Combined road-rail excavator from Liebherr – the A 922 Rail at the 2014 NordBau trade fair

The A 922 Rail is available with optional four-point supports and can, depending on the intended work area, be supplied with a rail-track undercarriage for broad-gauge rail systems or a friction drive wheel for narrow-gauge systems. Also optionally available: a 3.40m long luffing boom or a boom that can be repositioned laterally, in this case 3.60m long. There are also dipper arms 1.85m, 2.05m, 2.25m or 2.65m long that have been specially designed for work below overhead wires.

Two different counterweights can be specified. The standard counterweight gives the A 922 Rail a rear-end swing radius of 2,000mm, and is (for instance in Germany) permitted to use public roads in this form. Depending on country approval, a heavy HD Ballast with a rear swing radius of 2,050mm is also possible.

Another option for the A 922 Rail is an add-on axle, on which the tyres can be attached to the rear rail-wheel assembly in just a few minutes. By converting the road-rail excavator into a three-axle vehicle, it allows it to be licensed for use on public roads, for instance anywhere in Germany.

The A 922 Rail can be equipped with the optional LIKUFIX quick-change mounting for hydraulic working attachments. These can be detached and picked up quickly and safely without the operator having to leave the cab. When Liebherr attachments such as the tilt-rotator, ditch-cleaning bucket, clamshell grab or electromagnet, LIKUFIX achieves a significant increase in productivity.

Powerful Liebherr engine, easy maintenance

The A 922 Rail obtains its power from a 110kW (150HP) Liebherr D 834 diesel engine that complies with stage IIIB exhaust emission legislation and was developed in cooperation with MAN. As standard, the machine is equipped with a Liebherr particulate filter preparation kit, which contains a diesel oxidation catalyst. In place of the silencer module, a particulate filter module can also be installed easily for tunnel construction sites. It goes without saying that, if a silencer module is fitted, the thresholds of the stage IIIB emissions standard are also kept in check.

The diesel engine drives a duplex hydraulic pump with a rated output of 2 x 215 litres per minute. Each pump can be controlled separately, for troublefree operation of attachments with an intensive power requirement, such as mulchers or hydraulic pile drivers. While one pump is supplying power to the working attachment, the other permits the road-rail excavator’s travel and working movements to be supplied separately.

Liebherr HVI hydraulic fluid is used as standard on the A 922 Rail, and is capable of an operating life of more than 6,000 hours. Instead of fixed oil-change intervals, these are determined by the results of an oil analysis carried out every thousand hours of operation or once a year. To prolong the lifetime of the hydraulic fluid, and as a reliable service indicator, a magnetic rod is installed in the hydraulic fluid tank as a standard item, and can be easily removed and cleaned when necessary.

The large engine cover on the A 922 Rail opens to expose the entire right-hand side of the machine, and provides quick, convenient access to all servicing points. Day-to-day maintenance can be carried out from ground level; this keeps servicing periods short and makes the work safer. To clean the radiator, which is of generous size, the powerful cooling fan can simply be swung out forwards.

Well-equipped new two-person cab

A new design with an extremely clear layout, the A 922 Rail’s cab has ample space for the driver and a second person. The windscreen can be slid up as a complete unit, and the touch-screen display is intuitive to operate. The excavator uses a proportional-action control principle at left and right. Standard features include an air-sprung, heated driver’s seat with the seat base adjustable in height and angle, a lumbar support, a head restraint, a lap-type seat belt and ergonomically laid out control consoles that move with the seat. The high-quality specification also includes automatic air conditioning and a cruise control to make the driver’s task easier on lengthy road journeys.

Among the standard safety equipment on the A 922 Rail is pipe-burst protection for the lifting, luffing and dipper arm cylinders. There are two cameras to monitor the areas to the side and rear of the machine, with a separate display in the cab. The fully automatic central lubricating system, also standard equipment, avoids loss of working time due the need to grease various points manually.

Powerful LED lighting is an option for the A 922 Rail. As well as providing ample illumination, it is noted for its long life and low current consumption. The signal lights called for by rail operators such as German Rail can also be equipped with LEDs. The complete machine can be supplied with rail operating approval in accordance with German Industrial Standard DIN EN 15746.