The invention pertains to a method and apparatus for detecting and locating a fracture or discontinuity in the railway track section with improved safety. The invention uses an electrical property of a medium extending between the pair of rails, which in turn is used to determine the position of the rail break.
Current methods referred to as Ultrasonic rail break detection system and isolation method of rail break detection system are used to detect the rail break in specified railway track section. The first system works on a principle of block isolation and applying DC pulsating signal at one rail and receive it through another rail. This method needs isolation block joint and needs more maintenance. The second method works on a principle of transmitting the ultrasonic signal at one end of track and receives it at other end of the track. In this method the receiver signal strength is likely to be affected by change in atmospheric conditions.
To overcome the above limitations of the systems in vogue, a new improved device with novel characteristics is designed with following distinct advantages.
1) Low maintenance
2) Less power consumption
3) Independent of all possible atmospheric changes
4) Detect the absence of train on a specified railway track section.
5) Detect the rail fracture and discontinuity on a specified railway track section.
6) High immunity to electrical interferences.
7) Does not require isolation block joints


Accordingly, the present invention consists of necessary logic circuitry that is capable of improving the reliability of prediction of the rail fracture and discontinuity detection mechanism, with built in safety feature and comprises of a transmitter module receiver module, power supply module, and electrical parameter-monitoring module with predetermined characteristics.
Now the invention will be described in more detail with reference to the accompanying
drawings, bringing out a number of embodiments of the arrangement according to the
invention
Fig 1- A general arrangement of the current system as deployed in the railway track
section - rail break detection with isolation method.
1. DC power entry
2. Isolated track section
3. Rail 1
4. Rail 2
5. DC power exit
6.
FIG 2 - A General arrangement of the current system as deployed in the railway track section - ultrasonic method
7. Transmitter
8. Transmitter transducer 1
9. Transmitter transducer 2
10. Rail 1
11. Rail 2
12. Receiver 2 transducer 1
13. Receiver 2 transducer 2
14. Receiver 1 transducer 1
15. Receiver 1 transducer 2
16. Receiver 1
17. Receiver 2


FIG 3 - A general arrangement of the deployment of the present invention in a railway track section.
18. Transmitter terminal 1
19. Transmitter terminal 2
20. Receiver terminal 1
21. Receiver terminal 2
22. Rail 1
23. Rail 2
FIG 4 - A general arrangement of the deployment of the present invention in a railway track section - with rail break.
24. Rail break
25. Zone A 26.Zone B 27.Zone C 28.Zone D 29.Zone E 30.Zone F
31. Electrical Parameters monitoring module
Fig 5 - A general arrangement of the deployment of the present invention in a railway track section - with rail fracture.
31.Rail fracture
32.Rail 1
33.Rail 2
34.Electrical Parameters monitoring module


As shown in Fig 1, the present methods of railroad integrity detection are to apply a low voltage pulsated DC at one rail (4) and receive through the opposite rail (3) in electrical isolated segment or block (2). In this method, the presence or absence of current is used to detect the discontinuity in the rails. The major drawbacks of this method are 1) requires the mechanical isolation 2) requires periodic maintenance to ensure desired isolation. 3) Not suitable for high speed rail roadways 4) cannot precisely detect rail discontinuity point.
As shown in Fig 2, other current method of rail break detection is by ultrasonic method. In this method, the system basically consists of a transmitter (6) and receiver units (16) (17). The transmitter unit (6) wired to a transducers (7) (8) mounted on the rails (9) (10) to introduce an ultrasonic signal into the rail (9) (10) at a given point. A high-energy ultrasonic pulse is bi-directionally inserted into both rails (9) (10) via ultrasonic transducers (7) (8) at a programmable interval by the transmitter (6). The receiver transducers (11) (12) (13) (14) at both sides of the transmitter (6) receive the same signal. The strength and sequence of pulse is used to recognize and locate the position of the rail break.
The drawback in this method is detection efficiency that is subject to variation as it is a function of ambient temperature, affecting the attenuation levels of the signal.
FIG 3, wherein an improved fail safe rail break and fracture detection device as per our invention is shown in a deployment mode and transmits the coded signal at one end of the track section (17) (18) and receives the same at other end of the track section (19) (20). It is capable of continuously monitoring the transmitter voltage, transmitter current, receiver voltage and current. The nominal transmitter current In is the current passes through the rails (21) (22), when no train is on the track section and no rail break or fracture is present, for a given transmitted signal and depends on ballast conditions. If the transmitter current level increases more than the nominal and received voltage is zero, this means track section is electrically short by train wheel set at receiver end.


