Chapter 19 Outdoor Signalling - Installation, Testing & Maintenance PDF

Chapter 19: Outdoor Signalling - Installation, Testing and Maintenance of Equipment Section 1: General Instructions on Tools 19.1.1 (a) All staff engaged in the installation and maintenance of signalling equipment shall be in possession of rubber gl...

Chapter 19: Outdoor Signalling - Installation, Testing and Maintenance of Equipment Section 1: General Instructions on Tools 19.1.1 (a) All staff engaged in the installation and maintenance of signalling equipment shall be in possession of rubber gloves, proper tools pliers, screw drivers, etc. (b) While using metal tools like screwdrivers, nose pliers, cutting pliers, etc. near the working equipment, care shall be taken to avoid short circuiting and consequent blowing off of the fuse. Adequate number of insulated tools shall also be maintained. (c) A list of specific tools to be maintained, shall be circulated by PCSTE as per specific needs of zonal Railway. (d) A rubber floor mat shall be used for attending to circuits carrying more than 110 V. 19.1.2 Soldering Care (a) Staff working in the installation and maintenance of signalling equipment shall be conversant in use of soldering iron/gun for making good soldering joints. (b) Care shall be exercised to avoid dropping of particles of solder and clippings of wire on adjacent terminals and apparatus. (c) In addition to soldering irons of adequate wattage (65-125 W), for the type of work done, the following shall be at hand: (i) A small file for dressing the soldering tip (ii) A fire proof pad for wiping the tip (iii) A mica sheet of adequate size or a suitable stand for soldering iron (d) Electrical soldering irons shall be switched off when not in use over extended periods. (e) While making a soldering joint, the surface shall be thoroughly cleaned, fluxed and tinned. (f) Use of too much solder shall be avoided to prevent lumpy connection. (g) Soldering iron shall not be held on the wire connection for too long to avoid damage to insulation. Chapter 19: Installation, Testing & Maintenance of Signalling Equipment Page 387 of 530  (h) Imperfect joints are the result of any one of the following causes, which should be avoided: (i) Soldering iron not sufficiently hot. (ii) Soldering iron held on the connection for insufficient length of time. (iii) Unclean terminal or wire. (iv) A solder of improper composition or inferior fluxing agent. (i) A newly soldered connection shall not be disturbed till the solder has thoroughly cooled. (j) Railway to conduct the periodical training on proper practices for soldering, in-house or through outside agencies. 19.1.3 Wire Termination (a) While terminating wires, care shall be taken to bend the wires in clockwise direction. (b) Wire strippers shall be used for the purpose of stripping off the wire insulation. Cutting pliers shall not be used for the purpose. (c) Washers and check nuts shall be used whilst fastening. (d) Not more than two wires shall be terminated on one terminal. (e) Multi-strand wires shall be terminated on terminal lugs and covered with insulation sleeves. (f) Wires of cable shall be neatly terminated and properly bunched. (g) Crimping tools of appropriate design should be used and whenever lugs are crimped, proper soldering should also be ensured. Section 2: Installation of Signals 19.2.1 Colour Light Signals Installation (a) Colour Light Signals shall be multi-unit (approved type) and be provided with LED lamps (approved type). (b) Location of Signal: The location and spacing of signals shall be in accordance with codal provisions & approved plans. The signal shall be so located to extend a clear view to the Loco pilot of an approaching train and is as close to the track as permissible. The signal shall have a minimum visibility as indicated in para 7.1.11. (i) The height of normal aspect of the Colour Light signal shall be approximately at 3.65 meter from the rail level. Wherever this is not feasible due to local terrain, height of the signal post may be suitably increased or decreased to get a clear view of the signal. Chapter 19: Installation, Testing & Maintenance of Signalling Equipment Page 388 of 530  (ii) Exact location of new signal or shifted signal shall be decided, based on Signal Sighting committee report to be submitted as per Annexure: 19-A1 jointly by SSE(signal), traffic inspector and loco inspector, duly observing Schedule of Dimensions given in Annexure: 19-A2. (iii) Signals shall normally be placed on the left hand side of the relevant track. However in exceptional circumstances and due to site constraints, if any signal is to be placed on right hand side, in which case prior approval of competent authority, shall be obtained and such right hand signal shall be provided with an arrow mark (on rectangular plate with white back ground) pointing towards the track to which that signal pertains, to avoid any misjudgment by loco-pilot. (iv) A new signal, which is yet to be operational, shall be turned away from Track, must not be lit and shall be provided with a X across it. (v) The visibility of existing signals shall be checked jointly by SSE (Signal), traffic inspector and loco inspector and submit Signal Visibility Certification as per Annexure: 3-A1 and a time bound action shall be taken to improve the visibility, as per recommendation of the committee. (vi) A Signal post, which is having implantation less than schedule of dimensions, shall have infringing distance marked in red colour on white back ground. 