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Technical Documentation for Bell System products

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Small Format BSPs in Case Large format BSP LARGE FORMAT BSP

RELATED PAGES ON THIS SITE:      Bell System Publications      COLORS      WE SETS (Links on Home Page)  

BSPs are extremely useful documents to collectors, as they contain loads of information on product features,

ordering options, colors, wiring, maintenance and other technical details.

LARGE FORMAT BSPs - 8 1/2 X 11 inches

Individual BSPs ran from one to as many as 50 or 60 pages each.  For a particular product, seperate BSPs often covered Identification, Selection, Connections, Installation, Operation and Maintenance.  Each was typically stapled or glued together, and punched with 7 holes to fit 3, 4 or 7-pin binders.  Each was also identified with a BSP number (described below), a date and an issue number.  New issues were printed to describe new products and options, changes in technical specifications, different production parts, the adoption of new installation or service techniques and (occasionally) to correct errors.

Packages of updates were periodically distributed, and had to be manually filed in each binder set in use, to keep the documentation set up to date.  With literally thousands of BSPs published, this would have been quite a challenge for anyone lucky enough to have a large library of BSP binders.

Bookcase with SOME of the BSPs in a complete set
(Source: Bell Telephone Magazine, Summer 1952)

The number of BSPs exploded with the rush of new products in the 1960s and 1970s.
This creates an obvious problem for collectors.  If it's not enough of a challenge to find a reasonably complete set of BSPs for one's primary area of interest, things are complicated by wanting to know changes that happened during the life of a product. 
Several issues of each BSP are thus needed!

We've seen some BSPs with issue numbers in the 60s or even higher.  Some index documents that were frequently revised seem to have gone from issue 99 back to issue 1.

Therefore, the issue number AND date are thus required to uniquely specify a particular document.

SMALL FORMAT BSPS - 4 x 6 7/8 inches

Small Format BSPs in Case

Shown with a carrying case above, these compact BSPs were produced primarily for installers to take along on the job.  Sets were made up that contained the products most often used by an installer, and packaged in a hard board carrying case that was designed to fit conveniently in the installer's truck.  Here they are shown with other contents of the installer's truck at a 1959 Family Night in Roanoke, Virginia.

BSPs in Truck Gear
(Source: The Transmitter, January 1959)

While the same BSP numbers and content were used, the small format required the information to be typeset again, and corners and tabs were die cut, incurring additional cost and increasing the possibility of inconsistency and error.

These BSP s were made from the 1910s through the 1960s!


During 1969 and the early 70s several Operating Companies experimented with producing bound copies of sets of the large BSPs for installers.  Without the carrying case of the previous manuals, these often show signs of use -- wear and coffee stains.
The feedback was that their 8 1/2 x 11 inch size was too large for convenience.

Handbook - Illinois Bell, 1969  Handbook - New England Tel, 1970  Handbook - Pacific NW, 1970  Handbook - Pac Tel, 1973

New York Telephone's smaller size was considered more suitable for installer use.

Handbook - New York Tel, 1969

Beginning in 1970, the Bell System produced several sets of smaller format handbooks in the 6 1/2 x 8 1/2 inch format.  Each BSP was photo-reduced, so the additional typesetting step was eliminated.  The binding was simple and inexpensive, like a paperback book, so the books were cheaper, but not updateable.  They were reprinted with current useful BSP issues every year or two through the 1970s and into the early 1980s.  Old sets were discarded.

Station Service Manual   Key Systems Service Manual   Station Specialties Services Manual

Several series were eventually developed, covering topics of interest to different groups of installers.

STATION SERVICE MANUAL - Mainly single line sets and related components and techniques used primarily by residential installers.

KEY SYSTEMS SERVICE MANUAL - Mainly multi-line sets and related components and techniques primarily used by commercial installers.

STATION SPECIALTIES SERVICE MANUAL -  Covered special function equipment, such as speakerphone connections, automatic dialers, answering machines and announcement machines.

DATA SERVICES REFERENCE HANDBOOK - Devices (including modems) and procedures used to interface computers and other electronic data equipment to the telephone network.

INTERCONNECTION SERVICE MANUAL - Electrical interfaces required for voice, data and customer supplied TIE lines.

REGISTRATION SERVICE MANUAL - The FCC Registration Program, including specifications for jacks used to connect to the telephone network.
Handbook library

A library of just a few of the handbook sets published during the 1970s takes up about 6 feet of shelf space.


BSP Numbers were initially in the form:  Lss.nnn.vv

where L = the letter indicating the series
ss = the numeric 2-digit section number (occasionally 3 digits were used),
nnn = the 3-digit number of the BSP in the section, and
vv = a one or two digit numeric variation code, if needed.

