PNNL Hoisting and Rigging Manual
Overhead and Gantry Cranes
This section applies to overhead and gantry cranes, including semigantry, cantilever gantry, wall cranes, storage bridge cranes, and others having the same fundamental characteristics. These cranes may be top-running, under-running, single- or double-girder (see Figure 1, Crane Types). Hoist units and trolleys are most commonly electric powered, but can be air powered or hand chain operated. These cranes may be cab operated, pulpit operated, floor operated, or remotely operated. Such cranes are grouped together because all have trolleys and similar travel characteristics and are governed by Occupational Safety and Health Administration (OSHA) regulation, 29 CFR 1910.179, Overhead and Gantry Cranes.
Inspection, Maintenance, and Testing
Inspection requirements shall be derived from information provided by the crane manufacturer. Unless there is justification to do otherwise, the manufacturer's recommendations shall be followed. Inspection procedures should state the acceptance criteria for inspections and tests and shall be specific for the applicable make and model of crane.
Before initial use, new, reinstalled, altered, modified, or extensively repaired cranes shall be inspected in accordance with a written procedure. This inspection shall include the following functions: 1) hoisting and lowering, 2) trolley travel, 3) bridge travel, and 4) limit switches and locking and safety devices.
Pre-use and Daily Inspection
The crane custodian shall be notified and deficiencies shall be carefully examined and a determination made as to whether they constitute a hazard.
On each shift, before operating the crane, the operator shall perform the following operations:
- Test All Controls. If any controls do not operate properly, they should be adjusted or repaired before operations are begun.
- Verify Operation of the Primary Upper-Limit Device. The trip-setting of primary upper-limit switches shall be checked under no-load conditions by inching the block into the limit e.g., (running at slow speed).
- Visually Inspect Ropes and Load Chains. These visual observations should be concerned with discovering gross damage that may be a hazard.
- Ensure inspections (e.g., wire rope, chains, and crane) are current via inspection sticker, other documentation, or verbal confirmation from equipment custodian.
Each day of use, the operator shall carefully scan the crane for deficiencies that may occur between regular inspections including the following:
- check that motions are smooth and regular with no hesitations, vibration, binding, weaving, unusual noise, or other irregularity
- check for deterioration or leakage in lines, tanks, valves, drain pumps, and other parts of air or hydraulic systems.
Cranes in Regular Service, Inspection Interval—Cranes that are in use shall have visual.
Inspection by the operator or other designated personnel with records not required1 as follows:
- Normal service - monthly.
- Heavy service - weekly to monthly.
- Severe service - daily to weekly.
Note: For service definitions see Definitions and Acronyms, crane service.
Cranes Not in Regular Service. A crane that is used in infrequent service that has been idle for 1 month or more, but less than 6 months, shall receive a frequent inspection before being placed in service.
Instructions. The equipment custodian shall ensure that frequent inspection instructions are readily available.2 The frequent inspection instructions or an attachment thereto, shall state how deficiencies shall be reported.
Frequent Inspection Steps. The operator or other designated personnel shall perform the following.3
- Check that motions are smooth and regular for all speed steps, with no hesitations, vibration, binding, weaving, unusual noise, or other irregularity.
- Ensure that hooks and hook throat latches, if installed, show no noticeable damage, wear, or deformation.
- Ensure that brakes operate smoothly.
- Visually ensure that hoisting ropes4 and/or chains are in good condition. The hoist chain shall feed smoothly into and away from sprockets. Inspect the chain for excessive wear, twist, distorted links interfering with proper function, or stretch. Inspect hoist ropes for proper spooling onto the drums and sheaves.
- Ensure that there is no visible leakage of lubricant.
- Check the trip-setting of primary upper-limit switches under no-load conditions by inching the block into the limit (running at slow speed).
- If the crane is equipped with a lower-limit switch, check the lower-limit switch by slowly moving the block into the switch (no load on hook). The drum should be observed during this operation to ensure that at least two full wraps of wire rope remain on the drum at the lower limit.
- For a cab-operated crane, check for a charged 10BC (or larger) fire extinguisher and ensure that the extinguisher inspection tag is current.
- Complete any other inspections that are specific for the crane.