19.2.2 Mounting and Fixtures (a) Colour Light Signals may be mounted on a rigid ground post or a signal gantry. Route Indicators/Calling ON unit/Shunt signal unit to be provided as required. (b) Each signal unit shall be rigidly fixed in position. Markers to be provided to identify type of signal such as ‘G’, ‘P’, ‘A’, ‘AG’, ‘D’, ‘ID’, ‘IB’. (c) Signal posts shall be kept plumb and packed with suitable material. (d) Suitable packing may be used to close the excess gap from post to signal unit, surface base to post. The cable entry at the signal unit should be provided with wooden plug around the cable to close excess gap to prevent rodent entry. (e) Enameled/Retro-reflective Signal number plate shall be provided. It should be white back ground (for other than Gate stop signals) with black letters, as shown in Drg. No. 19-D10 (sheet 3). For Gate stop signals, the back ground shall be yellow colour. (f) Alignment: Each signal unit shall be aligned correctly for better visibility. (g) The signal ladder shall be firmly fixed with clamps and the bottom of ladder ie the ladder shoe, shall be concreted firmly. The ladder alignment shall meet the requirements of schedule of dimensions. Where infringing, the signal ladder shall be blanked off (refer chapter no 1 item no 8 note (c) of schedule of dimensions), by providing a metal sheet around the signal post including ladder. Chapter 19: Installation, Testing & Maintenance of Signalling Equipment Page 389 of 530  (h) The cable entries of the signal unit should be closed properly using cement to avoid rodent entry. (i) Signal numbering plate (as per Signalling plan) to be provided with black letters on white back ground. 19.2.3 Hoods and Back Screens Hoods of adequate size to counter act the effects of sunrays shall be provided. Where required, metallic mesh at suitable spacing shall be provided to protect lenses from outside interference. 19.2.4 Cable Entry Cables shall be used from the point of operation to the location box/signal unit and/or location box to the signal unit. Cable shall be protected suitably at the entry points of location box and signal post. 19.2.5 LED aspect unit consists of a cluster of LEDs in series and parallel combinations. LEDs in a signal aspect shall be arranged in more than one array, so that in the event of failure of a single LED, whole unit does not become blank. LEDs in the arrays shall be so inter leaved so that effect of failure of any array is spread out equally to maintain uniform visibility. Integrated (with built-in current regulators) LED signal aspects for regulating the current shall be used. Red/ yellow/green LED aspects shall be used for Main /Subsidiary signals, and lunar white LEDs shall be used for route indicator. 19.2.6 Same make of LED aspects shall be used at a station/section for ease of maintenance. 19.2.7 Gaskets and Sealing: All openings shall be gasketted and cable/wire entrance shall be sealed to make the enclosure water tight, dust-proof and vermin-proof. 19.2.8 Locking: The housing shall be kept locked. Section 3: Installation of IRS Point Machines 19.3.1 Requirements: Electric Point Machines of approved type shall be used. (a) Electric Point Machines shall be installed in accordance with approved plans. Ground fittings of approved design shall be used. Ground connections shall be thoroughly checked for any crack or improper welded joint. Normally the machine shall be installed beside the close switch leading to high-speed movements clear of all infringements. Before installation of the machine, it shall be ensured that. (b) The JE/SSE (P.Way) has made all the provisions at the Points as detailed in para 12.13.2 to 12.13.4 & Annexure: 12-A1 of Chapter 12 of SEM. (c) The machine has been properly cleaned and lubricated in accordance with the manufacturer's instructions and is working freely. (d) Proper alignment and level of connections is maintained between the machine and the point gears. Chapter 19: Installation, Testing & Maintenance of Signalling Equipment Page 390 of 530  (e) The top of sleepers which are to support the point machine are at level and that surrounding ballast is well tamped to prevent sinking during the passage of train. (f) The machine shall be so installed that it is clear of all infringements. (g) Proper drainage shall be provided to avoid water logging near point area. (h) Wiring from the point of operation to the location box/apparatus case nearest to the machine shall be in cable. The cable shall be of appropriate size to keep the voltage drop minimum. The connection between location box/apparatus case and point machine shall be through underground cable adequately protected below track and near point machine, through GI/RCC/DWC-HDPE pipe of approved type or any other approved means. It shall be tested for insulation and continuity before bringing into operation. (i) Crossovers shall be operated by separate point machines, one at each end. The detection of setting and locking of the points at the two ends of a crossover shall be connected in series. (j) Means shall be provided to cut off the motor feed in case of obstruction to the point movement after a predetermined time lag, based on the type of point machine used. The point operating control circuits shall have track circuit control, overload protection and cross protection. (k) The crank handles shall be provided to facilitate operation of points in case of failure of point machines. For this purpose, the points in the yard may be divided into convenient groups and to distinguish particular groups, crank handles with different wards shall be used. The slots provided, in the point machines for insertion of the crank handles shall be suitably modified to take only the crank handle applicable to the group. The crank handles shall, however, normally be locked. It shall be possible to release them for use in point machine by releasing a control from the control panel. With the crank handle released, it shall not be possible to clear the signal for the concerned routes. The interlocking of crank handle can also be achieved by using NX key of different wards. (l) The excess gap around cable entry to the machine shall be plugged to avoid rodent entry/water ingress. 