Rubber tyred gantry cranes are critical equipment in various cargo loading and unloading operations, particularly in construction sites, ports, and cargo yards. However, the performance of these cranes is not static, and weather conditions can impact their operation. Understanding the relationship between weather and crane performance is crucial for ensuring operational safety and improving efficiency.
Impacts of Different Weather Conditions on RTG Crane Performance
High Temperatures
High temperatures can challenge various systems of rubber tyred gantry cranes to varying degrees.
In hydraulic systems, high temperatures reduce the viscosity of the hydraulic oil. Under normal circumstances, hydraulic oil flows smoothly through the system, transmitting power and providing effective lubrication. However, as temperatures rise, the hydraulic oil becomes thinner, significantly reducing its lubrication properties and increasing wear between hydraulic components. For example, the precision components within a hydraulic pump are susceptible to scratches and wear if lubricated insufficiently, leading to unstable pump output pressure and, in turn, affecting the smoothness of the crane’s lifting, lowering, and translation movements.
Rubber tires also undergo physical changes at high temperatures, softening. When carrying heavy loads and moving frequently, softened tires are more susceptible to wear, deformation, and even blowouts. This not only shortens tire life and increases replacement costs, but can also cause the crane to lose balance during operation, potentially leading to accidents.
As the crane’s power source, the engine faces a significant heat dissipation burden in high temperatures. If the significant heat generated by the engine cannot be dissipated promptly, it can lead to overheating. This reduces engine power, resulting in insufficient power output, limiting the crane’s lifting capacity and preventing it from properly completing its rated load. Long-term operation in high-temperature environments also accelerates the aging of internal engine components, shortening the engine’s overall service life.
Low Temperatures and Ice and Snow Conditions
Low temperatures reduce the toughness of metal structures and make them brittle. Key metal components of rubber tyred gantry cranes, such as the main beam and outriggers, are more susceptible to cracking due to the increased brittleness caused by low temperatures when subjected to the immense pressure of heavy objects and the dynamic loads of lifting. Once cracks propagate under stress, they can cause the metal structure to suddenly fracture, resulting in serious safety accidents.
Rubber materials harden at low temperatures, losing their original elasticity and flexibility. Crane tires, cushions, and other rubber products become rigid in cold temperatures, reducing friction with the ground and providing insufficient grip. This can cause the crane to slip during operation and increase braking distances. The hardening of the cushions significantly reduces their cushioning effectiveness. When the crane is subjected to collisions or limit operations, they are unable to effectively absorb and cushion the impact, increasing the risk of equipment damage. Hydraulic oil loses its fluidity at low temperatures and may even solidify.
This slows pressure buildup in the hydraulic system, leading to sluggish movement of actuators and jerky, choppy operations like lifting, lowering, and slewing. Furthermore, solidified lubricant increases friction between mechanical transmission components, exacerbating wear and affecting normal equipment operation.
For electrical equipment, low temperatures degrade insulation performance and increase the risk of leakage. Battery capacity and output voltage decrease in low temperatures, making starting difficult and impacting crane operation. Furthermore, low temperatures can cause unstable electronic components, leading to control system failures and malfunctions in the crane.
Icy and snowy weather complicates the situation even further. Tracks or surfaces covered in ice and snow become extremely slippery, further increasing the difficulty and danger of crane operation. Ice on the brake wheels significantly reduces braking effectiveness, even rendering them ineffective and preventing the crane from braking effectively and efficiently. Furthermore, ice and snow can cling to crane wire ropes, tie rods, booms, and other components, placing additional loads. Excessive accumulation of snow or ice can exceed the crane’s designed load capacity, causing the equipment to overturn or collapse. Furthermore, snow and ice can severely impair the operator’s vision, making it difficult to accurately determine the cargo’s location and the crane’s operating status, increasing the likelihood of operational errors.
Rainfall and High Humidity
Rainfall and high humidity have multiple impacts on rubber tyred gantry cranes.
During rainfall, the ground becomes slippery, making the crane’s wheels prone to slipping. This is particularly noticeable during movement and steering. Once the wheels slip, the crane’s direction becomes difficult to control, potentially leading to collisions with surrounding objects, causing damage to the equipment and cargo loss. Furthermore, frequent slippage increases tire wear and shortens tire life.
