Danger Within Reach

production-line-mechanical-engineering

Thomas J. Cocchiola, PE, CSP, Mechanical Engineer ::::
Accident: A manufacturer designed, built, and sold a production line that produces decorative precast concrete pavers. The production line includes a conveyor that automatically feeds precast blocks into a hydraulically powered block splitting machine and positions them under a reciprocating splitter blade. In operation, the block splitter cycles repetitively and breaks the precast blocks into pavers, which are then pushed out through a discharge opening onto a downstream conveyor. The design of the production line requires workers to reach through the discharge opening of the block splitter to manually remove the last paver at the end of a production run.
After the production line was placed into service, the owner/operator became concerned about worker safety. The owner/operator recognized workers were able to reach through the block splitter discharge opening and reach the reciprocating blade (i.e., the danger zone). Consequently, a guard was fabricated and installed to reduce the size of the discharge opening. Unfortunately, the added guard did not prevent workers from reaching the danger zone. Continue reading “Danger Within Reach”

The Wrong Way To Clean A Meat Mixer/Blender

meat-pack-mechanical-engineering-failure

Thomas J. Cocchiola, PE, CSP, Mechanical Engineering Consultant ::::
Accident: A company that brands and sells meat products operates a plant with several production lines. The stainless-steel production machinery must be cleaned and inspected every day in accordance with government regulations. The meat products company used a subcontractor to clean all the machinery at the end of each day. A crew of workers from the subcontractor cleaned the machinery under the supervision of a meat company manager.
On the night of the accident, a worker was cleaning a relatively large mixer/blender that has two motor driven mixing elements that rotate within a relatively large stainless-steel tub. Two hinged doors at one end of the stainless-steel tub allow operators to discharge meat after it has been properly mixed. The subcontract worker was using a hose to wash a rotating element through one of the open discharge doors in accordance with normal cleaning practices at the plant. Unfortunately, the hose became entangled on the rotating element, which severed his hand.
Continue reading “The Wrong Way To Clean A Meat Mixer/Blender”

Importance of the Safety-Prop

hydraulic hoist

Thomas J. Cocchiola, PE, CSP, Mechanical Engineer / Safety Expert ::::
Case Synopsis: An accident occurred while workers were repairing a truck equipped with a roll-off hoist and a special purpose manure tank/spreader body. The hydraulically powered roll-off hoist mounted to the truck chassis can be raised and lowered while picking up or dropping off individual manure tank/spreader bodies.
After parking the truck in the repair shop, two workers began to change engine oil and grease the chassis while a third attempted to repair an air leak. The third worker activated controls to raise the manure tank/spreader body and then leaned in under the raised tank to reach the air lines.
Unfortunately, the worker was crushed and fatally injured when the hydraulic hoist unexpectedly lowered the tank/spreader body. Continue reading “Importance of the Safety-Prop”

Excessive Guard Opening: Watch Your Hands!

Thomas J. Cocchiola, PE, CSP, Mechanical Safety Consultant ::::
Accident: A corrugated box plant owned and operated a rotary die cutter equipped with a leading edge feeder that repetitively inserts individual blanks through a feed opening. In operation, a helper loads a stack of corrugated blanks onto the feeder during set up and replenishes the stack during production. A set of rotating rollers within the machine housing pulls blanks through the feed opening.
An accident occurred while an operator and a helper were getting ready to start a production run. The operator energized the machine during set up without starting the feeder. The operator intended to energize the feeder after set up was completed. The helper saw a rag on a stationary feed table and reached to remove it before production began. The rag inadvertently entered the feed opening and got caught between the rotating rollers as the helper moved it across the feed table. The helper’s hand was pulled through the feed opening along with the rag and was trapped between the rollers. Continue reading “Excessive Guard Opening: Watch Your Hands!”

Conveyor Modifications Result in Injury

Pallet Accident

Thomas J. Cocchiola, PE, CSP, Mechanical Engineer and Certified Safety Specialist ::::
Accident: A serious accident occurred the first time a truck driver was making a delivery to a relatively large auto parts store. The driver parked his truck trailer and unloaded pallets with the help of the store manager. The two men placed pallets onto an elevated platform that was approximately 9-feet above the floor of the shipping receiving area. The manager then operated a hydraulically powered lift to lower pallets to the floor. The driver continued unloading pallets from the trailer after the manager lowered the lift. Unfortunately, the driver accidentally fell from the unprotected edge of the elevated platform and was disabled as a result of the fall. Continue reading “Conveyor Modifications Result in Injury”

Pedal to the Metal

Crane Accident Expert

Thomas J. Cocchiola, PE, CSP, Mechanical Engineer ::::
Case Synopsis: An experienced crane operator was instructed to hoist and load 36-foot long steel rails onto the back of a flatbed truck. He had previously operated the crane to load rails many times without incident. The operator was using a hydraulically powered crane mounted to the back of the flat bed truck. The truck-mounted crane had an elevated operator compartment with control levers to extend/retract the boom and foot pedal controls for rotating the crane.
The accident occurred while the operator was hoisting and loading the very first rail of the day. He maneuvered the boom over the rail, hoisted it off the ground and rotated the crane to position the rail above the truck bed. The operator removed his foot from the pedal, which should have immediately stopped the crane rotation. Instead, the crane unexpectedly continued rotating and the rail collided with the operator compartment. The force of impact caused the operator to fall out of the crane and sustain injuries. Continue reading “Pedal to the Metal”