OVERHEAD CRANE
OPERATOR
SAFETY TRAINING
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TYPES OF OVERHEAD CRANES
Bridge Crane
Floor Mounted Jib
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Monorail Crane
Wall Mounted Jib
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Here is an assortment of overhead cranes.
Take pictures of the different types you may have at your facility and put them on
this page. You may also replace other pictures and drawings in this
presentation. To do so:
1. Download a picture from a digital camera or scan a picture onto your
computer.
2. Click on the “insert’ button on the toolbar above and select picture>from file
and then go to where the picture is stored on your computer. Click on that file
and it is inserted on the current slide.
3. You may crop it, downsize it, add borders and lighter or darken it. It’s easy
and adds immensely to the presentation.
4. You may also create a hyperlink from a smaller picture to a picture that takes
up the whole slide to see the details better. To do this, a) right click on the
picture, left click on ‘action settings’, select ‘hyperlinks, and then scroll down
to the slide where the full size picture is. A good place for it is at the end of
the slide show. Be sure to create a hyperlink back the the original slide to ease
in navigating back and forth between slides.
5. Many of the pictures in this presentation have hyperlinks to a full size picture
at the end of the presentation. Once you have created a hyperlink, it will stay
with that slide no matter what order you put the slides in.
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OVERHEAD CRANE REGULATIONS
• 29 CFR 1910.179 Overhead cranes and gantries
• 29 CFR 1926.554 Overhead hoists
• ASME B30.2 Overhead and gantry cranes (Top
running bridge, single or multiple girder, top
running trolley hoist)
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• ASME B30.11 Monorails and underhung cranes
• ASME B30.16 Overhead hoists (underhung)
• ASME B30.17 Overhead and gantry cranes (Top
running bridge, single girder, underhung hoist)
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These are the main standards concerning overhead cranes but certainly not all of
them. Many States have additional standards as do some industries such as
Maritime, Mining, Offshore oil platforms, etc.
We have included only the two OSHA standards and the B30.16. This is because
the are almost identical when it comes to operation and inspections.
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TYPES OF INSPECTION
FREQUENT: Frequent inspections are visual inspections and
examinations by the operator or other designated personnel.
Records are not required. Inspection intervals are:
• Daily to monthly
PERIODIC: Periodic inspections are visual and audio inspections and
examinations by designated personnel making records of external
conditions to provide the basis for continuing evaluation.
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• 1 to 12 month intervals
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29 CFR-1910.179(j)(1)(ii)
Inspection procedure for cranes in regular service is divided into two general
classifications based upon the intervals at which inspection should be performed.
The intervals in turn are dependent upon the nature of the critical components of
the crane and the degree of their exposure to wear, deterioration, or malfunction.
The two general classifications are herein designated as "frequent" and
"periodic" with respective intervals between inspections as defined below:
1910.179(j)(1)(ii)(a)
Frequent inspection - Daily to monthly intervals.
1910.179(j)(1)(ii)(b)
Periodic inspection - 1 to 12-month intervals.
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DEFINITIONS OF SERVICE
Normal Service: Involves operations of the crane with randomly
distributed load within the rated load limit or uniform loads of
less than 65% or rated load limit for no more than 25% of the time
for a normal work shift.
Heavy Service: Involves operation of the crane within the rated load
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limit that exceeds normal service.
Severe Service: Involves operation of the crane in normal or heavy
service with abnormal operating conditions.
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1. Some cranes are used more than others.
2. The frequency of service is a key factor in determining how often the crane
should be inspected and serviced.
3. Even cranes that are not used need to be inspected, lubricated and maintained.
Especially cranes that are out in the weather all year or in corrosive
environments.
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INSPECTION CHECK LIST
MONTH ___________________
Date Completed:_______ Inspected by: ___________
INSPECTION AREA
INSPECTION RESULTS
Sat.
Unsat.
N/A
Comments
Supporting Structure
Welds
Bolts
Bridge
Rails & Alignment
Trucks & Wheels
Motor & Drive Train
Brakes
Stops & Limit Controls
Trolley
Wheels
Motor & Drive Train
Brakes
Stops & Limit Controls
Rails & Alignment
Hoist
Wire Rope Condition
Rope Reeving
Chain Condition
Brakes & Ratchets
Equalizer Sheaves
Hoist Limit Control
Functional Operation
Electrical
Control Markings
Control Functions
Warning Alarms
Power Disconnect
Control Pendants
Festoons
Load Block
Sheaves
Pins
Swivel
Hook
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1. This is a sample of the inspection booklet found on your CD. You can print
one out for every crane. There are two versions, this one, and one that has
check boxes at the bottom of the page for the operator to initial that he has
performed a pre-shift inspection.
2. This is a good time to go out to one of the cranes in your facility and do an
inspection of it.
3. Pre-shift inspections do not have to be lengthy. You are basically looking for
obvious things that might be wrong with the crane.
4. Monthly or yearly inspections, of course, should be thorough and performed
by a competent individual.
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SUPPORTING STRUCTURE
CHECKING FOR TIGHTNESS
Note The Accumulation
Of Dirt And/or Paint
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Cracks In Paint Or Dirt Build-up
Often Is Caused By Loose Bolts.
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1. Check all fasteners for loose, stretched, missing, or broken fasteners.
