1. Ballasted Track 2. Ballastless Track Generally only ballast tracks are made on the ground. But for metro rail, the track is either elevated or underground. It is not possible to maintain the ballast track at such a place because the frequency of metro train is between 2 to 4 minutes. Therefore, concrete tracks are made in such a place. Maintenance of such track is very less. Below are pictures of three ballast tracks. The first picture is a close up. In the second picture the track is moving from elevated to ground label and then going underground in the tunnel. The third picture has a fully elevated track. In both these situations, daily maintenance of the ballast track is not possible. The ballast from the elevated will fall on the road below and track maintenance in the tunnel is a very difficult task. Therefore, only ballastless concrete track has to be made in the metro without ballast, which is also very expensive, but the maintenance demands are negligible.
Why are pieces of stone thrown on railway tracks?
Every day millions of people travel by train in India. Most of us must have seen railway tracks at some point of time. Small stones are laid, but have you ever wondered why stones are laid between railway tracks and on both sides of it? After reading this article you will get the answer to this question easily. There is a scientific reason behind the laying of small stones between railway tracks. Initially, railway tracks were constructed with the help of steel and wooden tracks, but in today’s time, instead of wooden tracks, cement is used. Rectangular ingots are used, called “sleepers”. In fact, the purpose of laying small stones between railroad tracks is to hold wooden planks or cement ingots firmly in place so that these ingots Hold the railway track firmly. In fact, when the train moves, it creates vibrations in the ground and the tracks. Apart from this, due to strong sunlight, the tracks expand and shrink in winter. Due to this, the entire weight of the train falls on the wooden or cement ingots, but due to the stones being laid between the tracks, all the weight goes on these stones, due to which the vibration, shrinkage of the tracks, the weight of the train all become balanced.
How are the tracks maintained at the same level for a distance of thousands of kilometres in railways? Will there ever be a danger if the tracks or stones go up and down due to human error?
When trains run at a speed of 100 km to 160 km per hour on the railway track or tracks, the railway department has also created a civil engineering department for their maintenance. The staff strength (man power) of this department is also the highest, after all, the maintenance (maintenance) of 69,182 route kilometer track is to be done. Track Maintenance Unit is made for the maintenance of the track. It consists of 40–45 trackman, keyman, mate (muqaddam) etc. The unit has an in-charge, called Pay Way Supervisor (PWS). Above two units there is a JE/SSE (P-way). This unit is given a section of 5-6 km. It is these people who maintain the track. Several measurements are taken and recorded in the maintenance registers. Some of the main measurements are as follows:- track gauge track level Super Elevation or Cant (CANT) of the track on the curve. Versions on Rounding Measurement of points and crossings in railway stations and yards. The question asked only about the track or the level of the tracks, so I will tell only about the level. The gauge, level and cant of both the rails of the track are measured by the same device. It is called track gauge and super elevation (level or cant) device. It is shown in the picture below. This measurement is taken on each sleeper. The distance between two sleepers is about 65 cm. Thus there are 1538 sleepers in a kilometer. It is the sleepers that keep both the tracks level. Where the level is not correct, a track is raised by pressure and the bottom of that sleeper is packed with ballast and again the level is measured. Now a days this work is being done by track machines. The machine itself does the ‘Major Shovel Packing’ of the track with hydraulic pressure, sets the level. There are many types of machines. The packing machine is called Track Tamping Machine. Check out some pictures of packing or tamping machines: The middle machine is named Tamping Express. It works fast. The green part that is visible in this has tools to crush the ballast under the sleeper. Packing of 3 sleepers is done in 5-6 seconds at a time. Then this green mechanism slides forward automatically and the next 3 sleepers are packed. After this the machine automatically runs for a further 6 sleepers and then the same process is repeated. Its live demonstration can be seen in the YouTube video in one of the answers I shared. You will love to see how much track machine technology has evolved. In this way track maintenance is done by machines. For this, one has to take the ‘Traffic Block’ of that railway line and that section, which is given by the train section controller, its duration can be anything from 1 hour, 2 hours or 3 hours. Blocks are given by looking at the position of the mail express. These blocks are also given at night. These machines are run by the track machine operator. Everything is computerized operation. The measurement of the track is visible to the machine operator on the dashboard. Along with the machine, there is also a staff to do the machine’s own maintenance. After every 2-3 hour block, he does a Thorough checkup of the machine. So in this way the level of the track can be kept the same for thousands of kilometers. There is a tolerance of 2–4 millimeters. As stated in the question, if the ballast has slipped due to rain or any other reason, then the train driver feels any jerk, then he tells the station master on walkie talkie at the next railway station. The station master informs the railway staff concerned and they go to that kilometer and rectify the defect manually. That is why monsoon patrolling of the track takes place in the rain. The section’s JE/SSE and officers also conduct weekly foot plate inspection from engine as well as guard’s brake. These inspections happen during the day as well as at night. These inspections are for checking the defects of the track. Note :- I am not a specialist in track department. So whoever is from this department can suggest improvements in the comments. So much so that we learn about each other department only from observation. The parent cadre of DRM or GM can also be from only one department. But they are also given working knowledge about every department and some they learn from their long job experience. To become a DRM one must have 25 years of service by the age of 52. GM also cannot be made under 55 years of age. Then the service record should be very clear.