DIAGRAM INFORMATION


Actual circuit wiring diagrams for BPO telephones will be found linked from the relevant telephone page or linked from the table below.  For CD users, N diagrams are held on the CD and will be transferred to your computer on installation.

Go the the BPO telephone list, click on the telephone of your choice - if a diagram is available then a link will be found (contact the author if you need a diagram that is missing).

BPO diagrams and drawings are either numbered or numbered with a lettered prefix.  The prefix on diagrams may be one or two letters of the alphabet and those with A, F, K, M, P, Q, S, U, W or X as the third letter of the prefix code take the same number of the associated circuit diagram.  The letters have the following significance:-

A - Apparatus or equipment
F - Floor plan
K - Trunking
M - Maintenance
P - Assembly
Q - Stock lists
S - Circuit
U - Shelf jack wiring or U link connections (J or SA series)
W - Wiring or routed circuit wiring
X - Cross-connection

In addition to the above joint circuit and wiring diagrams are given the basic and wiring codes, e.g. RP/RPW

Drawings are numbered in the range 60000 - 99999

Diagrams in general use are:-
General Wiring Diagrams are prefixed with SA
Wiring Diagrams that show wiring runs and wire colours are prefixed with SAW
Police apparatus diagrams are prefixed with PA
Fire alarm wiring diagrams are prefixed with FA
House Exchange systems are prefixed with Q
Testing diagrams are prefixed with T
Telephone wiring diagrams are prefixed with N
Telegraph theoretical diagrams are prefixed with TG
Telegraph wiring diagrams are prefixed with TGW