2. A good clue is checking for cracked paint around the fastener that shows there
has been movement.
3.
Sometimes a build up of dirt or grease can do the same thing.
4. Using a torque wrench to check for tightness does not always work.
Corrosion could give you a false reading.
5. Replace a loose or stretched bolt rather than tighten it. It probably has been
damaged.
6. Be sure to replace the bolt with a grade 8 or better.
7. If there are other bolts near by that show signs of looseness, then replace them
all.
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CRACKED WELDS
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Inspect Welds
For Cracks
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1. Check cracks in the structure and in all welds.
2. A crack in a weld will always start on the end and work itself along the entire
weld until it fails completely.
3. Many times a crack in the paint will be a clue to a weld that is failing.
4. If caught early, the crack many times can be ground out and re-weld.
5. Before welding on any part of the crane, make sure you have a certified
welder and if it is on a structural part of the crane you should get the
manufactures procedure.
6. Also, try to determine why it cracked in the first place. Is the crane being
overloaded or used improperly.
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BRIDGE SYSTEM
Support
System
Bridge
Trucks
Span
Structure
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Bridge
Rails
Power Panel
Bridge Drive
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1. Climbing up a and checking the bridge system is normally not part of the daily
inspection. Use these slides to familiarize the student with the components of
the bridge crane and how they work together to make a successful lift.
2. Many of these components can be inspected from the ground as the crane is
being operated. If something seems wrong, then a closer look would be
warranted.
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BRIDGE TRUCK DRIVE
Final
Drive
Shaft
Motor
Brake
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Drive
Motor
Drive
Wheels
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1. Climbing up a and checking the bridge system is normally not part of the daily
inspection. Use these slides to familiarize the student with the components of
the bridge crane and how they work together to make a successful lift.
2. Many of these components can be inspected from the ground as the crane is
being operated. If something seems wrong, then a closer look would be
warranted.
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DRIVE COUPLINGS
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Check Couplings for:
• Loose bolts
• Loose or missing keys
• Cracks
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1. Climbing up a and checking the bridge system is normally not part of the daily
inspection. Use these slides to familiarize the student with the components of
the bridge crane and how they work together to make a successful lift.
2. Many of these components can be inspected from the ground as the crane is
being operated. If something seems wrong, then a closer look would be
warranted.
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DRIVE MOTOR BRAKE
Brake
Drum
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Brake
Solenoid
Brake
Shoes
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1. Climbing up a and checking the bridge system is normally not part of the daily
inspection. Use these slides to familiarize the student with the components of
the bridge crane and how they work together to make a successful lift.
2. Many of these components can be inspected from the ground as the crane is
being operated. If something seems wrong, then a closer look would be
warranted.
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WHEEL ALIGNMENT FOR BRIDGE CRANE
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WHEELTREAD
WEAR AT AN
ANGLE
HEAVY
WEAR
WHEEL FLANGE
WEAR
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1. Climbing up a and checking the bridge system is normally not part of the daily
inspection. Use these slides to familiarize the student with the components of
the bridge crane and how they work together to make a successful lift.
2. Many of these components can be inspected from the ground as the crane is
being operated. If something seems wrong, then a closer look would be
warranted.
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TROLLEY SYSTEM
Hoist Machinery
mounted on trolley
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Trolley Trucks
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1. Climbing up a and checking the bridge system is normally not part of the daily
inspection. Use these slides to familiarize the student with the components of
the bridge crane and how they work together to make a successful lift.
2. Many of these components can be inspected from the ground as the crane is
being operated. If something seems wrong, then a closer look would be
warranted.
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MONORAIL CRANE TROLLEY
TROLLEY WHEELS
CENTERED ON
BEAM
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TROLLEY WHEELS
FUNCTION SMOOTHLY
WHEELS IN
GOOD CONTACT
WITH BEAM FLANGE
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1. Climbing up a and checking the monorail system is normally not part of the
daily inspection. Use these slides to familiarize the student with the
components of the bridge crane and how they work together to make a
successful lift.
2. Many of these components can be inspected from the ground as the crane is
being operated. If something seems wrong, then a closer look would be
warranted.
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WIRE ROPE CONSTRUCTION
WIRE ROPE
Wire Rope Replacement
Broken Wires: 6 randomly distributed
broken wires in one lay, or three broken
wires in one strand in one lay.
WIRE
STRAND
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Loss in Diameter: Reduction from
nominal diameter of:
1/64” for dia. up to & including 5/16”
1/32” for dia. 3/8” to & including 1/2”
3/64” for dia. 9/16” to & including 3/4”
PROPER WAY TO MEASURE
WIRE ROPE DIAMETER
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1. Wire rope comes in various sizes and construction. The most common is the
right regular lay wire rope of the 6X19 class.
2. The strands of a wire rope are made up of several wires twisted together.
3. Several strands are twisted together to form the wire rope.
4. Common wire rope will have either a fiber core or an independent wire rope
core or IWRC. For lifting purposes, IWRC is recommended because it resist
crushing.
5. The designation, 6X19, refers to the basic construction. The ‘6’ stands for the
number of strands, not counting the core, that are used in the rope. The ‘19’ refers
to the number of wire in each strand.
6. When measuring the diameter of wire rope, make sure to measure across the
stands and not the flat area between the strands.