Series Codes  ("L")
A - Central Office Maintenance
C - Installation and Maintenance (I&M) for Installers
D - Recovery and Repair
E - Toll Test Room Operation
F - Local Test Room Operation
G - Outside Plant
H - Buildings
J - Motor Vehicle and Construction Apparatus
M - Plant
P - Teletypewriter and Manual Telegraph Station and PBX I&M
R - Radio Systems
AA - Equipment Engineering
AB - Transmission Engineering and Data
AG - Outside Plant Engineering
AF - Foreign Wire Relations

950 Series - General Descriptive
Supply Operating Practices

For more details, see BSP 000-010-000  BSP Plant Series General Plan
Section Numbers for series C  ("ss")
10 - General
20 - Wiring
30 - Apparatus (including telephone sets)
40 - Magneto Stations & Public Telephones
50 - Station Systems and Apparatus
           for Specific Uses
60 - Reference
70 - Supplies

The BSP number was followed by the sequential Issue number and Date.

For example, C11.001, Issue 4, 7-25-41  "Plan for System Issued Practices."

Pages were normally on white paper.
Addenda were on pink paper.
Temporary Information Sheets were on yellow or light green paper.

During World War II, "WR-" prefix BSPs were printed on blue paper.
These documented Wartime Restrictions, including material substitutions.

In 1956, the C-series was reorganized and converted to full page format.
The "Station Operations Manual" was created, using a subset of the Css codes.
Many BSPs were moved to new subsections in the Station Operations Manual,
while others stayed in the Station Installation and Maintenance sections.

Station Installation and Maintenance Station Operations Manual

Division and Subdivision Codes, 1932
   (C10.002, i2, Sep32)

C10 - General
  C10 - Scope
  C11 - Plan for Issuing and Distribution
  C12 - Indices and Checking Lists
  C13 - Tables of Frequencies
  C14 - Public Relations
  C15 - General Routines
  C16 - Records and Reports

Division and Subdivision Codes, 1954-56

C10 - General  (C12.001, iA, PTT, Dec54)
  C10 - Scope
  C11 - Plan for Issuing and Distribution
  C12 - Indices and Checking Lists
  C14 - Public Relations
  C15 - General Routines

Division and Subdivision Codes, 1960
  (C16.000, i2, Oct60)

C16 - General
C17 - Tools and Materials
C18 - Components

C20 - Wiring
  C20 - General
  C22 - Building Entrances
  C24 - Station Wiring

C20 - Wiring (C12.002, iA, PTT, Dec54)
  C22 - Building Entrances
  C24 - Station Wiring

C23 - Wiring

C30 - Apparatus
  C30 - General
  C31 - Subscriber Sets
  C32 - Hand Telephone Sets, Desk Stands and Telephone Sets
  C33 - Protectors
  C34 - Dials, Dial Mountings, Dial Adapters and Apparatus Blanks
  C35 - Transmitters, Receivers and Receiver Holders
  C36 - Cords, Jacks, Plugs and keys
  C37 - Misc. Apparatus

C30 - Apparatus (C12.003, iA, PTT, Dec54)
  C30 - General
  C31 - Subscriber Sets
  C32 - Hand Telephone Sets, Desk Stands and Telephone Sets
  C33 - Protectors, Protected Terminals and Connecting Blocks
  C34 - Dials, Dial Mountings, Dial Adapters and Apparatus Blanks
  C35 - Transmitters, Receivers and Receiver Holders
  C36 - Cords, Jacks, Plugs and keys
  C37 - Misc. Apparatus

C38 - Station Sets
C39 - Coin Stations

C40 - Connections - Dial and Manual Stations - General
  C40 - General
  C41 - Station Sets by Class of Service
  C42 - Subscriber Sets
  C43 - Telephone Sets
  C44 - Hand Telephone Sets
  C45 - Dest Stands
  C46 - Line and Ringer Connections

C40 - Magneto Stations and Public Telephones (C12.304, i15, Dec56)
  C41 - Magneto Stations
  C42 - Coin Collectors
  C44 - Telephone Booths
  C45 - Signs
  C46 - Directory Cabinets, Holders and Shelves

C43 - Associated Station Apparatus

C50 - Other Apparatus and Connections
  C50 - General
  C51 - Magneto Stations
  C52 - Public Telephone Stations
  C53 - Station Systems
  C54 - Supplemental Equipment
  C55 - Apparatus for Specific Uses

C50 - Station Systems and Apparatus for Specific Uses
              (C12.305, i16, Dec56)
  C52 - Telephone Booths
  C53 - Station Systems
  C54 - Apparatus for Subscribers with Impaired Hearing
  C55 - Apparatus for Specific Uses
  C56 - Civil and Governmental Alarm Systems
  C57 - Radiotelephone Systems

C60 - Inspection, Testing and General Trouble Locating Methods
  C60 - General
  C61 - Inspection Plans
  C63 - Station Testing
  C64 - General Trouble Locating Methods
  C68 - Identifying Lines

