How and when does an overhead crane operator test the hoist brakes?
Federal regulation OSHA 29CFR1910.179(n) (3)(vii) states:
“The operator shall test the brakes each time a load approaching the rated load is handled. The brakes shall be tested by raising the load a few inches and applying the brakes.”
So how exactly does one apply the brakes on an overhead crane? Overhead crane brakes are applied automatically when hoisting motion stops. This braking action, referred to as holding brakes, requires specific brake torque settings. According to OSHA 29CFR 1910.179:
“Holding brakes for hoist motors shall have not less than the following percentage of the full load hoisting torque at the point where the brake is applied.
125 percent when used with a control braking means other than mechanical.
100 percent when used in conjunction with a mechanical control braking means.
100 percent each if two holding brakes are provided.”
To test the brakes we simply raise the load a few inches and stop hoisting. Holding brakes set automatically, and we’re now ready to proceed, right? Wrong! At this point we have only tested the holding brakes. What about the control brakes? Control braking exists to prevent the load from accelerating in the lowering direction. If the load is very high and a mechanical load control brake fails when you attempt to stop during load lowering, will the holding brakes still be able to stop the loadsafely? Probably not. We’ve seen this occur with very heavy loads where the holding brakes were unable to stop the load resulting in a loss of load control.
Now that we understand how an overhead crane’s holding brakes and control brakes combine to provide safe load handling, the process for checking control brakes is simple.
After checking to ensure that the holding brakes are functioning properly, hoist the load a little higher, maybe a foot or so more. Allow the holding brakes to stop and hold the load. Next, lower the load about halfway and again stop the load. For a crane equipped with a mechanical load control brake, this procedure tests both the holding brakes and the control brakes. If an overhead crane’s brakes are going to fail, they’re more likely to fail in the lowering direction.
This procedure should be followed with the first load of the shift, and anytime a substantially heavier load is handled later in the shift.
You can now see why holding brakes, when used in conjunction with control braking means other than mechanical, must be set to 125% of maximum hoist motor torque. Non -mechanical control brakes (eddy current) only control descent speed while the hoist is moving, and are unable to assist with any load holding.
Operators are the first line of defense in accident prevention. Understanding how overhead crane brakes function, and conducting a meaningful test goes a long way toward ensuring a safer and more reliable operation. Other standards that all overhead crane users should be familiar with include the ASME B30.2, ASME B30.11, ASME B30.16, and ASME B30.17. Also, read and be thoroughly familiar with your overhead crane user’s manual, and check local and State requirements to make sure you comply with all laws.
Tests are an attempt at a controlled failure. Operators must follow all safe work practices and ensure their body is never in a position to be contacted by the load.
NCCO Testing
Tuesday, July 26, 2011
Friday, July 15, 2011
Plate Clamp Safety
1. Plate clamp accident results in broken bones in a worker’s foot.
A worker lifts a 5/8″, 460-pound, plate of steel from a horizontal position and rotated the plate to vertical with a plate clamp. While attempting to attach a tag line to the clamp the plate slipped and landed on the worker’s foot breaking three bones.
An immediate accident investigation identified the following:
• The plate clamp being used was designated for 1-1/4″ to 2″ plate and was rated for 3-ton. The plate that slipped from the clamp was 5/8″ thick.
• The plate clamp used to lift and rotate the plate was clearly marked for vertical lifting only.
The following is additional information critical for plate clamp safety.
1) There are three types of plate clamps designed for overhead lifting. Be sure to use the correct clamp for the job task:
vertically lift only,
2. horizontal — to and from vertical through a 90-degree plane, and
3. horizontal — to and from vertical through a 180-degree plane.
2) Plate clamps are designed to lift the thickness of plate identified by the manufacturer’s identification plate located on the clamp. They must never be used to lift plates less than or greater than the thickness identified on the plate clamp identification tag.
3) Plate clamps must only lift one plate at a time. (The exception to this rule is lifting a stack of plates horizontally with two or four clamps approved for this type of lifting.)
4) Plate clamps must never be overloaded. Always calculate the plate weight and size your clamp appropriately.
5) Plate clamps are vulnerable to “under-loading” when they lift less than 50% of the WLL of the clamp.
6) Always center the plate clamp directly above the plate’s center of gravity. A plate that hangs out of level puts undue side stress on jaw teeth allowing load slippage.
7) If a tag line is to be used to control the load it must be fastened to the plate clamp prior to lifting. Remember that a steel plate may fall on its edge but then falls over to one side. Never place your body in the “fall-area.”