29 CFR 1910.176(h)(2)(i)
In using hoisting ropes, the crane manufacturer's recommendation shall be
followed. The rated load divided by the number of parts of rope shall not exceed
20 percent of the nominal breaking strength of the rope. (or a 5:1 safety ratio)
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WIRE ROPE
STANDARDS FOR SHEAVE
& DRUM RATIOS
D = Diameter of drum or sheave
d = Diameter of wire rope
Ratio = D / d
ASNE/B30.5 “MOBILE CRANES”
Minimum Ratios
Load Hoist
Boom Hoist
Load Block
Drum
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Sheave
18
15
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ABRASION RESISTANCE
FATIGUE RESISTANCE
Increases with larger wires
Decreases with smaller wires
Decreases with fewer wires
Increases with more wires
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1. Point out the trade-offs between abrasion and fatigue resistance.
2. Show how sheave size and wire rope diameter relate to each other and the
effects they have on wire rope life.
3. Review how sheaves are dimensioned.
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WIRE ROPE INSPECTION
FATIGUE BREAKS
FATIGUE FAILURE
Heavy loads over small sheaves
Repeated bending, normal loads
BIRDCAGE
STRAND KNICKING
Accentuated with heavy loads
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Sudden tension release
KINKED WIRE ROPE
HIGH STRAND
Crossed lines on drum
Improper socketing, kinks
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29 CFR – 1910.179(m)(1) Running ropes. A thorough inspection of all
ropes shall be made at least once a month and a certification record which
includes the date of inspection, the signature of the person who performed the
inspection and an identifier for the ropes which were inspected shall be kept on
file where readily available to appointed personnel. Any deterioration, resulting in
appreciable loss of original strength, shall be carefully observed and determination
made as to whether further use of the rope would constitute a safety hazard. Some
of the conditions that could result in an appreciable loss of strength are the
following:
(i) Reduction of rope diameter below nominal diameter due to loss of core
support, internal or external corrosion, or wear of outside wires.
(ii) A number of broken outside wires and the degree of distribution or
concentration of such broken wires.
(iii) Worn outside wires.
(iv) Corroded or broken wires at end connections.
(v) Corroded, cracked, bent, worn, or improperly applied end connections.
(vi) Severe kinking, crushing, cutting, or unstranding.
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DRUM INSPECTION
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1. Check to make sure the wire rope is spooled properly on the drum.
2. On lagged drums, make sure the rope hasn’t jumped a groove which could
damage the rope.
3. Check to make sure the dead end is secured properly.
4. Never hoist down to the point that there would be less than 2 wraps left on the
drum.
5. Check oil often.
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HOIST MACHINERY
HOIST
DRIVE
TROLLEY
TRUCK
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CHECK DRUM
GROOVES FOR
WEAR
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1. Check to make sure the wire rope is spooled properly on the drum.
2. On lagged drums, make sure the rope hasn’t jumped a groove which could
damage the rope.
3. Check to make sure the dead end is secured properly.
4. Never hoist down to the point that there would be less than 2 wraps left on the
drum.
5. Check oil often.
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HOIST MACHINERY
CHECK
RUNNING
SHEAVE
FOR WEAR
CHECK
CLEVIS
WEAR
CHECK
EQUALIZING
SHEAVE
FOR WEAR
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VERIFY
FUNCTIONING
LIMIT SWITCH
SINGLE REEVED DRUM
DOUBLE REEVED DRUM
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1. Check running and equalizing sheaves for wear and free movement.
2. Check the limit switch to make sure it stops the hook or load if two-blocked.
3. Check the oil often, especially if you detect any leakage.
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INSPECTING SHEAVES
CHECK FLANGES FOR
CHIPS, CRACKS, WEAR
CHECK GROOVE
WEAR
CHECK BEARINGS FOR
WOBBLE, GREASE, EASE
OF ROTATION
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150º
CONTACT
MEASURE GROOVE
WORN GROVES
PROPER SIZE GROVE
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1. Check for bearing wear and lubrication.
2. Check the flanges and treads.
3. Show how to use a sheave gauge.
4. Sheaves can only be repaired per manufacture’s procedures.
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CHAIN HOIST
Pocket
Wheel
Chain
Guide
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Bent Links
Stretched Links
Worn Links
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The chain hoist should be checked for the following:
1. Bent links (Usually a sign that it has been used to wrap around a load and bent
on sharp corners)
2. Stretched links. The links will be sucked in slightly on the sides. Also,
measure 5 links and check that measurement during your annual inspection.
3. Chain should not be rusted or brown. If the crane is in a corrosive atmosphere,
be sure to oil it often.
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HOOK INSPECTION
CHECK FOR:
[ Wear
[ Deformation
[ Cracks & Sharp Nicks
[ Modifications
[ Safety Latches
[ Swivel Wear & Lubrication
[ Hook Shackle Mousing
Wear & Deformation
Cracks &
Twisting
“Opening Up”
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Wear & Cracks
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1. Hooks with threads and nuts need to have threads inspected periodically.
2. Hooks can only be repaired per manufacturer’s procedures.
3. Wear in excess of 5% in the neck of the hook and 10% in other areas including
the bow of the hook is cause for removal.
