In accordance with the railway load transfer model, the parts that are laid at regular intervals in the direction of the rails, which transmit the forces acting on it from the rail on a wider surface and transfer it to the ballast layer, determine and protect the opening of the road and keep the road on its axis against side effects, are called sleepers.

Railway sleepers used in railway systems, axle weight, speed, technological developments in towing and towing vehicles and so on. the progress in the elements and the materials used in the production of traverse were in parallel with the problems of adaptation to these advances and the cost considerations.

Traverses used in rail systems are divided into four:

Wooden sleepers,
Steel sleepers,
Concrete sleepers,
Plastic (Polyurethane) sleepers.

In a railway superstructure, sleepers undertake the following tasks;

Transferring the load on the ballast by ensuring that the loads coming from the rails are spread,
Maintaining the width of the road formed by two rails,
Sloping the rails inward,
To prevent the road from escaping from the axis, to ensure that the railway stays on the axis,
Electrical insulation between two steel rails (on signaled lines),
To slope 1 / 20-1 / 40 inwards on the rails and to maintain the road clearance formed by two steel rail series.

Properties of Traverses

Abrasion resistance, hence hardness feature.
Elasticity Fracture and crush resistance,
Being suitable for the mounting of rails,
Resistance to external influences,
It is not too light in terms of stability of the superstructure,
not being too heavy for two workers to carry,
The cost is appropriate,
Reduces noise and maturity,
It is suitable for isolation,
Temperature and spirittubedurability,
Fasteners should be easily mounted, carrying, stacking, laying, and disassembling,
It must be sufficiently resistant against abrasion, breakage and crushing,
It must be of sufficient width and length,
Traverse material should not transmit electric current,
It must have the necessary friction to ensure friction between the crossbar and the ballast,
It must be resistant to the harmful effects of water, moisture, acid rains, grass, tree roots and microorganisms,

Let's examine these types of traverses one by one.

Features of Wooden Traverse

Positive Aspects of Wooden Sleeper;

Due to the flexibility in the natural structure of the wood, it prevents the impact effect as it flexes the forces coming from the rail and it does not damage the ballast since its friction is also low.
Maintenance costs are low.
It is flexible.
It is heavy enough not to disturb road stabilization and light enough to be transported.
It provides a noiseless journey.
It is insulating.

Negative Aspects of Wooden Sleeper;

RutubeIt is very affected by t.
It is likely to burn.
It is resistant to dressing, the road usually slides out on the curves.
It is difficult to maintain blister.
Their lifespan is short.

Steel sleepers are not preferred due to their high cost and being resistant to climatic conditions. However, steel sleepers use countries with suitable conditions. They have a mass of only 68 kg, allowing them to be placed easily. However, it cannot fully interact with the ballast layer.

Features of Steel Crossmember

Steel Traverse Positive Aspects;

Their lifespan is 45-50 years, approximately twice the creosote wooden sleepers.
It is easier and better stacked in shape and size.
Frames are lighter and easier to carry.
It is much easier and perfect to connect and disassemble rails to iron sleepers, it does not slack like in wooden sleepers.
Also, it does not require anti-fireplace material.
It is resistant to burning.
It is resistant to dressing because its ends are with nails.
It protects well.

Negative Aspects of Steel Crossmember;

Its light weight is not good in terms of superstructure stability.
Iron sleeper lines deteriorate faster than wooden sleepers.
It is not suitable for high speed and heavy load carrying.
Wooden sleepers are more elastic, stable and comfortable.
Iron sleepers make noise in the passage of trains, especially if the connections are not tightened well.
Since iron sleepers pass electrical current, it is difficult to isolate one rail array from another. Therefore, line circuits using rails are not used in electrical signs and automatic blocks.
Iron sleepers rutubethey do not rust.
Maintenance is difficult and costly.
It gives a noisy journey.

concrete sleeper

Concrete sleeper is a complex object where concrete and steel work like a single object, thanks to adherence. In reinforced concrete, it is the requirement of the properties of both materials to push the concrete to pressure and to pull the steel. The basis of reinforced concrete is the tensile stresses occurring within the body of the element and the pressure stresses of the concrete.

Features of Concrete Sleeper

Positive Aspects of Concrete Sleeper;

It protects well.
Makes little noise. (Less than iron travertine)
It is not affected by moisture.
It conducts very little electrical current.
It is resistant to external effects and fire.
Due to its weight, high speed and heavy load transportation is only possible with concrete sleeper as per the age.
It is resistant to fire.

Concrete Traverse Negatives;

It is difficult to maintain.
It requires more careful and machine work.
Cracks and breaks occur after drains.
For this reason, they must be replaced immediately.
In curves, there is a dressage in the direction of curves.
It is difficult to make in different shapes and lengths.
It damages the ballast too much.
There is no flexibility.
It is not preferred to be used on rotten platforms.
Dray suffers a lot of damage in the last one.

Properties of Plastic (Polyurethane) Crossmember

Plastic (Polyurethane) sleepers are used directly on ballasted and ballast-free railways, in tunnels, open lines of subways, bridges and viaducts. In the production of these sleepers, waste polystyrene and polyurethanes are used.

Positive Aspects of Plastic Sleepers

Plastic sleepers reduce noise and vibration
Heat and rutubeIt is resistant against.
It is resistant to chemical effects and all kinds of liquids.
It is the longest lasting travertine.
It is the best insulating travertine.
It is quite light.

Negative Aspects of Plastic Sleepers

Its light weight is not good for the stability of the superstructure.
It is not suitable for high speed and heavy load carrying.
It is not fire resistant.
It is not resistant to pressure stresses.
The costs are high.

What We Don't Know About Trains: What is Travers?