Transfer to System X and AXE10
Transfer to AXE10
In a simultaneous change-over, the last two TXE4s, in Selby, North Yorkshire and Leigh-on-Sea, in Essex, were taken out of service at 06.00hrs on Wednesday 11th March 1998.

Selby was replaced by a System X exchange and Leigh-on-Sea, by an AXE10 (System Y).



Photo: Checking for Dial Tone in Leigh-on-Sea ATE © Jon Rigby, March 1998.[All lines are tested pre and post transfer.]
| EXIT | Exchange Transfers | Numbering | Post-Transfer |
Exchange Transfers

How is it done?

Early transfers to System X and Y used wedges and break jacks to take the old exchange out of service, but this tended to increase the pre-transfer fault rate leading to noisy and dis (disconnected) lines. However, this gave the option of quickly bringing the old exchange back on-line, if for some reason the new exchange failed. As the replacement program gained integrity and was proven to be reliable, then it was both cost effective and easier to simply cut through the cables to isolate the old exchange.

  • The new exchange IDF is jumpered to the existing MDF.
  • Wedges on the new IDF isolate the new exchange.
  • At the transfer
    • The wedges of selected lines are withdrawn to give "double dial tone."
    • The power is cut off to the old exchange.
    • The cables are cut.
    • All of the remaining the wedges are removed to bring the new exchange into service.
  • Any temporary jumpers/wiring are recovered.

The Leigh-on-Sea exchange has been at Rectory Grove since the 1930s and the TXE4 equipment was installed in 1983. The new digital exchange cost £650,000 and serves approximately 12,000 subscribers (customers).

Numbering

Selby
Directory Name: Selby
Area Code (01757)

  TXE4

Previous		   System X

Existing		   System X

New		    
 
290000 to 291999
 700000 to 709999
    
210000 to 210999
211000 to 244099		  
290000 to 292999
 700000 to 709999
   

 
Leigh-on-Sea
Directory Name: Southend-on-Sea
Area Code (01702)

  TXE4

Previous

   System X

Existing

   System Y

New

    
  72000 to 79999
 710000 to 716999
 719000 to 719999
  470000 to 471999

 480000 to 482999 		  472000 to 479999
 710000 to 716999
 719000 to 719999 		   


The 72000-79999 numbers are now prefixed with 4 making six-digit numbers in the range 472000 to 479999. The 710000-716999 and 719000 to 719999 numbers remain unchanged.  A System X unit had also co-existed alongside the TXE4 for many years serving as an overlay unit with numbers in the 470000 to 471999 and 480000 to 482999 ranges.

Post-Transfer
Post-Transfer
The Leigh-on-Sea conversion was notable as the TXE4 was one of the few remaining exchanges with mixed 5 and 6 digit numbers.






Colin Jackson and John Watts agree that the transfer went smoothly.[Official photo March 1998.]
   
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