4. An increase in the hook throat opening of more than 15% is cause for removal.
5. Any twist in the hook of more than 10% is cause for removal.
6. The hook safety latch should be present and function properly.
Accident 014504732 - Employee Killed When Struck By Loose Crane Hook
At approximately 8:15 am on January 29, 1990, employee #1 was working on a
large steel panel weighing approximately 2,608 pounds and measuring 22 feet
long and 6 feet wide. The panel was supported by an overhead crane chain and
hook and was set on metal horses at an angle. The hook slipped off of the
steel panel and struck employee #1 on the head, resulting in his death.
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HOOK INSPECTION
Throat
Opening
o
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Twisted
Hook
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10 percent
Maximum
Allowable
Wear
15%
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1. Hooks with threads and nuts need to have threads inspected periodically.
2. Hooks can only be repaired per manufacturer’s procedures.
3. Wear in excess of 5% in the neck of the hook and 10% in other areas including
the bow of the hook is cause for removal.
4. An increase in the hook throat opening of more than 15% is cause for removal.
5. Any twist in the hook of more than 10% is cause for removal.
6. The hook safety latch should be present and function properly.
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CRANE BLOCK
SHEAVE GROOVE
NOT WORN, SHEAVES
TURN FREELY
SIDE PLATE
BOLTS TIGHT
SHEAVE PIN
& BEARING
TIGHT
HOOK NUT
TIGHT
& THEADS
INSPECTED
PERIODICALLY
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SHEAVE PIN
KEEPER IN PLACE
AND TIGHT
SAFETY
LATCH
FUNCTIONING
CHECK FOR DISTORTIONS
OR WEAR
HOOK ROTATION &
SWIVEL SMOOTH &
TIGHT
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1. The sheaves and bearings need to be inspected as discussed earlier.
2. The side plates and any additional weights attached to the their sides need to be
inspected for loose or missing bolts or other fasteners.
3. The hook should rotate freely on the swivel bearing. Check for excessive
movement.
4. The hook shank and nut should be separated periodically and the threads
inspected for corrosion and other damage. The lose of more than 20% of the
treaded area due to corrosion is cause for removal.
5. The safety latch must be in place and functioning properly.
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ELECTRICAL CONDUCTORS
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Check Conductors for:
• Loose fasteners
• Burned surfaces
• Dirt and corrosion
• Electrical connections
Current Collectors
ride on this surface
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Always lock out the crane before working around the electrical conductors.
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CURRENT COLLECTORS
Electrical
Conductors
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Check Collectors for:
• Good spring tension
• Collector surfaces are
not corroded or burned
• Electrical connections
• Ease of movement
Current Collectors ride
against conductors
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Always lock out the crane before working around the electrical conductors.
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FESTOON SYSTEMS
CABLE TERMINATION
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ELECTRICAL
CONNECTORS
TIGHT
PROPER
CABLE
TENTION
FREE TROLLEY
MOVEMENT
INSULATORS
IN GOOD
CONDITION
STRAIN RELIEF
ADJUSTED FOR
CORRECT
LENGTH
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1. Festoons need to be checked for proper cable tension, free trolley movement
and wire connections.
2. Also, make sure there are no pinch points during bridge or trolley movement.
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PENDANT AND CONTROLS
ALL CONTROL
FUNCTIONS
CLEARLY
LABELED
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1. Many times the pendant controls get dropped or banged up during operation.
2. Never use the pendant to pull the crane around.
3. Use a strain relief chain or cable to protect the wires from pulling out.
4. Make sure all controls are marked and legible.
5. Check for buttons that are broken or stick.
6. Always check the emergency stop button on the pendant.
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SAFE CRANE OPERATIONS
MAX. SWL 10,000 lbs
Know the SWL of the crane and
never exceed it
MAX. SWL 10,000 lbs
ACME
ACME
55 TON
TON
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Follow all placards, warning
labels and signs on machine
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1. The safe-working-load of the crane should be easily visible to the operator.
2. The safe working load would be the maximum load of the “weakest link” on the
crane. For example: If the maximum SWL of the hoist was 5 tons, then the
SWL, but the beam that it was hung under was good for 7 ½ tons, the SWL of
the crane could not exceed 5 tons and if stenciled on the beam, it should reflect
the 5 ton rating.
3. All warning labels on the crane including crane operation instructions must be
on the crane and legible.
29 CFR 1910.179(b)(5) Rated load marking. The rated load of the crane
shall be plainly marked on each side of the crane, and if the crane has more than
one hoisting unit, each hoist shall have its rated load marked on it or its load
block and this marking shall be clearly legible from the ground or floor.
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LOCK
-OUT TAG
-OUT
LOCK-OUT
TAG-OUT
ALWAYS DE-ENERGIZE ELECTRICAL
SYSTEMS BEFORE INSPECTING AND
WORKING ON THEM.
DANGER
DO NOT
OPERATE
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Before adjustments and repairs are started on a crane the following precautions
shall be taken:
29 CFR - 1910.179(l)(2)(i)(a) The crane to be repaired shall be run to
a location where it will cause the least interference with other cranes and
operations in the area.
(b) All controllers shall be at the off position.
(c) The main or emergency switch shall be open and locked in the open position.
(d) Warning or "out of order" signs shall be placed on the crane, also on the floor
beneath or on the hook where visible from the floor.
(e) Where other cranes are in operation on the same runway, rail stops or other
suitable means shall be provided to prevent interference with the idle crane.
