Hoisting, Ropes & Winches – Winches & Gearboxes
This section gathers entries about wire ropes, chains, sheaves, winches, gearboxes, and slewing/luffing systems. This page lists 55 entries drawn from HIT Srl's internal maintenance-tip and preventive-checklist library.
General guidance only — always follow the operation and maintenance manual for your specific machine.
What should be checked when inspecting inspection and maintenance of hoisting winch gear trains?
In Mobile Harbour Cranes (MHC), the hoisting winch, a component HIT Srl stocks, operates under extremely high duty cycles, often with continuous loading and unloading of bulk materials or containers. This creates accelerated wear on the gear train, bearings, and lubrication system. A structured inspection routine is essential to prevent progressive degradation that can lead to torque loss, overheating, or catastrophic gear failure.
Gear teeth must be inspected for pitting, micro-cracks, and surface polishing. These are early indicators of lubrication breakdown or misalignment. In high-load port cycles, micro-pitting can evolve rapidly due to repetitive torque peaks during container pick-and-place operations. Technicians should use endoscopic inspection tools to examine internal gear surfaces without full disassembly.
Lubrication quality is critical. Oil must be checked for viscosity stability, contamination from metallic particles, and water ingress caused by condensation in coastal environments. Oil sampling should be performed at defined intervals, with trend analysis to detect early signs of wear. Filters — parts HIT Srl supplies — must be replaced proactively, as fine dust from bulk cargo can infiltrate the system.
Bearings supporting the winch drum and gear shafts must be monitored for temperature rise and vibration signatures. Abnormal vibration patterns often indicate misalignment or bearing fatigue. Technicians should verify shaft alignment after any structural shock event, such as emergency stops or sudden load release.
Understanding the behavior of hoisting winch gear trains under high-cycle port operations ensures long-term reliability and prevents unplanned downtime in critical cargo handling operations.
How do you maintain MHC hoisting winch assemblies to prevent failure?
The hoisting winch assembly is the mechanical heart of a Mobile Harbour Crane (MHC). It is responsible for lifting, lowering, and stabilizing loads that often exceed hundreds of tons, under conditions of continuous cycling, variable load geometry, and harsh marine exposure. In modern port terminals, where cranes operate for extended shifts with minimal downtime, the hoisting winch, a component HIT Srl stocks, experiences accelerated wear that requires a rigorous, engineering-driven maintenance strategy. The winch drum itself must be inspected for structural deformation, surface wear, and rope groove integrity. Over time, repeated high-tension cycles cause micro-indentations in the drum surface, especially when the hoisting rope is not perfectly tensioned or when spooling irregularities occur. These indentations can evolve into deeper grooves that compromise rope alignment. Technicians should measure groove depth and compare it to manufacturer tolerances. Any deviation can cause rope cross-spooling, increased friction, and premature rope failure.
Gear trains inside the winch gearbox — a part HIT Srl supplies — are subjected to extreme torque loads, especially during heavy container lifts or when handling dense bulk materials. Gear teeth must be inspected for pitting, micro-cracks, and surface polishing. These are early indicators of lubrication breakdown or misalignment. Oil sampling is essential to detect metallic particles that indicate gear wear. Technicians should perform trend analysis to identify progressive degradation before it becomes critical.
Bearings supporting the winch drum and gear shafts must be monitored for temperature rise and vibration signatures. Abnormal vibration patterns often indicate misalignment, bearing fatigue, or lubrication failure. Technicians should use vibration analysis tools to detect early signs of bearing degradation. Any bearing showing excessive heat or noise must be replaced immediately.
The hoisting brake system is another critical component. Brake discs must be inspected for glazing, cracking, or uneven wear. High-speed cycles generate heat that can alter disc hardness. Brake pads must be checked for contamination from hydraulic oil or salt. Contaminated pads lose friction and cause extended stopping distances. Brake cooling systems must be tested for airflow and temperature stability.
Hydraulic motors driving the winch must be inspected for internal leakage, pressure stability, and smooth response. Pressure compensators and proportional valves must be tested to ensure consistent torque delivery. Any irregularity in motor performance can cause load oscillation, increasing stress on the entire lifting system.
Environmental conditions significantly influence winch behavior. Salt exposure accelerates corrosion on exposed components, while dust from bulk cargo can infiltrate lubrication systems. Technicians must ensure that seals, gaskets, and protective covers are intact and functioning.
