Useful Notes: Guide to Railway Telephones

Transcription

1 Useful Notes: Guide to Railway Telephones Copyright F. M. Spowart These notes are uncontrolled and NOT Network Rail endorsed, they are for information and guidance ONLY, NOT for testing or commissioning purposes.

2 Page One of Six Telephone Categories: Railway telephones come into five different categories: 1. CB: Central Battery: These are the most common and are operated by simply lifting the handset*, they are powered remotely via the line wire. 2. MAG: Magneto: These contain batteries to power the circuit, but are still operated the same as the CB type above. Sometimes referred to as LB for local battery. 3. AD: Autodial: These have a keypad in which the user enters a number* to call the required location. These are generally connected to a remote telephone exchange. 4. MD: Monodial: These are similar to the CB or MAG, but the user lifts the handset and presses a button which dials a preset number stored in the memory. 5. PETS: Public Emergency Telephone System: These are similar to the above types, but have extra connections which fully monitor features such as handset damaged, off-hook, charger fail, ringer fail etc. *Some phones may require a single button to be pressed. Types (old and modern): Over the years the telephones have progressed from a few different types to an extensive range, some still used, some obsolete. The main phone manufacturers today are: GAI-tronics Titan Range, DAC Titan Range and Racal RA Range. The now least popular ranges are: Plessey 745, Racal RA 705, DAC Commander (mainly used inside control rooms) and the STC selective. Other phones of some type may still be used. The phones are either coloured Goose Grey (SPT s, Point Zone phones etc), or Canary Yellow (for level crossing public use). The S.M.A.R.T. option is available on some phones, this stands for self-monitoring and reporting telephone. The Eastern Voice & Data Company seen on the labels on the phones is the company which repairs and refurbishes the phones and returns them to Network Rail via DHL. To give you a perspective on what some of the weather resistant phone cost, the Racal RA 708 (grey) phone Cat No: 87/ to purchase costs , the DAC Titan (yellow) phone Cat No. 87/ costs All prices include VAT! Source:

3 Page Two of Six Standards: Document NR/L2/TEL/ (June 2010) list the relevant standards for lineside telephones specification. Here are just a few important specs listed. Ring voltage: 30v to 100v rms. Line voltage: 20v to 70v DC (20v to 57.5v for PETS system). 15mA minimum loop resistance (off-hook). Public intended use phones must have inductive coupling for hearing impaired people. All external line cables shall have an external diameter of 7 15mm. The line cable conductor size shall be between 0.5mm 0.9mm. Press to call buttons shall initiate a call, but must not disconnect the handset whilst the button is pressed. The background noise level in which the speech will not be impaired is 70dB (an equivalent of a large idling lorry with a diesel engine). All label fonts should be in San Serif and a minimum of point 10, black text on white label. SPT s shall be positioned so the user can see all of the elements of the signal, and permit the user to operate the telephone whilst standing up (approx m high). Unauthorised entry using standard screwdrivers or pliers should not be possible. NO additional holes shall be drilled into the mounting plate. MINIMUM bending radius of the tail cable is; 12 X diameter of cable used. The following cable colour is used for all phones (although not all may be used): Pair A leg B leg 1 Orange White 2 Green Black Labelling: The twist in the pairs shall be maintained This should be applied to all phones. Labels which must be attached are; Phonetic Alphabet, Lift Handset or Press button instructions, the grid reference of the exact location, the location of which the phone will call, the telephone number of who to contact in an emergency (if applicable), the point number, signal number or LC at which the phone is at. The appropriate SPT or point zone phone stickers shall be attached to the external side of the door. Yellow public phones must have the black phone on yellow background label applied. The NOT FOR 999 CALLS sticker MUST NOT be applied to public emergency telephones, these are only used for phones such as; local control phones at level crossings, platform ready to start telephones etc. (Check local documents before attaching this sticker). The limited clearance sticker shall be applied if applicable to the location. Any other relevant sticker required for that location. (Again check local documents).

