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Rheinmetall

Rheinmetall D IIa
   Video
Rheinmetall SASL IIc
   Video
History
Models
Manuals
Promotional material
Advertisements and articles
Patents
Links

Rheinmetall D IIa

The Rheinmetall calculator looks like it has a fairly standard design similar to the many other stepped drum calculators such as the Unitas/TIM or Archimedes. This version has an 8-column keyboard with input register display, and a carriage containing an 8-digit counter and 16-digit register.

It has some nice unique features. The carriage can slide right or left without needing to be lifted up. It can be shifted by turning the large knob at the front-left of the machine, not unlike the Monroe calculator. There is no separate lever for selecting whether the counter is incremented or decremented. The counter is always incremented when you turn the crank. You can however make a correction by turning the crank while holding down the C button, which undoes the previous addition or subtraction.

This particular model has automatic division. After setting up the division, you merely have to turn the crank repeatedly and everything happens automatically. When the register underflows during the division the next turn of the crank engages the correction button, the turn after that undoes the last subtraction, the next turn shifts the carriage to the left, and then the long division continues at the next position.

The mechanism uses stepped drums. To allow the digits to be fairly close together, each stepped drum is shared by two adjacent digits. There is a differential that can either transfer the motion of the crank to the calculation mechanism, or to the mechanism that controls the other aspects of automatic division such as the carriage shift.

It has serial number 7,843, which can be found in several places on the machine. The Rheinmetall machines were numbered consecutively, and this number dates my machine to about 1931. Later versions replaced the two selection levers with buttons.

Rheinmetall D IIa video

Rheinmetall SASL IIc

The SASL model was the most advanced calculator that Rheinmetall produced. This "Superautomat" has automatic division, fully automatic multiplication, and an extra register that can be used as a totaliser or a memory register. This version has a 9-column keyboard with input register display, and a carriage containing an 8-digit counter, two 17-digit registers, and a 3-digit item counter.

The main register, the extra register, and the counter register each have a clearing lever to their right. Clearing the main register usually also clears the counter, but that can be disabled by a lever underneath the carriage. The large lever on the right adds the main register to (or subtracts it from) the extra register, and also clears that main register and increments the item counter. Whether it adds or subtracts is selected by a switch on the left of the register. The knob on the back right clears the item counter. The lever on the left allows the carriage to be quickly moved any amount. Lastly, between the clearing levers is a small switch that activates a transfer from the extra register back to the main register, which is then executed when the extra register is cleared.

For the automatic multiplication there is a numerical keypad on the right side in which to enter the multiplier. The entered number is visible in a small window at the front of the machine. The other factor is entered in the main keyboard. Pressing the multiplication button then starts the process that multiplies those two numbers and adds the result to the main register. There is a lever switch on the right with which you can control whether the main register is automatically tranferred to the extra register before the multiplication begins.

There is a tabulation mechanism too. The red button on the right hand side sets the current position of the carriage as the home position. This is used in automatic division. To enter the dividend (numerator) of a division, enter it on the keyboard and press the division key on the right. The carriage will be shifted to the selected home position, and the dividend set in the main register. Enter the divisor, and then press the division key on the left to start the calculation. The small metal lever on the left will stop the division after the current digit, and to abort a division by zero there is a small knob on the left near the carriage which will stop calculation of the current digit by triggering an underflow.

This machine has an electric motor. Behind a small panel at the back is a set of jumpers that can be arranged to select the type of electricity (AC or DC) and the voltage of the power supply.

It has serial number 68,472, which can be found on the back of the machine. The Rheinmetall machines were numbered consecutively, and this number dates it to about 1939. The carriage has the serial number 56,666 on some of its internal parts.

Rheinmetall SASL IIc video

History

Rheinmetall has a long and complicated history. The company "Rheinische Metallwaren- und Maschinenfabrik Actiengesellschaft" was founded in Düsseldorf on April 13, 1889 by Heinrich Ehrhardt. He had a state contract to make ammunition, but the company also made other metal products, such as pipes, using a patented process that was also symbolised by the company logo. In 1901 they acquired an arms manufacturing plant in Sömmerda. This had been founded in 1827 by Nikolaus von Dreyse, and was where Dreyse pistols and guns were made, and after the takeover Rheinmetall continued developing and making them. They were one of Germany's largest arms manufacturers through the first world war.