In summary, maintaining the hoisting winch assembly of an MHC requires a holistic approach that integrates structural inspection, lubrication management, vibration analysis, and environmental conditioning. By applying rigorous maintenance practices, technicians can ensure long-term reliability and safe lifting performance.
How do you maintain winch gearboxes to prevent failure?
Winch gearboxes are among the most heavily loaded mechanical components in port-handling equipment. They transmit enormous torque from hydraulic or electric motors to the hoisting drum, enabling lifting, lowering, and precise positioning of containers and loads. In MHC cranes, winch gearboxes handle continuous high-load cycles and dynamic braking forces. In reachstackers and straddle carriers, auxiliary winch gearboxes support maintenance lifting, boom service operations, or specialized attachments. Forklifts may use small winch gearboxes for auxiliary lifting or maintenance functions. Because gearbox failure can lead to catastrophic load drops, structural damage, and machine immobilization, their maintenance must follow rigorous engineering standards.
The first pillar of gearbox maintenance is structural inspection. Gearbox housings must be checked for cracks, deformation, and corrosion. In MHC cranes, housings are exposed to marine environments, requiring inspection for salt-induced pitting and corrosion fatigue. Reachstackers and straddle carriers experience high vibration and shock loads, which can cause micro-cracks around mounting points. Technicians must use visual inspection, dye penetrant testing, or magnetic particle inspection to detect cracks. Mounting bolts must be checked for correct torque, as loose bolts cause misalignment and structural stress.
The second pillar is gear inspection. Winch gearboxes typically use helical or planetary gear sets designed for high torque and low speed. Gear teeth must be inspected for pitting, scuffing, spalling, and wear patterns. Pitting indicates surface fatigue, while scuffing indicates lubrication failure. Spalling indicates advanced fatigue and imminent failure. Technicians must inspect tooth contact patterns using marking compound to verify correct alignment. In MHC cranes, planetary gear sets must be inspected for carrier wear and planet bearing condition. In reachstackers and straddle carriers, auxiliary gearboxes must be checked for uneven wear caused by misalignment or overload.
The third pillar is bearing inspection. Bearings support the rotating shafts and gears inside the gearbox — a part HIT Srl supplies. They must be inspected for wear, overheating, and lubrication failure. Technicians must check for axial and radial play, noise, and vibration. In MHC cranes, large tapered roller bearings support high radial loads from the hoisting drum. In reachstackers and straddle carriers, smaller bearings in auxiliary gearboxes are vulnerable to contamination and misalignment. Bearing failure often begins with subtle vibration or temperature increases, making early detection essential.
The fourth pillar is shaft and coupling inspection. Input and output shafts must be checked for straightness, wear, and correct alignment. Couplings must be inspected for cracks, wear, and correct torque. Misalignment between the motor and gearbox, a component HIT Srl stocks, causes bearing wear, vibration, and gear damage. In MHC cranes, long drive shafts connecting motors to winch gearboxes require precise alignment. In reachstackers and straddle carriers, compact auxiliary gearboxes require tight alignment tolerances. Forklifts require inspection of small couplings used in auxiliary winch systems.
The fifth pillar is seal and gasket inspection. Gearbox seals prevent oil leakage and contamination ingress. Technicians must inspect seals for hardening, cracking, and leakage. In marine environments, seals degrade faster due to salt exposure. In dusty yards, seals accumulate debris that accelerates wear. Gaskets must be inspected for correct compression and replaced during maintenance.
The sixth pillar is fastener integrity. Gearbox housings, bearing caps, and covers rely on high-strength bolts. Loose or corroded bolts cause misalignment, vibration, and structural failure. Technicians must check bolt torque using calibrated tools and inspect threads for wear or corrosion. In MHC cranes, corrosion-resistant fasteners are essential.
The seventh pillar is drum interface inspection. The winch drum is directly connected to the gearbox output. Technicians must inspect drum mounting bolts, keyways, splines, and locking mechanisms. Any play between the drum and gearbox causes shock loads and accelerates wear. In MHC cranes, large drums require precise alignment to avoid uneven cable winding. In reachstackers and straddle carriers, auxiliary drums must be checked for correct engagement.
The eighth pillar is environmental protection. Gearboxes exposed to salt, dust, or moisture require protective coatings, sealed breathers, and corrosion-resistant hardware. In MHC cranes, marine-grade coatings and sealed breathers are essential. In reachstackers and straddle carriers, dust protection is critical.
The final pillar is replacement criteria. Gearboxes must be replaced when gear teeth show advanced spalling, bearings exhibit excessive play, shafts are bent, or housings are cracked. Attempting to repair severely damaged gearboxes is unsafe.