19.3.2 Point Machine, Notches, Gaskets, Sealing (a) Electric Point Machine shall be provided with suitable gaskets and wire entrances shall be sealed to make them water tight and dust proof. All the extra openings shall be closed as far as possible. (b) Locking: Electric Point Machine covers shall be locked. The cover provided for insertion of crank handle shall also be locked with separate key providing access only for crank handle and crank handle key. (c) Notches in Stretcher Blades: Notches/Notch profile of the locking, driving and detection slides should not be tampered/reconditioned. Worn-out slides should be replaced with new ones. Chapter 19: Installation, Testing & Maintenance of Signalling Equipment Page 391 of 530  Initial Adjustment of Point Machine 19.3.3 Adjustment of Driving Rod The points shall be adjusted by operating the machine first by hand cranking. The insertion of hand crank should disconnect the power supply to the machine. When the machine has been fastened down, the throw bar connections shall be set up and the point machine hand cranked to one end of the stroke positioning the locking blades so as to allow the appropriate locking dog to pass through notches. The closed switch shall be adjusted to just in contact with the stock rail. Then the connections shall be tightened further by 2 mm to 3.5 mm to impart a springing action to the tongue rail. The machine should be hand cranked to the opposite end of the stroke and the setting repeated for the other switch. Note: it is recommended that adjustment for driving rod and lock rod shall be done for the close switch nearest to the point machine first. 19.3.4 Adjustment of Detector Contacts The machine shall be hand cranked to the end of the stroke to close the tongue rail. Insert 1.6 mm test piece between stock rail and switch rail at 150 mm from toe of the switch and operate the point. Ensure detector contacts just make. A test gauge of 3.25 mm shall be inserted between the switch rail and stock rail at a distance of 150 mm from the toe of the switch. The detector connection of the closed switch shall be adjusted till the appropriate detector contacts are just broken. The same shall be repeated at the other end of the stroke. All the relevant nuts shall be tightened. Note: Where lock slide is provided in the machine, during switch detector adjustment the test shall first be done with fictitious locking. After completing the above test, same test be repeated with machine properly locked. 19.3.5 Adjustment of Friction Clutch (a) When IRS rotary type electric point machine under obstruction test draws less than 1.75 times the normal operating current, machine needs to be checked for proper functioning at site. (b) Obstruction Test: The point driving rod and the lock connections of the machine must be so adjusted that with 5 mm thick test piece obstruction placed between the switch and the stock rail at 150 mm from the toe of the switch: (i) The point cannot be locked. (ii) The point detector contacts should not assume the position indicating point closure and (iii) Friction clutch should slip. Chapter 19: Installation, Testing & Maintenance of Signalling Equipment Page 392 of 530 19.3.6 Testing of Point Machine (a) Obstruction Test: The point driving rod and the lock connections of the machine must be so adjusted that with 5 mm thick test piece obstruction placed between the switch and the stock rail at 150 mm from the toe of the switch: (i) The point cannot be locked (ii) The point detector contacts should not assume the position indicating point closure (iii) Friction clutch should slip (b) The Technician shall check whether the current required to operate the machine in either direction is the same (approximately). The reason for unbalance, if any, shall be investigated and eliminated. Note: In general, excessive current indicates the friction due to rubbing of rods with rods/sleepers, poor packing, lifting of tongue, improper lubrication, dirt/dust accumulation etc. causing extra load on the machine. The cause to be identified and rectified duly advising Traffic/P.way departments. (c) Test the spring in each switch and ensure sufficient spring. It shall not be too excessive to cause excessive wear on machine part, neither it shall too less to hold the switch against the stock rail. In either of the case, the point drive rod shall be adjusted. (d) Friction clutch where provided shall slip at a value prescribed by the Manufacturer. (e) Badly worn-out pins shall be replaced; the holes shall be reamed out and fitted with a oversized pin. Split pins where provided shall be properly split out. (f) Voltage and current shall be checked periodically at the motor terminals, as per Annexure: 19-MS2. This will indicate any undue friction on the points or improperly fastened terminals at cable terminations. (g) Cable and wire insulation and continuity tests shall be done. (h) The essential requirement for interlocking of point shall be periodically checked. (i) It shall be ensured that during obstruction in the point, the feed to point is automatically disconnected or friction clutch is tripped on overload described by manufacturer and reconnects only when a fresh operation is done. Where sequential operation of point machine is done, the maximum time before disconnection may not exceed to 3.5 times the normal operating time of one machine. (j) Each sectional JE/SSE (Signal) shall test the operating values of the machine and adjustments of the machine by obstruction test every month. The Sectional incharge of the section shall carry out these tests once in three months. Chapter 19: Installation, Testing & Maintenance of Signalling Equipment Page 393 of 530