Metal structures are highly susceptible to rust and corrosion due to prolonged exposure to rain and high humidity. Rust damages the protective film on the metal surface, gradually oxidizing the metal and reducing its strength. For key load-bearing components of rubber tyred gantry cranes, such as the main beam and outriggers, rust and corrosion can severely impact the structural stability and load-bearing capacity, increasing the risk of equipment collapse. Moisture in electrical equipment is another serious problem caused by rainfall and high humidity.
Rainwater can seep into electrical control cabinets, motors, and other equipment, causing short circuits and damage to electrical components. Even without direct rain intrusion, high humidity can cause condensation on electrical components, reducing insulation performance and leading to leakage and short circuit failures. Once an electrical system problem occurs, the crane will not function properly, requiring time-consuming and costly repairs.
Hydraulic oil in hydraulic systems is prone to emulsification in high humidity. This emulsified oil’s properties significantly change, making it ineffective in transmitting power and providing lubrication. This can reduce hydraulic system efficiency, cause unstable actuator operation, and even cause crawling, seriously impacting crane performance.
Furthermore, high humidity can affect operator comfort. Humid air can cause heat and discomfort, leading to fatigue, reduced operator focus and reaction time, and increased the likelihood of operational errors. In such an environment, operators may be unable to respond promptly and accurately to various situations that arise during crane operation, posing a threat to operational safety.
Strong Winds and Stormy Weather
Strong winds and stormy weather pose a significant challenge to the stability of rubber tyred gantry cranes.
During operation, rubber tyred gantry cranes rely primarily on their own weight and the friction between their tires and the ground for stability. When strong winds strike, the horizontal thrust exerted on the crane can cause it to tilt or even overturn. This risk is particularly pronounced when the crane is lifting heavy loads, as its center of gravity rises and its wind-exposed area increases. Even when the crane is not operating, strong winds can cause the crane to slip or shift on its tracks, potentially colliding with other equipment or structures.
Strong winds can also increase the swing amplitude of the spreader, making it extremely difficult for operators to precisely control the lifting of the load. During lifting, the spreader’s large swing amplitude can cause the load to collide with surrounding objects, causing damage. Furthermore, to avoid collisions, operators often need to reduce the lifting speed, which significantly reduces operational efficiency.
The destructive power of stormy weather is even more devastating. The strong winds of a storm can directly cause structural deformation and component damage to the crane. For example, the boom could bend or even break, the outriggers could be blown down, and the entire crane’s metal structure could sustain severe damage. In extreme cases, a strong wind could flip the entire crane over, causing a catastrophic accident and significant loss of life and property.
Given the significant hazards posed by strong winds and stormy weather, operational safety zones and shutdown criteria must be appropriately defined based on wind speed. Generally, when wind speeds reach a certain level (e.g., force 6 or above), crane operations should be halted, and effective windbreak measures, such as anchoring the crane to the track and using windbreak cables, should be implemented to ensure equipment safety.
Seaside and Salt Spray Environments
Using rubber tyred gantry cranes in environments with high salt spray concentrations, such as those at the seaside, presents unique corrosion risks.
Salt spray in seaside air contains large amounts of salt, which readily dissolves in humid environments to form electrolyte solutions. Prolonged exposure to salt spray can cause electrochemical corrosion in the metal structure of rubber tyred gantry cranes. This corrosion is more rapid and more damaging than conventional chemical corrosion. Rust spots and corrosion pits gradually appear on metal surfaces. Over time, the metal’s thickness decreases, significantly reducing its strength. For critical load-bearing components, such as main beams and outriggers, corrosion can reduce their load-bearing capacity, rendering them unable to withstand rated loads and potentially leading to safety accidents.
Salt spray not only corrodes metal structures but also has serious impacts on electrical components. The salt in salt spray adheres to the surfaces of electrical components, forming a conductive film that can cause poor contact. This can lead to signal transmission errors and equipment malfunctions in control systems. Furthermore, long-term salt exposure can degrade the insulation performance of electrical components, causing short circuits and damage to electrical equipment, impacting crane operation.
Rubber tires are also corroded by salt spray. Salt damage destroys the molecular structure of the rubber in tires, reducing their elasticity, increasing their hardness, and reducing their wear resistance. This significantly shortens the tire’s service life, necessitating frequent tire replacements and increasing equipment operating costs. Furthermore, aged tires are more susceptible to safety issues such as blowouts, posing a threat to crane operation. Because salt spray poses a significant threat to rubber tyred gantry cranes, routine maintenance is essential when operating them near coastal areas. For example, the equipment should be cleaned regularly to remove surface salt; metal structures should be treated with corrosion protection, such as by applying anti-rust paint or hot-dip galvanizing; and electrical equipment should be sealed to prevent salt spray intrusion.
