The B2 Suitcase Radio and the SOE

Purpose and Operational Need

During the Second World War, the ability for agents and resistance movements in occupied Europe to maintain secure, two-way communication with London was paramount for the success of Special Operations Executive (SOE) missions. The B2 radio, officially designated as the Type 3 Mk II, was developed to meet the requirement for a portable, reliable transceiver that could be transported into hostile territory without drawing immediate suspicion [3].

Development and Design

The B2 was developed in 1942 by then-Captain John Brown at SOE Station IX [3]. The manufacturing of these sets was handled by the Radio Communication Department of the SOE, based at Stonebridge Park [3].

The device is known by several designations, including Type 3 Mk II, Type B Mk II, B.II, and most commonly, the B2 [3]. It was designed as a clandestine transceiver, meaning it could both transmit and receive signals, allowing agents to send intelligence reports and receive operational orders from the UK [3].

Historical Characteristics and Variants

The B2 was produced in two primary configurations to suit different methods of infiltration and operational environments:

• The Suitcase Variant: The initial version was housed in an unobtrusive leather suitcase, typically brown or red [3]. This allowed an agent to travel through checkpoints and cities appearing as a civilian traveler. This specific variant is easily identified by three front locks: two simple locks on the sides and a central lock that required a key [3].
• The Parachute-Drop Variant: Later in the war, the B2 was adapted for delivery via parachute to resistance groups already operating in the field [3]. In this configuration, the equipment was divided into two waterproofed metal containers, marked ‘G’ and ‘H’ [1]. Container ‘G’ held the transmitter and receiver, while container ‘H’ contained the power pack and a spares box, which included the aerial and headphones [1]. These cases featured an oil-seal for waterproofing in case of water landings and included webbing guides so they could be carried by men or mules [1].

Users and Deployment

The B2 was issued extensively to a variety of clandestine operators across occupied Europe, including:

• SOE Agents: Used by operatives infiltrating occupied territories to establish communication links [3].
• Resistance Movements: Provided to various local resistance groups to coordinate sabotage and intelligence gathering [1].
• Intelligence Agents: Specifically utilized by Norwegian intelligence agents and other special forces [1, 3].

Operational Context and Limitations

While the B2 provided a vital lifeline to London, the nature of clandestine radio work was inherently dangerous. Operators were subject to detection by enemy direction-finding (DF) equipment. Some early clandestine sets, such as those developed for the Secret Intelligence Service (SIS) at Little Horwood, had been discontinued due to a “telltale regenerative signal” that made them easy to locate [4]. The B2 represented an evolution in portable communications, though the risk of capture remained a constant threat for any wireless operator (W/T operator) in the field.

Surviving Examples

Several examples of the B2 radio are preserved in museums today, providing insight into the technical ingenuity of the SOE’s Radio Communication Department:

• Imperial War Museums: Holds a Type 3 MK II (B Mk II) set in its parachute drop cases [1].
• Musée de la Libération de Paris: Displays a British clandestine radio Type 3 MK.II (valise radio B2) [2].