OSHA: Tower Crane Disassembly Jobsite Snapshot ... · Top View of the Tower Collar Components...
Transcript of OSHA: Tower Crane Disassembly Jobsite Snapshot ... · Top View of the Tower Collar Components...
OSHA: Tower Crane Disassembly Jobsite Snapshot
Introduction: This snapshot will review the events that occurred during a “Self‐Climbing Tower Crane
Disassembly,” that resulted in the fatality of one of the disassembly team members.
Scope of Work: Tower crane disassembly. A crew was dispatched to disassemble a self‐climbing tower crane
consisting of five counterweights, outer & inner jib, hoist unit, counterdeck, tower top, cab, climber front/back
halves and twenty‐six tower sections. The twelve top tower sections (26‐15) were removed with the use of a
tower crane climber unit to the 21st floor collar tie in. There were three (3) Collar Tie In Systems for this tower
crane. The Collar Tie In Systems were located on floors 21, 14 and 7 each connected to Tie Beams that connect
to each Floor Shoe. The photo and diagram below are examples of the Tower Crane Collar Tie In System. As
the tower climber unit was lowered to each collar tie in system, the collar tie in, tie‐beam (struts) and strut
foot would have to be removed before the tower climber unit could continue with disassembly.
Top View of the Tower Collar Components (Collar, Tie‐Beam or Strut that connects to the Floor Shoe)
Side View Floor Shoe that connects to the struts and secured to the floor with 22” Bolts that were involved in the task
Scope of Work continued: A crew of three men was assigned the task to drive out the pins that secure the
floor shoe to the building’s concrete floor.
Two men would be tasked on that floor to drive the pins through both the floor shoe and the building’s
concrete floor. The other man would be at area one floor below in the barricaded area to make sure the
dropping pins would not strike working personnel. The tools used by this crew was a sledge hammer and spike
maul. Examples of each are pictured below:
Sledge Hammer Spike Maul
The spike maul used did not have a Warning Notice stating: CAUTION: Spike mauls are designed to drive in Railroad
Spikes, not to drive pins. These mauls should not be struck with steel sledge hammers. Strike only with a softer metal
like malleable iron, brass, or copper. If you strike this tool with a steel tool, it might fragment and cause serious injury
or death.
Incident Event: A crew member held the spike maul on the floor shoe pins while the other crew member used
a sledge hammer to strike the maul. While striking the spike maul with the sledge hammer a metal fragment
from the striking surface of the sledge hammer struck the holder of the spike maul directly in his left side chest
area, lodging into the pulmunary vein.
Employer’s Actions: Safety Alert
TO ALL: Shop Mechanics, Crane Assemble/Disassemble Crews
RE: Spike Maul and Sledge Hammer Hazard
All Shop Mechanics, Crane Assemble/Disassemble Teams must inspect their Spike Maul and Sledge Hammer(s)
for and any defects to the striking surface. Ensure spike maul is approved for striking with another tool.
THE SAFE USE OF HAMMERS INVOLVES CERTAIN BASIC RULES:
Safety glasses are absolutely necessary when using any striking tools. If your eye is hit with even a
small fragment such as a flying wood chip or metal fragment ‐ it could cause serious and lasting
damage.
A hammer handle should always be swung so the face contacts the surface you are hitting squarely.
You should never strike from an angle.
When using a hammer to strike another metal tool, such as a punch or chisel, aim the blow or cut away
from your body. The tool being struck must be in perfect condition. This means a punch should never
have a mushrooming head, or the handle on a wood chisel should not be cracked.
Only the face of the hammer should be used for striking. Never strike with the side or cheek of a
hammer; these areas are simply not designed or tempered for striking.
If a hammer shows dents, cracks, chips, mushrooming or excessive wear, do not try to re‐grind it to
shape. It is worn out and dangerous ‐ discard it! Discard any hammer that exhibits even the slightest
hairline fracture.
If the handle on a hammer is loose, splintered, or cracked, the head may fly off and strike the user or
another person. Hammers with broken or split handles, should be repaired or discarded.
Remember that broken, worn out, bent or damaged tools are not only unproductive and frustrating to
work with, but if repeatedly used, they will almost certainly lead to an accident or injury.
Remember when it comes to the safe use of striking tools; use your safety glasses and gloves.
Employer’s Research and Resolution: Warwood Tool Manufacturer in Wheeling, WV has developed a “Spike
Maul” that can be safely struck by a steel sledge hammer. The tool is complete, tested under ASME
requirements and for sale on their website. The tool specifications are as follows;
Overall Assembled Weight: 13lb Head Weight: 12lb Length of head from struck face to striking face: 16" Diameter of striking and struck surface: 1 3/8" It will be outfitted with a 36" Wood Handle (can be fitted with fiberglass handle also) and painted yellow on the face
that employees will strike. The end that strikes pins will be blue