After the war the manufacture of arms was no longer possible. The Sömmerda plant used its precision engineering expertise to specialise in office equipment such as typewriters, bookkeeping machines, and calculators, while the larger Düsseldorf plant made larger steel items such as agricultural equipment. Richard Berk, who had worked at Ludwig Spitz was hired to design calculators. The first machines were made in 1922, but in the first four years calculator production remained very low with only about 600 machines made.

In 1926 Berk was let go, and August Kottmann replaced him. Kottmann had risen through the ranks, and had designed a way for the calculators to do automatic division and be driven by electric motor, and was now able to implement that design. The hand-driven calculators also were given the automatic division mechanism. In 1930 their first fully automatic calculators "Superautomat" were released. Versions of these machines were in production until the 1960s. Adding-listing machines were also released in 1933, and Kottman also designed a very successful invoicing machine, a combination of a typewriter and calculator, released in 1932.

In 1933 Rheinmetall acquired August Borsig Maschinenbau AG, a large manufacturer of locomotives and in 1936 when the merger was fully completed the name changed to Rheinmetall-Borsig AG. The headquarters was moved from Düsseldorf to Berlin, and by now the company was also making arms again for the German Ministry of War. During the second world war the company was nationalised and fully occupied with making weapons, ammunition and other military equipment, and very few office machines were produced. The large factories in Berlin and Düsseldorf were heavily bombed, but the smaller Sömmerda plant survived relatively intact.

After the war and the division of Germany, Rheinmetall split apart. The Sömmerda plant fell under Soviet occupation, and was soon ordered to return to office machine production. The company became an SAG, a Sowjetische Aktiengesellschaft, in 1946. Curt Herzstark worked there for about a year to finalise the development of his Curta design, but decided to flee the Soviet regime and go to Liechtenstein to put his machine into production. In what became West Germany the Rheinmetall plants in Berlin and Düsseldorf were rebuilt, but obviously were not allowed to make arms. The fact that there were essentially two independent companies with the same name and logo became problematic, because the Sömmerda calculators and adding machines were exported to the West through Berlin, and competed with Rheinmetall Düsseldorf, which also made some adding machines in the late 1950s.

In Sömmerda the calculators continued to be developed, especially because of the Western export market. In 1952 the company was renamed to VEB Mechanik Büromaschinenwerk Rheinmetall Sömmerda. In the early 1960s the company name was shortened to VEB Büromaschinenwerk Sömmerda and the Rheinmetall brand name was dropped in favour of Soemtron. They began developing electronic invoicing machines, eventually fully transitioning into electronics, and became part of Robotron in 1978. Rheinmetall in West Germany returned to manufacturing arms, and today is a well known for making various armoured vehicles, gun turrets and tank guns, though they also have an automotive division that makes car parts.

Models

The first hand-driven machines came with various keyboard and register sizes. They were given model numbers I or II, depending on register size, followed by a letter denoting the keyboard input size. They were first made in 1922, but production volume was very low. Only about 600 were made in the first 4 years, after which new management increased production dramatically.

When variants and other types of calculator were made, the size designation was prefixed by one or more letters. When automatic division was introduced, the letter D was added, and later the simpler calculators without automatic division were given the letter K. Electrically driven ones got the letters ED (they had automatic division) or ER (with multiplier keys). The fully automatic machines (with automatic multiplication) were named Super Automat and were given the model letters SA. Further letters were used to denote additional properties or functions of the machine. Most of these variants were introduced in the first half of the 1930s. It should be noted that in certain territories these machines were sold under other brand names. In the US the name Mathematon was used, in the UK they were called Muldivo, and in France Metall.

The model letters are a little confusing, as the dividing line between what counts as a base model and what is extra functionality is vague. Not every letter combination is valid, so I have made a table of all calculator models for which I have found online evidence for in photos, ads or brochures.

Manuals

Anweisung zum Gebrauch der Rheinmetall Rechen-Maschinen     (PDF, 28.9 MB or archive.org)
Rheinmetall-Borsig Aktiengesellschaft
1936-1940
No. 675
100 page book
148mm × 209mm × 5mm

This is the German instruction book for all the Rheinmetall calculator models that were available in the late 1930s, namely the manual models with or without automatic division, and the electrically driven models KE, KEW, KES, KEWS, EDWL, SAL, and SASL. The last pages show the other products that the Sömmerda factory produced, such as typewriters, and adding machines.

