| Name | “Sentry” Public Telephone Enclosure |
| Date | early 1980s |
| Manufacturer | Various |
| Usage | US Phone Booth head box- environments where maximum security for coin telephone instruments is required—such as bus terminals, subways, or high-theft-risk areas |
| Further notes |
| KS-20842, also known as the “Sentry” Public Telephone Enclosure: Overview & Functionality The KS-20842 Sentry is an indoor/outdoor telephone enclosure engineered to serve in environments where maximum security for coin telephone instruments is required—such as bus terminals, subways, or high-theft-risk areas. It accommodates both single and double unit configurations and supports clustered group installations for efficient public access. Documentation & Timeline The Bell System Practices (BSP) documentation for the Sentry includes: Section 508-452-100, Issue 7: Covers Identification and Installation procedures for single and double-unit Section 508-452-101, Issue 1: Details Cluster Arrangement installation guidelines (October 1981). Section 508-452-102, Issue 1: Outlines Maintenance procedures (December 1981). These BSPs place the initial rollout of the Sentry in the early 1980s, with formal practices codified by late 1981. Design & Construction The structure features a rugged, high-strength steel post and a ¼-inch-thick aluminum housing, ideally designed to withstand vandalism and harsh environments. It can be installed surface-mounted or embedded in concrete for added security. Power and telephone wiring can enter the enclosure either from the top or the bottom. Optional directory facilities can be incorporated to enhance user access. Manufacturer Details While distributed under the Western Electric / Bell System brand, the exact manufacturer of the KS-20842 is not specified in available documentation. However, the practical design and materials (steel/aluminum heavy construction) suggest that a security-focused contractor—possibly similar to those who produced other robust enclosures—was engaged. In Summary The KS-20842 “Sentry” is a specialized telephone enclosure introduced in the early 1980s, tailored for locations demanding heightened durability and security. Its modular design—capable of handling single, double, or clustered deployments—along with optional directory features, reflects a thoughtful approach to tough public environments. Though Western Electric distributed it, the actual manufacturer remains unidentified. |
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