1910.179(l)(2)(ii) After adjustments and repairs have been made the crane
shall not be operated until all guards have been reinstalled, safety devices
reactivated and maintenance equipment removed.
1. The emergency shut off musts be visible and accessible.
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SAFE CRANE OPERATIONS
Acme Bridge Crane
Operation and
Maintenance
Manual
Read and understand
the operators manual
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ACME CORPORATION
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The Operator and Maintenance Manual should be available and every person that
operates the crane should have read the safe operations section.
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SAFE CRANE OPERATIONS
Acceptable methods of determining weight
You may find the weight from:
Data on manufacturing label plates.
Determine the
weight of the load
from accurate
sources
Manufacturer documentation.
Blueprints or drawings.
Shipping receipts.
Weigh the item.
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Bill of lading (be careful)
Stamped or written on the load
Approved calculations
Never use word of mouth to establish the weight of and item!
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1. Knowing the weight of the load is essential to safe overhead crane operations.
With mobile cranes, picking up a load that is too heavy could cause the crane
to tip. Not so with overhead cranes. Severe damage could result in trying to
lift a load that exceeds the SWL.
2. There are many ways to learn the weight of a load. The most accurate is, of
course, weighing it yourself.
3. If you do weigh an item, be sure to mark the weight somewhere on the load
for the next guy that has to lift it.
4. There will be times when you just have to make an a guess. Using the best
calculations that you can, come up with an estimate and then double it. It it is
well within the capacity of the crane, go ahead and make the lift. If by
doubling it, it is within 75% of the capacity of the crane, then you should
weigh it.
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SAFE CRANE OPERATIONS
MAX. SWL 10,000 lbs
MAX. SWL 10,000 lbs
ACME
5 TON
Cranes shall not be used
for side pulls except when
specifically authorized by a
responsible person who
has determined that the
stability of the crane is not
thereby endangered and
that various parts of the
crane will not be
overstressed.
5
TON
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29 CFR - 1910.179(n)(3)(iv)
Cranes shall not be used for side pulls except when specifically authorized by a
responsible person who has determined that the stability of the crane is not
thereby endangered and that various parts of the crane will not be
overstressed.
1. Side pulling on a crane may cause the wire rope on the drum to cross and be
susceptible to kinks and crushing.
2. It could also put stress on the trolley causing damage.
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SAFE CRANE OPERATIONS
MAX. SWL 10,000 lbs
MAX. SWL 10,000 lbs
ACME
5 TON
5
TON
Never hoist a load
over the heads of
employees
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29 CFR – 1910.179(n)(3)(vi)
The employer shall require that the operator avoid carrying loads over people.
1. Never allow a rigger to stand under a load as it descends for the purpose of
controlling it.
2. Use a tag line instead.
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SAFE CRANE OPERATIONS
MAX. SWL 10,000 lbs
MAX. SWL 10,000 lbs
ACME
5 TON
The employer shall
insure that the
operator does not
leave his position at
the controls while
the load is
suspended.
5
TON
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29 CFR – 1910.179(n)(3)(x)
The employer shall insure that the operator does not leave his position at the
controls while the load is suspended.
1. Always put the load down and secure it before leaving the area.
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SAFE CRANE OPERATIONS
MAX. SWL 10,000 lbs
MAX. SWL 10,000 lbs
ACME
ACME
55 TON
TON
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.
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29 CFR - 1910.179(n)(3)(vii)
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.
1. As brakes become worn, they may stop a smaller load, but not one at or near
capacity.
2. It is good practice to load test your crane at least every 3-4 years.
38
SAFE CRANE OPERATIONS
MAX. SWL 10,000 lbs
MAX. SWL 10,000 lbs
ACME
5 TON
The load shall not be
lowered below the
point where less than
two full wraps of rope
remain on the hoisting
drum.
5
TON
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29 CFR - 1910.179(n)(3)(viii)
The load shall not be lowered below the point where less than two full wraps of
rope remain on the hoisting drum.
1. You never want to run out of hoist line. Many cranes have automatic stops that
can be set so this will not happen. Still it is good practice to check you line when
lowering loads down close to the limit of your line.
39
SAFE CRANE OPERATIONS
At the beginning of each
operator's shift, the
upper limit switch of
each hoist shall be tried
out under no load.
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29 CFR - 1910.179(n)(4)(i)
At the beginning of each operator's shift, the upper limit switch of each hoist shall
be tried out under no load. Extreme care shall be exercised; the block shall be
"inched" into the limit or run in at slow speed. If the switch does not operate
properly, the appointed person shall be immediately notified.
1. The upper limit switch will keep the load or hook from being pulled into to
hoist, possibly parting the line.