C60 - Reference Sections (C12.306, i17, Dec56)
  C61 - General
  C63 - General Apparatus Requirements
  C64 - Magneto Stations and Coin Collectors
  C65 - Station Systems for Specific Uses
  C66 - Station Systems for Specific Uses - Provisional Sections
  C66.5 - Station Wiring Plans

C70 - Tools, Gauges and Test Sets
  C70 - General
  C71 - List of Tools, Gauges and Test Sets
  C73 - Tools
  C74 - Gauges
  C75 - Test Sets

C70 - Minor Station Systems
C71 - Major Station Systems

C80 - Government Systems
C85 - Common Systems


In the early 1960s, the numbering format was changed. 
All series were unified in a single all numeric numbering system.
The initial letter was eliminated and the number was in the all numeric form:

where ddd = Division Number,
sss = Division-specific Subdivision Number, and
kkk = Key Number.

"ddd" Division Number Codes
000-019 General Info
020-023 Common
024-179 Apparatus and Tools
200-289 Switching Systems
300-379 Transmission Systems and Testing
400-449 Radio
460-469 Customer Equipment, Common
470-489 Special Services
500-529 Station Equipment (Telephones)
530-559 PBX
570-589 Teletypewriter
590-599 Data Systems

620-649 Outside Plant
660-669 Test Center Operation
680-689 Plant Assignment
720-729 Motor Vehicles
740-749 Supplies
760-779 Buildings
780-789 Plant Extension Engineering
800-839 Equipment Engineering
850-889 Transmission Engineering & Data
900-939 Outside Plant Engineering
940-944 Radio Engineering
945-949 Training Material
950-989 General Descriptive
For more details, see BSP 000-000-000  Numerical Index Division 000

The BSP number is followed by the sequential Issue number and Date.

For example, 000-010-010, Issue 5, April 1964  "Bell System Practices - Plant Series   General Plan"

In typical Bell System fashion, BSPs were created to document the new numbering plan and
conversion tables from old to new numbers.
000-000-000  -  Numerical Index Division 000
000-000-001  -  Master Alphabetical Index of all Divisions
000-010-010  -  BSPs - Plant Series - General Plan
000-010-020  -  Uniform Numbering Plan - Procedures for Conversion
000-020-xxx  -  Conversion from old series to Plant Series


BSPs were initially issued in about 1930.  They evolved from "circular letters," informal "practices" and a similar format document called AT&T Specifications.  The goal was to provide overall organization for all written instructions used by Plant and Engineering people.  Bulk shipments were made from Western Electric to the Operating Companies for distribution to employees.

After World War II, The Bell System struggled to catch up with demand that couldn't be serviced with wartime production and manpower constraints.  On June 8, 1951, a task force was convened to study the use of BSPs, update some 8,000 sections of BSPs and to make recommendations for the future.  Among the changes proposed were:
  • Reduction of the number of series for clarity,
  • Increased use of charts and graphs to simplify presentation,
  • Include in BSPs material often sent in "general letters."
  • Change organization, numbering plan and indexing.
BSP Working Group in 1952
(Source: Bell Telephone Magazine, Summer 1952)

The updating activity took several years.  During the 1950s and 60s some BSPs were renumbered and filed in different sections (making hours of entertainment for collectors trying to find a particular set or piece of equipment).

Between about 1960 and 1963, the 9-digit numbering plan was adopted and phased in to use.  It was probably done for the convenience of Bell System computers, but adds to the challenge for today's collector trying to trace a product's development.

You can read the entire 1952 BTM article on BSPs (The Bell System's Best Sellers) here (13 MB):


As you can easily see, the chance of finding anyone with a complete set of BSPs readily available is exceptionally small.  It's even difficult to get a set of BSPs showing the evolution of a particular phone or component over a period of 5 to 10 years. 

For many years, collectors were lucky enough to be able to order BSPs directly from Lucent's web site.  That has since stopped, so BSPs must be found on-line or on the used market.  I've had some luck searching the internet for a BSP using "bsp" followed by the BSP's number in quotes -- e.g. bsp "000-010-010"
When written, this returned a match on the site

Several sites are building libraries of BSPs and wiring diagrams from BSPs in pdf format.
The TCI Library is the most comprehensive, with well over 10,000 documents.
Please contribute scans of any BSPs or related documents you have.
Some sources are listed on the links page: links

The handbooks still appear fairly frequently at telephone shows and on-line auctions at reasonable prices.
Other BSP books and binders seem to command premium prices currently.

Some phone club members are scanning groups of BSPs and making them available on CD.
If you need BSPs, you should consider joining a collector club.  You may find a source and will certainly find folks with similar interests who can help with wiring or troubleshooting issues, even if the documentation is difficult to find.  No matter how much or how little you know, there are probably areas in which you can now or will soon be able to help others.

Happy hunting!

"You can't have too many BSPs!"

Please send any comments, additions and corrections.

Last update: 3 Jan 2014

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©2004-14 paulf.  All rights reserved.