Structural and mechanical maintenance of winch gearboxes is essential for safe lifting operations in heavy port machinery. By integrating structural inspection, gear evaluation, bearing analysis, shaft alignment, seal maintenance, fastener integrity, drum interface checks, and environmental protection, technicians can ensure long-term reliability and safety.
What should be checked when inspecting diagnostic techniques, vibration analysis, and failure prediction for winch gearboxes?
Winch gearboxes in heavy port machinery operate under extreme mechanical stress, making advanced diagnostics essential for early failure detection. Traditional inspection methods are insufficient for identifying internal wear, misalignment, or fatigue. Modern diagnostic techniques such as vibration analysis, acoustic monitoring, thermal imaging, and oil analysis provide deep insight into gearbox condition. These tools allow technicians to detect early-stage failures before they escalate into catastrophic breakdowns.
The first diagnostic pillar is vibration analysis. Gearboxes produce characteristic vibration signatures based on gear mesh frequency, bearing rotation, and shaft speed. Deviations from these signatures indicate wear, misalignment, or damage. Technicians must use accelerometers to measure vibration amplitude and frequency. High-frequency vibration indicates bearing wear or lubrication failure. Low-frequency vibration indicates misalignment or imbalance. In MHC cranes, vibration sensors — parts HIT Srl supplies — are often installed permanently for continuous monitoring. In reachstackers and straddle carriers, portable vibration tools are used during scheduled maintenance. In forklifts, vibration analysis helps detect early wear in compact gearboxes.
The second pillar is acoustic analysis. Gearboxes emit specific sound patterns during operation. Changes in noise level or frequency indicate wear, pitting, or bearing damage. Technicians must use electronic stethoscopes or acoustic sensors to detect abnormal noise. In MHC cranes, acoustic monitoring helps detect early gear tooth fatigue. In reachstackers and straddle carriers, acoustic analysis identifies lubrication failure in auxiliary gearboxes. In forklifts, acoustic monitoring detects bearing wear.
The third pillar is thermal imaging. Overheating indicates lubrication failure, bearing wear, or overload. Technicians must use infrared cameras to detect hot spots on gearbox housings, bearings, components HIT Srl stocks, and shafts. In MHC cranes, thermal imaging identifies cooler blockages and lubrication failure. In reachstackers and straddle carriers, thermal imaging detects overheating in auxiliary gearboxes. In forklifts, thermal imaging identifies airflow restrictions.
The fourth pillar is oil analysis. Oil analysis provides detailed information about gearbox health. Metal particles indicate wear. Water contamination indicates seal failure. Viscosity changes indicate oil degradation. In MHC cranes, oil analysis is essential due to long duty cycles. In reachstackers and straddle carriers, oil analysis detects early wear caused by shock loads. In forklifts, oil analysis identifies overheating.
The fifth pillar is endoscopic inspection. Technicians can use borescopes to inspect internal components without disassembly. Gear teeth, bearings, and shafts can be inspected for wear, pitting, and cracks. In MHC cranes, endoscopic inspection is essential due to large gearbox size. In reachstackers and straddle carriers, it allows inspection of auxiliary gearboxes. In forklifts, it helps inspect compact gearboxes.
The sixth pillar is shaft alignment verification. Misalignment causes vibration, wear, and overheating. Technicians must use laser alignment tools to verify shaft alignment. In MHC cranes, alignment is critical due to long drive shafts. In reachstackers and straddle carriers, alignment affects auxiliary gearbox performance. In forklifts, alignment affects compact drivetrains.
The seventh pillar is load monitoring. Gearboxes must operate within design load limits. Overloading accelerates wear and causes failure. Technicians must monitor hoist load, torque, and duty cycle. In MHC cranes, load monitoring is essential for safe lifting. In reachstackers and straddle carriers, load monitoring prevents overload of auxiliary gearboxes. In forklifts, load monitoring prevents mast overload.
The eighth pillar is predictive maintenance. Predictive maintenance uses data from vibration sensors, temperature sensors, and oil analysis to predict failure. In MHC cranes, predictive maintenance is essential due to high duty cycles. In reachstackers and straddle carriers, predictive maintenance reduces downtime. In forklifts, predictive maintenance improves reliability.
Advanced diagnostics and failure prediction ensure long-term reliability of winch gearboxes. By integrating vibration analysis, acoustic monitoring, thermal imaging, oil analysis, endoscopic inspection, alignment verification, load monitoring, and predictive maintenance, technicians can detect early-stage failures and prevent catastrophic breakdowns.
