From road to rail: the Liebherr A 922 excavator

With the A 922 Rail excavator, Liebherr has created a machine that is suitable for work on both railway tracks and road construction that quickly navigates jobsites thanks to its mobile undercarriage. Liebherr presented the A 922 Rail Litronic at the recent Innotrans 2024 in Berlin.   The excavator is equipped with a rail travel drive mounted on both sides of the undercarriage.

When entering the rails, the travel drive lifts the tires to rail height. The inside wheels of the dual tires ensure travel of the excavator on the tracks. The A 922 Rail also includes the quick coupler system, attachments and safety systems developed by Liebherr, all customized for the machine. 

Powered by a 163 hp engine, the A 922 Rail achieves a fast-working speed with smooth working movements. The innovative hydraulic concept of the A 922 Rail consists of a Liebherr variable displacement double pump with independent control circuits. This allows the operation of high-performance hydraulic attachments independently of the working and travel movements of the railroad excavator. 

RELATED: Liebherr introduces its Gen 8 PR 776 crawler dozer[1]

The delivery rate of the proven Liebherr variable displacement double pump was increased to two x 220 litres per minute to boost performance.

The heavy ballast was also redesigned to yield the best bearing load values with improved weight distribution and a more compact rear dimension of 2 metres.

Liebherr undercarriage

The A 922 Rail is available with various undercarriage versions with different track widths and rail wheels, which make it possible to use it on tracks worldwide.  An independent variable displacement pump for the rail travel drive provides the best traction and safe propulsion. Standard integrated brakes in the rail wheel shorten the braking distance in both the lowered and elevated position, enhancing safety.

Double cab

The spacious double cab features a standard roll over protection structure (ROPS) and a modern interior design for comfortable, focused and productive work.

Entrance lighting is provided to make accessing the cab easier.  Liebherr designed the cab with a generous use of glass and standard rear and side cameras to provide an exceptional view of the working area and swing range. The touchscreen colour display, as well as the other control elements on the console, are all perfectly matched to one another to form the perfect unit.

Occupational safety is extremely important in track construction, so Liebherr offers its own safety systems, which are tailored to the machine requirements. The safety technologies include load torque, height and sway limitation and the virtual wall.

Solidlink 33-9

To meet construction site requirements economically and reliably, Liebherr offers an extensive portfolio of attachments for the A 922 Rail. The new rail tongs are specially designed for the proven gripper mechanism of the GMZ 22.

The attachment was developed for Liebherr's railroad excavators in close collaboration with machine operators. It enables efficient work with the track strand.  The A 922 Rail exhibited at the Innotrans was equipped with a Solidlink[2] 33-9 quick coupler.

The new Solidlink 33-9 model adds more couplings to the fully automatic quick coupling system, with all the advantages. The expansion of the couplings to include a second high pressure circuit also allows the use of hydraulic attachments such as tamping equipment in rail construction, mulchers with flaps or Liebherr stick extensions. The Solidlink fully hydraulic quick coupling system allows attachments to be changed quickly and safely from the operator's cab. 

Service-orientated 

The service-orientated machine design of the A 922 Rail guarantees short maintenance times and minimizes the associated maintenance costs, according to Liebherr.

All maintenance points are easily accessible from the ground.

The new generation has simplified access to important components even further, including air, oil and fuel filters, the main battery switch, the central lubrication point for the undercarriage and the pilot valves for the hydraulic system.

References

1. ^ Liebherr introduces its Gen 8 PR 776 crawler dozer (www.equipmentjournal.com)
2. ^ Solidlink (www.equipmentjournal.com)