Anweisung zum Gebrauch der Rheinmetall Rechen-Maschinen mit elektrischem Antrieb     (PDF, 16.6 MB or archive.org)
Rheinmetall-Borsig Aktiengesellschaft Werk Sömmerda (Thür.)
1940-1945
31 page booklet
149mm × 209mm × 2mm

This is the German instruction book for all the Rheinmetall calculator models SAL IIc and SALS IIc. There is no copyright date, but it is likely from before the Soviet occupation, and after the manual above.

Anweisung zum Gebrauch der Rheinmetall Rechen-Maschinen mit Handbetrieb und selbstättiger Division     (PDF, 16.0 MB or archive.org)
Rheinmetall-Borsig Aktiengesellschaft Werk Sömmerda (Thür.)
1952-1957
32 page booklet
149mm × 209mm × 2mm

This is the German instruction book for the Rheinmetall calculator model D IIc, a hand-driven calculator with automatic division. There is no copyright date, but the company name used indicates it is from after 1952.

Anweisung zum Gebrauch der Rheinmetall Rechen-Maschinen mit elektrischem Antrieb     (PDF, 14.2 MB or archive.org)
Rheinmetall-Borsig Aktiengesellschaft Werk Sömmerda (Thür.)
1952-1957
32 page booklet
149mm × 209mm × 2mm

This is the German instruction book for the Rheinmetall calculator model KEW IIc, an electrically driven calculator with electric carriage shifting and stop-division. There is no copyright date,but the company name used indicates it is from after 1952.

Gebrauchsanweisung für die Modelle Simplex und Duplex     (PDF, 8.24 MB or archive.org)
Rheinmetall Aktiengesellschaft Düsseldorf
1955-1956
17 page stapled booklet
211mm × 146mm × 2mm

This is the manual for the Simplex and Duplex adding-listing machines. These were only briefly in production, from 1955 to 1956. Note that the rear cover of the booklet is missing.

Rheinmetall Rechenmaschinen Ersatzteile und Ersatzpreisliste
Rheinmetall-Borsig Aktiengesellschaft Werk Sömmerda
1940?
113 page book
211mm × 296mm × xmm

This is a book showing the replacement parts of the calculators, with a price list. The book has no copyright date or printer's code, but the company name used means it was probably printed between 1936 and 1945.

Rheinmetall Rechenmaschinen Ersatzteile
VEB Mechanik Büromaschinenwerk Rheinmetall Sömmerda
1953
83 page book
209mm × 296mm × 5mm

This is another replacements parts list for the calculators, with just the parts numbers and no pricing. It has no copyright year, but the printing code dates it to 1953.

Rheinmetall Addiermaschinen Ersatzteile
VEB Mechanik Büromaschinenwerk Rheinmetall Sömmerda
1959
47 page book
210mm × 296mm × 3mm

This is a replacements parts list for the adding machines, with just the parts numbers and no pricing. It has no copyright year, but the printing code dates it to 1959.

Leitfaden für Addiermaschinen-Mechaniker
VEB Mechanik Büromaschinenwerk Rheinmetall Sömmerda
1959
50 page book
209mm × 295mm × 4mm

This is a guidebook to the adding machines, intended for the mechanics who repair and service these machines. It explains the various parts and mechanisms of these machines. It has no copyright year, but the printing code dates it to 1959.

Rechenmaschinen Ersatzteile
VEB Büromaschinenwerk Sömmerda
1961
83 page book
208mm × 296mm × 5mm

This is a replacements parts list for the calculators, with just the parts numbers and no pricing. It has no copyright year, but the printing code dates it to 1961.

Ersatzteile für Soemtron Addiermaschinen
VEB Büromaschinenwerk Sömmerda
1963
93 page book
211mm × 297mm × 5mm

This is a replacements parts list for the adding machines, with just the parts numbers and no pricing. It has no copyright year, but the printing code dates it to 1963.

Technische Instruktion Soemtron Rechenmaschinen
VEB Büromaschinenwerk Sömmerda
1964?
50 page spiralbound book
297mm × 208mm × 4mm

This is a guidebook to the calculators, intended for the mechanics who repair and service these machines. It explains the various parts and mechanisms of these machines. It has no copyright year, but is probably from about 1964.

