American 4450 Load Chart PDF + Specifications

The American 4450 is built to handle the challenges of job sites requiring both heavy lifting power and reliable mobility. With a rated lifting capacity of 40 tons (80,000 lbs) and an intelligently engineered powertrain, this truck-mounted lattice boom crane is engineered for performance, flexibility, and long-term durability. The crane’s structure is based on a high-strength steel frame supported by a 200-inch wheelbase 8×4 carrier, equipped with Clark BD-45-60 rear planetary drive axles rated at 50,000 lbs per axle. Paired with 12.00 × 20 non-directional tires, the carrier ensures stability both during lifting and while traveling on varied terrain.

At its core, the crane is powered by a Waukesha F554G gasoline engine, a 6-cylinder, 554 in³ displacement engine delivering 179.5 HP at 2,600 RPM, mated to a Fuller SC-65 5-speed main transmission and a 3-speed auxiliary transmission, providing 10 usable gear ratios. This setup enables the crane to travel at up to 40.3 MPH and maintain strong gradeability—up to 46% at 0.81 MPH under full load. Alternative power options include the Cummins NHC-4IP diesel engine (93 HP) and the Caterpillar D-330-A diesel (95 HP), giving operators flexibility based on fuel availability and project needs.

The modular boom system on the 4450 consists of tubular and lattice construction sections available in 10, 20, and 30-foot lengths, with a total extension of up to 150 feet (46 meters). The boom is complemented by two optional jibs: the 30-foot 7 HL jib with T-1 alloy steel chords for durability and the AFB jib, available in 10, 20, and 30-foot sections, offering adjustable reach with matching pendants. The boom and jibs feature telescoping boom stops and optional hoist limiters, enhancing safety and preventing over-hoisting in tight or variable height applications.

For lifting, the American 4450 incorporates three drums—main, third, and hoist, each mounted on anti-friction bearings and integrated with Speed-O-Matic hydraulic clutches that provide smooth, self-adjusting engagement. The single line pull for hoisting, clamshell, or dragline use is rated at 17,300 lbs, with line speeds reaching up to 299 FPM depending on the engine configuration. Dragline pull capacity reaches 18,000 lbs, and the third drum supports up to 5,000 lbs, allowing simultaneous operation with controlled load lowering.

Safety and operational reliability are prioritized through several design features. The controlled boom lowering system (CBL) reduces swing during descent and provides added control, even under heavy or over-running loads. Boom hoist operation is independent and driven by gear mechanisms, using air-clutched expanding bands for positive and secure boom positioning. The braking system includes drum brakes with cooling flanges and internal expanding clutches, which ensure consistent stopping power even under continuous heavy use.

The operator cab is a full-width, enclosed unit offering excellent visibility through full safety glass, including sliding side windows and a fold-down front windshield. The ergonomic layout includes finger-tip hydraulic controls for hoisting, swing, and boom functions, a comprehensive instrument panel, and dual electric heaters for all-weather operation. A telescoping A-frame makes counterweight handling and transport easier, folding low over the cab for better clearance when on the road.

The crane’s lubrication system is engineered for longevity, with anti-friction bearings, bronze bushings, and needle bearings in jib sheaves, many of which require minimal or no daily lubrication. All primary bearing and gear components are pressure-lubricated for smooth, maintenance-friendly operation.

In conclusion, the American 4450 stands out as a highly capable and well-rounded lattice boom truck crane. Its 40-ton lifting capacity, modular boom and jib system, and strong hydraulic and mechanical performance make it a reliable workhorse for contractors and operators who require both power and adaptability. Whether for lifting structural components, executing dragline or magnet operations, or performing in confined or uneven job sites, the 4450 delivers the robust features and serviceability expected of a proven American crane design.