The structure of a Light Signal Construction battalion
The average U.S. Army Signal Corps Construction Battalion consisted of roughly five hundred personnel organized into two construction companies with a headquarters and medical detachment. Each company operated twelve construction teams of pole linemen, supported by cable splicers, repeater technicians, switchboard operators, wire chiefs, installers, teletype operators, radio operators, electricians and support staff.
During the Normandy invasion and subsequent campaigns, radio was essential during the first days when wire could not yet be laid. Task‑force signalmen used SCR‑300, SCR‑284 and SCR‑499 radios to maintain contact between beach commanders and command ships.
However, once the beachhead was secure and wire lines were installed, most routine traffic shifted to wire because radio transmissions were easily intercepted and jammed. German forces frequently entered American voice nets and broadcast bogus orders, prompting commanders to insist that sensitive traffic be sent by wire.
Pole linemen constituted the core of construction companies. They erected telephone poles, strung open‑wire lines and Spiral‑4 multi‑pair cable, and repaired or replaced damaged lines. Linemen used body belts, pole climbers, pliers, hammers, screwdrivers, splicing clamps and lag wrenches.
Field linemen laid field wire along the ground from switchboards to front‑line units, often under direct fire. They spliced broken wires and occasionally operated portable magneto switchboards or telephones.
Signal Battalion Personnel Breakdown into roles
| Role / Military Occupational Specialty (MOS) | Approximate Number in Battalion | Typical Duties and Comments |
|---|---|---|
| Pole linemen (Team members – MOS 238) | ≈264 pole linemen (11 per team × 12 teams × 2 companies) | Formed the bulk of the unit. Linemen installed, repaired and maintained wire and cable lines; climbed poles, dug holes, set poles, strung wire and Spiral‑4 cable, spliced wire and used heavy line construction equipment. They wore body belts, pole climbers, pliers, hammers and splicing clamps as described in FM 24‑20 and worked in all weather. |
| Telephone & telegraph construction team chiefs (Staff sergeants) | 24 (12 per company) | Led each construction team; supervised linemen and coordinated with wire chiefs and operations officers. |
| Cable splicers (MOS 039) | 8 (4 per company) | Specialized in splicing and repairing lead‑covered telephone/telegraph cables; dried moisture with paraffin, tested splices and used ohmmeters and megohmmeters. Usually assigned to a cable‑splicing section. |
| Field linemen (MOS 641) | Part of linemen total; some assigned to switchboard sections | Laid and maintained ground‑laid field wire from switchboards to forward units; spliced, operated portable field telephones and occasionally manned switchboards. |
| Wire chiefs (MOS 261) | 2 (1 per company) | Supervised installation, testing, repair and maintenance of central‑office equipment and wire lines. Directed installation of switchboards and telephones and localized line troubles using test instruments. |
| Telephone repeatermen / carrier technicians (MOS 187) | 2–4 per battalion | Installed, adjusted and maintained repeater and carrier equipment for long‑distance trunk lines, made voltage and load tests and ensured proper gain and balance. |
| Switchboard operators (MOS 650 and 309) | 16–20 | Operated magneto and common‑battery switchboards; answered calls and connected circuits; performed minor maintenance. Each field switchboard was staffed around the clock. Temporary operators could be drawn from linemen when needed. |
| Telephone/teletype installers and repairmen (MOS 095, 097, 232) | 6–8 | Installed and maintained central‑office equipment, switchboards and automatic switchgear (e.g., BD‑72 or BD‑71 boards). Repaired short circuits and substituted for repeatermen. |
| Telegraph/teletype operators (MOS 236 & 237) | 8–12 | Operated telegraph and teletype equipment in battalion and company message centers. Teletype operators prepared perforated tape, maintained logs and operated at 20 words per minute. |
| Radio operators | 8–10 | Operated SCR‑299, SCR‑399 and other HF radio sets in battalion headquarters to maintain contact when wire lines were cut. Provided backup communications. |
| Electricians / power plant operators (MOS 132, 415) | 2–4 | Maintained generators and power distribution for switchboards, repeater sets and lighting; set up portable generators for cable‑repeater huts and message centers. |
| Medical detachment | ≈12–15 | Provided first aid and evacuation; often borrowed from the battalion's attached medical detachment. |
| Mess, supply & motor personnel | ≈40–50 | Cooks, mess sergeants, supply sergeants and motor sergeants maintained rations, equipment and vehicles, including 2½‑ton cargo trucks, pole‑setting trucks and jeeps. |
| Headquarters staff (officers and clerks) | ≈20 | Battalion commander, executive officer, S‑3 operations officer, signal property officer, intelligence officer, chaplain and clerical staff. |
Signal Corps Construction Battalions enabled effective command and control across the European Theater. By maintaining thousands of miles of wire and cable, they ensured that orders, fire missions, logistics requests and intelligence reports flowed continuously. First Army alone used more than 5,000 miles of field wire. Without these lines, Allied operations would have relied solely on vulnerable radio communications. The specialized roles within these battalions, from pole linemen and cable splicers to repeater technicians and switchboard operators, illustrate the complexity of wartime communications.