Technische Instruktion Soemtron Rechenmaschinen SARK
VEB Büromaschinenwerk Sömmerda
1964
24 page stapled booklet
296mm × 209mm × 2mm

This is a guidebook to the SARK calculator, intended for the mechanics who repair and service these machines. It supplements the guide above, explaining the mechanisms that are specific to the SARK model. It has no copyright year, but its printing code suggests it is probably from 1964.

Promotional material

Tages-Merkbuch für 1940
Rheinmetall-Borsig Aktiengesellschaft Werk Sömmerda/Thür.
Eilers Werke, Bielefeld
Leather bound diary notebook for 1940
1939
84mm × 115mm × 8mm

This leatherbound pocket diary was made by Eilers Werke for Rheinmetall. At the front there are some pictures of Rheinmetall's products (typewriters, calculators, adding machines). At the back are many pages of useful information - important dates, postage rates, a map of motorways, European Lufthansa flights, conversions for currencies weights and measures, population sizes of cities and countries, and traffic signs.
It is fascinating to see which dates were considered important enough to mark on the calendar. These included birthdays of prominent Nazis (Hitler, Hess, Göring, Goebbels, Alfred Rosenberg, Horst Wessel, Dietrich Eckart) and German icons (Beethoven, Wagner, Dürer, Goethe, Schiller, Luther, Frederick the Great), and various dates related to the rise of the Germany and the party (e.g. Versailles treaty, Annexation of Austria, Nuremberg Laws). The map of Germany's motorways is also interesting as very many were being planned and not yet built, showing their grand ambitions.

Rheinmetall AES Flyer
Rheinmetall-Borsig
1946-1949?
2-sided flyer
208mm × 296mm

This is a flyer for the Rheinmetall AES adding machine.

Rheinmetall FMR Flyer
Rheinmetall-Borsig
1946-1949?
2-sided flyer
208mm × 296mm

This is a flyer for the Rheinmetall FM and FMR bookkeeping machine. It combines a typewriter with an adding machine.

Rheinmetall KELR Flyer
Rheinmetall-Borsig
1946-1949?
2-sided flyer
208mm × 296mm

This is a flyer for the Rheinmetall KELR calculator. It is electrically driven, and has automatic division and back transfer.

Rheinmetall SAL Flyer
Rheinmetall-Borsig
1946-1949?
2-sided flyer
208mm × 296mm

This is a flyer for the Rheinmetall SAL calculator. It is an electrically driven fully automatic calculator.

Rheinmetall SASL Flyer
Rheinmetall-Borsig
1946-1949?
2-sided flyer
208mm × 296mm

This is a flyer for the Rheinmetall SASL calculator. It is an electrically driven fully automatic calculator with an extra register.

Rheinmetall Leaflet
Rheinmetall-Borsig
1953
5-part folded leaflet
Folded 106mm × 150mm, unfolded 529mm × 150mm

This is a leaflet featuring the Rheinmetall AHS, AES, and AES We/33 adding machines, as well as the D, KEW, EL, KELR, an SAR calculators.

Advertisements and articles

Below are some of the advertisements that I have found by Rheinmetall (and Borsig), not only for calculators, and a couple of articles.

Ernst Martin's 1925 book Die Rechenmachinen has an entry for Rheinmetall, but this was before the automatic division was introduced.

The 1930 book Organisations-Lexikon by Walter le Coutre and Walter Thoms has an entry for Rheinmetall, which includes mention of the models D, ED, and AER.

The newspaper articles that mention Rheinmetall are all about its role as arms manufacturer before and during the second world war. Also included here is a photo from Life magazine of Hitler's visit to the factory.

Patents

Here is a selection of the many calculator patents. I have excluded patents for adding machines and bookkeeping machines.

Links

• Rechnerlexikon has a page for the Rheinmetall, the model D, and many others.
• Rechenmaschinen-Illustrated has a page with Rheinmetall models.
• Christian Hamann has a Rheinmetall Mathematon which seems to be a rebadged KE.
• Rechenautomat.de by Harald Schmid has a lot of information about Rheinmetall and its calculators.
• Wim Hasselo has several Rheinmetall calculators in his collection.

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