Link-Belt ATC-3250 Auto-Adjusts for Boom Deflection
📅 Wed June 20, 2007 - National Edition
Link-Belt’s 250-ton (220 t) ATC-3250 is equipped with a 43.3 to 223.1-ft. (13.2 to 68 m), full power, seven-section, latching boom. The sections extend independently by means of one double acting, single stage hydraulic cylinder. Four pinned positions of 0, 46, 92, and 100 percent on each section provide thirty-eight extend combinations for increased capacities when varying the extensions of the telescoping sections.
A 17.7 to 43.3-ft. (5.4 to 13.2 m) two-piece, lattice fly and four lattice fly extensions are available as options for additional reach. Each of the extensions is 19.7 ft. (6 m) and extends the fly length to 63 ft. (19.2 m), 82.7 ft. (25.2 m), 102.4 ft. (31.2 m), and 122.1 ft. (37.2 m).
All of these attachment combinations have offset positions of 0, 20 and 40 degrees. The 43.3-ft. (13.2 m) attachment with all four lattice extensions used in combination with the main boom reaches a maximum tip height of 358 ft. (109.1 m).
The ATC-3250 features the LoadCom load radius compensating system. Given the inevitable boom deflection under load, operators have to precisely adjust the boom elevation and winch to keep a load from drifting out. On the 3250, the LoadCom feature eliminates the guesswork. As a load lifts, the LoadCom system automatically compensates for this boom deflection by activating the boom hoist.
The galvaneal cab with acoustical insulation has a tilting capsule for high boom angle lifting. This capsule, consisting of the seat, joysticks, pedals, and main console, tilts independently of the cab. This system makes the operator more comfortable and eliminates the need to secure personal items as in a regular tilting cab. The cab has a sliding composite door, large tinted glass windows, and a hydraulically adjustable, cushioned seat with headrest. The controls and instrumentation are ergonomically designed and conveniently positioned. Outrigger controls also are located in the operator’s cab.
Two electric-over-hydraulic, dual-axis levers with fine metering capability control the winches, boom hoist, and swing.
Heating and air conditioning, a cabin pre-heater with a pre-settable timer, AM/FM stereo with CD player, power front window, floodlights, and an integrated cab walk are standard.
Axial piston, constant displacement motors with final layer and third wrap indicators drive the main (front) and auxiliary (rear) winches. The main and auxiliary grooved hoist drums contain 1,148 ft. (35 cm) of 0.83 in. (2.1 cm) wire rope. Maximum line pull for each winch is 24,504 lbs. (11,114.8 kg) and the maximum line speed is 508 ft. (154.7 m) per minute.
The variable swing brake system on the ATC-3250 gives the operator greater flexibility. In free swing mode, the operator can simply return the control lever to neutral or gradually reverse the direction of the swing control lever to bring the upper to a smooth stop. In automatic brake mode, the upper will automatically stop when the controller returns to the neutral position. Swing speed is 1.8 rpm.
The ATC-3250 has 530 hp (390 kW) Mercedes-Benz engine and ZF AS-Tronic automated, 16-speed manual transmission that delivers a top speed of 52.8 mph (85 kmh). With five axles, the ATC-3250 features a 10 by 8 by 8 drive/steer configuration. This combination of power and traction allows the 3250 to tackle 61 percent grades. Also, a third axle lift system is incorporated that provides more inter-bridge spacing to comply with certain transportation requirements found throughout North America.
The primary steering, controlled by simply turning the steering wheel, varies with the speed of the crane. Below 15.5 mph (25 kmh), axles 1, 2, 4, and 5 steer in combination. As the speed of the crane increases, axle 4 and then axle 5 sequentially return to center until axle 1 and 2 become the only two axles steered. There also are five additional steering modes including independent front, combination, crab, independent rear, and a temporary crab steering mode. The temporary crab mode allows the crane to drive away from an obstruction like a curb or a wall. The carrier has other mobility conveniences like cruise control, engine compression brake, and a driveline intarder. The intarder, produced by ZF, is a hydrodynamic driveline brake that is integral to the transmission.
The suspension is a hydro-pneumatic system with automatic ride height leveling and level adjustment capabilities. The leveling adjustment allows the operator to tilt the 3250 laterally and longitudinally from the carrier cab. The operator can level the crane before deploying the outriggers so they can fully extend prior to raising the crane on its jacks.
Standard features include:
• An automatic outrigger leveling system.
• One touch outrigger deployment.
• Central lubrication for carrier and upper structure.
• Air and electrical connections for a boom dolly or trailer.
• A free swing and boom hoist float for transporting the boom over the rear with a boom dolly.
• Meets SAE structural and stability requirements.
For more information, visit www.linkbelt.com.