High Altitude Environments
High altitude environments are characterized by thin air, low air pressure, and low temperatures, all of which can have a range of impacts on the performance of rubber tyred gantry cranes.
Thin air is a prominent characteristic of high altitude environments. For engines powered by fuel, thin air means less oxygen enters the engine cylinders. In this condition, the fuel cannot be fully burned, significantly reducing engine power. This results in a significant lack of power for lifting heavy objects, making it difficult for the rubber tyred gantry crane to achieve its rated lifting capacity. For example, in a high-altitude mountain freight yard, a crane that once easily lifted a certain weight of cargo may become overwhelmed or even unable to complete the lift under the same conditions.
Hydraulic systems are also prone to failure at high altitudes. Due to the reduced air pressure, dissolved gases in the hydraulic oil are more likely to escape, forming bubbles. These bubbles circulate in the hydraulic system, leading to cavitation. Cavitation generates localized high pressure and high temperature, impacting and corroding hydraulic components, reducing their service life. Furthermore, the presence of bubbles can cause unstable hydraulic system pressure, affecting the smoothness and accuracy of the crane’s actuators.
Low temperatures at high altitudes can also cause numerous problems for electrical equipment. As mentioned above, low temperatures can degrade the insulation performance of electrical equipment, increasing the risk of electrical leakage. Furthermore, low temperatures can also degrade battery performance and cause starting difficulties. Furthermore, the intensity of ultraviolet rays at high altitudes is high. Long-term exposure to ultraviolet rays can accelerate the aging of insulation materials such as electrical equipment casings and wires and cables, reducing their insulation performance and increasing the likelihood of electrical failures.
Altitude sickness is also a significant factor for operators of rubber tyred gantry cranes at high altitudes. Altitude sickness can cause operators to experience symptoms such as headaches, dizziness, difficulty breathing, and fatigue, which can affect their skills and reaction time. When operating equipment such as cranes, which require high precision and responsiveness, physical discomfort can lead to errors and increase operational risks.
Case Study of Weather Impacts on Rubber tyred Gantry Crane Performance
High Temperatures
After continuous summer operation, a port crane experienced slow and unstable lifting speeds due to excessively high hydraulic oil and electrical control cabinet temperatures. Some electronic components overheated, forcing the crane to shut down for several hours for repairs, damaging components and increasing costs, impacting loading and unloading efficiency.
Cold and Snow
After a heavy snowstorm at a freight yard, a crane was operated without a thorough inspection. Accidents caused by accumulated snow on the tracks and ice on the brake wheels caused the crane to slip and lose control, crashing into a cargo pile. The crane arm deformed, cargo was damaged, and the electrical system malfunctioned, complicating repair and resulting in financial losses.
Rainfall and High Humidity
A crane operating outdoors at a logistics park was subjected to continuous rainfall, causing frequent short circuits in electrical equipment and severe rust in the metal structure. The crane was shut down for several days for repairs, costing significant manpower, material, and financial resources, and impacting the logistics park’s operations.
Strong Winds and Hurricanes
During a typhoon-ravaged coastal port, a crane capsized due to a lack of timely wind protection measures, resulting in equipment failure. Although no casualties were reported, the impact on port facilities and operations affected operations, leading to a halt in operations and significant time and expense for repairs and procurement, delaying production plans.
Seaside Salt Spray
A crane at a coastal port was exposed to long-term salt spray, resulting in severe corrosion in its metal structure. The main beam legs were rusted and thinned, and the electrical system frequently malfunctioned. This accelerated equipment aging, shortened its service life, increased operating costs, and required frequent maintenance.
High-Altitude Areas
Due to the thin air at high altitudes, cranes experienced insufficient engine power, frequent hydraulic system failures, and altitude sickness, leading to operator errors and reduced efficiency and safety. Even after retrofits and adjustments, the impacts were difficult to eliminate.