Cranes in Regular Service, Inspection Interval—Cranes that are in use shall be visually inspected by a qualified inspector who will document apparent external conditions. These documents will provide the basis for a continuing evaluation, as follows:
- Normal service - yearly.
- Heavy service - yearly.
- Severe service - quarterly.
Cranes Not in Regular Service. A crane that is used infrequently and has been idle for a period of 6 months or more shall receive a periodic inspection before being placed in service.
Qualified Inspector. A qualified inspector shall perform periodic inspections.
Requirements of Periodic Inspection Procedure. A periodic inspection procedure shall provide specific inspection requirements and methods. Inspection acceptance criteria shall be provided with the inspection procedure or by reference to another document that is available to the inspector. The procedure shall be based on the requirements and recommendations of the manufacturer (or qualified engineer in the absence of manufacturer recommendations), and the activity, operating environment, severity of service, and equipment history. A periodic inspection checklist follows:
- Include pre-inspection safety requirements (e.g., lock and tag requirements) and ensure that the crane is in the proper location for inspection.
- Include inspections recommended by the manufacturer or a qualified engineer.
- Require a check of all limit devices, including hoist limit switches and bridge and trolley travel limit switches.
- Require a check of functional operating mechanisms.
- Require a check of control systems, if applicable, to include electrical apparatus for signs of pitting or any deterioration of visible controller contacts.
- Require a check for leakage in lines, tanks, valves, pumps, and other parts of air or hydraulic systems.
- Require a visual inspection of hooks for cracks, increased throat opening, twists, damage to hook retaining nuts, collars, or pins, and welds or rivets used to secure the retaining members. (See Hooks.)
- Require inspection for deformed, cracked, or corroded members.
- Require an inspection for loose bolts or rivets.
- Require an inspection for cracked or worn sheaves, drums, and load or idler sprockets.
- Require an inspection of running ropes and/or load chain, including end connections.
- Require an inspection for worn, cracked, or distorted parts such as pins, bearings, shafts, gears, rollers, locking and clamping devices.
- Require a check of brake systems parts, lining, pawls, and ratchets.
- Require a check of rail alignment and rail condition.
- Require a check of load, wind, and other indicators over their full range, for any significant inaccuracies.
- Require a check of gasoline, diesel, electric, or other power plants for improper performance or noncompliance with applicable safety requirements.
- Provide a document on which to record measurements, tests, or examinations.
- State the acceptance criteria for measurements, tests, and examinations.
- Provide specific "how-to"-type instructions for any inspection activity that is not "common sense" to qualified inspection personnel.
Note: See Wire Rope Inspection regarding wire rope periodic inspection requirements. See Monthly Chain Inspection and Load Chain Inspection regarding load chain periodic inspection.
The responsible engineering or maintenance organization should use predictive maintenance examinations or tests as necessary to diagnose problems and predict maintenance requirements (e.g., chemical/microscopic tests of used lubricants and vibration analysis of rotating equipment).
Wire Rope Inspection
Monthly Wire Rope Certification. For in-service cranes (overhead traveling cranes and gantry cranes), a monthly documented rope inspection is required. Cranes not in regular use that have been idle for 1 month or more, but less than 6 months shall have an inspection before returning to service. Cranes that have been out of service for more than 6 months shall have a periodic wire rope inspection before returning to service. Monthly inspection shall be performed in accordance with Wire Rope.
Periodic Wire Rope Inspection. Periodic wire rope inspection is required. Periodic inspection, more thorough than the monthly rope inspection, should be performed in conjunction with and on the same schedule with the crane periodic inspection as required by Periodic Inspection. See Wire Rope for rope inspection details.
Monthly Chain Inspection (Welded Link and Roller Type)
Monthly Chain Inspection. For overhead and gantry cranes that are in service, load chains shall be inspected monthly. Cranes not in regular use that have been idle for 1 month or more, but less than 6 months, shall have a chain inspection, equal to a monthly chain inspection, before returning to service. This inspection shall include end connections and the hoist chain to check for excessive worn, twisted, or distorted links interfering with proper function, or stretching beyond manufacturer's recommendations. This inspection shall be documented with a certification record that includes the date of inspection, the signature of the person who performed the inspection, and an identifier of the chain that was inspected.