8) Keep loads low to the ground and stay out of the “fall-area.”
9) Be especially careful when lifting steel plate to any elevated area. The plate will act like a sail and the wind load can cause the plate to swing out of control resulting in loss of the load. In these cases the “Fall-area” must be expanded.
10) Never allow shock-loads when using plate clamps.
11) Read the specification sheet that’s supplied with the purchase of every plate clamp. It’s a good idea to laminate these sheets so they can withstand the elements in the field, and where they will be readily available to users.
12) Inspect plate clamps before each use. You must understand the manufacturer’s specifications on tooth, pin, and assembly wear and rejection criteria. This information is manufacturer specific, so you must be knowledgeable of each manufacturer’s specs.
13) Specific plate clamps are designed to lift finished and polished plates with non-marring smooth gripping surfaces. These should be used in pairs supported by slings and a spreader beam.
14) Plate clamps are not designed to lift plates which exceed a 300 Brinell Hardness.
To avoid accidents when lifting steel plate also consider the following:
• Prior to lifting a plate, the user should determine if there is a safer way to accomplish the work.
• Inspect plate clamps thoroughly and remove any excessively worn clamps from the work area.
• Get professional advice before cutting a hole in the plate where a shackle may be attached. You may have insufficient metal above the hole resulting in metal tear and loss of load.
A worker lifts a 5/8″, 460-pound, plate of steel from a horizontal position and rotated the plate to vertical with a plate clamp. While attempting to attach a tag line to the clamp the plate slipped and landed on the worker’s foot breaking three bones.
An immediate accident investigation identified the following:
• The plate clamp being used was designated for 1-1/4″ to 2″ plate and was rated for 3-ton. The plate that slipped from the clamp was 5/8″ thick.
• The plate clamp used to lift and rotate the plate was clearly marked for vertical lifting only.
The following is additional information critical for plate clamp safety.
1) There are three types of plate clamps designed for overhead lifting. Be sure to use the correct clamp for the job task:
vertically lift only,
2. horizontal — to and from vertical through a 90-degree plane, and
3. horizontal — to and from vertical through a 180-degree plane.
2) Plate clamps are designed to lift the thickness of plate identified by the manufacturer’s identification plate located on the clamp. They must never be used to lift plates less than or greater than the thickness identified on the plate clamp identification tag.
3) Plate clamps must only lift one plate at a time. (The exception to this rule is lifting a stack of plates horizontally with two or four clamps approved for this type of lifting.)
4) Plate clamps must never be overloaded. Always calculate the plate weight and size your clamp appropriately.
5) Plate clamps are vulnerable to “under-loading” when they lift less than 50% of the WLL of the clamp.
6) Always center the plate clamp directly above the plate’s center of gravity. A plate that hangs out of level puts undue side stress on jaw teeth allowing load slippage.
7) If a tag line is to be used to control the load it must be fastened to the plate clamp prior to lifting. Remember that a steel plate may fall on its edge but then falls over to one side. Never place your body in the “fall-area.”
8) Keep loads low to the ground and stay out of the “fall-area.”
9) Be especially careful when lifting steel plate to any elevated area. The plate will act like a sail and the wind load can cause the plate to swing out of control resulting in loss of the load. In these cases the “Fall-area” must be expanded.
10) Never allow shock-loads when using plate clamps.
11) Read the specification sheet that’s supplied with the purchase of every plate clamp. It’s a good idea to laminate these sheets so they can withstand the elements in the field, and where they will be readily available to users.
12) Inspect plate clamps before each use. You must understand the manufacturer’s specifications on tooth, pin, and assembly wear and rejection criteria. This information is manufacturer specific, so you must be knowledgeable of each manufacturer’s specs.
13) Specific plate clamps are designed to lift finished and polished plates with non-marring smooth gripping surfaces. These should be used in pairs supported by slings and a spreader beam.
14) Plate clamps are not designed to lift plates which exceed a 300 Brinell Hardness.
To avoid accidents when lifting steel plate also consider the following:
• Prior to lifting a plate, the user should determine if there is a safer way to accomplish the work.
• Inspect plate clamps thoroughly and remove any excessively worn clamps from the work area.
• Get professional advice before cutting a hole in the plate where a shackle may be attached. You may have insufficient metal above the hole resulting in metal tear and loss of load.
