Specifications & Drawings

Open Wire Specifications & Drawings

United States Department of Agriculture, Rural Electrification Administration

Telephone Engineering & Construction Manuals


Section 625, Issue No. 6, August 1962: Open Wire Pole Top Assembly Units

A significant contribution by the Rural Electrification Administration (REA), known today as the Rural Utilities Service (RUS), was the embarking upon a loan program for telecommunications borrowers during the Truman Administration. 


Having sung the praises of the REA rural electric loan program’s success since its 1935 inception, Congress was eager to expand the program for the benefit of telecom customers in the country who, had either experienced poor service from existing farmers’ mutual telephone systems or simply lacked service entirely.


The the key benefit of the loan program was to the hundreds of consumers served from these newly formed associations.  This dose of significant financial investment to rural areas of the South, Midwestern states and the remote areas of the mountain Western United States, both extended new service and greatly improved existing phone service.


For many of the same reasons that electric distribution and Generation & Transmission cooperatives were formed, telephone cooperatives formed similarly: furnishing service in areas where for-profit communications companies found it impossible to serve prospective consumers where it had not been profitable to do so previously.


The REA’s engineering division in Washington, D. C. administered the rural  borrowers’ initial and on-going technical needs.  Design, testing and standardization assistance for the rural communication cooperative was just a small part of its purpose. RUS also advised on cooperative business practices, accounting, inventory purchasing/control and human resource considerations for each cooperative, among other important assistance.


In the early REA program, standardized rules were seen to be tantamount, not only for the technical construction of individual systems, but in their subsequent operation, proper maintenance and continuously successful business administration. 


Telephone borrower standards made it possible for a cooperative association–in nearly every state–to build structures, lines and systems to a higher degree of strength and reliability.  Additionally, by using equipment on the “Barrowers Approved List,” each interconnected system could be assured of quality equipment and interconnection reliability.  REA’s conservative standards became successful, and helped to promote a growth industry for equipment manufacturers–by insisting upon a high degree of service reliability for member-consumers.


As with all technological developments, these standards underwent significant evolution since 1948.  While we cannot include Bell System Practices (BSPs) here, as they are currently proprietary, it is possible to publish the REA/RUS specifications and drawings.  Most of these are based upon similar Bell System and General Telephone Company designs.  Hence, as they are in the public use catagory, we can share these with you. 


More recent REA/RUS open wire specifications offer glimpses of pre- and post-1955 “O” Carrier, 16-channel technology period designs.  Phantom construction techniques are illustrated in some designs.  Use of some styles incorporating a three channel “C” Carrier circuit methodology can be distinguished.  Hopefully, these specifications will answer many construction questions about open wire methods.  Including insulator use, tying in conductors, aeolian vibration control, overcurrent and overvoltage protection, as well as various transposition schemes displayed, subtly hinting at their deviously rich mathematical design complexity.


This website’s administrator anticipates historical design information dervived from the American Raiload Association’s (presently the Association of American Railroads) Communications Section designs in the future.   These included some of the earliest consolidated standards derived from Western Union, Postal Telegraph and Overland Telegraph systems, as well as the invididual railway companies’ architecture. 


It was once commented to this author, “Rock Island Railroad’s communications designs . . . were just a little different from about every other railroad’s way of doing things. . .”  Perhaps every railway adopted some unique feature which placed them slightly apart from other transportation organizations’ designs.  However, most were quite faithful to the Communication’s Section A.R.A. methods in comparable construction.


These were well-designed open wire and multi-pair cable pole head configurations for various applications.  Here, one found some of the earliest suspended cable (with horseshoe clamps on strand), carrying open wire phantomed crosarm style construction, wooden cross-connect boxes, corner poles, storm guyed fixtures, river crossing structures, terminal poles, and special application structure designs. 


Every several years, representatives of AT&T and the individual railroad communications departments would meet for an annual consortium to share mutual technical problems.  Post-conference, the published Transactionsappeared.  These included technical papers introduced at the various committee meetings (i.e. “Inductive Coordination Committee”), on technical problems, design architecture of structures, legal and contractual agreements, right-of-way coordination, and a multitude of issues which might cause problems for either the rail systems communications’ groups and their civilian telephone counterparts. 


Many of these published Transactions originated in the pre-World War I era and whose content filled the pages with interesting information and specifications as they met over the decades to decide these important mutual issues.

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