4 Page Three of Six Types of phones in use today: Cat No 87/ Type AD Colour Yellow Use at LC s Buttons One (with Number 1)~ ~ Number programmed via internal keypad or via PC program or over another phone Cat No 87/ Make DAC Type MAG Buttons Recall button Power Four type D batteries (Take off front to access them) Cat No 87/ Type CB Buttons None Cat No 87/ Make DAC Type CB Buttons None

5 Cat No 87/037943* Type Xing Colour Yellow Use at LC s Buttons One push to call Illumination LED illuminated Guide to Railway Telephones Page Four of Six *87/ will replace this phone in future Designed specifically for PETS I and II Cat No 87/ Make Racal RA 708 series Type CB Loop Buttons One push to call Cat No 87/ Make Racal RA 708 series Type MAG Buttons One push to call Power Three type C batteries (Remove black cap at bottom via small allen screws to access them) Cat No 87/ Type CB Colour Yellow Use at LC s (but NOT for PETS ) Buttons None

6 Page Five of Six Other types of phones for reference only: Plessey 745 Racal RA 705 DAC Commander STC Selective (Mechanical) (STC stands for Standard Telephones & Cables Ltd). Accessories: Cable Glands: Make Gland Type: Brass Gland Type: S/Steel Titan 54/ / Racal 54/ / Allen Key sizes required to access wiring of phones: 3mm for Titan phones. 5mm for DAC (non-titan) phones. 6mm for Racal RA 708 phones. (All phones are pictured above which these tools relate to)

7 Page Six of Six Specific functions/features present on some (but not all) phones: Function/Feature Usually set to (if applicable) Used for Battery Enable switch (Mag Connects/disconnects internal Enabled type only) battery Mutes microphone until dialling Mute before dialling Enabled has taken place Set to terminate call after a Enabled (user must select a Call time out link predetermined limit (if phone time) left off the hook) Impulses used to call a number Loop disconnect NA (most phones now use DTMF) Time break recall (TBR) Earth Loop Recall (ELR) Switch Hook Flash DTMF (Dual tone multifrequency) [or LD ] REN (Ringer Equivalent Number) Switchable between three NA NA To break the call and try again without hanging up handset Tones (as opposed to impulses) used to make the call (Touch- Tone phones) Number to determine how many phones will work on one circuit Basic S&T Faulting procedures: The S&T department now cover all telephones on the lineside including the actual phone and tail cable up to the loc or stump box at where it is terminated. Telecoms cover the main cable into the stump box or loc. Depending on the fault, the S&T will usually go to the phone first and check for ringing, hearing and speech. Some faults can be rectified simply by checking the plug points inside the phone or loose/broken cores. It is a good idea to use a test phone on the tail cable at the phone and then the loc to see if the phone is actually faulty. If the phone seems OK, and the phone is a MAG type, check the batteries in the phone, for all other types the line voltage should be checked at the phone and loc, this should be between 20 & 70v DC**. A lower voltage will affect the volume of the phone, so this could be the cause of the fault. If voltage is present at the loc and not at the phone the tail cable is faulty. If voltage in loc is out of spec or dead, the fault is passed to Telecoms to deal. Depending on the phone and the fault, the handset part or backplate containing the circuit parts can be changed instead of the whole phone. Spare unused parts must be returned and labelled as a working spare. A P.E.T.S type system will give a code to the signaller to give the state of the fault and possible cause. **This may depend on actual phone used, some phones have a min and max limit. This document is uncontrolled. It is NOT endorsed by Network Rail, nor is it for commissioning or testing purposes. The relevant Network Rail documents MUST be used for this. This document is subject to possible omissions and/or errors, therefore the author cannot be held responsible for any incidents related to railway telephones. Created & written by F. M. Spowart Network Rail S&T department Retford March 2012 Version 1