Thursday, July 7, 2011
Mobile Crane Operator & Train-the-Trainer Baton Rouge, LA September 22 - 26
You won't find a more complete Mobile Crane Operator Trainer's Program anywhere. Crane Tech provides more training, more support materials, and more specialized instruction.
Receive comprehensive Mobile Crane Safety training Plus one full additional day dedicated to trainer specific instruction. If you want a complete program that prepares you for teaching this subject this is the program!
Major Course Topics
● Crane Operational Characteristics
● How to Read & Apply Load Charts
● Proper Mobile Crane Set-up
● Use of Jibs & Extensions
● Stability & Structural Competence
● Frequent & Periodic Inspections
● Accident Prevention
● Causes of Crane Failures
● Determine Load Weight
● Rigging Safety
● Sling Selection
● Rigging Inspection
● Balancing Loads
● Crane Hands Signals
● Personnel Lifting
● OSHA/ASME Compliance
Cranes & Equipment Included
● Telescopic truck cranes
● Rough terrain cranes
● Lattice boom - truck cranes
● Lattice boom - crawler cranes
● Carry deck cranes
● Boom trucks
● Rigging for the crane operator
The following are provided with each Train-the-Trainer program.
● Detailed Training Syllabus - provides an hour by hour trainer's guide matched to your Leaders Instruction Manual.
● PowerPoint Presentations - Crane Tech provides one or more presentations for each Train-the-Trainer course that are keyed to the instruction syllabus for high impact training.
● Workshops - Interactive workshops to enhance your students' learning experience.
● Tests - Pretests and post-tests professionally developed and keyed to your training materials.
● Performance Tests - Hands-on performance tests for most programs help ensure your personnel are properly qualified.
● Student Manuals - * You receive ten each of keyed student manuals to get your training started off right.
To find out more about this seminar and Mobile Crane Operator 2011 schedule.
Call today 1-800-521-7669 or Register Online.
Wednesday, July 6, 2011
Forklift Operator Training - Train-the-Trainer - Tampa, FL July 21, 2011
Forklifts are involved in more industrial accidents than any other single type of equipment. Crane Tech's Forklift Safety Train-the-Trainer course is specifically designed for Trainers required to teach this subject. You will learn OSHA's Powered Industrial Truck standard, and receive specific guidance on how to evaluate your staff's training needs, and skills. Learn how to deliver quality training that meets Federal guidelines.
The following are provided with each Train-the-Trainer program.
● Detailed Training Syllabus - provides an hour by hour trainer's guide matched to your Leaders Instruction Manual.
● PowerPoint Presentations - Crane Tech provides one or more presentations for each Train-the-Trainer course that are keyed to the instruction syllabus for high impact training.
● Workshops - Interactive workshops to enhance your students' learning experience.
● Tests - Pretests and post-tests professionally developed and keyed to your training materials.
● Performance Tests - Hands-on performance tests for most programs help ensure your personnel are properly qualified.
● Student Manuals - * You receive ten each of keyed student manuals to get your training started off right.
This seminar will be held on July 21, 2011 in Tampa, FL. For more information please contact our Seminar Sales Agent @ 1-800-521-7669 or Register Online.
Tuesday, July 5, 2011
Mobile Crane Load Charts
Simply put, the only way to know if the load you are lifting with a mobile crane is within the limitations of the crane is to relate the lift to the manufacturer’s load chart and notes.
Persons who are not crane operators regularly have questions regarding lifting safety. The purpose of this Tech Tip is to help those less familiar with crane load charts better understand the questions to ask and the information that must be followed.
An experienced crane operator enters the cab of an unfamiliar crane expecting to find certain information on the load chart. Just as you may expect to find certain information when you enter an unfamiliar automobile. You locate the speedometer and fuel gauge, then locate windshield wiper, outside mirror, and seat adjustment controls. You do this because you know these controls must exist to operate safely. Similarly, certain information will always be located within a crane’s load rating chart and notes. You just have to know what you’re looking for.
The mobile crane industry is long past the days of a single page load chart. Load charts have become increasingly complex. There is specific information you must obtain prior to attempting to lift a load.
1. How is the crane configured? Are the outriggers fully extended and set, partially extended and set, or will the lift be made on rubber tires?
2. How much counterweight is installed on the crane?
3. What are the boom and jib/extension configurations? If the lift will be made with an extension or jib you must locate the load chart that provides ratings for these accessory devices.