A checklist near the operator's station is recommended. Cranes (with load chain) that have been out of service for more than 6 months shall have a periodic load chain inspection before returning to service.
Load Chain Inspection (Welded Link and Roller Type)
Periodic Load Chain Inspection, Welded Link
Periodic load chain inspection should be performed in conjunction with the overall crane periodic inspection. Periodic load chain inspection, more thorough than the monthly inspection, shall include a careful link-by-link inspection of load chain as follows:
- check for link wear to less than 90% of the original bar diameter
- check for nicking, cracking, or corrosion of a link that, when ground out to a smooth surface, leaves less than 90% of the original bar diameter
- check for stiffening or poor hinging of linkage
- check for distortion by bending or kinking of 15% of any overall link dimension
- check for evidence of heat damage
- check for elongation in excess of the manufacturer's recommended allowable
- check for worn, nicked, or corroded fittings.
Note: See Hoist Rope and Load Chain Replacement, bullet 2, regarding welded link-type load chain replacement.
Periodic Load Chain Inspection, Roller Type
Test the hoist under load in lifting and lowering directions and observe the operation of the chain and sprockets. The chain should feed smoothly into and away from the sprockets.
If the chain binds, jumps, or is noisy, first see that it is clean and properly lubricated. If the trouble persists, inspect the chain in accordance with the following:
- Roller chain should first be inspected while it is in the hoist space. With the hoist suspended in normal position, apply a light load of approximately 100 lbs.
- Check for elongation following the hoist manufacturer's instructions. In absence of specific instructions, the chain can be checked by determining the normal pitch and measuring a 12-inch (30.5 centimeter) section of chain that normally travels over the load sprocket. Using a caliper-type gage, check the dimension from the edge of one chain pin to the corresponding edge of another pin for the number of pitches per foot. If elongation exceeds 0.25 inch (6.3 millimeters) in 12 inches (30.5 centimeters) the chain shall be replaced. For example, a 0.75-inch pitch chain should measure 12 inches over 16 pitches. Chain shall be rejected if measurement over 16 pitches exceeds 12.25 inches.
- Check chain for twist. The chain shall be replaced if the twist in any 5 feet (1.52 meters) section exceeds 15 degrees.
- Check for straightness in plane perpendicular to plane of rollers. A chain that has a bow exceeding 0.25 inch (6.3 millimeters) in any 5-foot (1.52 meter) section shall be replaced.
- Additional inspection of the chain should be made by removing chain from hoist and cleaning it thoroughly in an acid-free solvent. A check should then be made for any of the following deficiencies:
- pins turned from their original position
- rollers that do not run freely with light finger pressure
- points that cannot be flexed by easy hand pressure
- side plates that are spread open (a visual check of the pin head extension at the damaged area, as compared to the pin extension at a free end of the chain, can determine the amount of spread and the condition of the chain)
- corrosion, pitting, or discoloration of chain (generally indicative of serious impairment)
- gouges, nicks, or weld splatter.
Note: See Hoist Rope and Load Chain Replacement, item 3, regarding roller-type load chain replacement.
Inspection of Cranes Not in Regular Use
Cranes that are out of service shall be inspected before being returned to service. The following identifies inspection requirements for returning cranes to service:
Idle greater than 1 month. A crane that has been idle more than 1 month, but less than 6 months, shall be given a frequent inspection and a documented monthly hook, rope, or load chain inspection.
Idle greater than 6 months. A crane that has been idle more than 6 months shall have a periodic inspection, including a documented hook, rope, or load-chain inspection.
Standby. Standby cranes shall have a frequent inspection and a documented (equivalent to monthly) hook, rope, or chain inspection every 6 months.
Note: Cranes that are out of service AND are exempt from inspections shall be tagged out of service in accordance with the facility-specific lock and tag procedure. Standby cranes are not out of service.
Hooks shall be inspected in conjunction with the frequent and periodic crane inspection. Monthly documented hook inspection is required. See Hooks for hook inspection details.
Inspection records shall be kept throughout the life of the crane indicated as follows:
Pre-Use and Frequent Inspection. No records retention is required. A frequent inspection verification checklist is recommended.
