Master Copy for IRTMTCALD by IRICEN Dynamic Track

Master Copy for IRTMTC/ALD by IRICEN

Dynamic Track Stabilizer (DTS/DGS General – During maintenance operations such as tamping, lifting, slewing, deep screening etc. the lateral resistance of track gets reduced which rebuilds gradually with passage of trains. This consolidation can also be achieved faster, uniformly and more effectively by means of a Dynamic Track Stabilizer. MAIN FEATURES: Elimination of initial differential settlements which are caused by the impact of passing trains. The track geometry achieved by tamping machines is retained for a longer duration. Homogenous structure of ballast bed is built up. Lateral track resistance increases resulting in enhanced safety against track buckling. Speed restrictions are relaxed faster.

MAIN UNITS & THEIR FUNCTIONS: STABILIZER UNITS: The machine has two dynamic stabilizer units which run on the track beneath the main frame, make contact with the rail heads through eight flange rollers on the inside and four roller discs on the outside. The two synchronized vibration units cause the track to vibrate horizontally. The frequency is adjustable from 0 to 45 Hz from the cabin. Two centrifugal force, independent of the frequency, can be up to 320 k. N.

TECHNICAL DATA: ENGINE: (OLD STOCK) DEUTZ-BF-12 L-513 C 460 BHP (AIR COOLED) (NEW STOCK) KTA-1150 L FROM KCL 473 BHP AT 2200 RPM LENGTH OVER BUFFER 17250 MM WIDTH 2800 MM HEIGHT ABOVE RAIL 3790 MM BOGIE PIVOTS SPACING 12000 MM BOGIE WHEEL BASE 1500 MM WHEEL DIAMETER 730 MM WEIGHT 57 TONNES AXLE LOAD: (I) FRONT AXLE LOAD 14. 5 TONNES (II) REAR AXLE LOAD 14. 0 TONNES SPEED: (I) SELF PROPELLED 60 KMPH (II) IN TRAIN FORMATION 50 KMPH

POWER TRANSMISSION

WORKING PRINCIPLE OF DGS (1) Mechanism of DTS – Heavy dynamic consolidating units are pressed firmly against both rails by hydraulic pressure. Flywheels produce a horizontal oscillations (some of machines use vertical oscillations also) directed laterally to the track, which together with a vertical load is transmitted onto the track and subsequently to the ballast bed. The dynamic effect of directional oscillation causes the sleepers to be "rubbed into' the ballast bed and produces a "flowing movement" of the ballast which get denser by filling of the voids. This compaction causes not only a controlled and uniform settlement of the track but also an enhanced friction between sleeper and compacted ballast bed, thus increasing lateral track resistance.

WORKING PRINCIPLE OF DGS The oscillation frequency is adjustable. The impact by the dynamic force and simultaneously applied static force are important aspects of functioning of DTS. Hydraulic cylinders attached between the machine frame and the consolidating units apply vertical static loads on both rails. The vertical load helps in maintaining firm contact between the consolidating units and the track for transmitting the oscillation. The vertical static pressure is also adjustable.

WORKING PRINCIPLE OF DGS (2) Levelling System in DTS – DTS is equipped with a levelling system, which prevents the longitudinal, and cross level values achieved after tamping from varying due to differential settlement of various segments of track during operation of DTS. The transducers of the longitudinal level and the cross level measuring system recognize the tendencies towards formation of faults of this kind and influence the load control with their measuring signal via the automatic governor, thus counteracting the tendency of propagation of the faults. (3) Speed of Working of DTS – The speed of working can be controlled by an adjustable hydrostatic drive. If the track geometry is corrected by several passes of the tamping machine, then a low speed of working of 0. 5 kmph to 1. 0 kmph is selected for first and second passes of the machine. For subsequent passes, higher working speed is selected. (4) Stabilization Achieved by DTS- It is possible to permit speed of 40 kmph on freshly deep-screened tack, if ballast is adequate and Dynamic Track Stabilizer has been used behind the tamping machine.

Modes of Working of Dynamic Track Stabilizer (DGS) The machines are capable of working in following two modes (1) Maximum Settlement/Constant Pre Load Mode (i. e. Levelling system- (2)-Controlled Settlement/Variable Pre Load Mode (i. e. Levelling system-ON) – OFF)– In the this mode of working, the machine works to achieve higher consolidation through maximum pressure (vertical load)and thus larger settlement, however, the settlement achieved in this mode of working is usually irregular, though the consolidation level of ballast bed is high. In this mode of working, the DTS machines are capable of settling the track in a controlled manner while maintaining the track geometry, both longitudinal and cross level. A settlement value is preselected (around 30% of lift during tamping)and the pressure (vertical load) in the long cylinders is controlled by levelling system. In some machines measuring and control system has been installed which can remove any residual fault in track geometry.

WORKING PRINCIPLE OF DGS The standard range of pressure variation is 40 to 100 bar which corresponds to effective loads from around 165 to 355 KN. For track maintenance operation, pressure range of 60 to 80 bar is used which gives effective load of around 230 to 290 kn. DTS is equipped with a leveling system which prevents the longitudinal and cross levels values from varying appreciably due to differential settlement of various segments of track. The transducers of longitudinal level and cross level measuring system recognize the tendencies towards formation of faults of this kind of influence the load control with their measuring signal via automatic governer, thus counteracting the tendency of propagation of faults

The speed of working can be controlled by an adjustable hydrostatic drive from 0 to 2. 5 Kmph. If the track geometry is corrected by several passes of tamping machine, hen a low working speed of 0. 5 to 1 Kmph for the first and second passes of the machine. For subsequent passes, higher working speed is selected. In one pass, the machine carries out stabilization equivalent to passage of 1 lakh tones of traffic. It is possible to permit speed of 40 Kmph on freshly deep screened track if ballast is adequate and dynamic track stabilizer has been used behind the tamping machine. For PRC sleeper oscillation frequency range of 32 to 37 Hz is adopted

RECORDING AND MONITORING SYSTEM: A proportional chord-leveling device enables controlled settlement of the track. A steel chord is spread over each rail between the sensor rods which are jointed to the inside axles of the bogies. They form the reference base of the recording system of the longitudinal level. By means of a sensor rod between the stabilization units, on which a recording value transmitter is attached to the left and right hand side, the settlement is recorded and monitored.

APPLICATION The application of the dynamic track stabilizer anticipates the initial settlement in a controlled manner without altering the track geometry. After tamping the DGS lowers the track as required, gripping the rail heads with roller clamps and serving the track into horizontal oscillations. And at the same time each rail is automatically pressed down in accordance with the readings of the leveling device and Super – elevation Gauge. DGS is a firm and proven part of the track maintenance. By this we can achieve horizontal stability along with rise in safety and earlier removal of speed restriction as it also improves the lateral stability.