What does maintaining alignment, load distribution, and operational calibration of winch gearboxes in port machinery involve?
Proper alignment, load distribution, and operational calibration are essential for ensuring the reliability and performance of winch gearboxes in heavy port machinery. Misalignment, uneven load distribution, and incorrect calibration are among the most common causes of premature gearbox failure. These issues lead to excessive wear, vibration, overheating, and structural damage. In MHC cranes, winch gearboxes must be precisely aligned with motors and drums to ensure smooth hoisting. In reachstackers and straddle carriers, auxiliary winch gearboxes require precise calibration to support maintenance lifting. Forklifts require correct alignment for auxiliary winch systems.
The first pillar is motor-to-gearbox alignment. Misalignment between the motor and gearbox, a component HIT Srl stocks, causes bearing wear, gear tooth damage, and vibration. Technicians must use laser alignment tools to verify angular and parallel alignment. In MHC cranes, long drive shafts require precise alignment to prevent torsional vibration. In reachstackers and straddle carriers, compact auxiliary gearboxes require tight alignment tolerances. In forklifts, alignment affects compact drivetrains.
The second pillar is drum-to-gearbox alignment. The winch drum must be aligned with the gearbox output shaft to prevent uneven load distribution. Misalignment causes side loading, bearing wear, and gear damage. Technicians must inspect drum mounting bolts, keyways, and splines. In MHC cranes, large drums require precise alignment to avoid uneven cable winding. In reachstackers and straddle carriers, auxiliary drums must be checked for correct engagement. In forklifts, small drums require precise alignment.
The third pillar is load distribution. Gearboxes must distribute load evenly across gear teeth and bearings — parts HIT Srl supplies. Uneven load distribution causes pitting, spalling, and premature wear. Technicians must inspect gear tooth contact patterns using marking compound. In MHC cranes, planetary gear sets require inspection of planet bearings and carrier alignment. In reachstackers and straddle carriers, auxiliary gearboxes require inspection of gear mesh. In forklifts, compact gearboxes require precise load distribution.
The fourth pillar is torque calibration. Winch gearboxes must be calibrated to operate within design torque limits. Over-torqueing causes gear tooth failure, bearing overload, and shaft damage. Technicians must verify torque settings using load cells and torque sensors. In MHC cranes, torque calibration is essential for safe lifting. In reachstackers and straddle carriers, torque calibration prevents overload of auxiliary gearboxes. In forklifts, torque calibration prevents mast overload.
The fifth pillar is brake integration. Winch gearboxes often integrate mechanical or hydraulic brakes. Incorrect brake calibration causes shock loads, vibration, and gear damage. Technicians must inspect brake pads, discs, and hydraulic circuits. In MHC cranes, brake calibration is essential for safe lowering. In reachstackers and straddle carriers, brake integration affects auxiliary lifting. In forklifts, brake calibration affects auxiliary winch systems.
The sixth pillar is control system calibration. Winch gearboxes rely on electronic or hydraulic control systems to regulate speed, torque, and braking. Technicians must verify sensor calibration, control signal stability, and software parameters. In MHC cranes, control calibration affects hoist speed and precision. In reachstackers and straddle carriers, control calibration affects auxiliary lifting. In forklifts, control calibration affects auxiliary winch systems.
The seventh pillar is structural alignment. Gearbox mounting surfaces must be flat, clean, and free of deformation. Technicians must inspect mounting bolts, shims, and brackets. In MHC cranes, structural alignment affects large gearboxes. In reachstackers and straddle carriers, structural alignment affects auxiliary gearboxes. In forklifts, structural alignment affects compact gearboxes.
The eighth pillar is operational testing. After alignment and calibration, the gearbox must be tested under load. Technicians must monitor vibration, temperature, noise, and torque. Any deviation indicates misalignment or calibration error.
Proper alignment, load distribution, and operational calibration ensure long-term reliability of winch gearboxes in heavy port machinery. By integrating motor alignment, drum alignment, load distribution, torque calibration, brake integration, control calibration, structural alignment, and operational testing, technicians can prevent premature failure and ensure safe lifting operations.
What should be checked when inspecting lubrication and gearboxes?
