What are the Types of Sleepers in Railway

Looking for types of sleepers in the railway? Then you came to the right place. Here all your doubts about railway sleeper types will be cleared.

In railway transportation, they are the parts that are laid perpendicular to the rails at certain intervals, spread the loads on them to a wider area, and transmit them to the lower part through ballasts and form the platform together with the rails.

The sleepers used in rail systems serve as a kind of beam. Just as in masonry structures, beams are made to spread the vertical loads to a wider area, we can say that the sleepers used in rail systems are used for the same purpose. The sleepers vary according to axle weight, project speed, train-trailer type, and cost. The sleepers, which carry the loads on them using ballasts, are among the superstructure elements of the railway project.

Sleepers Usage Purposes

• Transferring the loads from the rails to the ballast by spreading them over a wider area
• Maintaining the platform width created by two rails
• Ensuring that the rails are inclined inward
• To prevent the road axis from slipping and to keep the railway on the axis (axle duty)
• To provide electrical insulation between two steel rails

Features That Sleepers Should Carry

• Abrasion resistance, therefore hardness
• Elasticity, resistance to breaking and crushing
• Convenient for the assembly of rails
• Ability to resist external influences
• The superstructure is not very light in terms of stability
• Not too heavy for two workers to carry
• Affordable cost
• The fact that it can reduce noise and pitch
• Being suitable for isolation
• It is resistant to heat and moisture
• Sufficient width and length
• Having the necessary friction to ensure adherence with ballast

Sleeper Types in Railway

Different types of sleepers manufactured for reasons such as axle weight, project speed, cost are as follows:

• Wooden Sleepers
• Reinforced Concrete Sleepers
• Steel Sleepers
• Plastic (Polyurethane) Sleepers

Sleepers types, which have advantages and disadvantages compared to each other, cost, climatic conditions, geography, service purpose, etc. It is preferred according to the effects.

Wooden Sleepers

Wood is preferred for reasons such as being flexible due to its structure, that it can meet the force on it by stretching, being lightweight, inexpensive to maintain, insulating, providing noise-free travel, while it is not preferred for reasons such as being a flammable material, being highly affected by moisture, and having a shorter life span.

Steel Sleepers

It is preferred for reasons such as fire resistance, long life of 45-50 years, easy workmanship due to its lightness, it is not preferred for reasons such as not resistant to moisture ( corrosion effect), costly maintenance, high speed, and not suitable for carrying heavy loads.

Reinforced Concrete Sleepers

Concrete is preferred due to its resistance to pressure and steel to tensile strength, being less affected by moisture, making less noise, and being resistant to fire, but it is not preferred for reasons such as being difficult to maintain, damaging ballast, and not being flexible. (Note: Transportation with heavy loads and high speed is only possible with reinforced concrete sleepers.)

Plastic (Polyurethane) Sleepers

While it is preferred for reasons such as being quite light, long-lasting, resistant to heat and moisture, reducing noise and shaking, it is not preferred for reasons such as high costs, not resistant to pressure, not suitable for high speed and heavy load carrying. They are used in ballasted and ballasted railways, in tunnels, subways, bridges, and viaducts.

Key Components of a Railway System:

• Rail, is a line where the train moves. At the beginning of the invention, rails were made of wood, now rails are made of steel or special metal. The distance between the rails is called a track. The track or rail width varies from country to country, for Indonesia, it is around 1067 mm.
• The base frame can be made of assembled steel, carbon steel, or other materials that have high strength and stiffness against loading. In addition, the material must be able to withstand impact (maintain deformation).
• The body of the car usually separated from the base frame. For locomotives, the car body consists of an engine room and an engine room. As for the carriage, the body of the train consists of a sitting room for passengers and a small bathroom, for premium cars it is not impossible to have a minibar, meeting room, etc.
• A bogie, is a one-wheel system on a train, both on the locomotive and in the wagon. Bogies are generally used for wheels with more than two axles (axles) in one train. Its function is to provide the train’s flexibility to the rails so that the wheels can continue to follow the direction of the rail when passing bends or curves (turning or cornering trails). Inside the bogie, there is usually a system of squeezing, braking, anti-slip, and of course steel wheels and axles.
• A tender, is a container or room for storing coal, water or petroleum. These materials are used as fuel for steam locomotives.
• The propulsion system, depending on the technology used, includes steam engines, diesel engines, electric motors and electromagnetic engines.
• Electrical systems, ranging from generators, power continuation equipment, cables and lights.
• Braking system, usually has been integrated with the bogie.
• Steering control system, usually a lever that can adjust the acceleration of the train.
• Safety Equipment, an emergency kit, such as a glass breaker and fire extinguisher.  
• Obstacleremoval equipment, this tool is usually located in front of the muzzle of the locomotive, the edges of the carriage in the form of a hard metal impact-resistant plate.

Types of Trains in the World:

1. Steam Train

This type of train is the first engine train built by humans, which was previously drawn by horse power. The steam train takes advantage of the ability of water when heated in a steam boiler. The compressed water vapor will generate enormous pressure and is able to move the pistons, engine gears and finally move the train wheels.

After James Watt succeeded in making a steam engine, several engineers succeeded in making the world’s first steam train prototype such as the steam train made by Richard Trevithick, Matthew Murray and William Hedley, but of the many scientists above, George Stephenson’s steam train was the one that was considered successful in the market.