Monthly Hook, Wire Rope, and Load Chain Inspection. The most recent records, dated and signed by a qualified inspector, shall be retained in the crane maintenance file.
Periodic Inspection. The most recent records, dated and signed by a qualified inspector, shall be retained in the crane maintenance file.
A preventive maintenance program based on the crane manufacturer's recommendations shall be established. If the manufacturer's recommendations are not available or complete, a preventive maintenance program shall be developed by the responsible maintenance or engineering organization.
Preventive Maintenance Procedure
Preventive maintenance shall be performed in accordance with written procedures. Procedures shall state specific precautions, such as lock and tag requirements, to be taken before beginning maintenance. A copy of the preventive maintenance procedures shall be retained in the crane history file.
The most recent copy of dated records that document maintenance of critical items such as hoisting machinery, sheaves, hooks, chains, ropes, and other lifting devices shall be retained in a maintenance file. Maintenance records shall be retained in the crane history file, or an electronic recordkeeping system may be used. If a computer system is used, and maintenance records are not retained in the crane history file, the crane history file shall state where the electronic maintenance records are available.
Precautions Before Maintenance. Before adjustments or repairs are started, the following precautions shall be taken, as applicable.
- The crane to be repaired shall be moved to a location where it will cause the least interference with other equipment and operations in the area.
- Controllers shall be set in the off condition.
- The main switch (crane disconnect) shall be de-energized and locked, tagged, or flagged in the de-energized position.
Note: Facility-specific lock and tag procedures shall be strictly followed. While maintenance is under way, "Warning" or "Out of Order" signs shall be placed on the crane. If personnel have access to the floor beneath the crane, place warning signs that are visible from the floor.
- Lock and tag procedures shall be followed.
- Effective markings and barriers shall be used when maintenance work creates a hazardous area on the floor beneath the crane or crane runway.
- Where other cranes are in operation on the same runway, rail stops or other means shall be provided to prevent interference with the idle crane or work area.
- Where temporary protective rail stops or other means are not available or practical, a signal person shall be placed at a visual vantage point for observing the approach of an active crane and warning its operator when reaching the limit of safe distance from the idle crane or work area.
- Only trained personnel shall work on energized equipment when adjustments and tests are required.
After maintenance work is completed and before restoring the crane to normal operation, the following activities shall be completed:
- Guards shall be reinstalled.
- Safety devices shall be reactivated.
- Replaced parts and loose material shall be removed.
- Maintenance equipment shall be removed.
Adjustments and Repairs
Any hazardous conditions disclosed by inspection or during operation shall be corrected before normal operation of the crane is resumed. Adjustments and repairs shall be done only by designated personnel.
Adjustments shall be maintained to ensure correct functioning of components. The following are examples:
- functional operating mechanisms
- limit devices
- control systems
Repairs or replacements shall be made as needed. The following are examples:
- Crane hooks showing indications described in Hooks shall be repaired or replaced.
- All critical parts that are cracked, broken, bent, or excessively worn shall be replaced.
- Pitted or burned electrical contacts should be corrected only by replacement and in sets. Control parts should be lubricated as recommended by the manufacturer.
- Function labels on pendant control stations shall be kept legible.
- If repairs of load-sustaining members are made by welding, identification of materials shall be made and appropriate welding procedures shall be assigned by a qualified welding engineer. The welds shall be made by a qualified welding operator.
Hoist Rope and Load Chain Replacement
Replacement Rope. The end of the rope shall be anchored by a clamp securely attached to the drum, or by a socket arrangement approved by the crane or rope manufacturer. For wire rope requirements, see Wire Rope.
Replacement Load Chain (Welded Link Type). The replacement welded link chain shall be the same size, grade, and construction as the original furnished by the crane or hoist manufacturer, unless use of a different type is justified. Repairing welded link chain by welding or heating shall not be attempted.
If for any reason a chain that is different from the original is used, or the original chain is unknown and the manufacturer is not available to specify the proper replacement, a qualified engineer shall approve the specification of the replacement chain.