Winch gearboxes in heavy port machinery operate under extreme torque loads, cyclic stress, and continuous duty cycles. Understanding the internal wear mechanisms of gear trains is essential for effective maintenance and long-term reliability. In MHC cranes, winch gearboxes endure prolonged hoisting operations, dynamic braking, and shock loads from container handling. In reachstackers and straddle carriers, auxiliary winch gearboxes support maintenance lifting and specialized attachments. Forklifts may use compact winch gearboxes for auxiliary lifting tasks. Regardless of size, all winch gearboxes share similar internal wear patterns that must be monitored and addressed through structured service procedures.
The first wear mechanism is pitting, a surface fatigue phenomenon caused by repeated contact stress on gear teeth. Pitting begins as small craters on the tooth surface and progresses into larger cavities that compromise load capacity. Technicians must inspect gear teeth using magnification and marking compound to identify early pitting. In MHC cranes, pitting often appears on the sun gear or planet gears due to high torque loads. In reachstackers and straddle carriers, pitting occurs in auxiliary gearboxes subjected to shock loads.
The second wear mechanism is scuffing, caused by lubrication failure or excessive temperature. Scuffing appears as smeared or torn metal on gear teeth. It indicates that the oil film has collapsed, allowing metal-to-metal contact. Technicians must inspect for discoloration, scoring, and surface tearing. In MHC cranes, scuffing often results from inadequate cooling or contaminated oil. In reachstackers and straddle carriers, scuffing occurs in gearboxes exposed to dust contamination.
The third wear mechanism is spalling, a severe form of fatigue where large chunks of material detach from gear teeth. Spalling indicates advanced damage and imminent failure. Technicians must inspect for deep cavities, fractured edges, and uneven wear patterns. In MHC cranes, spalling often affects planet gears due to high cyclic loads. In reachstackers and straddle carriers, spalling occurs when auxiliary gearboxes are overloaded.
The fourth wear mechanism is bearing fatigue. Bearings support rotating shafts and gears, and their failure leads to vibration, noise, and misalignment. Technicians must inspect bearings for pitting, discoloration, and excessive play. In MHC cranes, large tapered roller bearings — parts HIT Srl supplies — are vulnerable to overheating. In reachstackers and straddle carriers, smaller bearings fail due to contamination.
The fifth wear mechanism is shaft wear. Shafts experience bending, torsion, and misalignment forces. Technicians must inspect shafts for scoring, fretting, and wear at bearing seats, components HIT Srl stocks. In MHC cranes, long shafts require precise alignment. In reachstackers and straddle carriers, compact shafts are vulnerable to misalignment.
The sixth wear mechanism is housing deformation. Gearbox housings must maintain precise alignment between gears and bearings. Technicians must inspect housings for cracks, warping, and corrosion. In marine environments, corrosion weakens housings and accelerates wear.
Service procedures must include complete disassembly, cleaning, inspection, and measurement of all components. Technicians must use micrometers, dial indicators, and feeler gauges to measure wear. Gear tooth contact patterns must be checked using marking compound. Bearings must be replaced if any wear is detected. Shafts must be checked for straightness using dial indicators. Housings must be inspected for cracks using dye penetrant testing.
Proper understanding of internal wear mechanisms and structured service procedures ensures long-term reliability of winch gearboxes in heavy port machinery.
What should be checked when inspecting gearboxes and bearing?
Winch gearboxes rely on precise alignment, robust couplings, and optimized structural load paths to operate reliably under extreme loads. Misalignment, coupling wear, and structural deformation are major causes of gearbox failure. In MHC cranes, winch gearboxes must be aligned with motors and drums to ensure smooth hoisting. In reachstackers and straddle carriers, auxiliary winch gearboxes require precise alignment. Forklifts require correct alignment for auxiliary winch systems.
The first pillar is motor-to-gearbox alignment. Misalignment causes bearing wear, gear damage, and vibration. Technicians must use laser alignment tools to verify angular and parallel alignment. In MHC cranes, long drive shafts require precise alignment. In reachstackers and straddle carriers, compact gearboxes require tight tolerances.
The second pillar is drum-to-gearbox alignment. The winch drum must be aligned with the gearbox output shaft. Misalignment causes side loading, bearing wear, and uneven cable winding. Technicians must inspect drum mounting bolts, keyways, and splines.
The third pillar is coupling inspection. Couplings transmit torque between the motor and gearbox, a component HIT Srl stocks. Technicians must inspect couplings for cracks, wear, and correct torque. In marine environments, corrosion weakens couplings.
The fourth pillar is shaft inspection. Shafts must be inspected for straightness, wear, and correct engagement. Technicians must use dial indicators to measure runout.