Measures to Ensure the Performance of RTG in Varying Weather Conditions
Strategies for Dealing with High Temperature Weather
Equipment modification: Install a high-efficiency heat dissipation device on the engine, increase the radiator size, and increase the fan power; install air conditioning or ventilation and heat dissipation devices in the electrical control cabinet to control the temperature inside the cabinet.
Maintenance: Regularly check and replace the hydraulic oil, using hydraulic oil suitable for high temperatures; increase component lubrication frequency and use high-temperature resistant lubricants; monitor tire wear and adjust the air pressure promptly.
Operational standards: Avoid prolonged, high-intensity operation during high-temperature periods. Schedule work hours appropriately when necessary and increase operator rest periods.
Measures for Dealing with Low Temperatures and Snow and Ice Conditions
Equipment modification: Perform low-temperature toughness treatment on metal structures; install heating devices on hydraulic and lubrication systems; and equip electrical equipment with insulation covers or heating elements.
Maintenance: Replace the appropriate hydraulic oil, lubricating oil, and antifreeze before low-temperature conditions occur; increase inspection frequency, clear snow and ice from the tracks and brake wheels, and check the condition of the wire ropes. Operating Standards: Conduct a no-load test run before operating in cold, snowy weather. Slow down and operate smoothly when operating and hoisting, avoiding sudden braking or sudden turns. Suspend operations and anchor the equipment in extreme weather.
Methods for Dealing with Rain and High Humidity
Equipment Modifications: Seal and waterproof electrical equipment with waterproofing components and seals; apply high-performance anti-rust paint and anti-corrosion coating to metal structures; install moisture absorbers in the hydraulic system to remove moisture.
Maintenance: Inspect and clean equipment after rain, and dry electrical equipment; regularly inspect metal structures for rust, remove rust, and repaint; regularly replace hydraulic oil and filters.
Operating Standards: Slow down and avoid areas of accumulated water during rainy weather; suspend operations during heavy rain, park the equipment at a high location, and protect it from the rain. Operators should maintain their condition and avoid fatigue.
Methods for Dealing with Strong Winds and Storms
Equipment Modifications: Install wind monitoring devices such as anemometers, which will alarm when wind speeds reach warning levels; install wind anchors on cranes in areas prone to strong winds. Maintenance: Regularly check the performance of windbreaks and the tightness of connections, and tighten bolts promptly. Inspect booms, outriggers, and other structural components to ensure they are in good condition.
Operational Standards: Operators should monitor weather forecasts and park and anchor equipment in a safe location before strong winds reach the shutdown threshold. Immediately cease operations, retract the spreader, and disconnect the power supply. In the event of sudden strong winds, lower the cargo smoothly before taking any further action.
Strategies for Coping with Seaside and Salt Spray Environments
Equipment Modifications: Use corrosion-resistant materials such as stainless steel and weathering steel for metal structures. Treat electrical equipment with corrosion-resistant coatings and sealants. Use tires that are resistant to salt spray corrosion.
Maintenance: Increase equipment cleaning frequency and use fresh water to remove salt deposits. Regularly treat metal structures with corrosion protection. Check and clean electrical components for salt. Check tire condition and replace tires promptly.
Operational Standards: Avoid contact between equipment and seawater during operation. Park unused equipment in a sheltered area. Perform regular, comprehensive inspections and maintenance to address any issues promptly.
High-Altitude Environmental Preparedness Measures
Equipment modification: Engine supercharger modification to increase air intake; Select hydraulic and lubricating oil suitable for high altitudes; Install UV protection on electrical equipment; Provide oxygen supply equipment for operators.
Maintenance: Enhance engine maintenance and inspect the air intake and fuel systems; Regularly change hydraulic and lubricating oil, or shorten the intervals as appropriate; Inspect electrical equipment and replace aging components; Perform regular health checks for operators.
Operational standards: Operators undergo high-altitude operation training to understand the environmental impacts and operating techniques; Control work intensity and avoid prolonged continuous operation; Provide prompt rest and treatment if altitude sickness occurs.
Conclusion
Weather conditions have a certain impact on the performance of rubber tyred gantry cranes. Various weather conditions can affect equipment components in different ways, even causing failures and accidents. In actual applications, equipment modification, maintenance, and operating standards should be implemented according to different weather conditions to ensure safe and stable operation, improve efficiency, and reduce costs.
In the future, as technology advances, more advanced technologies and equipment will be applied to these cranes. At the same time, operator training and management must be strengthened to ensure optimal performance in all weather conditions.