4. Over what operating areas will the load be handled? Working Area charts define specific areas of the crane that relate to load ratings. Areas such as Over the Side, Over the Rear, Over the Front, and 360-degree Rotation lead you to specific load charts. Make certain you know the area where the load will be lifted from, the area the load will pass through, and the area the load will be placed. Base lifting capacities on the area with the least load rating according to the working area chart. The combined information to this point will lead you to one or more pages within a load chart.
5. Does the crane have sufficient load hoist reeving? Reeving charts indicate the type ofwire rope and the number of parts of wire rope required to lift loads. A reeving chart which indicates 28,000 lbs. capacity for a two-part reeving will require more reeving prior to making a lift that exceeds 28,000 lbs.
6. To determine how much load the crane can safely handle you must also know the length of the boom (hydraulic cranes show boom lengths in a row at the top of the load chart), and the load radius of the suspended load (hydraulic cranes show radius in a column on the left side of the load chart). When boom length and/or radius is between the values printed on the load chart you must select the boom length and/or radii with the least load rating. Keep in mind that a shorter boom length may have the lesser rating. You cannot assume that taking load values from the next longer boom length is safe.
7. Equally important to the load ratings shown on the chart are the load chart notes. Load chart notes provide critical information relating to operation, set up, configuration, and restrictions.
8. Finally, you must account for all accessory weights. Items such as load blocks, extensions, jibs, and rigging must be added to the weight of the load to determine the total load imposed on the crane.
Don’t hesitate to ask a crane operator for clarification. And, don’t think twice about challenging what you are told. Load charts may have become more complex, but the key information provided has not changed significantly. Knowing what to look for is a good start to a safer job site. Safety is a team effort that requires both the operator and management working with the same safety objectives. Don’t compromise your job site safety. Find out more at Cranetech.com
Persons who are not crane operators regularly have questions regarding lifting safety. The purpose of this Tech Tip is to help those less familiar with crane load charts better understand the questions to ask and the information that must be followed.
An experienced crane operator enters the cab of an unfamiliar crane expecting to find certain information on the load chart. Just as you may expect to find certain information when you enter an unfamiliar automobile. You locate the speedometer and fuel gauge, then locate windshield wiper, outside mirror, and seat adjustment controls. You do this because you know these controls must exist to operate safely. Similarly, certain information will always be located within a crane’s load rating chart and notes. You just have to know what you’re looking for.
The mobile crane industry is long past the days of a single page load chart. Load charts have become increasingly complex. There is specific information you must obtain prior to attempting to lift a load.
1. How is the crane configured? Are the outriggers fully extended and set, partially extended and set, or will the lift be made on rubber tires?
2. How much counterweight is installed on the crane?
3. What are the boom and jib/extension configurations? If the lift will be made with an extension or jib you must locate the load chart that provides ratings for these accessory devices.
4. Over what operating areas will the load be handled? Working Area charts define specific areas of the crane that relate to load ratings. Areas such as Over the Side, Over the Rear, Over the Front, and 360-degree Rotation lead you to specific load charts. Make certain you know the area where the load will be lifted from, the area the load will pass through, and the area the load will be placed. Base lifting capacities on the area with the least load rating according to the working area chart. The combined information to this point will lead you to one or more pages within a load chart.
5. Does the crane have sufficient load hoist reeving? Reeving charts indicate the type ofwire rope and the number of parts of wire rope required to lift loads. A reeving chart which indicates 28,000 lbs. capacity for a two-part reeving will require more reeving prior to making a lift that exceeds 28,000 lbs.
6. To determine how much load the crane can safely handle you must also know the length of the boom (hydraulic cranes show boom lengths in a row at the top of the load chart), and the load radius of the suspended load (hydraulic cranes show radius in a column on the left side of the load chart). When boom length and/or radius is between the values printed on the load chart you must select the boom length and/or radii with the least load rating. Keep in mind that a shorter boom length may have the lesser rating. You cannot assume that taking load values from the next longer boom length is safe.
7. Equally important to the load ratings shown on the chart are the load chart notes. Load chart notes provide critical information relating to operation, set up, configuration, and restrictions.
8. Finally, you must account for all accessory weights. Items such as load blocks, extensions, jibs, and rigging must be added to the weight of the load to determine the total load imposed on the crane.
Don’t hesitate to ask a crane operator for clarification. And, don’t think twice about challenging what you are told. Load charts may have become more complex, but the key information provided has not changed significantly. Knowing what to look for is a good start to a safer job site. Safety is a team effort that requires both the operator and management working with the same safety objectives. Don’t compromise your job site safety. Find out more at Cranetech.com
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