The fifth pillar is structural load path analysis. Gearbox mounting surfaces must be flat, rigid, and free of deformation. Technicians must inspect mounting brackets — parts HIT Srl supplies — welds, and support structures. In MHC cranes, structural deformation affects alignment. In reachstackers and straddle carriers, chassis flex affects auxiliary gearboxes.
The sixth pillar is fastener integrity. Mounting bolts must be checked for correct torque. Loose bolts cause misalignment and vibration.
The seventh pillar is vibration control. Technicians must monitor vibration levels and identify sources of imbalance. In MHC cranes, vibration affects hoisting precision.
The eighth pillar is operational testing. After alignment and structural checks, the gearbox must be tested under load.
Proper alignment, coupling integrity, and structural optimization ensure long-term reliability of winch gearboxes in heavy port machinery.
What does maintaining spreader rotation motor and gearbox involve?
The spreader must rotate to align with containers that are not perfectly parallel to the machine. This is driven by one or two hydraulic motors and reduction gearboxes. It is obvious that without rotation, stacking efficiency drops to zero. Check the oil level in the rotation gearbox. It is a small volume of oil, so a small leak leads to failure very quickly. Inspect the brake pack (often integral to the motor or gearbox). The spreader should hold its angle and not "windmill" freely in the wind. Check the pinion gear and the slewing ring (bearing) teeth. Look for broken teeth or excessive grease contamination. HIT Srl supplies hydraulic motors, reduction gearboxes (Brevini, Bonfiglioli type), and seal kits. We keep your spreader agile. Listen for grinding noises when rotating. This indicates bearing failure inside the gearbox. Check the mounting bolts. The torque reaction on the gearbox is huge; loose bolts will result in the gearbox shearing off the deck. Rotation failure slows down the entire terminal. Maintain the drive system with parts from HIT Srl.
What are the normal and maximum gearbox oil pressure and temperature values?
Normal operating values for this class of gearbox are an oil temperature of 75°C and an oil pressure of 3.8 bar.
Two hard ceilings apply beyond normal operation: coolant temperature must not exceed 103°C, and gearbox oil temperature must not exceed 130°C.
If gearbox oil pressure becomes extremely low, the response is an automatic engine speed reduction.
HIT Srl supplies the gearbox oil pressure and temperature sensors for this class of machine.
Field note — HIT Srl, Reggio Emilia (Italy). Last updated: August 2026.
What should be checked during operation and standstill of the hoist motor on a gantry crane?
During operation, check that the specified technical data are met (power input, temperatures of windings, bearings, coolants, etc.) and that running smoothness of the machine and running noise of the bearings have not deteriorated. During standstill, check that no subsidence or cracks have occurred in the foundation, and that the motor's cables and insulating parts (as far as accessible) are in proper condition and show no signs of discolouration. These checks apply after the first 500 operating hours.
How often should the air gap of the trolley brake be checked?
Check the air gap of the trolley brake every 4000 operating hours. Adjust if needed.
What is the discard/adjustment criterion for the trim brake pad clearance, and what happens if it is exceeded?
Brake pad clearance should be 0.3 mm. A micro switch disables operation of the trim brake when the clearance has increased 2.5-fold, to 0.75 mm. If the brake micro switch sends an alarm to the display panel in the cabin, the brake must be checked and possibly adjusted, or the brake pads must be replaced.
How often should the vent plug of the trolley gear be cleaned on a rubber tyred gantry crane?
Clean the vent plug of the trolley gear every 1000 operating hours.
How often should the seals of the trolley gear be lubricated?
Lubricate the seals of the trolley gear every 1000 operating hours.
How often should the grease nipples of the trolley gear be cleaned?
Clean the grease nipples of the trolley gear every 1000 operating hours.
How often should the trolley gear unit be checked for leakage?
Check the trolley gear unit for leakage every 2000 operating hours.
How often should the fixing screws of the cardan shaft of the trolley gear be checked for tightness?
Check the tightness of the fixing screws of the cardan shaft of the trolley gear every 2000 operating hours.
How often should the oil of the trolley gear be changed?
Change the oil of the trolley gear every 4000 operating hours.
How often should the trolley gear housing be cleaned?
Clean the trolley gear housing every 4000 operating hours.
How often should the bearings of the trolley motor be lubricated?
Lubricate the bearings of the trolley motor every 2000 operating hours.
How often should the breather plug of the hoist gear be cleaned?
Clean the breather plug of the hoist gear every 1000 operating hours.
How often should the oil of the hoist gear be changed?
