M4 Enigma machine for German naval use.
A German Naval 4-rotor Enigma enciphering machine (M4), made by Heimsoeth and Rinke, Berlin, 1943.
Operational M4 Enigma machine, for exclusive German Naval use, serial number M5521, and aluminum rotors I, III , VII, and Beta rotor and reflector, all with matching numbers M5521, lamp-board display, standard QWERTY keyboard of 26 keys, white on black, battery switch, ebonite steckerbrett (plugboard), with 5 cables, the case lid with 4 spare cables, a colored glare screen, pasted typed instructions in German (in facsimile), and a set of 10 spare bulbs, inner front panel with ink stamp "Klappe schliessen." The keyboard and rotors set in a black crackle finish metal case. Slight oxidation of metal brackets on front panel, the lock located below the external power socket is a replica. Facsimile manual included. Mounted in an oak outer case with metal lock and carrying handle, 13¾ x 11 x 6¼ inches.
WITH: German Naval Telegraph Key, gray metal, 7½ x 3 x 2 inches.
A RARE, FULLY OPERATIONAL, M4 KREIGSMARINE ENIGMA MACHINE, 1943 VINTAGE, ALL ROTORS MATCHING, ONE OF THE RAREST OF ALL THE ENIGMA MACHINES, IN FINE CONDITION. The M4 was used by Admiral Doenitz U-boat forces and not the entire German navy; it would have been on U-boats, U-boat support ships, and shore installations supporting U-boat operations. This example believed to have been from a U-boat base on shore rather than from a U-Boat due to its fine condition and that it was purchased by the Enigma Museum from a family in Norway. Admiral Doenitz ordered the M4 in late 1941, as he suspected (rightly) that the security of the Naval 3 rotor machine had been compromised with the capture of U-570 in August 1941. He ordered it specifically for the use of the growing U-Boat fleet, which Germany required to take the war to the Allies in the Atlantic. For this campaign, the Naval High Command needed to know, on a daily basis, the positions of the U-Boats, and the vessels needed to receive orders as to where they were to go, and all this information had to be secure.
In terms of the numbers of M4 machines now extent, various estimates have been made. After February 1942 when the M4 became operational, perhaps some 500 U-Boats were constructed, and as the machines were also replaced in the earlier submarines, it is likely that from 1942, 700 to 800 submarines had been equipped, most with two M4s each (they needed the two machines with the two settings for when the changeover of coding occurred at midnight). This would make a total production of probably just over 1600 machines in the period 1942-45. Since over 80% of all U-boats were sunk in World War II, the survival rate is particularly low, and of course Captains had strict orders to smash their machines when captured. We know the Allies, in late 1945 and early 1946, assembled the majority of the 'Allied captured' U-Boats in Lisahally, Northern Ireland, and in Loch Ryan, Scotland, some 154 vessels in all. 121 of these submarines were stripped, and scuttled in deep water in short time. The Danish, Dutch, and French also had a few U-boats, and the Danish sold two of theirs to the Israelis, soon after the war. The Americans gathered the U-boats which surrendered (in mid-1945) along the eastern seaboard and any machines captured from those submariness would have gone to Annapolis Naval Base.
The numbers of surviving M4s both from surviving submarines and from the shore bases along the Atlantic coasts (given that at least 70% of commanders should have destroyed their machines before surrendering) CAN BE ESTIMATED AT A MAXIMUM OF PERHAPS 120 EXAMPLES EXTANT, mostly now languishing in Government storerooms around the world. The M4s, all came directly into the hands of the Allied Naval Forces after the war, whether it be in Britain, France, Australia, US, Denmark or Holland, and were not allowed to slip out of military control. The US/British forces rounded up as many M3 (army) machines as they could from the surrendering German Forces and many of them were sold back to the Eastern Bloc on a clandestine basis, which allowed the Allies to listen in to military orders throughout the Cold War. Of the surviving M4s it is suspected that for every 10 M3s there might be one M4. Analysis of the 24 Museums around the world that exhibit Enigma machines, show a total of about 50 Enigma machines on display, of which 7 are M4s, taken from captured U-Boats. The remainder are M3s, with the occasional late war M6 or M7.
The story of the German Enigma machine starts in WWI, when the British were intercepting and reading all the German Navy signals, which gave them a significant advantage at sea throughout the War. The Enigma was patented by Arthur Scherbius in 1918, but it was not until 1926 that the code-breaking of the WWI naval signals by the Western Allies was discovered by the German High Command. The Enigma was then chosen as the German enciphering machine for the military. The early enigmas had 3 interchangeable rotors, which scrambled plain-text messages to produce a cipher text message, which was then sent via Morse code to a receiver machine with the same settings. The breaking of the Enigma codes by the Allies was one of the most important breakthroughs of World War II, and is regarded as shortening the war by at least 2 years. It started when Polish cryptographers passed on to the British their research on the codes in 1937, and in 1939 the French captured a German submarine with a codebook, and other information was retrieved by a spy in Germany. The outcome of this was that the 3 rotor code was broken early on in the war by the code breakers at Bletchley Park set up in 1937, who included Turing, Foss, Knox and many others. When the M4 came into use on February 1, 1942 it took over 9 months for Bletchley to crack that code, assisted by the capture of codebooks from U-599 in October 1942. Various other devices were added to the M4 from 1944 to complicate the messages, notably a UKW-D, a field rewireable refractor to replace the reflector and extra wheel. This example does not have the locking key but is unlocked.
IT IS ONE OF THE RAREST OF ALL ENIGMA MACHINES.