A party line (multiparty line, shared service line, party wire) is a local loop telephone circuit that is shared by multiple telephone service subscribers.
Party line systems were widely used to provide telephone service, starting with the first commercial switchboards in 1878. A majority of Bell System subscribers in the mid-20th century in the United States and Canada were served by party lines, which had a discount over individual service. During wartime shortages, these were often the only available lines.
British users similarly benefited from the party line discount. Farmers in rural Australia and South Africa used party lines, where a single line spanned miles from the nearest town to one property and on to the next.Subscriber Trunk Dialling Call Zones, NSW State Parliament speech, May 3, 2000
History
Telephone companies offered party lines beginning in the late 1800s, although subscribers in all but the most rural areas may have had the option to upgrade to individual line service at an additional monthly charge. The service was common in sparsely populated areas where subscribers were spread across large distances. An example is Australia where these were operated by the Government Postmaster General's Department. In rural areas in the early 20th century, additional subscribers and telephones, often numbering several dozen, were frequently connected to the single loop available.
Party lines provided no privacy in communication. They were frequently used as a source of entertainment and gossip, as well as a means of quickly alerting entire neighbourhoods of emergencies such as fires,Such a system in described in becoming a cultural fixture of rural areas for many decades.
The rapid growth of telephone service demand, especially after WWII, resulted in many party line installations in the middle of the 20th century in the United States. This often led to traffic congestion in the telephone network, as the line to a destination telephone was often busy. Nearly three-quarters of Pennsylvania residential service in 1943 was party line, with users encouraged to limit calls to five minutes. Shortages persisted for years after each war; individual lines in Montreal remained in short supply at the end of 1919 and similar shortages were reported by telephone companies in Florida as late as 1948. Some rural users had to run their own wires to reach the utility's lines.
Objections about one party monopolizing a multi-party line were a staple of complaints to telephone companies and letters to advice columnists for years and eavesdropping on calls remained an ongoing concern.
In December 1942, University of Tennessee's strategy in an American football game versus University of Mississippi was revealed to the opposing coach, when a telephone on the Ole Miss team's bench had been inadvertently wired to the same party line. In May 1952, an alleged bookmaking operation in St. Petersburg, Florida, was shut down after one month of operation in a rented storefront using a party-line telephone. In June 1968, the conviction of three Winter Park, Florida, men on bookmaking charges was overturned as police had used a party-line telephone in a rented house on the same line as the suspects to unlawfully intercept their communications.
In 1956, Southern Bell officials refused a request from a public utilities commissioner in Jackson, Mississippi, to segregate party telephone lines on racial boundaries.
While primitive lockout devices to prevent two subscribers from picking up the same line at the same time were proposed relatively early, multiple simultaneous calls did not become viable until the initial tests of transistorised pair gain devices in 1955. Any handset off-hook therefore tied up the line for everyone.
Many jurisdictions required a person engaged in a call on a party line to end the call immediately if another party needed the line for an emergency. Such laws also provided penalties for abuse by falsifying emergency situations. In May 1955, a Rhinebeck, New York, woman was indicted by a grand jury after her refusal to relinquish a party line delayed a volunteer firefighter's effort to report a grass fire. The fire destroyed a shed and a barn. She was given a suspended sentence. In June 1970, a sixteen-year-old girl and a woman were charged after refusing to relinquish a party line to allow a distress call as three boys drowned in a pond in Walsenburg, Colorado.
Decommissioning By the late 1980s, party lines were removed in most locales. They were not supported by new technologies and subscriber-owned equipment such as answering machines and computer modems. Meanwhile, the electro-mechanical switching equipment required for their operation was rapidly becoming obsolete, supplanted by electronic and digital switching equipment. The new telephone exchange equipment offered vertical service code calling features such as call forwarding and call waiting, but often was incompatible with multi-party lines. Party lines in the United States were ineligible for Universal Service Fund subsidies, leading telephone companies to convert them to individual lines to benefit from these subsidies.
In 1971, Southern Bell announced plans to gradually phase out all party lines in North Carolina.
One of the last manual telephone exchanges with party lines in Australia was closed down in 1986 in the township of Collarenebri, where most town residents had a telephone number of only three digits. To make a call outside the exchange area it was necessary to call the exchange to place a call. For rural residents, many were on a single telephone line identified by a number and a property name, such as "Gundabluie 1". Each party on that single line was identified by a letter, and the ringing pattern for that party would consist of the corresponding letter in Morse code. This distinctive ring would alert all parties on the line who the call was for.
