Liebherr’s new A 922 Rail Litronic Excavator can be equipped with a range of undercarriage options, enabling it to be used on both railway and road construction projects.
A rail travel drive is mounted on both sides of the dual-tire wheeled undercarriage. When the excavator enters the tracks, the rail travel drive lifts the tires to rail height, allowing the inside wheels to rest on the tracks. Liebherr says direct contact between the rubber tires and the rail delivers high travel speeds and traction for towing trailers or wagons.
The A 922 Rail is powered by a 163-horsepower Tier 4 Final diesel engine. The standard automatic idling function reduces the engine speed to idle as soon as the operator lets go of the joysticks. The engine will return to its original speed as soon as proximity sensors in the joysticks recognize the operator’s hand moving toward the lever again. This ensures that the set engine speed is available immediately, Liebherr says, which results in fuel saving and reduced noise.
A variable displacement double hydraulic pump with independent control circuits allows hydraulic attachments to be operated independently of the excavator’s working and travel movements. For improved performance, flow capacity has been increased to 2 x 58 gallons per minute. The counterweight was also redesigned to improve lift capacity and weight distribution while reducing the rear size to 78 inches wide.
Two-Person Cab
The spacious cab features a double seat layout for two-person operation, which is required in many countries for safety monitoring while working on railroad tracks. Entry lights illuminate the doors for easy entry and exit. Large glass windows and standard rear and side cameras provide all-around views of the jobsite and swing range.
Three seat options are available – standard, comfort and premium – with even the standard option offering suspension, heat, a headrest, lumbar support and other features.
Machine data, cameras, automatic air conditioning, Bluetooth and other operational functions can be controlled via two 9-inch touchscreen displays. Quick access keys can be programmed by the operator for frequently used menu items.
Service and Safety
All maintenance points are easily accessible from the ground with simplified access to air, oil and fuel filters, the main battery switch, the central lubrication point for the undercarriage and the pilot valves for the hydraulic system.
Liebherr says safety systems have been tailored to the machine requirements, including load torque, height and sway limitation and a virtual wall.
An independent variable displacement pump for the rail travel drive provides traction and safe propulsion, while the standard integrated brakes in the rail wheel shorten the braking distance in both the lowered and elevated position.
New Attachments and Quick Coupler
In addition to the base machine and track drive system, the A 922 Rail also comes equipped with a quick coupler and new attachment options specifically for rail work.
New attachments include:
- Grab GMZ 22 with rail tongs for tasks such as aligning, positioning or loading rails.
- Parallel grab GMP 25 with mast tongs for placement of masts for overhead lines to electrify railway lines.
- Sorting grab SG 20B with universal tongs for loading and sorting rubble or for clamping individual sleepers.
The in-cab display can store up to 20 attachments, allowing operators to quickly set the oil pressure and flow at the push of a button.
When equipped with a Solidlink 33-9, additional couplings are added to the fully automatic quick coupling system. A second high-pressure circuit allows the use of hydraulic attachments such as tamping equipment in rail construction, mulchers with flaps or Liebherr stick extensions. The system also allows attachments to be changed quickly and safely from the cab.
Quick Specs
- Operating Weight: 45,000 – 51,600 lbs
- Horsepower: 163 hp
- Bucket Capacity: 0.31 – 1.24 yd³
Read the full article here
