Direct Wire Boards

In the early 1900s, some alarm systems utilized telegraph wires. These wires would run from the customer’s building to the direct wire board in the alarm company’s central station.

At this time, the customer was not able to arm or disarm their systems themselves. Instead, they had to signal to the central station operators when they wanted their alarm system to be armed and disarmed. A wall-mounted box—called a transmitter, customer terminal, or subscriber terminal—would be located inside of the customer’s building. The customer would flick a switch on this box a few times, sending a signal via telegraph to the direct wire board. Some boxes had Day and Night painted on either side of the switch to make it easier for the customer to remember which way to turn it. When central station operators heard a bell and saw red or green lights by a customer’s module, they would know to arm or disarm the system.

This switch could be used manually or put on a set schedule. The schedule was more reliable, but it meant that the customer could only leave or enter their building between certain hours without the police coming.

The direct wire system was limited by distance. A DC power circuit had a range of only 30 miles, so the customer’s property had to be within 30 miles of the central station.

The direct wire system was in regular use until the 1950s, and fell out of use completely by the 1970s.

The board in the Wayne Alarm museum was built in the early 1900s by Edwin T. Holmes, who commercialized the electromagnetic burglar alarm and established the first alarm networks. The board was used by Rhode Island Electrical Protection in Providence, RI for decades before falling out of use as technology improved. During renovations in the 1950s, the small room that this board was kept in was accidentally sheetrocked over. This was not discovered until the 1990s, when RIEP sold to ADT and vacated the office. Urban explorers broke into the vacant building and found the hidden room with this perfectly preserved direct wire board inside.