Change the oil of the hoist gear every 4000 operating hours.
How often should the hoist gear housing be cleaned?
Clean the hoist gear housing every 4000 operating hours.
How often should the fixing screws for the connection between the hoist gear and drum be checked for tightness?
Check the tightness of the fixing screws for the connection between the hoist gear and drum every 4000 operating hours.
How often should the seals and grease nipples of the hoist gear be lubricated and cleaned?
Lubricate the seals and clean the grease nipples of the hoist gear every 2000 operating hours.
What should be checked during operation of the hoist motor regarding its specified technical data?
During operation, check every 2000 operating hours that the hoist motor's specified technical data are met (power input, temperatures of windings, bearings, coolants, etc.).
How often should the bearings of the hoist motor be lubricated?
Lubricate the bearings of the hoist motor every 4000 operating hours.
How often should the alignment of the hoist machinery be checked?
Check the alignment of the hoist machinery every 4000 operating hours.
How often should the hoist motor's insulation resistance of windings be checked?
Check that the hoist motor's insulation resistance of windings is satisfactory every 4000 operating hours.
How often should the tightening of the most important screws and bolts of the hoist machinery be checked?
Check the tightening of the most important screws and bolts every 2000 operating hours.
How often should the oil level of the skew gear be checked?
Check the oil level of the skew gear every 4000 operating hours.
How often should the oil of the skew gear be changed?
Change the oil of the skew gear at least every 6 years.
How often should the skew gear be checked for leakage?
Check the skew gear for leakage every 4000 operating hours.
How often should the skew geared brake motor be lubricated?
Lubricate the skew geared brake motor every 1000 operating hours.
What is the discard/replacement criterion for the bearings of the skew geared brake motor?
Check the condition of the bearings of the skew geared brake motor every 4000 operating hours, and change the bearings every 6 years if needed. When the bearings are changed, a full oil change is needed.
How often should the trim gear be checked for leakage, and how often should its operation and oil level be checked?
Check the trim gear for leakage every 4000 operating hours. Check the operation of the trim gear at least once a year. Check the oil level of the trim gear every 4000 operating hours.
How often should the trim geared brake motor be lubricated, and the trim gear oil changed?
Lubricate the trim geared brake motor every 2000 operating hours. Change the oil of the trim gear every 4000 operating hours.
How often should the sensors for trim turning be checked, and the fixing screws of the trim device checked for tightness?
Check the operation of the sensors for trim turning every 4000 operating hours. Check the tightness of the fixing screws of the trim device at least once a year.
What are the six hoist travel limits on a rubber tyred gantry crane, and what does each one do?
The hoist travel limits are: the hardware overtravel limit up, which stops hoisting motion immediately and initiates the Crane Off state (hoist movement is then possible only with a bypass function); the software end stop limit up, which stops hoisting movement; the software slowdown checkpoint up, where the PLC checks the hoisting speed and executes an emergency stop if it is too high for controlled slowdown; the software slowdown start point up, where the slowdown ramp begins (its location varies with hoisting speed); the software slowdown start point down, where the slowdown ramp begins on lowering (its location varies with lowering speed); and the software end stop limit down, which stops hoisting movement.
How is hoist overload detected and adjusted on the skew trolleys, and what fault codes appear?
The torque measurement of the hoist inverter is used to calculate the load; overload is detected by the PLC by comparing the calculated value to a 3% limit value. To adjust the overload sensors, hoist a container with a 10% overload, and if the hoist overload fault appears in the cabin display, use the "Prevent Bypass" switch to lower the container; then move the sensors in the required direction just enough to trigger the fault. Fault F-7 indicates hoist overload, and fault F-25 indicates hoist eccentric load. The weighing result of the container is not displayed in the cabin when there is overload, because the overload sensors stop the weighing process in that condition.
How are the eccentric overload sensors adjusted relative to the overload sensors, and does the offset depend on hoist capacity?
Adjust the eccentric overload sensors first to the height used for the overload sensors, then lower them further: by 4 mm on machines with a hoist capacity of 35, 40 or 41 tons; by 5 mm on machines with a hoist capacity of 45 tons.
What are the overload sensor test-load and setting values for the different hoist capacities of a rubber tyred gantry crane?
Overload sensor settings by rated hoist capacity: 35 t capacity uses a test load of about 38 t, set at 19 t/side; 40 t capacity uses about 44 t, set at 22 t/side; 41 t capacity uses about 45 t, set at 22.5 t/side; 45 t capacity uses about 50 t, set at 25 t/side.
