The function of this machine is to remove fouled ballast from underneath the railway track so that fresh clean draining ballast can be substituted. The machine is specifically designed to work on points, turnouts and crossings. The major materials handling elements are a horizontal excavating chain, a vertical cell type bucket wheel and three troughed belt conveyors. The excavating chain removes all of the ballast to a depth of 30Omm below the underside of the sleepers. The bucket wheel digs a trench beside the railway track, allowing the excavator chain to rake ballast back into the trench. The bucket wheel also elevates ballast onto the conveyor system. The conveyor system comprises of a cross conveyor, main transfer conveyor and 6m long slewing discharge conveyor for dumping spoil into railway wagons or road vehicles. The undercutter is provided with a centre jack for lifting the machine some 30Omm above the rails. From this position, the machine can be rotated end for end and placed back on the rails, or it can be placed on special off-tracking rails for sideways travel to a parking bay beside the railway track. A set of motorised off-track wheels are provided for this purpose.
		BASIC DESIGN PARAMETERS OF THE MACHINE Material 75mm ballast Rate 200 tph No. Buckets 14 Bucket Speed 12 rpm Conveyor Width 50Omm and 65Omm Travel speed 40 kph The machine is equipped with the following drives and functions:-
DRIVES Main travel drive Undercutting creep drive Bucket wheel drive Excavator chain drive Cross conveyor drive Main conveyor drive Spoil conveyor drive Spoil conveyor slew drive Off tracking drives (2-off) Air compressor for brakes Oil cooler drive Travel gear box coolant drives (2-off) Air conditioners (2-off) Air brakes HYDRAULIC CYLINDERS Bucket wheel in-out Bucket wheel up-down (2-off) Excavator chain up-down Excavator chain slew Spoil conveyor raise/lower Centre jack raise/lower (2-off) POWER SYSTEM The machine is powered by a 250KW turbo charged, 2 stroke Diesel direct coupled to four pumps as follows: Axial Piston Pump - Main traction Axial Piston Pump - Bucket Wheel Gear Pump - Creep traction Gear Pump - Oil cooler The undercutter is also equipped with a 175cfm air compressor for general use OPERATION The undercutter has four operator positions and an additional roving pendant for some functions. Fast travel driver's seats are provided inside two air conditioned cabins, one at each end of the machine, enabling the unit to be driven conventionally in either direction over long distances of railway track. A work position operators chair is used for undercutting. This position incorporates a console of indication lights, gauges and the Programmable logic Controller system. The operator has a comprehensive view of the machine working parts. The centre jack and off tracking drives are operated from a external platform on the machine. This is to enable the operator to have better feel, hearing and vision of these operations. A roving pendant control can be used from the ground to slew and luff the discharge conveyor. This machine is an ideal example of prototype design, development and construction. Techniplan have taken a basic concept and developed it to an efficient, reliable, modern machine. All design and manufacture was carried out in Brisbane, Australia to strict Quality Assurance procedures.