Original Item. Only One Available. This is an original German WWII Kleiner Klappenschrank zu 10 Leitungen, or small ten-line field telephone switchboard, dated 1939. This compact communications apparatus was designed for German military telephone networks, allowing a single operator to manage and connect up to ten telephone lines. It retains its manufacturer's identification plate, military acceptance markings, and handwritten line identification labels.

The switchboard is housed in a rectangular wooden case with dovetailed corners, metal fittings, and a hinged lower compartment. The upper metal panel carries twenty knurled screw terminals arranged in pairs for the ten telephone circuits, together with additional connections and a red release button. The front contains ten circular connection buttons, a row of mechanical signal indicators, and ten brass-lined sockets for connecting telephone circuits. A horizontal locking bar runs across the indicator assembly, retaining a paper identification strip with several handwritten German names and abbreviations.

Of particular interest is the manufacturer's identification plate, marked 6659 and 1939, separated by an encircled FL monogram. This trademark is attributed to Franz Lange, Feinmechanik und Elektrowerke of Berlin, a German manufacturer of electrical and communications equipment. Additional markings inside the wooden case include an impressed 1939 date, a circular inspection mark, and a faded German military eagle and swas. acceptance stamp with an indistinct accompanying number.

The case measures approximately 6" x 7" x 13 ½" [15.2 x 17.8 x 34.3 cm].

Condition is fair to good overall, with considerable age, handling, and storage wear. The wooden case remains structurally intact but exhibits numerous scratches, abrasions, finish loss, and localized chipping. The exposed metal panels and fittings show oxidation, accumulated grime, and surface discoloration. The principal operating controls and signal indicator assembly remain present, although their mechanical condition is untested. The lower compartment retains its internal connection hardware and associated wiring, but the ten removable connecting cords are missing. The protective metal top cover and carrying strap are also absent. The manufacturer's plate and principal markings remain legible. This switchboard is offered as a historical collectible, with electrical functionality untested.

Historical Context

The Kleiner Klappenschrank zu 10 Leitungen was developed in 1933 as part of the modernization of German military field telephone equipment. Its design simplified the earlier Feldklappenschrank OB 17, reducing the size and weight of the apparatus while retaining the essential functions of a ten-line telephone exchange. The revised system used a single connecting cord for each telephone circuit, eliminating several mechanical arrangements employed by its predecessor and making the switchboard easier to transport and operate.

During WWII, wired telephone communications formed an important part of the German military command system. Field telephone networks connected headquarters, artillery batteries, observation posts, and subordinate formations, allowing commanders to exchange orders and operational information. These networks were installed and maintained by the Nachrichtentruppen, or signal troops, whose responsibilities included laying telephone cables, operating exchanges, and repairing damaged communications lines.

The ten-line Klappenschrank was intended for smaller communications centers where several independent telephone circuits needed to be managed from one location. Each connected line had its own electromagnetic signal flap, connection button, and socket. When an incoming telephone call was received, the corresponding flap dropped to indicate which circuit required attention. The operator could then select that line, answer the caller, and establish a connection with the requested destination.

Operation required an external field telephone, normally the Feldfernsprecher 33, or FF 33. This supplied the handset and hand-cranked generator needed for speaking and signaling. Once the operator had contacted the intended recipient, the appropriate connecting cord was inserted into the receiving line's socket, establishing a direct telephone connection between the two parties. The operator could then release the connection buttons and continue handling additional calls.

The system also permitted several telephone circuits to be joined for conference calls. This capability was useful when coordinating activities among multiple military positions or distributing the same instructions to several telephone subscribers. At the end of a conversation, a participant could operate the telephone's generator to signal the exchange, allowing the operator to disconnect the cord and return the circuit to service.

The Klappenschrank could also be adapted to particular communications requirements. Additional terminals allowed the connection of an external alarm bell and battery, while a separate Amtszusatz attachment permitted access to central-battery or automatic telephone networks. A multipole connector inside the case also provided for connection to a remote line terminal, allowing the incoming telephone cables to be organized away from the main operating position.

Portable switchboards were especially useful at temporary headquarters and field communications posts, where telephone networks had to be established and altered as military formations moved. Signal personnel could connect newly laid field cables to the exchange, assign the individual circuits, and maintain communications between positions. During combat, damaged telephone lines required frequent repair, particularly when artillery fire or troop movements disrupted existing connections.

The Klappenschrank remained part of the German military's field communications equipment throughout WWII. Its compact wooden construction, straightforward operating arrangement, and compatibility with the widely issued FF 33 telephone made it suitable for the decentralized telephone networks maintained by German signal units.