Roller Chain Replacement. The roller chain shall be replaced if any of the conditions exist as stated in Load Chain Inspection (Welded Link and Roller Type). Repairing of roller chain by welding or heating shall not be attempted. Follow these guidelines:
- The replacement chain shall be the same size, grade, and construction as the original chain furnished by the hoist manufacturer unless otherwise recommended by the manufacturer because of actual working conditions.
- When the chain is replaced, disassemble and inspect the mating parts (sprockets, guides, and stripper) for wear; replace, if necessary.
- When the chain is replaced, it should be reeved in the recommended manner and should operate freely over all load and idler sprockets. All connecting links and chain end fasteners should be inspected and properly secured. The hoist manufacturer's recommendations should be followed on the selection and installation of connecting links.
- The roller chains, discarded or new, shall not be used for slings.
After Load Chain Replacement. After chain (roller type or welded-link type) replacement and before the initial load, do the following:
- Ensure that the proper chain is used.
- Ensure that chain limit overtravel restraint requirements are met to prevent the chain from running off the hoist.
- For hand-operated hoists, before the load chain can be completely run out of the hoist, it shall be restrained in the fully extended position.
- An electric- or air-powered hoist shall not be installed where the load hook can be lowered beyond rated hook travel under normal operating conditions unless the hoist is equipped with a lower limit device.
Whenever a load chain (welded link type or roller type) is replaced, the following most recent documentation shall be retained in the crane maintenance file:
- date replacement was completed
- purchase order (PO) number and PO item number, if known
- chain manufacturer
- size, grade, construction, and manufacturer's certification of the breaking strength.
Pre-operational Check After Maintenance or Repair
A pre-operational check shall be performed to verify the proper function of activities such as crane motion controls and interlocks. Special attention shall be given to those areas likely to have been affected by maintenance or repair.
A closely controlled lubrication plan is required to prevent over- or under- lubrication. The lubrication frequency shall be specified by the responsible engineering or maintenance organization and should be based on the manufacturer's recommendations. If inspection finds over- or under-lubrication, the lubrication method or frequency shall be adjusted. Lubricant types used on motors, bearings, gear boxes, and other lubrication points shall be specified by the responsible engineering or maintenance organization and should be as recommended by the crane manufacturer. Lubricants used on wire rope and chain should be as recommended by the manufacturer and shall be as specified by the responsible engineering or maintenance organization or qualified inspector.
- Normal Operation. Sheave bearings, including equalizer sheaves, shall be individually lubricated on a regular schedule.
- Load Blocks in Water. Load blocks that are immersed in water shall have special provisions to prevent lubricant loss to the water. In this case, lubrication frequency and lubricant type should be carefully evaluated.
Hoist Rope Lubrication. Hoist ropes, except for stainless steel rope (consult manufacturer), shall be lubricated. When ropes are immersed in water, the type of lubricant shall be selected to reduce the loss of lubricant to water.
Motor Lubrication. For those motors that require lubrication, a closely controlled lubrication plan is required.
Periodic Load Test
Scheduled load tests are not routinely required. Overhead and gantry cranes may be load tested up to 100% of rated capacity when (if) specified in a critical lift procedure. For cranes that frequently make critical lifts, especially if the lifts are at or near rated capacity, responsible management may implement a periodic load-test program. Such periodic load-tests shall not exceed the rated capacity. Responsible management shall set the load-test frequency. (A 5-year frequency is recommended.)
Cranes Removed from Service
At the discretion of facility management, a crane that has been out of service may be load tested before returning to service. Consider the following when determining whether a load test shall be required: 1) Will the crane make critical lifts? 2) What is the general condition and age of the crane? 3) What is the previous load test and maintenance history of the crane? This load test shall be done only after a return-to-service inspection is completed and should not exceed the rated capacity.
Before initial use, new, reinstalled, altered, repaired, or modified cranes shall be tested by a designated person to ensure that the crane is in good operating condition, including the following functions:
- lifting and lowering
- trolley travel
- bridge travel
- limit devices.
Check the hoist limit device(s), primary and secondary if so equipped, by slowly moving the block into the switch (no load on hook). Then check the hoist limit device(s) at increasing speeds up to the maximum speed.