2. Never use the limit switch to operate lower your load.
40
SAFE CRANE OPERATIONS
•
•
•
•
•
•
•
•
•
•
•
Read and understand the operators manual
Follow all placards, warning labels and signs on machine
Know the SWL of the crane and never exceed it
Determine the weight of the load from accurate sources
If an estimate of the load is near the max. capacity of the crane,
then use a dynamometer to measure the exact weight
Use a loud signal, such as a whistle, horn or bell or verbal
warning to alert employees of crane movement
Never hoist a load over the heads of employees
Never use limit switches or end stops as operating controls
Begin each shift by testing the upper limit switches
Avoid running the crane into the end stops or limit switches
Never walk backward when guiding a load
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Summary of safe crane operations
41
SAFE CRANE OPERATIONS
• Never hoist two or more separately rigged loads on a single hook
even if the combined weight is within the capacity of the crane
• Never wrap the hoist line around the load
• Never electrical load and/or hoist-limit switches or warning devices
• Start lifts slowly and avoid shock loading
• Always place the hook directly over the center of gravity or the
designated lifting point
• Use taglines to help maneuver the load
• Never use taglines to swing the load
• Before hoisting the load, check for loose parts that might shift or fall
• On cranes with wire rope hoist lines, there should never be less than
two wraps on lagged (grooved) drums and three wraps on unlagged
• When lifting near or at capacity, test the brakes after the load is
raised a few inches
• Suspend and transport loads at a level that allows the operator a
clear view
• Never drag slings, cables or chains across the floor
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Summary of safe crane operations
42
SAFE CRANE OPERATIONS
Cab-operated overhead cranes:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Enter and exit cab only through approved access ways
Never walk along runway tracks
Never climb or jump from one crane to another
Use both hands to climb access ladder
Keep unnecessary items out of the cab
Complete the pre-shift inspection checklist before operation
Know the location of emergency shutoff switches
Know emergency evacuation routes
Place all controls in the OFF position before turning the main switch ON
Maintain a portable fire extinguisher in the cab
Never move the cab without a signal from the designated signal giver
Avoid bumping crane and carriage stop blocks
If a power failure occurs, place all controls in the OFF position
Park the cab in an approved, designated position
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Summary of safe crane operations
43
HAND SIGNALS
Multiple Trolleys
Lower Load
Bridge Direction
Trolley Direction
Move Slowly
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Raise Load
Stop
Emergency Stop
A
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1. Hand signal charts should be posted in the work area.
2. Always have one person designated as the signal giver.
3. Use clear precise motions.
4. Review each hand signal and any other hand signals you might be using
5. Anyone can give the emergency stop signal.
44
WIRE ROPE SLING INSPECTION
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1. Wire rope slings are to be inspected on a regular basis and a record kept of
these inspections. Refer to the inspection card for inspection criteria.
2. As of July 2000 wire rope slings are to have a tag which indicates the lifting
capacities of the sling for vertical, choker, and basket hitches.
45
COMMON CAUSE FOR REMOVAL
Severe wear, abrasion or scraping
Kinking
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A
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1. Kinking in the eyes and other parts of the wire rope sling is nearly always the
result of it going around a pin or pick point that is of a less diameter than the
rope itself.
2. Using slings with thimbles in the eye will prevent this.
3. It is not recommended using a wire rope sling in a tight choker.
46
FLEMISH EYE
Separate rope into 2 part,
3 adjacent strands and 3
adjacent strands and core.
These 2 parts are re-laid
back in opposite directions
to form an eye and the ends
are secured with a pressed
steel sleeve.
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1. The Flemish eye is also know as a “Molly Hogan” or a “Farmers” eye.
2. The strength of the eye is in the wrap and not the steel sleeve.
3. They may be used with a thimble also.
47
TURNBACK EYE
PRESSED STEEL SLEEVE
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A
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1. Turnback eyes are made by bring the rope back onto itself and crushing a
steel sleeve around it.
2. The strength of the eye is in the sleeve and if not done properly may pull out.
3. Turnback eyes are not recommended for lifting.
48
TYPES OF TERMINATIONS
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1. Wedge sockets are very handy if you are changing blocks or hooks often.
2. Slings should not be used that have eyes made with wire rope clips.
3. Eyes made with wire rope clips may be used to terminate the dead end of the
hoist line.
49
CHAIN SLING INSPECTION
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1. Chain slings are to be inspected on a regular basis and a record kept of these
inspections. Refer to the inspection card for inspection criteria.
2. Chain slings are often used to hold steel while it is being welded. Always
check to make sure no heat damage has occurred. Heat damage can be detected
by discolored metal.
50
SYNTHETIC SLING INSPECTION
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1. This slide and the next two show the different types of sling damage that can
occur. Refer to the inspection record of additional inspection criteria.
2. Synthetic slings are required to be inspected on a regular basis and a record kept
of such inspections.
3. Never tie a knot in a flat sling to shorten it.
4. Never use synthetic slings around high heat sources or hot work.
5. When taking a sling out of service, cut the eyes in it or destroy it. If you don’t it
may find its way back into service.
51
SYNTHETIC SLING INSPECTION
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1. The manufacturer’s tag should be on the sling and contain the SWL.
2. This tag must also be legible.
3. Nylon slings are also susceptible to damage through ultra-violet light. Always
keep your slings out of the sun when not in use.
4. Wet nylon slings can be used but lose 15% of their strength.
52
SHACKLES
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DEFORMATION
BOLT SUBSTITUTION
WEAR
A
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1. Shackles must be load rated and have the WLL written on them along with the
manufacturer and country where they were made.
2. Only shackles of the screw pin or bolt type may be used for lifting.
3. If a shackle is used as a permanent part of the hoist line, then it must be
moused closed or use the bolt type with a cotter pin.
