Mechanized Methods of Track Maintenance

The need to switch over from manual to mechanized methods of track maintenance is progressively being felt due to the following reasons.

(a) Beater packing is a very hard and strenuous job and thus the labourers have a tendency to shirk from doing this type of work.

(b) It is difficult to ensure the uniform quality of the compaction under the sleepers carried out by manual means due to the uncertainties associated with the varying physical strength of the labourers, commitment of the workers, varying weather conditions, and other allied factors.

(c) The intensity of the pressure and shock that the ballast is subjected to when the beater is being used is very high and in many cases exceeds the crushing strength of the stone. This results in the progressive clogging of the ballast section.

(d) Traffic densities, axle loads, and speeds have increased considerably on Indian Railways considerably in the recent past. Beater packing does not enable track geometry to be maintained within the tolerances prescribed for a satisfactory length of time.

(e) The retention of the packing done via manual maintenance is not very good and the track geometry gets distorted in a short time due to high-speed traffic.

(f) Manual maintenance is not much suited to the modern track, which consists of long welded rails and heavy concrete sleepers.

(g) With the increase in traffic density, the time available between trains is becoming progressively short. It is, therefore, becoming increasingly difficult to maintain tracks by manual methods, which take a considerably long time.

(h) When a track is maintained manually, it takes considerable time for it to get fully consolidated and, therefore, speed restrictions exist for a long period after track renewal work has been completed.

(i) Manual methods do not emphasize on the identification of defects and monitoring of the work being done. These are, however, done in the case of modern methods of track maintenance, thereby giving move effective results.

Some of the important heavy track machines being used on Indian Railways (IR) are listed in Table 20.1.

Table 20.1 Track machines in use on IR

(contd)

Table 20.1 (contd )

Type of track machine

Functions

Remarks and output

Plassermatic 08 Dnomatic tamper

Tamping, levelling, and lining simultaneously. Consists of 32 tamping tools and can tamp two sleepers at a time.

Output is 2000 sleepers per hour

Plasser 09 CSM tamper

Tamping, levelling, and lining simultaneously. The machine advances continuously, while tamping is done from sleeper to sleeper.

Latest track machine with an output of 2500 sleepers per hour

Plasser 08-275 unimat P and C tamper

Tamping points and crossings. Consists of 16 independent tiltable tamping tools, which can tamp points and crossings as well as plain tracks.

Good machine for tamping points and crossings. Can tamp 1 turnout in a 4-hour block.

Plasser

VDM-800

consolidator

Used for crip and shoulder consolidating so as to improve the retention of packing.

Output is 1000 sleepers per hour

DGS-62 N stabilizer

Dynamic track stabilizer that uses vibrating rollers to further stabilize the track.

Output is 500 sleepers per hour

Matisa R-7

ballast

regulator

To regulate ballast profile by transferring ballast from one place to another.

Can regulate ballast of 1 km of track per hour

Plasser RM-80 BCM

Ballast cleaning machine used to excavate, clean, and put the screened ballast back in the track and to remove unwanted material.

Can handle 650 m3 of ballast per hour

Switch

relaying

machine

Wm-22

To remove and install parts or complete assemblies of points and crossings.

Can relay about two sets of points and crossings every day

Track relaying trains (TRT)

Relaying the entire track automatically with very little manual effort. Consists of four different units and other ancillary machines with a total cost of over Rs 100 million.

Latest state-of-the art machine. Can accomplish the relaying of 1 km of track per day in a 4-hour block.

On railways, the mechanized maintenance of tracks normally involves the use of mechanical tampers, which are used to tamp or pack the ballast. Mechanical tampers are generally of two types, namely, off-track tamper and on-track tampers.

Modern Methods of Track Maintenance | RAILWAY ENGINEERING | Off-track Tampers