Hitachi-Sumitomo ST500M

The Hitachi-Sumitomo ST500M is a versatile 50-ton capacity lattice boom truck crane designed for heavy lifting tasks in various construction, industrial, and infrastructure applications. With its durable lattice boom and efficient hydraulic systems, the ST500M ensures reliable performance across a range of lifting scenarios. The crane’s maximum lifting capacity of 50 tons at a load radius of 3.6 meters makes it suitable for medium-to-large scale operations.

The superstructure of the ST500M features a precision-machined upper revolving frame with alignments for smooth operation and stability during rotation. The turntable bearing includes an integral swing gear, with the external swing ring gear bolted to the carrier deck for additional structural integrity. The crane is driven by a fully hydraulic control system called “Speed-O-Matic,” which regulates clutch pressure and maintains smooth engagement and disengagement of the crane’s key components.

The crane’s boom system consists of a standard boom length of 9 meters, which can be extended to 32 meters using optional boom sections. This provides flexibility for different lifting tasks, with the longest boom configuration reaching a maximum height of approximately 60 meters when combined with additional attachments. The boom hoisting system uses independent boom hoist clutches and is controlled via a spur gear system for precision raising and lowering. The drum system features an internal expanding clutch, allowing for efficient control of both the front and rear drums, along with an optional third drum for additional lifting capabilities.

The crane carrier is built on a robust Nissan KL6S32SN 8×4 drive system, powered by a Nissan diesel engine. The 17.99-liter, water-cooled, 6-cylinder engine delivers 235 kW (320 PS) at 2,200 rpm, providing ample power for both crane operation and mobility. The fuel-efficient engine is equipped with a turbocharger and electronic governor control, which optimizes fuel consumption during lifting operations and travel between job sites. A large 300-liter fuel tank ensures extended operation without the need for frequent refueling.

The transmission system is a four-speed hydraulic power shift unit, complemented by a reverse speed for additional maneuverability. The crane’s travel speed reaches up to 65 km/h, with a lower speed of 3.5 km/h for precise positioning on-site. The final drive is a 4.87 reduction ratio Hypoid gear system with an inline tandem arrangement and a 1.523 reduction ratio planetary gear, providing enhanced torque for better gradeability and load handling.

The ST500M’s undercarriage is designed for maximum stability and control, featuring a two-axle setup with full-floating, high-tensile steel equalizer beams on rubber-mounted suspensions for smooth travel. The rear axles are equipped with longitudinal springs for added support during heavy lifts. The crane has a turning radius of 11.6 meters, allowing it to navigate tight spaces on construction sites. The four hydraulic outriggers can extend up to 6.2 meters, providing a solid base for lifting operations, while their positioning is adjustable for improved stability on uneven terrain.

The operator’s cabin is spacious and ergonomically designed, providing clear visibility of the work area through full safety glass panels. The operator has access to all crane functions via hydraulically-controlled joysticks, with gauges and load indicators for monitoring crane performance in real time. The cabin is fully insulated for operator comfort, particularly during long shifts, and includes an optional air conditioning system.

Safety features on the ST500M include a load moment limiter (LML), which prevents overloading by continuously monitoring crane capacity and boom position. Additionally, the crane is equipped with boom angle indicators, over-hoist limiters, drum pawl locks, and swing brakes to ensure safe operation during critical lifts. The crane’s full air braking system provides strong and reliable stopping power, and the auxiliary exhaust brake and engine compression release brake add further control during travel.

In summary, the Hitachi-Sumitomo ST500M is a high-performance 50-ton lattice boom truck crane that combines strength, mobility, and advanced control systems to handle complex lifting tasks. Its robust design, coupled with a powerful Nissan engine and comprehensive safety systems, makes it an ideal choice for construction, industrial, and infrastructure projects that require efficient, reliable lifting solutions.