The transmitter current tends to increase, if the wheel set moving towards the transmitter point and peak at the wheel set is exactly on the transmitter point.
As shown in fig 4, the track section is divided in to six zones (24) (25) (26) (27) (28) (29). If rail break occurs (23) in the zone A (24), the transmitter current will at In/a and receiver voltage is zero. The transmitter current will be at In/b, In/c, In/d and In/e and receiver voltage is at zero if rail gets break at zone B (25), C (26), D (27), E (28). The transmitter currents will be In/a < In/b < In/c < In/d < In/d< In. The transmitter current may same as In or less if break happened in the zone F (29). The monitoring logic circuitry will detect rail break in the specified track section at any zone based on transmitter current, receiver voltage and receiver current. The monitoring logic communicates rail break information to a remote computer. The monitoring logic circuitry is capable of differentiating the rail break conditions from track occupied conditions and performance is independent of the changes in the atmospheric conditions.
As shown in fig 5, suppose rail fracture has occurred (30) in the track section, the impedance offered by track section tends to increases over the expected normal, consequently the transmitter current and receiver voltages tends to decrease from nominal levels, this levels are used to detect the fracture. The rail fracture detection mechanism also considers the impedance offered by the fractured rail.
Although the invention has been described in considerable detail with particular reference to certain preferred embodiments, thereof, variations and modifications can be effected within the spirit and scope of the invention as described herein above and as defined in the appended claims.

We claim
1) An improved fail safe device to detect rail break and fracture over a railway
track section comprising of transmitter module, receiver module, electrical
parameters monitoring module and power supply module and is capable of
functioning independent of atmospheric conditions with a provision to
calculate rail break location mechanism.
2) An improved fail-safe device as claimed in claim 1, the transmitter module
with high immunity to the electrical interferences comprising of an electrical
modulator, amplifier, code generator and filters.
3) An improved fail-safe device as claimed in claim 1, the receiver module with
high immunity to the electrical interferences comprising of an electrical
demodulator, fail safe comparator and filters.
4) An improved fail safe device as claimed in claim 1, the health monitoring
module comprising of an electric converters, counters, wireless
communication circuitry and data storage devices.
5) An improved fail-safe device as claimed in claim 1, the power supply module with high immunity to the electrical interferences comprising of an electrical rectifiers, switches, isolation transformers, filters, feed back and control hardware.
6) An improved fail safe device as claimed in claim 1, provision exists by means of suitable circuitry to monitor the frequency of changes in the receiver voltage along with the changes in the transmitter current which in turn is capable of detecting the rail break and rail fracture.


7) An improved fail safe device as claimed in claim 1, provision exists by means
of suitable circuitry to monitor the frequency of changes in the receiver
voltage along with the changes in the transmitter current which in turn is
capable of detecting the rain break location.
8) An improved fail safe device as claimed in claim 1, provision exists by means
of suitable circuitry to monitor the frequency of changes in the receiver
voltage along with the changes in the transmitter current which in turn is
capable of detecting the absence of train over a railway track section.
9) The device according to any one of the claims 1 to 9 substantially as herein
described with reference to and as shown in FIG 1 to 3 of the accompanying
drawings.