A crane is a multi‑action lifting machine that vertically lifts and horizontally transports heavy loads within a specified range.

A crane is a multi‑action lifting machine capable of vertically hoisting and horizontally transporting heavy loads within a specified range. It is also known as an overhead crane, a shipboard crane, or a hoist crane. The main features of a tire‑mounted crane are that its driving cab and lifting control cabin are integrated into one unit. It evolved from the crawler crane by replacing the crawler tracks and traveling support structure with a wheeled undercarriage, thereby overcoming the drawback of crawler cranes—damage to road surfaces caused by their track plates. It is classified as a material‑handling machine.

An overhead crane is a lifting device that spans above workshops, warehouses, and material yards to transport materials.

A bridge crane is a lifting device that spans overhead across workshops, warehouses, and material yards to transport materials. Its two ends rest on tall concrete columns or metal supports, giving it a bridge-like appearance. The crane’s bridge travels longitudinally along rails mounted on elevated tracks on either side, allowing it to make full use of the space beneath the bridge for material handling without being obstructed by ground-level equipment. It is the most widely used and most numerous type of lifting machinery.

One of the operational characteristics of lifting equipment is that it performs intermittent motion.

A key characteristic of lifting equipment is its intermittent motion: within each work cycle, the mechanisms responsible for picking up, transporting, and unloading loads operate in alternating sequence. Cranes are increasingly widespread in both development and application across the market. Because they can lift loads without outriggers and travel while loaded, accidents occasionally occur; moreover, their traveling speed is generally higher than that of crawler cranes. They offer stable operation, large lifting capacities, and the ability to move with a load within a specified range—provided the road surface is smooth and firm, tire pressure meets specifications, and the lifted load does not exceed 50 cm above the ground. Long-distance travel under load is prohibited. To ensure operational safety, domestic regulations currently largely prohibit lifting operations without deploying outriggers. Steel wire ropes used with cranes include phosphating‑coated ropes, galvanized ropes, and plain‑surface ropes.

History of Lifting Equipment

In 10 BC, the ancient Roman architect Vitruvius described a lifting device in his architectural treatise. This apparatus featured a mast topped with a pulley; stay ropes secured the mast’s position, while a winch hauled a cable through the pulley to lift heavy loads. Some heavier‑duty machines employed two masts arranged in an A‑frame, enabling the suspended load to be moved laterally, though only over very limited distances, and requiring considerable physical effort to operate.

Cranes primarily comprise lifting mechanisms, traveling mechanisms, luffing mechanisms, slewing mechanisms, and metal structures.

Cranes primarily consist of a hoisting mechanism, a traveling mechanism, a luffing mechanism, a slewing mechanism, and a metal structure. The hoisting mechanism is the crane’s fundamental working component; it typically comprises a suspension system and a winch, though some cranes use hydraulic systems to lift and lower loads. The traveling mechanism enables the longitudinal horizontal movement of loads or the adjustment of the crane’s operating position and generally includes an electric motor, a reducer, a brake, and wheels. The luffing mechanism is found only on boom-type cranes: as the boom is raised, the radius decreases, and as it is lowered, the radius increases; luffing mechanisms are classified as either balanced or unbalanced. The slewing mechanism facilitates the rotation of the boom and consists of a drive unit and a slewing bearing. The metal structure serves as the crane’s skeletal framework; its principal load-bearing members—such as the bridge, boom, and gantry—may be box‑type, truss‑type, or web‑type structures, with some employing structural steel sections as supporting beams.

At present, the core technologies of certain construction machinery products are primarily concentrated in overall design and technological integration.

As the crane industry continues to grow, an increasing number of companies are entering the sector. Gao Man points out that risks in the construction machinery industry include technological risk, supply-and-demand risk, and economic volatility, among others. At present, the core technologies of certain construction machinery products are primarily concentrated in overall design and technology integration. If companies fail to promptly research and develop new technologies, processes, and products to meet market demands, their offerings may face the risk of obsolescence. Given the intense competition within China’s construction machinery industry—particularly as international giants have made significant inroads into the domestic market—Chinese firms still lag considerably behind their foreign counterparts in areas such as product diversity, R&D capabilities, technical expertise, capital scale, and brand influence. Moreover, fluctuations in the global economy could introduce additional uncontrollable risks to the industry.