List of all Diagram types:-

Prefix Code Description Remarks
1 to 500 399 Fully dimensioned drawings of apps and equip approved for production
AD Air Defence drawings and diagrams
ADA Air Defence drawings and diagrams
ADF Air Defence drawings and diagrams
ADK Air Defence drawings and diagrams
ADL Air Defence drawings and diagrams of cable networks was ROC
ADP Air Defence diagrams
ADU Air Defence diagrams
ADW Air Defence diagrams
ADX Air Defence diagrams
AGS UAX No. 7 diagrams
AS Area of search plans for Repeater stations
AT Auto exchange ccts; wholly or partially electronic; trunk toll; misc ccts
AT/ATW Auto exchange ccts; wholly or partially electronic; trunk toll; misc ccts
ATM Auto exchange ccts; wholly or partially electronic; trunk toll; misc ccts
ATU Auto exchange ccts; wholly or partially electronic; trunk toll; misc ccts
ATW Auto exchange ccts; wholly or partially electronic; trunk toll; misc ccts
ATX Auto exchange ccts; wholly or partially electronic; trunk toll; misc ccts
AU Auto exchange ccts; wholly or partially electronic; trunk toll; misc ccts
BB Broadband utilization
BM Cable and network diagrams
C Cable and network diagrams that are security classified
CB CB exchange ccts
CBU CB exchange ccts
CBW CB exchange ccts
CBX CB exchange ccts
CU CB exchange ccts
CBS CBS exchange ccts
CBSU CBS exchange ccts
CBSW CBS exchange ccts
CBSX CBS exchange ccts
CBU CBS exchange ccts
CBW CBS exchange ccts
CBX CBS exchange ccts
CC Communication charts Regional
CCS(L) Cable cross section diagrams
CD Contour drawings insufficiently dimensioned for inclusion in main series
CN External plant and protection
CSU CBS exchange ccts
CTS Drawings, diagrams etc for training branch
CU
CV Valve characteristic curves
CX
D Boundary maps, key plans and cable network diagrams covering the whole country
DL Drawing lists for selected jobs
DR Drilling for apparatus
DT Data transmission and associated equipment
DTN Telegraph defence ccts and accommodation plans
DTW Data transmission and associated equipment
DT/DTW Data transmission and associated equipment
DWL Data transmission and associated equipment
E Diagrams of non-STD transmission equipment and early equipment
EC Installation particulars of equipment
ECW Installation particulars of equipment
ED Drawings of Transmission equipment
EDA Drawings of Transmission equipment
EG Drawings and diagrams for electronic exchanges
EGA Drawings for electronic exchanges
EGC Diagrams developed under the auspices of the JERC
EGF Diagrams developed under the auspices of the JERC
EGN Diagrams developed under the auspices of the JERC
EGU Diagrams developed under the auspices of the JERC
EGX Diagrams developed under the auspices of the JERC
EQ Semi-auto equipment fire emergency ccts
ER Semi-auto equipment fire emergency ccts
ES Accommodation and equipment layout plans of buildings was EX SK series
ETC Drawings, diagrams etc for training branch was CTS series
ETE Drawings and diagrams of Radio stations, Tele Exchs & Telegraph layouts
EW Non-standard transmission equipment
E/EW Non-standard transmission equipment
EX Drawings and diagrams for all divisions in research branch, except R12
EX/SK Superseded by ES series
F Main cable development forecast diagrams
FA Fire alarm ccts
FA(L) Fire alarm ccts
FAW Fire alarm ccts
FDA Drawings for factory divisions
FDH Drawings for factory divisions
FY Drawings for factory divisions
GMT Clocks and Greenwich mean time cct
GMTW Clocks and Greenwich mean time cct
HF HF diagrams
IF Factory diagrams
LA Circuit lab diagrams
LD Label diagrams for pasting into instruments
LFS Factory drawings
LL Drawings of local line network
LR Misc drawings and diagrams
MISC
MOH Drawings of items provided for the department of health
MS Experimental and temporary ccts
MSU Experimental and temporary ccts
MSW Experimental and temporary ccts
MSX Experimental and temporary ccts
MT Vehicles and associated equipment
MTF Methods for fitting items on vehicles for M Branch
MU Main underground HF and carrier cables, land end and sea earth cables
MU-FM Main underground HF and carrier cables, land end and sea earth cables
MU-TT Test tablet diagrams.  Suffix TT added to associated MU number
MU4000(HF) Main network diagrams, motorway cables layout diagrams
MW Main network diagrams, motorway cables layout diagrams
N Telephone, Call offices and pbx ccts loose leaf
ND Network diagrams of private ccts
NT/NTA Ex National Telephone Company
PA Police alarm ccts
PA(L) Police alarm ccts
PF Phonogram and tele/telegraph ccts and installations
PFU Phonogram and tele/telegraph ccts and installations
PFW Phonogram and tele/telegraph ccts and installations
PFX Phonogram and tele/telegraph ccts and installations
PLAN Miscellaneous diagrams, maps, networks and proposals
P/DC Telecoms power plant ccts
P/DCW Telecoms power plant ccts
P/EL Electric light fittings
P/ELD Illumination intensity
P/HG Heating layouts.  Boiler room and fuel hopper arrangements
P/LG
P/MSC Miscellaneous
P/P Engine room, switch gear wiring diagrams
P/PN Pneumatic diagrams
P/TC Power plant drawings
P/VN Ventilation layouts
Q House exchange telephone systems loose leaf
Q(L) House exchange telephone systems loose leaf
R Master copies of tracings from blanks, illustrations for books etc
RA Relay adjustment cards
RES Drawings and diagrams for all divisions in research branch
RP Repeater and amplifier equipment and ccts
RPA Repeater and amplifier equipment and ccts
RPW Repeater and amplifier equipment and ccts
RPX Repeater and amplifier equipment and ccts
ROC NOW ADL
RSF Repeater station distribution frame layouts
RSS Repeater station distribution frame layouts
RT Automatic exchange routiner ccts
RTM Automatic exchange routiner ccts
RTU Automatic exchange routiner ccts
RTW Automatic exchange routiner ccts
RTX Automatic exchange routiner ccts
RW Automatic exchange routiner ccts
S Parts and composite parts of common use
SA Circuits of telephone subscribers apparatus
SA(L) Circuits of telephone subscribers apparatus
SA/SAW Circuits of telephone subscribers apparatus
SAJ Circuits of telephone subscribers apparatus
SAW Circuits of telephone subscribers apparatus
SAX Circuits of telephone subscribers apparatus
SC Scales for electrical measuring instruments Previously on CD
SD Standard data
SHEET
SUB/A Woolwich data drawings
SUB/B Dover data drawings
SUB/C Dalmuir data drawings
SUB/D CS Ariel drawings
SUB/E CS Iris drawings
SUB/F CS Alert drawings
SUB/G CS Sentinel drawings
SUB/H Southampton CMD drawings
SUG/J Misc Nautical drawings
SUB/K Foreign charts
SUB/L Contracts charts
SUB/LS Misc equipment affecting all ships
SUB/M Beacons at shore ends
SUB/N Methil cable depot
SUB/P CS Monarch drawings for cable ship equipt for PO use use designed externally
SUB/Q CS Monarch drawings for cable ship equipt for PO use use designed externally
SUB/R Cable section sheets
SUB/S PO designed equipment
SUB/T Cable shore ends
SUB/U Common equipment for new ships
SUB/V
SUB/W CS Iris
SUB/X Greek consultancy
SUB/Z Sketches, schedules, graphs etc
SUP/D Packaging
T Testing circuits and diagrams
TG Telegraph ccts - theoretical
TG(L) Telegraph ccts loose leaf
TGM Telegraph ccts
TGK Telegraph ccts
TGU Telegraph ccts
TGW Telegraph ccts - wiring
TGX Telegraph ccts
TK Auto exchange trunking and grading diagrams
TL Telephone, trunk, misc and power
TLU Telephone, trunk, misc and power
TLW Telephone, trunk, misc and power
TLX Telephone, trunk, misc and power
TP Telephone exchange equipment installation drawings and diagrams
TPW Telephone exchange equipment installation drawings and diagrams
TPX Cross connection field for meter pulse supplies
TRT Testers for telephone exchange equipment
TRTM Testers for telephone exchange equipment
TSB Diagrams for test equipment
TSL Diagrams for test equipment (test section Studd Street)
TSU Drawings and diagrams for the Technical support unit
TTC Training branch material
TU
WB Laboratory drawings and diagrams
WB/WBM Laboratory drawings and diagrams
WBM Laboratory drawings and diagrams (assembly)
WBW Laboratory drawings and diagrams
WE War emergency diagrams (1939)
WL Radio station drawings and maps
WM Radio station drawings and maps
XED Drawings and diagrams of non-standard equipment for experimental purposes
XM ATE crossbar exchanges 5005
XP ATE crossbar exchanges 5005
XQ ATE crossbar exchanges 5005
XS ATE crossbar exchanges 5005
XX ATE crossbar exchanges 5005
Y Diagrams and drawings for R12
Z Drawings and diagrams for RS division before transfer to GCHQ


This list is included in the Diagram spreadsheet

 
 
 
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Last revised: December 06, 2010

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