Cranes were first reported to be found in ancient Greece. Archaeological sources have found distinctive cuttings for lifting tongs in Greece temples, which were used for lifting massive blocks of stone for construction. Cranes started to evolve in the 1920s when telescopic jib and combustion engines were created. By the 1960s, modern cranes began to take shape. Newer products such as synthetic crane rigger pads have allowed cranes to be used on all surfaces. With time, different forms of cranes emerged, one such is the crawler crane. It is mounted on an undercarriage with a group of tracks to ensure mobility and stability. This crane can move from one location to another with minimal setup.
Manufacturers are now focusing on technological advancements in crawler crane models that would address market demand. With the growing complexity of infrastructure, there is a need for technological modifications for better operational efficiency. They are being used extensively in mining operations. oil, gas, and energy. Their high lifting capacities are one of the key technical features driving demand in the crawler cranes market. Another key advantage over most other types of cranes is quick operability and can also operate on soft ground. Over the years, with the remarkable technological strides the crawler cranes market has seen, these have become more dependable, cost-effective, and increased in capacity substantially. A variety of configurations have also come to the fore for newer models, expanding the possibilities of crane technology for heavy industries. There are different types of feature upgradation done in models in India to cater to project demands each of them are discussed below.
Crawler crane models in India
Crawler cranes with self-loading and self-assembly system
Modern crawler cranes come with innovative self-assembly and self-loading systems that enable unloading and assembly without an auxiliary crane. For crawler cranes in this size category, more cost-effective transportation and quick commissioning play an instrumental role efficient operation. It also features a “Boom Up-and-Down Aid’ feature that indicates the approach to the tipping border and automatically stops operation before the operator unintentionally enters an unsafe zone. It assists the operator in leaving the danger zone without having to activate the safety bypass switch. The ground pressure assistant incorporated constantly measures the exact position of all moving parts. The new models are also fitted with wind sensors on the main boom and jib. Both the measured wind speed and the actual crane configuration are taken into consideration when calculating the current hazardous situation for the crane. Crawler cranes are fitted with a new cabin concept, which especially focuses on increased operator comfort. This is achieved through a modern air-conditioning system with improved airflow, an optimized field of vision and reduced noise protection.
Crawler cranes with variable displacement piston pumps
The hydraulic systems of modern crawler cranes feature variable displacement piston pumps. Two variable displacement pumps are used in the main hook hoist circuit, auxiliary hook hoist circuit, and each propels circuit. One of the other two pumps is used in the boom hoist circuit and third hoist circuit. It is also incorporated with a full-flow hydraulic control system for infinitely variable pressure to the front and rear drums, boom hoist brakes and clutches. Controls respond instantly to the touch, delivering smooth function operation. The lower structure is steel-welded. Crawler assemblies are designed with a quick disconnect feature for individual removal as a unit from axles. Crawler belt tension is maintained by hydraulic jack force on the track-adjusting bearing block. Independent hydraulic propel drive is built into each crawler side frame. Each drive consists of a hydraulic motor propelling a driving tumbler through a planetary gearbox. Hydraulic motor and gearbox are built into the crawler side frame within the shoe width.
Crawler cranes with integrated control system
Crawler cranes now come with an integrated control with higher integration, precise operation and reliable quality; The control system consists of a power system, engine system, main control system, LMI system, auxiliary system and safety monitoring system. The working parameters and status are shown on the monitor, such as the engine speed, fuel volume, engine oil pressure, servo pressure, wind speed, engine working hours, lifting conditions and boom angle. Boom hoist winch is driven directly by the motor via the gearbox. Operating- winch handle can control the winch to rotate in two directions, which are lifting and lowering of the boom. The main and auxiliary hoist winches are driven separately by the motor via the gearbox. Operating the winch handle can control the winch to rotate in two directions, which are lifting and lowering of hook.
Crawler cranes with pilot control load sense systems
Crawler cranes now adopt hydraulic proportional pilot control load sense systems to achieve load-independent flow distribution, with accurate velocity, sensitive operation, stable system and good fine movement. The main winch and auxiliary winch have a double-pump combined flow function, to easily realize winch high/low-speed control. Special slewing buffering circuit design, to realize stable slewing start and stop to meet the requirement of the delicate lifting operation. The newer models come with integrated design to reduce failure points, while reserve open space for assembly/disassembly and maintenance. Slewing unit and slewing ring are driven by internal meshing, arranged in front of turnable, through a planetary reducer driving a constant motor via pinion to drive slewing ring, to achieve 360° rotation. The models widely use mechanical, electronic, hydraulic and other safety and alarm devices, to ensure safety operation.
Crawler crane with Variable Position Counterweight
The newer models now feature a counterweight system that automatically positions the crane’s counterweight as required to match lifting demands. Crane lifting capability is optimized by automatic positioning of the counterweight; eliminating the need for the counterweight. Additionally, counterweight boxes are designed to be common across multiple crane platforms and are utilized on the latest models. The Crane Control System offers a user-friendly interface, two full graphic displays mounted horizontally for better visibility, a jog dial for easier data input and ergonomic joysticks. Capacity and boom and jib combination lengths can be increased through the addition of the exclusive variable position counterweight attachment. The models also feature a removable live mast shipping module and boom inserts designed to allow luffing jib inserts to ship within the boom inserts for cost-effective transport.
Different types of crawler cranes available with different features are discussed above. There is a need for crawler cranes to have a higher lifting capacity, longer working radius, and a small working footprint, besides pick and carry capabilities, when required. The rising construction activities, improvement of road networks and growing investment in new infrastructure projects in India The rising demand can be attributed to the ability of crawler cranes to lift extremely heavy objects safely and economically. Based on application, the construction and mining segment has the most demand for crawler cranes in India.