In 1989, the Chesapeake and Potomac Telephone Company replaced party lines with individual lines in Talcott, West Virginia, a rural area which once had as many as sixteen subscribers on one line. Universities also phased out the systems, which were once common in student dormitories. Illinois State University terminated its last party line in 1990.. Woodbury, Connecticut's independent telephone company abandoned its last party lines in 1991, the last in that state to do so. The same year, Southwestern Bell announced its intentions to replace all of its party lines in Texas with individual line service by November 1994, and the company's last party line finally shut down in 1996.
Pacific Bell phased out most of its party lines by 1997, and the last ones operating in Nevada shut down in 2001. SBC Ameritech still had operating party lines in Michigan as late as 2002. First published in The New Yorker, December 16, 2002. USA Today reported in 2000 that over 5,000 party lines still existed in the United States, but the majority of them were only connected to one telephone, and therefore appeared like individual telephone service at cheaper rates."Party Lines", AT&T Archives, June 6, 2012.
Selective ringing To signal specific subscribers on party lines selectively, telephone operating companies implemented various signaling systems.
The earliest selective system was the code ringing system, in which each telephone subscriber was assigned a specific ringing cadence (not to be confused with modern ring tones).
Although various systems were implemented, one that limited the number of coded rings but established a uniform and readily understood format, was to first give the subscriber number as individual digits, which could be from one to four digits long per exchange, separated by the instructional word "ring" followed by the two digits of the ring code where the first digit indicated the number of long rings, followed by the second digit indicating the number of short rings. Thus spoken, for example, as "nine, three; ring two, two" to mean subscriber No. 93 with ringing code 2 long and 2 short, and written as "93R22", (and if outside the given exchange, then the exchange would be asked for by name before the requested number and ringing code, e.g. "Rockridge nine, three; ring one, two" i.e. "(On the) Rockridge (exchange), (subscriber No.) nine, three; ring one long, and two short," and written as “Rockridge 93R12”. (The two examples cited in this paragraph are taken directly from usage in the 1935 American film Party Wire.) Whilst this practice was common, it was not ubiquitous, since despite giving a standard configuration for terse, easily interpreted numbers with their respective ring codes, its chief functional drawback was with the first ring always being long and the second always being short, which limited the number of brief and thus practical ringing combinations that could be used on single multiparty subscriber numbers.
Further to this functional deficiency was a twofold practical deficiency. For though one was only to answer one's own ringing code, every party on the same subscriber line could hear all the ringing codes. This meant firstly, frequently ringing telephones were a disruptive annoyance, as each party on the line had to stop to listen every time the telephone rang to determine if they were the party being called on any given ring. Secondly, if any party on a given line should so be inclined, there was the opportunity to listen to other parties' calls.
More selective ringing methods were introduced using various technologies.
In the system of divided ringing, the ringing circuit was separated from the talking circuit by adding a ground connection between the central office and the subscriber stations for ringing. On the same subscriber line, one party used the tip side of the line and ground for ringing, whilst the other party on the same line used the ring wire and ground for ringing, to achieve full selectivity for two-party lines, in which only the selected station would ring. These names for the wires are derived from the paired cord plugs—used on a manual switchboard—composed of three parts: the tip and the sleeve separated by a narrow metal band called the ring, each of these three components being insulated from one another.
In the Bell System, the two stations were thus called the tip party and the ring party, In combination with code ringing, this method could be extended to four and eight subscribers to reduce the number of disturbances. In several variations of divided ringing, also called grounded ringing, the bells were activated with polarized current, so that full selectivity was achieved for up to four parties.
Another selective ringing system was based on using different ringing frequencies for each station on the party line. In North America, this was used mostly by independent telephone systems, while the Bell System abandoned frequency selective ringing in the early 1900s. Initially four frequencies were used, which were based on a system of harmonic multiples of a frequency of Hz. Combined with divided ringing, this provided fully selective service for up to eight stations.
All fully selective ringing systems on party lines still brought the inconvenience of finding the line in use occasionally, by hearing talking when one picked up the phone to make a call. All party lines also required special equipment to complete calls to another party on the same party line.Revertive call circuit, US patent 3461246 filed July 22, 1966 by Schneider Gerhard O K of Stromberg Carlson Corp
Characteristics
In the local-battery system of the early cranked magneto phones, the phone's own battery powered its transmitter as well as the receiver of the called phone. If too many phones were off-hook and listening, the additional receivers would load down the transmitter's battery with a voltage so low that no phone could receive an intelligible signal.