Dozer Engulfment Case Study Jack Katlic Sr VP-Fuel Supply, AEP- Retired Mark Skiles Director of...
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Transcript of Dozer Engulfment Case Study Jack Katlic Sr VP-Fuel Supply, AEP- Retired Mark Skiles Director of...
Dozer Engulfment Case Study
Jack KatlicSr VP-Fuel Supply, AEP- Retired
Mark SkilesDirector of Technical Support, MSHA
Phil SouthernBodygard
Sunnie SouthernBodygard
Dozer Engulfment Case Study
• Agenda– Surge Pile Hazards
– Surge Pile Accidents
– Solutions for Stronger Cab Windows
– Demonstration
– Conclusion
– Panel Discussion
Dozer Engulfment Case Study
• Purpose– Share one method the coal industry has implemented to save lives
Surge Pile Safety
Directorate of Technical Support Mine Safety and Health Administration
Slides with the MSHA logo were adapted from the MSHA website and can be found at: www.msha.gov
Surge Pile Hazards
• Since 1980, 19 persons have died in coal mining related surge pile accidents
• Most of the accidents have involved a hidden cavity created when material “bridged” over a feeder
Causes of “Bridging” Over a Surge Pile Feeder
• Bridging can occur– When equipment transverses
the material at the surface of the pile
– Surface material compacts creating a false roadway
– “Settling in” may occur in an idle pile and increase risk
A hidden cavity collapsed under the dozer while it was pushing coal on the pile
Partially Buried Bulldozer in Fatal Accident in Pennsylvania
• Most fatal accidents occurred when the dozer cab windows either broke, or were pushed into the cab, allowing coal to fill the cab
Note: orange object under windshield is an self contained self rescuer (SCSR)
Windshield pushed back into cab
Available Solutions for Stronger Cab Windows
• MSHA initiative– Use of very high-strength glass
• Massey approach– Add supports to the inside of the cab windows - combined with using
somewhat stronger glass
• Use of polycarbonate windows – Adequate strength– Support around edges needs to allow for higher deflection – Issue of scratch-resistance
• Bodygard system– A customized polycarbonate system
Massey Subkit
• The first system
• Most widely used
• Effective in saving lives
• System design– is comprised of metal bars attached to the inside of the cab
– keep the cab and glass from collapsing on the operator
The Massey Approach
•Installed support bars on the inside of the cab windows
•The supports for the right-side door window are shown here
•Horizontal support bars and additional edge support for the windshield are shown here
The Massey Approach
•Massey’s successful burial demonstration
•The glass cracked but it held the coal out of the cab
The Massey Approach
Massey Subkit
• Advantages– Keeps cabs from
collapsing
– Least expensive
– Saves lives
• Disadvantages– Obscures vision especially
when backing up
– Causes cycildelic affects that result in complaints of headache from operators
– Metal bars rattle and increase noise level in the cabin
– Metal bars loosen and crack door glass that must be replaced
PPG Preformed Pre-designed Product
• Created as by request of MSHA to overcome the deficiencies of the subkit
• System design– A chemically hardened preformed pre-designed product
– Installed by gluing the glass into a gasket is installed in same manor as standard glass packages
PPG
• Advantages– Does not obstruct vision
– Resists static pressure up to 40 psi
• Disadvantages– Preformed therefore
application is limited to Caterpillar and Komatsu dozer’s* standard cab packages
– Requires fixing of any deformation of the cab prior installation of the glass
– Most expensive
– May crack when impacted
– May pop-out under stress
PPG Preformed Pre-designed Product
Pounds per square inch
*Molds are only for dozers not for end loaders
Bodygard System
• Custom engineered
• Custom installed
• Polycarbonate system– Outboard seat is created
– Material is mechanically attach to the cab
• Inhibits internal collapse
• Unbreakable
• Noise insulator
• On site installation
• All manufacturers
• MSHA approved
Case Study History
• Massey conducted drop tests of 3 systems to determine the most effective system
• The following demonstration shows the results of the test
Body Guard
• Advantages– Unbreakable
– Does not obstruct vision
– Can be made to fit anything (all makes and models of existing equipment)
– Absorbs and insulates sound
– Broad based system
– Onsite customized installation on all cabs
– Installed on site by drilling and attaching to cab
– Cut to specs and attached to ensure stability
• Disadvantage*– Is less scratch resistant that
regular glass therefore a protective covering is applied that is easy and inexpensive to replace
Bodygard System
*Protective replicable material is applied to improve the scratch
resistance
Conclusion
• Based on the results of the drop test, Massey signed a national contract with Bodygard to perform their installations
BODYGARD
1 Lincoln Center, Shinnston, WV 26431
“The Safety Window People”
www.bodygard.com 304-592-1980