UNDERGROUND INFRASTRUCTURE


The UK underground network consists of a large amount of plant and cable.  It is good to consider the plant as starting at the exchange and finishing either at customers premises or where overhead cabling starts.

The menu below tries to list the items in the order they are fitted or used and starts from the exchange and finishes at the Distribution point.
Underground Network Overview 1
Underground Network Overview 2


EXCHANGE MAIN DISTRIBUTION FRAME - External cable termination point
EXCHANGE CABLE CHAMBER
CABLE PRESSURE & PRESSURE RACK
DUCTS
TRENCHING
RODDING
CABLE TYPES
CABLE CREEPAGE
MAIN CABLE - E Side cable - Exchange to Cabinet
LOADING COILS
REPEATERS - Amplifier boxes installed in manholes
JOINT BOXES AND MANHOLES - Overview
JOINT BOX AND MANHOLE COVERS - List of all covers and additional information
JOINT BOX - General description
FRAMES & COVERS - Covers and Frames - GPO
FRAMES & COVERS - Covers and Frames - NTC
KEYS, JOINT BOX
LIFTERS, MANHOLE COVER
MOLEPLOUGHS
DISTRIBUTION CABLE - D Side cable - Cabinet to DP's
JOINTING CABLES
JOINTING CABLES - Lead cables
IDENTIFYING PAIRS ON NEW HOUSING ESTATES
LOCATING CABLES and FAULTS
POSTS, MARKING
BOX, JOINT - Pre-fabricated joint boxes and covers
CABINETS - Green street cabinets
PILLARS
POSTS, JOINTING - Small posts used on housing estates
POLE TEST BOXES - Used where underground connects to open routes
DISTRIBUTION POINTS - Terminal blocks

 


OVERVIEW OF THE COMPLETE LOCAL TELEPHONE NETWORK

Quick Find Joint Box and Manhole Covers identifier - The full range

 

 

 
BACK Home page BT/GPO Telephones Search the Site Glossary of Telecom Terminology Quick Find All Telephone Systems

Last revised: December 06, 2025

FM