Railway Signal Engineering

  PTCC - Power and Telecommunication Co-ordination Committe. Central standing committee for co-ordination of Power and Telecommunication system. Local Telephone Equipment ( LTE). LTE is used to provide 20 local telephones at HQ. Types of cables  A) Quad Cable 0.9 mm or 1.4 mm dia. 1.4 dia Quad used for Block Section more than 12 kms. Suitable for underground laying. Used for control Circuits and block interfaces. IRS Specifications IRS: TC 30/05 B) PIJF cable-  Multi pair ( from 10 pairs to 200) Multi dia ( 0.5 mm/0.63 mm/0.9 mm) Suitable for underground laying. Used for exchange subscriber lines or branch cables branching off from main quad cable. C) Twisted Pair Switch Board Cable ( 0.5 mm/0.6 mm) Not designed for underground laying. Used for indoor applications such as distribution to various telephone subscribers in a building. Jointing Kit- For quad cable jointing- RTSF ( Reinforced Thermo Shrink Jelly Filled kit) type jointing kit to be used. Laying - Quad cable ...

Frequency alloted by WPC to Indian Railway is 146.2 - 167.95 Mhz VHF - Line of sight,Reflection, Scattering. Type of operation : Half Duplex ( for present Railway operations) Equipment- Walkie-talkie set,Base radio Antenna- Whip, Ground Plane  Feeder cable- 50 Ohms Unbalanced Coaxial cable  Mobile Station   The Mobile station represents the terminal equipment used by cellular subscriber by GSM system. Mobile system has two entities. Mobile Equipment (ME) Subscriber Identify Module ( SIM) Functions of SIM card- User authentication  Storage of subscriber related information.  Base Station Subsystem ( BSS) BSS has two entities. 1. Base Transceiver Station( BTS) 2. Base Station Controller ( BSC) BTS - It facilitates wireless communication between User equipment( mobile)  and network. Antenna is also part of BTS. It serves as Accesss point for Mobile devices to connect to network. Transmit and receive radio signals to and from mobile devices. Each BTS has a de...

  Accident has been classified in categories from A to R excluding I and O. Serious Accident  - Accident to a train carrying passengers which is attended with loss of life or grievous hurt to a passenger in the train or with serious damage to Railway property exceeding 2 Cr shall be deemed to be a serious Accident. Train Accidents- Divided into following parts A) Consequential Train Accident  - It is a Accident having serious repercussion in terms of human life,human injury, loss to Railway property or interruption to rail traffic. Train accidents are classified  as - Collision -             All cases under category A-1 to A-4 Fire -                      All cases under category B-1 to B-4 Level Crossing-    All cases under category C-1 to C-4 Derailment-          All cases under category D-1 to D-4 Miscellaneous-     All cases u...

  Minimum distance centre to centre of tracks . I) For existing works - 4265 mm II) For new works/ additions to existing works - 5300 mm Minimum horizontal Distance from centre of track to any structure- For Existing Works- 2135 mm For new works/ additions to existing works - 2360 mm Maximum Steepest Gradient in Station yard A) Existing Works - 1 in 400 B) For new works and alterations to Existing Works- Recommended gradient- 1 in 1200 Maximum ( steepest) gradient   - 1 in 400 Steeper than 1 in 400 and upto 1 in 260  - CRS permission required  Steeper than 1 in 260 - Railway Board permission through CRS For above purpose,  a Station yard means:- Station yard will be taken to extend- i) On Single line to a distance of 50 m beyond stock rail joint of outermost points at either end of station. ii) On Double line where multiple aspect of signaling is provided to a distance of 50 m beyond stock rail joint of outermost points. In the absence of point, from BSLB t...

  Act means Railway act ,1989. Block Back - Means to despatch a message from a block station to intimating to block station in rear on a double line, Or Next block station on either side on a single line,that the block section is obstructed or to be obstructed. Shunt Key is the authority for the driver to shunt from Starter upto First Stop Signal of concerned block section.The key authorizes driver to pass Advance Starter at ON during shunting. Block Forward -  Means to despatch a message from a block station to intimating to block station in advance on a double line,that block in advance is obstructed or to be obstructed. Substitute for Adequate Distance  - 1) Sand hump of approved design 2) Deraining switch under approved Special instructions  Minimum Equipment of fixed Signals In Automatic Block territory on single line- Home and Starter IB Section -  There are three Push buttons in IB panel. PB 1- To reset Axle counter when IB Home passed at ON PB 2- To re...

  Data Components - A data communication system has five components. 1.  Receiver  2. Sender 3. Message  4. Transmission media- Path by which message travels. Ex Twisted pair wires, Coaxial cable,fibre optic cable and radio waves 5. Protocol  Protocol is set of rules used by computers to communicate with each other across network.  Protocols can be classified as Proprietary Protocol ( specific make) Open source Protocol ( Any make). Bandwidth -  It is defined as amount of data that can be transmitted into a fixed amount of time. Usually expressed in bps ( bits per   second) Fundamental Characteristics of Data Communication   1. Delivery- System must deliver data to correct destination  2. Accuracy- System must deliver data accurately  3. Timeliness- System must deliver data in a timely manner  4. Jitter- Jitter refers to variation in packet arrival time. It is uneven delay in the delivery of audio and video packets,which r...