СДУ-138

СДУ-138

The SDU-138 is an electromechanical adding machine manufactured in 1956 by the Ryazan Factory of Calculating and Analytical Machines in Ryazan, USSR.

The machine is equipped with a 220-volt electric motor (type ЭД-1). It features a wide carriage designed for preparing large spreadsheets and balance sheets for accounting purposes. The SDU-138 was a clone of the German Astra L Breitwagen (wide carriage), which was originally manufactured in the mid-1930s.

A short "filler" story in the 1951 issue of "Büromarkt" magazine (p. 828) discusses the new factory being built in Ryazan. The detail about the factory potentially using dismantled German equipment is a significant historical note, as many Soviet factories were outfitted with "reparations" from East Germany after WWII. It states the following:
As reported by AHD, production recently started at the calculating machine plant built in Ryazan in recent years. In addition to the mass production of the SDU-110 calculating machine, development work is underway on a new high-performance model, the SDU-138. By the end of the year, the plant intends to deliver several thousand calculating machines to the Soviet financial administration. Previously, the Soviet Union imported complex calculating and accounting machines from Germany and the USA, as there was a lack of local specialists. It is alleged that the new calculating machine plant in Ryazan utilizes German plant equipment dismantled in the Eastern Zone (East Germany)."
Source: Rechnerlexikon

The condition of this specific machine is relatively good considering its age. It is complete, except for the rubber front feet and the missing printing module cover. As pictured, it remains uncleaned and unrestored, exactly as it was when acquired in 2024. The history of this machine traces back to the Latvian town of Rūjiena, where it was discovered in the early 1990s.

Weight: 18,8 kg.
Dimensions: 23/46 x 50 x 22/32 cm.

Year of manufacture: 1956

Serial №: 046245 / 3263

Manufacturer:
	Рязанский ордена Красной звезды завод счётно-аналитических машин (Рязанский завод САМ) Ryazan Factory of Calculating and Analytical Machines of The Order of the Red Star Ryazan, USSR