A New Method for Using Fiber-Optic Rail Circuits on Railway Spans

Integration of Georgian with European transport market, putting in action of the transport corridor of Europe-Caucasus-Asia, increase of the country internal freightage and traffic speed made new demands rise up towards safety movement of the railway transport, reliable operation of equipment’s and decrease of expenses on the technical service, resulting in widening of scientific researches in this direction.

One of the basic problems of the railway traffic safety is monitoring of the rail/wheel-set interaction and timely detection of its undesirable results.

In this respect the spans are especially dangerous objects.

Ascertainment of accurate location of the rolling stock, detection of the worn out or damaged wheel-set and rail, control of the load on the axles of the rolling stock and its identification is one of the basic problems of engineering science. Many works are carried at and numerous devices are created in this direction. In spite of this, research problems in this area becomes more and more actual.

We consider the arrangement of the optical-fiber rail circuits of new type on the rail with the use of the tightly attached fiber-optical cable, as an achievement of future of the devices of automatics and tele-mechanics on the way of perfection of the traffic safety and information controlling system of trains.

The sensitivity of the optical cable is manifested in a violation of the linearity of the light it conducts. During physical impact the fiber optic cable undergoes deformation and vibration. This process is classified into two groups - micro bends and macro bends. Conducted light is scattered at the bend. Part of the scattered light returns to the light emitter.

On this principle is built OTDR (Optical Time Domain Reflectometer) device. In fact, the fiber optic cable at the bend turns into a sensor. On the basis of analysis of the back-scattered signal, the type of impact that caused the bending is established. The time required from sending the signal to receiving the backscattered signal with high accuracy sets the distance to the bend.

The article discusses a new innovative method that will enable:

-       detect out or damaged wheel-set in the rolling stock;

-       detect without fail the span occupation of rolling stock;

-       ascertain precise location of occupation of the span by the rolling stock;

-       determine a place of the worn out or damaged rail (rail);

-       identify the rolling stock;

-       detect overheated boxes in the rolling stock;

-       control the load on the rolling stock axles.

The elaborated method will significantly increase traffic safety of the rolling stock and speed of movement and practically eliminates catastrophes. For testing of the rolling stocks it will no longer be necessary to arrange and construct expensive, stationary systems; to displace them on the long distances. Correspondingly, the time waste and expenses on detection of the wheel-set wear and damage will decrease, which results in significant economic effect.