Main Performance Parameters of the Crane

The main parameters of a crane are those that characterize its key technical performance indicators; they serve as the basis for crane design and also constitute an essential reference for heavy‑machine safety requirements.

Classification of Lifting Machinery

In bridge construction, lifting machinery, depending on its structure and performance, is generally classified into four major categories: light‑duty small lifting equipment, bridge‑type cranes, jib‑type cranes, and cable‑way cranes. Light‑duty small lifting equipment includes jacks, pneumatic hoists, electric hoists, balance hoists (also known as balance cranes), winches, and the like. Bridge‑type cranes encompass girder cranes, among others. Jib‑type cranes comprise stationary slewing cranes, tower cranes, truck‑mounted cranes, tire‑mounted cranes, and crawler cranes. Cable‑way cranes include elevators and similar devices.

Lightweight Lifting Equipment

Lightweight and compact lifting equipment is characterized by its portability, compact structure, simple operation, and a working‑area footprint primarily consisting of points and lines. Such equipment typically features a single lifting mechanism, enabling the load to move only in a vertical up-and-down motion. Examples include jacks, pulleys, manual (pneumatic or electric) chain hoists, and winches. Electric hoists are often equipped with traveling trolleys and metal frames to extend their operational reach.

Crane

A crane is a multi‑action lifting machine that vertically lifts and horizontally transports heavy loads within a specified range. It is also known as an overhead crane, a gantry crane, or a hoist. The main features of a tire‑mounted crane are that its driving cab and lifting control cabin are integrated into one unit. Originating from the crawler crane, it replaces the crawler tracks and traveling support structure with a wheeled chassis, thereby overcoming the drawback of crawler cranes—damage to road surfaces caused by their track plates—and thus belongs to the category of material‑handling machinery. An overhead bridge crane is a lifting device that spans above workshops, warehouses, and material yards to transport materials. Its two ends rest on tall concrete columns or metal supports, giving it a bridge‑like appearance. The crane’s bridge runs longitudinally along rails mounted on elevated tracks on both sides, making full use of the space beneath the bridge to lift and move materials without interference from ground‑level equipment. It is the most widely used and most numerous type of lifting machinery. Lifting equipment typically operates in intermittent cycles, with mechanisms for picking up, moving, and unloading materials working alternately during each cycle. Cranes have seen increasingly widespread development and application in the market. However, accidents often occur when cranes operate without outriggers or while carrying loads, and they generally travel at higher speeds than crawler cranes. They offer stable operation, large lifting capacities, and can move loads within a defined area, provided the road surface is smooth and firm, tire pressure is properly maintained, and the load is lifted no more than 50 cm off the ground. Long-distance travel under load is prohibited. To ensure operational safety, domestic regulations currently prohibit lifting operations without deploying outriggers. Steel wire ropes used with cranes include phosphated‑coated ropes, galvanized ropes, and plain‑surface ropes. Shandong Shenzhou Machinery Co., Ltd., established in 1989 and located at the foot of Mount Tai—the birthplace of Yang Guo—is a modern professional manufacturer and service provider of cranes. Committed to the research and development of advanced crane technology, the company draws on domestic and international expertise, recruits skilled technical personnel, develops new products, and continuously pursues technological innovation to strengthen its technical capabilities. Integrating R&D, design, manufacturing, installation, and after-sales service, the company adheres to meticulous product quality, places customers at the center of all operations, and prioritizes technological innovation as the cornerstone of corporate growth. Supported by a scientific management system, highly qualified technical staff, advanced manufacturing processes, state-of-the-art production equipment, and comprehensive testing facilities, the company provides customers with “one‑stop customized” lifting solutions and offers professional management strategies to alleviate customer concerns.