The steam train was successful in cutting the cost of shipping goods at that time and became the safest long-distance transportation. Since it was first created in the 1800s, steam trains have reached their peak with various types of steam trains, namely:

1. Mallet locomotive, is a type of train whose locomotive has an articulation (connection) in the middle of a steam boiler. The front wheels have their own bogies that are free to move, while the rear wheels are connected to the main frame of the locomotive. In this system, the front drive wheels will get a higher steam pressure than the rear wheels, but this pressure will be transferred to the rear wheels as they move. The inventor of this steam locomotive is a Swiss engineer named Anatoie Mallet. This system is widely used in Europe, America and the Dutch East Indies (Indonesia).
2. Garrat locomotive, is a type of steam train that has two tenders, separate from the boiler which is located in front and behind. The driving wheels are under tender and have their own bogies, so that the garrat locomotive has two articulations. The inventor of this system was a British engineer named Garrat. This type of train is widely used in the continent of Africa, East Asia, Australia, parts of Europe and South America.
3. Meyer locomotives, like garrats, are a type of train that has two articulations, but the two connections are located under the boiler. The design of this locomotive is obtained by making each bogie for the front and rear driving wheels, so that they seem to be separated from the body of the locomotive. With this design, a steam locomotive that can move more flexibly and efficiently is obtained, because all the driving wheels will get the same steam pressure. The inventor of this system was a French engineer named Jean-Jacques Meyer in 1868. This system was widely used in Europe, America and also the Dutch East Indies.

Because steam trains use firewood and coal as their main fuel, which produces a lot of thick smoke, Towards the end of the 19th century, this type of train began to be abandoned, replaced by diesel and electric trains which were considered environmentally friendly and more fuel efficient.

2. Diesel Trains

In the country it is often called KRD or diesel rail car. This type of train uses a diesel engine as its propulsion motor and liquid fuels such as solar as its main fuel. There are two types of trains, namely hydraulic diesel rail (KRDH) and electric diesel rail (KRDE).

1. Hydraulic Diesel Railroad, is a type of diesel-engined train, where this machine is used to pump oil and then channel it to hydraulic devices to move the locomotive wheels. KRDH has been used in Indonesia with locomotf series BB301 to BB304. Currently KRDH is no longer used due to high maintenance costs.
2. Electric Diesel Rail Train, is a type of diesel-engined train, where diesel is used to rotate generators to produce electrical energy. Then, the electrical energy is used to drive a large electric motor, and finally drive the locomotive wheels. Currently KRDE is widely used in developing countries, including Indonesia, and almost all long-distance trains operated by PT Kereta Api Indonesia (PT KAI) are of the KRDE type.

3.Electric Rail Train (KRL)

The electric railroad is a type of train that moves by utilizing an electric motor as its main engine, where the power source is obtained directly from the overhead power grid (LAA) via a pantograph (a device located above the carriage, in direct contact with the LAA wire).

In fact, LAA is a high-voltage wire capable of supplying the DC electric current used by KRL electric motors. LAA is located hanging in the middle of the rail, following the track of the rail and usually has a voltage of 1.5 kilo volts.

Usually electric trains are built in urban areas that are densely populated and high in mobility, such as Tokyo, Amsterdam, Beijing and other big cities. In Indonesia, KRL can be found in the Greater Jakarta area.

The routes served by the Indonesian KRL include: the north-south route (Jakarta city-Bekasi-Cikarang-Depok-Bogor) and the west-east route (Rangkasbitung-Maja-Serpong-Tangerang-Tanah Abang) as well as the circular lines (Manggarai- Jatinegara-Pasar Senen-Kampung Bandan-Tanah Abang and vice versa). In the future, Manggarai Station will become the main station for all Jabodetabek trains and airport trains.

Nearly 90% of the KRL cars operated by PT Kereta Commuter Indonesia (a subsidiary of PT KAI) are wagons originating from Japan and the rest from Korea. To keep ticket prices low, the carriages were bought secondhand but roadworthy. Most recently, KRL will bring 192 units of the 205 series from East Japan Railways, this used train is claimed to have a younger manufacturing year than the previous unit.

4. Mass Rapid Transit (MRT)

MRT ( mass rapid transit ) or in Indonesia it is called Moda Raya Terpadu, is a type of electric train that has a speed above ordinary KRL, high capacity and frequency and has a fully automatic signaling and control system.

Because everything is automatic and fast, the MRT must have a special lane and be free from asphalt highway intersections. Hence, we often find that an MRT system is built on an elevated line, a ground line ( at ground ) and an underground route ( subway ). This train system is very suitable to be applied in crowded cities such as Singapore, Bangkok and Tokyo.

Indonesia itself has the MRT, which was completed last April in Jakarta, which is a 15.7 km long roundabout route for the Lebak Bulus roundabout with 13 stop stations. The plan is for the MRT network to be expanded in phases 2 and 3, up to a total track of 110.8 km.

5. Light Railways

Light rail is an electric train system that operates in urban areas, where it weighs about 20 tons, its rail construction is built together with other traffic, cars and buses. There are two types of light trains:

1. Trams, are light trains that have rails in the city, where a train set consists of 2-3 carriages. Tram tracks usually coalesce with road asphalt.
2. LRT( ligth rail transit ), is a light train that has a more special line than trams, separate from the asphalt road, but still side by side with urban roads. The LRT usually consists of 2-4 cars.

Light trains are widely used in various countries in Europe and have undergone modernization, for example machinist automation, operating on special tracks, anti-collision systems, use of low floors that make it easier to get on and off passengers. Indonesia itself has tram tracks in Solo City and the Jabodebek LRT.

For information, the physical construction of the LRT for phase one is being built, namely the Cawang-Harjamukti, Cawang-Jatimulya and Cawang-Dukuh routes with a total track of 43 km.