4. Shackle that only use a cotter pin to keep the pin in are not legal for lifting.
When inspecting them, look for:
•
Wear
•
Deformation
•
Pin or bolt substitution
•
Non-rated shackles
•
Worn threads on the pin
53
SHACKLES
IN-LINE
45 DEGREES
90 DEGREES
LOAD
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Side Loading Reduction Chart
For Screw Pin & Bolt Type Shackles Only†
Angle of Side Load
0° In-Line
45° from In-Line
90° from In-Line
Adjusted Working Load Limit
100% of Rated Working Load Limit
70% of Rated Working Load Limit
50% of Rated Working Load Limit
† DO NOT SIDE LOAD ROUND PIN SHACKLES
A
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1. The working load limit, WLL, shown on the shackle is for vertical loads.
2. Round pin shackles are ones which do not have a nut on the end of the pin and
should not be used for lifting..
54
EYE BOLTS
WRONG!
DO NOT REEVE SLINGS ONE EYE BOLT
TO ANOTHER. LOAD ON BOLT IS ALTERED.
DIRECTION OF PULL
In-Line
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ADJUSTED WORKING LOAD
CAUTION!
Full Rated Working Load
45 Degrees
30% of Rated Working Load
60 Degrees
60% of Rated Working Load
STRUCTURE MAY BUCKLE FROM
COMPRESSION FORCES.
A
S
1. The rated capacity of a eye bolt drops significantly when pulled other than
vertically.
2. Emphasize the dramatic drop to the students.
3. Threading a sling through the eye bolts increases the stress on the eye bolts by
two and should never be done.
55
BELOW-THE-HOOK LIFTING DEVICES
BALANCED
“C” HOOK
COIL
LIFTING
HOOK
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BALANCED
PALLET FORK
TELESCOPIC
COIL GRAB
A
S
1. These are a few of the types of below-the-hook lifting devices. There are
many more.
2. Be careful of home-made lifting devices.
3. Any lifting device must be load rated and have a manufacturer’s nomenclature
plate on it indicating its weight and SWL.
4. Add pictures of the different types of lifting devices you have at your facility,
including: spreader and lifting beams, plate clamps, barrel clamps or hooks.
56
SLING ANGLES
Tension in slings
Sling Angle
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Compression in load
Stresses in the slings and the load increase as the sling angle decreases
A
S
1. When slings are brought together and form a hitch arrange as shown above the
stresses in the slings increase and a compression force on the load is created.
2. As the sling angle decrease the stresses in the sling and on the load increase.
57
l bs
57
5
500 lbs
500 lbs
60°
1000 lbs
70
5
lb
s
70
5
lb
45°
bs
1000 lbs
5l
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1000 lbs
SLING ANGLES
1000 lbs
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s
l
00
10
10
00
bs
30°
lbs
s
5735 lb
5735 lb
s
5°
1000 lbs
1000 lbs
1000 lbs
A
S
1. Review each of the different sling angle configurations and point out the increase
in the stresses.
2. Sling angles of 60 degrees are the best to use because of the minimal increase of
stress in the slings. When required to use smaller sling angles, slings need to be
selected based on the increased stress and not on the weight of the load.
3. When the sling angle is 30 degrees for a 1000 lbs load, the compression loads
which are crushing the load will be 866 lbs. Depending on the structural strength of
the load, it may be damaged.
58
500 lbs
500 lbs
SLING ANGLES
Load in each sling
leg = 500 x Load
Angle Factor
L
Factor of
Angle “A”
1000 lbs
H
A
A
1000 lbs
1000 lbs
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Load Angle Factor = L/H
Sling Angle Degree (A)
90
1.000
1.155
60
50
1.305
45
1.414
2.000
30
Load On Each Leg Of Sling = (Load / 2) X Load Angle Factor
A
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1. All that is need to calculate these stress is the weight of the object and a
measuring tape.
2. As shown in the slide above, the length of the sling is divided by the height of
the sling connection to the top of the load.
3. The answer is then multiplied by the portion of the load it is to support and this
will be the stress in the sling.
Example: If my sling was 8 feet long and the height ‘H’ was 4 feet, 8 divided by 4
equals 2. The portion of the weight the sling is to support is half of 1000 lbs or 500
lbs. 2 X 500 = 1000 lbs which is the stress in the sling.
59
ESTIMATING WEIGHTS
Acceptable methods of determining weight
You may find the weight from:
Data on manufacturing label plates.
Manufacturer documentation.
Blueprints or drawings.
Shipping receipts.
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Weigh the item.
Bill of lading (be careful)
Stamped or written on the load
Approved calculations
Never use word of mouth to establish the weight of and item!
1.
2.
3.
4.
A
S
Knowing the weight of the load is critical to a safe lift.
Not all information is reliable.
The surest way to find the weight is to weigh the load.
If the object is solid and made up primarily of one material then you
could calculate the weight.
60
ESTIMATING WEIGHTS
Calculating the weight
To find the weight of any item you need to know its volume and unit weight.
• Volume x Unit weight = Load weight
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• Unit weight is the density of the material
• Unit weight is normally measured by pounds per cubic foot.
A
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1. Anytime you calculate the weight it is really only an estimation. But it will get
you in the “ball park”.