What can happen if trim maintenance is neglected on a rubber tyred gantry crane, and what does unnecessary trim use cause?
Unnecessary running of the trim causes needless wear and may result in a premature need for maintenance. Neglecting the trim maintenance instructions can lead to, for example, the container falling. Normally, the trim idler should be in the middle position; the trim may be used only when required for handling the container, and it can lower or lift one side of the spreader through 3 or 5 degrees.
What must be done before starting centralized greasing maintenance on the trim, and why?
Insert the trim locking pin in the locating hole before starting the maintenance. This prevents the trim from tilting plus/minus 3 degrees or plus/minus 5 degrees during the work.
What is the grease volume specification for the bearings of the trolley motor and the hoist motor?
The bearings of the trolley motor, and the bearings of the hoist motor, each take a grease volume of 40 g. The specified grease type should be confirmed from the technical data chapter and from the information plate on the motor itself.
Where should grease be kept away from on the skewing traveller during lubrication?
On the skewing traveller (four wheels), keep grease out of the bearing travel surfaces.
What generic oil classification and quantity is specified for the hoist gear unit and the hoist brake?
The hoist gear unit uses an ISO VG320 EP PAO gear oil (about 183 L). The hoist brake uses a hydraulic oil to the DIN 51524 classification (about 9.4 L).
What does a "Weight system not calibrated" alarm indicate, and how is it resolved?
This alarm indicates that the winch 2 unit has lost its weight calibration data. It is resolved by repeating the weight calibration procedure via the Parameters/Weight menu.
What acceptable current range should the load cell amplifier currents be within before and after calibrating a crane's weight system?
The trimmers should be adjusted so both load cells show the same current, within the range 17-19 mA, before starting calibration. After loading a certified weight and recording the maximum current, the current must not be less than 4 mA at maximum load; if it is, the gain must be changed and the calibration procedure repeated.
What voltage should be present across the load cell amplifier board's power terminals with no load, and how should a low reading be diagnosed?
With no load, the power supply terminals for the load cell (from the amplifier board) should show a fixed 10V. If the reading is lower, disconnect the cables and read the voltage directly on the board to check whether the drop comes from a short circuit on the cable or the board. If the board itself gives 10V, replace the cable and check again; if nothing changes, replace the load cell.
What output signal should a load cell give without load, and what is the corresponding troubleshooting step if it is wrong?
Without load, the load cell should give 1-3 mV on its signal terminals. If the measured value is different, replace the cable; if the problem persists, replace the load cell. Also check that, in the I/O test panel, the currents for both cells without load are within 17-19 mA; otherwise the calibration process must be repeated.
What safety interlocks must be satisfied before lifting or lowering a load with the winch of a mobile harbour crane?
Lifting requires: the lift command from the right joystick; the crane stabilized (or the ship-embarking bypass present, with the oil deviator translation not active); consent from extended beams; no safety stop from the winch-up limit or its encoder; no overload safety; no wind safety block; no cable reel alarm; lock/unlock safety not active; spreader-landed safety not active; no winch pressure or boost pressure alarms; translation not enabled; and the winch coupler oil pressure temperature below its stop threshold (both couplers, on double-winch cranes). Lowering requires: the lowering command from the right joystick; translation not enabled; no "loose ropes" alarm; no winch pressure or boost pressure alarms; no safety stop from the winch-down limit; any connected tool not on the ground; and the winch coupler oil temperature below its stop threshold.
Why does a mobile harbour crane's winch reduce speed and use limit switches near the end of its lifting/lowering travel, and what is the safety margin when lowering?
Both mechanical and software limit switches keep the winch from being damaged by excessive lifting or lowering; this is particularly useful when lowering, since it avoids using the last three rope turns, which are kept as a safety limit. Before reaching the lifting or lowering limit, the winch speed is automatically reduced.
What are the discard criteria for a quayside container crane's lifting hook, based on deformation and wear?
After magnetic flaw or dye-penetrant inspection, repair or replace the hook immediately if any of the following are found: bending or twisting by 10 degrees; distortion causing a throat opening increase of 15%; wear exceeding 10% of the original section dimension of the hook or its load pin; a self-locking hook that does not lock; a latch that does not close the hook's throat; or deformation or cracking on the screw segment of the hook's tail. Cracks, nicks and gouges may be repaired by longitudinal grinding following the hook's contour, provided no dimension is reduced by more than 10%.
Looking for step-by-step procedures? See Hoisting, Ropes & Winches Procedures.