26-11-2012, 05:44 PM
Design of Monorail Systems
[attachment=41231]
Introduction
Overhead monorails are primarily used to lift large or heavy items and move them
horizontally. Monorails can be driven manually or powered. Power-operated
overhead monorails systems are typically powered by air, hydraulics, or electricity.
Overhead material handling systems can be supported on single or multiple girders
and can be top-running or bottom-running. Bottom-running systems travel along
the bottom flange of the supporting beam and are typically associated with
monorails and bridge cranes. Multiple girders and top-running systems are typically
not associated with monorails but rather with overhead or gantry bridge cranes.
This course covers the basic design of a monorail with a bottom-running manuallydriven
trolley hoist on a single girder or beam.
The course will first discuss how monorails can increase productivity and efficiency,
reduce injury to individuals, produce cost savings, and even improve quality.
Operation safety and inspection of monorails will also be discussed since the actual
design calculation of a monorail beam is only a portion of a well-planned overhead
material handling system.
The procedure presented for the design of a monorail beam is primarily based on
the Crane Manufacturers Association of America (CMAA) Specification No. 74
Specifications for Top Running & Under Running Single Girder Electric Traveling
Cranes Utilizing Under Running Trolley Hoist. Fatigue checks and deflection
limitations will also be discussed. Connections and supports will only be briefly
discussed. An example of a basic monorail beam design is provided to assist in
better understanding of the information presented in this course.
Case Studies
Using monorails or other overhead material handling systems help increase
productivity, efficiency, and safety while reducing costs and injury to personnel.
Cases studies have shown that the use of such systems can do all of these things.
Two case studies are presented below.
Operation Safety
The safe operation of a monorail has some impact to the design of a monorail
system. Engineers need to be concerned with the operational safety of the
monorails they design. To that end, engineering drawings should include some or
all of the items listed below:
• maximum lift design load
• safety, impact, or load factors used
• maximum angle or load due to side pull
• method and locations of labeling stating maximum capacity, warnings, etc.
Additionally, the engineer needs to have a full understanding of how the final
monorail system is anticipated to be operated. Without operations input, a monorail
can be poorly designed for the intended use, ultimately resulting in the death or
injury of the operator and/or bystanders.
Pre-planning
Remember the Six P principle: Prior planning prevents pretty poor performance.
Identifying all, or as many of, the design parameters in the initial stages of design
allows for a better designed and operational system.
Some basic initial information and design criteria needed for the design of a
monorail system includes:
• Design load rating or lift load
• Safety, load, or impact factors to use
• Design codes or other specifications
• Minimum clearances required
• Special requirements specific to the project
• Minimum or Maximum hook height
• Path of monorail
• Preferred method of support
• Connection types: welded or bolted
• Understanding of final use
[attachment=41231]
Introduction
Overhead monorails are primarily used to lift large or heavy items and move them
horizontally. Monorails can be driven manually or powered. Power-operated
overhead monorails systems are typically powered by air, hydraulics, or electricity.
Overhead material handling systems can be supported on single or multiple girders
and can be top-running or bottom-running. Bottom-running systems travel along
the bottom flange of the supporting beam and are typically associated with
monorails and bridge cranes. Multiple girders and top-running systems are typically
not associated with monorails but rather with overhead or gantry bridge cranes.
This course covers the basic design of a monorail with a bottom-running manuallydriven
trolley hoist on a single girder or beam.
The course will first discuss how monorails can increase productivity and efficiency,
reduce injury to individuals, produce cost savings, and even improve quality.
Operation safety and inspection of monorails will also be discussed since the actual
design calculation of a monorail beam is only a portion of a well-planned overhead
material handling system.
The procedure presented for the design of a monorail beam is primarily based on
the Crane Manufacturers Association of America (CMAA) Specification No. 74
Specifications for Top Running & Under Running Single Girder Electric Traveling
Cranes Utilizing Under Running Trolley Hoist. Fatigue checks and deflection
limitations will also be discussed. Connections and supports will only be briefly
discussed. An example of a basic monorail beam design is provided to assist in
better understanding of the information presented in this course.
Case Studies
Using monorails or other overhead material handling systems help increase
productivity, efficiency, and safety while reducing costs and injury to personnel.
Cases studies have shown that the use of such systems can do all of these things.
Two case studies are presented below.
Operation Safety
The safe operation of a monorail has some impact to the design of a monorail
system. Engineers need to be concerned with the operational safety of the
monorails they design. To that end, engineering drawings should include some or
all of the items listed below:
• maximum lift design load
• safety, impact, or load factors used
• maximum angle or load due to side pull
• method and locations of labeling stating maximum capacity, warnings, etc.
Additionally, the engineer needs to have a full understanding of how the final
monorail system is anticipated to be operated. Without operations input, a monorail
can be poorly designed for the intended use, ultimately resulting in the death or
injury of the operator and/or bystanders.
Pre-planning
Remember the Six P principle: Prior planning prevents pretty poor performance.
Identifying all, or as many of, the design parameters in the initial stages of design
allows for a better designed and operational system.
Some basic initial information and design criteria needed for the design of a
monorail system includes:
• Design load rating or lift load
• Safety, load, or impact factors to use
• Design codes or other specifications
• Minimum clearances required
• Special requirements specific to the project
• Minimum or Maximum hook height
• Path of monorail
• Preferred method of support
• Connection types: welded or bolted
• Understanding of final use