The actuating mechanism of the upper-limit device shall be located or adjusted so that it will trip the device in sufficient time to prevent contact of the load block or load with any part of the trolley or bridge, travel-limiting devices and locking and indicating devices, if provided.
Note: Operational testing of altered, repaired and modified cranes may be limited to the functions affected by the alteration, repair, or modification, as determined by a qualified person.
Rated Load Test
New, reinstalled, altered, repaired, and modified cranes should be load-tested prior to initial use, as determined by a qualified person.
Load testing of altered, repaired and modified cranes may be limited to the functions affected by the alteration, repair, or modification, as determined by a qualified person. To resolve questions, the crane manufacturer should be consulted.
The replacement of load chain and rope is specifically excluded from load-test requirements; however, an operational test of the hoist shall be made in accordance with Operational Tests, before returning the crane to service.
When rope clips or wedge socket end connections are used on a load line, the hoist should be cycled several times with a load no less than the maximum operational load (normally 100% of the rated capacity). Next, if rope clips are used, check and retighten nuts to the recommended torque. If a wedge socket is used, verify that the rope is properly seated.
If a load test is conducted, the load shall be not less than 100% of the rated load of the crane or hoists, whichever governs; or more than 125% of the rated load of the crane or hoists, whichever governs; unless otherwise recommended by the manufacturer or a qualified person.
The load-test weight should be within a tolerance of (+0%, -5%) and shall be traceable to a recognized standard or verified by engineering calculations. Any one of the following options will meet this requirement:
- Use a calibrated (+0%, -5%) load-measuring device during the load test.
- Determine the test load with a calibrated load-measuring device before the test.
- Calculate the test load based on known unit weights and dimensions of the test fixture. Dimensions and calculations must be checked (signed and dated) by a qualified engineer and determined to be accurate within tolerance (+0%, -5%).
Prerequisite to Load Test
Load tests shall be performed only after inspection and maintenance of the crane are confirmed as current and any outstanding discrepancies have been addressed.
If a load test is conducted, it shall be performed as follows or as modified by a qualified person:
- Hoist the test load a distance to ensure the load is supported by the crane and held by the hoist brakes.
- Transport the test load by means of the trolley for the full length of the bridge.
- With the trolley as close as practical to one end of the crane, transport the test load by means or the bridge for the full length of the runway in one direction and in the other direction with the trolley as close as practical to the other end of the crane.
- Lower the load, and stop and hold the load with the brakes.
After the test is completed, the load-test report shall be signed and dated by the person in charge of conducting the load test. The person in charge shall ensure that the test is placed in the crane maintenance file.
Hook Non-destructive Testing
Hook nondestructive examination (NDE) is not routinely required before a load test. If the crane hooks are to have NDE, the NDE should be done after the load test.
Crane Maintenance Files
The crane maintenance file is a compilation of various documents and records relating to operation, maintenance, inspection, testing, evaluating and repair of the equipment. The file may be centrally located or proportioned into satellite holding areas. The methods selected for establishing adequate information retention and retrieval shall be determined by the equipment custodian, who is the responsible person for ensuring that a safe and reliable maintenance program is in place.
The crane maintenance file shall contain, as a minimum, the required current dated periodic inspection records and other documentation to provide the user with evidence of a safe and reliable maintenance program. Inspection records should be retained in a format and location that provides for ease in accessibility. Maintenance file information should provide a source for comparing present conditions with past conditions to determine whether existing conditions show a trending pattern of wear, deterioration, or other comparable factors that may compromise safe, continued use of the equipment. Length of record retention shall be determined by the equipment custodian's established maintenance program.
Figure 1 Crane Types
Figure 1-1. Top-Running Single-Girder Bridge with Underhung Trolley Hoist
Figure 1-2. Overhead Floor Operated Crane and Gantry Crane
Figure 1-3 Semigantry Crane
Figure 1-4. Wall Crane
Figure 1-5. Underhung Cranes
Underhung Floor-Operated Crane
Underhung Cab-Operated Crane
Figure 2. Hand Signals
2Inspection instructions provided by the manufacturer may be sufficient. For complex equipment or equipment in a hostile environment, a frequent inspection procedure prepared onsite may be needed.
4See Wire Rope for rope-inspection details.