New Holland adds ADT

New Holland Construction's new articulated dump truck (ADT), the AD250, features a centrally located ROPS/FOPS cab mounted on rubber pads. It is the company's first ADT, sharing approximately 85% of its technology with Case's ADT.

One of the latest OEMs to add an articulated dump truck (ADT) to its construction-equipment line is New Holland Construction (Booth G-150). In fact, the new AD250 with a 23,000-kg (50,707-lb) payload is just the initial model of an ADT line that the company plans to expand "in the very near future," according to Kirk Gillette, General Manager Marketing, New Holland Construction, North America. A smaller ADT model will be introduced later in the year, with a bigger one being unveiled at CONEXPO.

ADTs have become much more prominent in North America over the past couple of years, gaining a reputation as powerful earthmoving machines capable of working in bad weather, on difficult worksite terrain, and in confined work conditions. The AD250, like all articulated dump trucks, allows a tight turning radius because it has an articulation and oscillation joint between the cab and the body that enables the front of the truck to move independently of the body. The front and rear frames of the six-wheel-drive truck are linked by a heavy-duty articulation pin joint and taper roller bearing ring. The frames are manufactured from Hardox 400 high-tensile steel from SSAB. The semi-independent front and rear suspension system features a rear system with a double beam linked by elastic pin to a torque-reducing structure. The hydro-pneumatic front suspension with air-over-hydraulic cylinders automatically levels the trucks' height whether it is loaded or empty.

The center-pin oscillation mechanism and ground following rear tandem keep the AD250 wheels on the ground at all times, maintaining the truck's stability on rough terrain. There is also an inter-axle differential locking system to extricate the vehicle from soft ground, making it suitable for sites with inclined and soft surfaces such as housing developments, industrial parks, golf courses, landfills, land reclamation sites, and dam construction sites. The truck hauls an SAE struck load of 10.6 m³ (13.9 yd³) or a heap load of 13.3 m³ (17.4 yd³).

The ADT features fully hydraulic power steering, and a standard automatic six-speed ZF WG210 transmission with manual override offers six forward and three reverse speeds. A microcomputer automatically shifts up and down, selecting the gear-optimized-for-payload and traveling speed. The truck's maximum speed is 51.5 km/h (32 mph). A backup, emergency steering system ensures that the AD250 can be steered if the primary steering function is lost.

The AD250 is powered by a Cummins 6CTA diesel turbocharged engine with a 114- x 135-mm (4.49- x 5.3-in) bore and stroke. The 8.3-L engine offers 194 kW (260 hp) at 2200 rpm and 1123 N•m (828 lb•ft) at 1300 rpm. Centralized greasing allows the complete machine to be lubricated from only two locations. The powered engine hood opens and closes easily to allow fast and convenient access to the engine compartment.

Independent front and rear braking systems and large capacity disc brakes for service brakes ensure greater safety. A locking brake is provided that enables all wheels to be locked simultaneously to hold the entire vehicle solid and steady during loading and unloading.

Bobcat's four-wheel-steer loader

Bobcat's new A220 is a compact loader with four steerable axes that is powered by a 2.92-L Deutz BF4M1011F four-cylinder diesel engine.

Engineers from the Bobcat Co. (Booth G-100) have combined the smooth ride of a small wheel loader with the compact size, tight turning radius, and maneuverability of a skid-steer loader on the new A220 all-wheel-steer (AWS) loader. Potential applications for the machine include landscaping and nursery, concrete and flatwork, building construction, utility installation, municipalities, industrial, and rental applications.

The A220 offers two different steering modes with a flip of a switch in the cab: AWS and skid steer. According to Mike Fitzgerald, Bobcat Product Specialist, a member of the A220 design team since its inception two years ago, "There are dozens of skid-steer loaders and compact wheel loaders on the market today, (but) no one else has a loader with both options in one machine."

The steerable axle ends have permanently lubricated u-joints for minimum maintenance. Shown is the maximum turn angle during AWS; during skid-steer operation, the axles stay straight.

There are many benefits of having two steering modes. "All-wheel-steer mode minimizes the disturbance of ground and other surfaces and consequently decreases wear on the tires," he said. "Skid-steer mode allows operation in tight, confined areas."

Because the A220 is built with the same mainframe as a Bobcat 863 skid-steer loader and T200 compact track loader, it offers the same multiple attachment capabilities. "What makes this machine unique is its transmission with steerable axle ends," said Fitzgerald. "In all-wheel-steer mode, the inside wheels turn at a sharper angle and at a slower speed than the outside wheels."

While both steering modes are controlled by a single joystick, in all-wheel steer (AWS), the right and left sides work together to minimize turf damage and lower tire wear (left). In skid steer, each side works independently to allow the loader to counter-rotate for maximum maneuverability (right).

Other features of the A220 include a two-speed travel option, low-effort joystick controls, a low-speed/high-torque "inching" mode, a foot-pedal accelerator, and a rated operating capacity of 1000 kg (2200 lb). The inching mode (or creep) is activated by the push of a button, which puts the A220's speed at 5 km/h (3.1 mph), half the machine's normal speed. This control feature allows the machine to maintain full engine power for operating hydraulics and attachments at slower speeds in applications that require precise movements with high torque.