A German fire control calculator from 1935, manufactured by Zeiss Jena. Finland purchased the calculators in 1943 to serve as backup calculators in heavy RMB batteries. After the war, the equipment was modernised in Finland in 1953. After the modernisation, the equipment was used in conjunction with RMB cannons until 1969, when both the calculators and cannons were phased out.

SPECIFICATIONS:

• lateral advance: 36 degrees approx.
• vertical advance: 18.75 degrees
• target speed: 0–150 m/s
• (up to 300 m/s with the modernised version)
• weight: 156 kg
• weight of base: 24 kg

References: Vehviläinen Raimo et al., Itsenäisen Suomen Ilmatorjuntatykit 1917–2000, Sotamuseo, Helsinki 2005; Palmu Pentti, Yön yli päivään – Suomen ilmatorjunnan vaiheita 1925–1990, Ilmatorjuntaupseeriyhdistys Ry, Helsinki 1989; Ilmatorjuntajoukot 1925–1960, Ilmatorjuntaupseeriyhdistys Ry, Helsinki 1963