[Nick Beale]

I'm interested in what you have to say about TypeX. What's your source for it being a licensed ENIGMA and where did you see about the Germans acquiring some?

I can, with some hard-won authority, take issue with the article that Ed provided the link to. I've been working on Luftwaffe Ultra messages since 1990 and I've only done from mid-January 1944 to the end of the war so far! I think the guy meant that Kriegsmarine messages are much more numerous, which is understandable for several reasons: ships at sea carried ENIGMA machines, aircraft didn't that I know of (especially since operating the thing was a two-man job: one to encode and one to transcribe).

U-boats in packs had to signal frequently, it's how the system worked. If aircraft in flight signalled it was by R/T or W/T and using a code table (or in clear). Luftwaffe Ultra therefore comes from ground establishments, many of which had access to landlines and didn't need to transmit over the air for much of the time. In my own experience, some units you get next to nothing from, others are talking most days.

Things really catch fire when there's intense ground action, normal comms are disrupted, units are force to relocate etc. France after 6 June 1944 is a case in point. Conversely, when things settle down (Italy after about September 1944, when units were getting re-established on more permanent bases) the volume of traffic falls. All through 1944-45 there is masses from Yugoslavia, Greece and Albania - a combination of difficult geography, poor comnications infrastructure and partisans would account for that. I guess.

Yes, there is Luftwaffe ULTRA - and Heer too (including lengthy equipment, personnel and manpower returns for divisions, corps and armies)