2. Always error on the safe side in your calculations.
61
ESTIMATING WEIGHTS
Here are some examples
of common materials and
their unit weight:
The unit weight is:
pounds per cubic foot
METALS
Aluminum
Brass
Bronze
Copper
Iron
Lead
Steel
Tin
MASONARY
Ashlar masonry
Brick, soft
Brick, pressed
Clay tile
Rubble masonry
Concrete, cinder, haydite
Concrete, slag
Concrete, stone
Concrete, reinforced
MISC.
Asphalt
Glass
165
535
500
560
480
710
490
460
160
110
140
60
155
110
130
144
150
TIMBER
Cedar
Cherry
Fir, seasoned
Fir, wet
Hemlock
Maple
Oak
Pine
Poplar
Spruce
White pine
Railroad ties
LIQUIDS
Diesel
Gasoline
Water
EARTH
Earth, wet
Earth, dry
Sand and gravel, wet
Sand and gravel, dry
34
36
34
50
30
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30
30
28
25
50
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80
160
52
45
64
100
75
120
105
A
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1. It’s wise to have similar “cheat sheets” for materials that you handle frequently.
2. Knowing the unit weight of different materials helps in weight estimation.
3. Knowing the difference between steel (490 lbs), reinforced concrete (150 lbs),
and wood (25-65 lbs) is useful.
62
CALCULATING VOLUME
2 ft high
Volume of a cube
8 ft long
Length x Width x Height = Volume
8 ft x 4 ft x 2 ft = 64 cubic feet
4 ft wide
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If the material was cedar, then all we would have to do to determine
it’s weight would be to multiply the unit weight of cedar x 64.
Unit weight x Volume = Weight
34 lbs. X 64 cubic ft. = 2,176 lbs.
A
S
1. Cubes are easy to calculate.
2. Finding the weight is as simple as multiplying the volume of the cube by the
unit weight of what it is made of.
63
CALCULATING VOLUME
Volume of a cylinder
10 ft long
Pi x Radius Squared x Length = Volume
π x Radius² x Length = Volume
3.14 x 1² ft x 10 ft = 31.4 cubic ft
2 ft wide
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If the material was reinforced concrete, then all we would have
to do to determine it’s weight would be to multiply the unit weight
of reinforced concrete x 31.4.
150 lbs. X 31.4 cubic ft. = 4,710 lbs.
A
S
1. The volume of a cylinder is a little more difficult, but not rocket science.
Having a scientific calculator and knowing how to use it is a good idea.
2. Again, just multiply the volume in cubic feet by the unit weight to find the
weight of the load.
64
CALCULATING VOLUME
8 ft long
Volume of pipe
Calculating the volume of pipe is a bit trickier but it is
just simply subtracting
the volume of the hole from the volume of the pipe.
If the pipe were one inch thick,
three feet wide and 8 feet long,
then we would figure the volume
of the entire pipe and subtract the
volume of the hole to get the the
volume of the material.
1 in. thick
3 ft wide
3.14 x (1 ½ ft.)² x 8 feet = total volume of pipe (56.52 ft³)
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3.14 x (1ft 5 in.)² x 8 feet = volume of hole (50.41 ft³)
56.52 ft³ – 50.41 ft³ = 6.11 ft³
Volume of material x unit weight = total weight
If this pipe were steel then the unit weight would be 490
lbs.
6.11 x 490 lbs = 2,9994 lbs.
A
S
1. Finding the volume of a pipe is not too much different than finding the volume
of a cylinder. You just have to do it twice and then subtract the volume of the
hole from the total volume of the pipe.
2. It is helpful to know how to change fractions into decimals. Calculators are a
must for this. To change 1 foot 5 inches (or 17/12ths) into a decimal, simple
divide 12 into 17 which would be 1.4266.
65
CALCULATING VOLUME
For thin pipe a quick way to *ESTIMATE the volume is to split the pipe
open and calculate the volume like a cube. The formula would be:
π x diameter = width, so:
π x diameter x length x thickness x unit weight = weight of object
3.14 x 3 ft x 8 ft x 1/12 ft (or .08 ft) x 490 lbs = *3,077.2 lbs
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8 ft long
1/12 ft = 1 in. thick
3.14 (π) x 3 ft diameter = 9.42 (width)
A
S
1. This is only an estimate and should not be used with thick pipe.
2. Simply spit the pipe down the middle and open it up into a thin plate.
3. Then calculate the the volume of the cube that is created.
4. To find the width, multiply pi times the diameter.
66
WEIGHT TABLES
WEIGHT TABLES
Weight tables are an excellent way to calculate load weight.
If you are handling certain materials often, then having a chart
that gives you the weight per cubic foot, cubic yard, square foot,
linear foot or per gallon. Here are a few examples:
METAL PLATES
STEEL PLATES weigh approximately 40 lbs per sq. ft. at 1 inch thick.
1/2 inch thick would then be about 20 lbs. per sq. ft.
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A steel plate measuring 8 ft. x 10 ft. x 1/2 inch would then weigh about
3,200 lbs.
(8 x 10 x 40 lbs = 3,200 lbs.)
BEAMS
Beams come in all kinds of materials and shapes and lengths. STEEL
I-BEAMS weigh approximately 40 lbs a linear ft. at 1/2 inch thick and
8 inches x 8 inches. If it were 1 inch thick then it would be 80 lbs a
linear ft. If it were 20 feet long at 1 inch thick then it would weigh about
1,600 lbs.
(20 ft. x 80 lbs. = 1,600lbs.)
A
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