National Boom Trucks Hit the Streets
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July 7, 2004 - Two new boom trucks from National Crane, manufactured by Manitowoc Cranes, Manitowoc, Wis., are hitting the streets with large capacities and longer booms. The National Series 500E, which became available in May, provides an 18-ton capacity and a 71-foot, three-section boom. The National Series 600E has a 20-ton capacity and a 90-foot, four-section boom. With a longer boom, the operator can perform more lifts without the use of a jib, which reduces setup time and improves efficiency. The 600E will begin shipping to customers by the end of the summer.
With the addition of a 45-foot, two-section jib, the 600E offers a maximum vertical reach of 140 feet. Maximum tip height on the 500E is 121 feet when a 41-foot, two-section jib is added.
Both boom trucks feature a state-of-the-art hydraulic system to optimize performance. This control strategy matches the required flow to the speed/demand of the function while the variable displacement piston pump is regulated to maintain a constant pressure to the eight-section main valve. Main valve spools are designed to both meter and limit the maximum flow to each function. Available oil flow is optimized by using gravity for boom down. Because the pump pressure is constant, smooth metering is assured regardless of load.
Standard features on the 500E and 600E boom trucks are self-lubricating, easy-glide wear pads to reduce boom chatter and vibration, internal anti-two block to eliminate external reels and wires, adjustable swing speed, auxiliary stabilizers, and quick-reeve boom tip and sheave blocks to simplify rigging changes.
Improved serviceability is a significant highlight of the National 500E and 600E boom trucks. Their removable winches allow the internal telescoping cylinders to be removed quickly without dismantling the booms. Bearings on the booms' extend and retract cables can be greased through access holes in the boom side plates. Internal anti-two block wire routing eliminates potential damage, and the boom sheave cases are open, allowing access to replace the internal anti-two block wire and observe internal boom components. Additionally, internal boom parts have been reduced, which decreases service time when rebuilding the machine.
Accessories for both cranes include radio remote controls with an operating range of about 250 feet, a 300-pound capacity personnel basket, a heavy-duty 1,200-pound personnel basket with up to 4-passenger capacity, and hydraulic oil cooler, and continuous rotation.
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Capacity Chart for 600E equipped with Jib |
For more information, go to www.nationalcrane.com .
