not required.