The Rebirth of UKW A

Hello all,

I suppose you have had enough of my crypto quiz by now. Actually, I had
expected more outlandish answers than I got. You all seem to have kept your
imagination in check and your feet firmly on the ground. Matt came closest
to the correct answer. UKW A was indeed rewired to UKW C, another reflector
that few of us have come across.

On 24 September 1936 Chiffriermaschinen Gesellschaft Heimsoeth und Rinke
received an Enigma related order from Oberkommando des Heeres Waffenamt, Nr.
12232/36 (Heer). The exact content of this order is not known but another
document refers to position 2 of the order. Position 2 concerns the rewiring
of 6397 former UKW A reflectors to UKW C in accordance with schematic
diagram Ch 11 Tz 217. The 6397 reflectors consisted of 5936 Army Enigma
machines, until Nr. A 6844, and 461 Navy machines, until Nr. M 961.

On 1 March 1938 Chiffriermaschinen Gesellschaft Heimsoeth und Rinke seems to
make an overview of the situation concerning the rewiring of UKW A. Since
the original order of 24.9.1936 the situation have been complicated by the
fact that many more Enigma machines have been delivered with UKW A. H & R
states that until the letter from OKH, Nr. 1879/37 Wa B 7/VI b 3, on 22
October 1937 another 656 Army machines have been delivered, until Nr. A
7500, and a further 150 Navy machines, until Nr. M 1111. The Navy also have
two printing Enigma machines, M 201 and M 202, that are equipped with UKW A.

This should bring the number of UKW A to be rewired to 6397 + 808 = 7205.
However, for some reason the Naval machine M 611 no longer exists, such that
the total number is 7204. Furthermore, H & R says that a large part of the
612 UKW A reflectors that belong the Navy already have been rewired and that
this work will be paid for by the Navy.

One would expect the story to end here but on 31 August 1938 we find yet
another letter from H & R that claims there still are confusion about the
exact number of UKW A to be rewired. The number of UKW A belonging to the
Army should be 5936 + 656 reflectors delivered after the original order of
24.9.1936. The exact breakdown is the following:
	  67 pcs.		A  868 - A  934
	 277 pcs.		A  936 - A 1212
	6248 pcs.		A 1253 - A 7500
     -----------------------------------
	6592 pcs.

As we can see A 935 is missing from this list and there is a large gap of 40
machines missing, A 1213 to A 1252. A 935 might have been lost or destroyed,
but the other 40 machines seem to have been delivered to another customer.
The added confusion comes from the fact that OKH earlier have told H & R
that in reality they have received 6705 Enigma machines equipped with UKW A.

	3248	Heer	(Army)
	3335	Luft	(Air Force)
	  66	SS	(Schutzstaffel)
	  47	RP	(Reichspost ??)
	   9	Hansa	(??)
	---------------------------
	6705

As 3248 + 3335 + 9 = 6592 it might look like the 66 SS and 47 RP machines
were not part of the original count of machines controlled by OKH. On top of
this it now appears that Heereswaffenamt has decided that they only want to
pay for the 3248 reflectors that really belong to them. OKH wants to annul
position 2 of the original order and instead issue a new order for the
rewiring of only the 3248 Army reflectors. Clearly H & R are not at pleased
by the turn of the events and claims that their original unit price of 5.45
RM (Reichsmark) for the rewiring of UKW A was a fixed price based on the
original number of 6397 reflectors.

Who in the end paid for what we do not know but at least the rewiring has
now finally started. H & R informs OKH that 600 UKW A has already been
rewired and returned to the Army depot (Heeres-Zeugamt) at Schöneberg and
another 300 reflectors are undergoing modifications. Furthermore, the Air
Force has repeatedly asked H & R to fetch their reflectors at the Air Force
depot (Luftnachrichten-Zeugamt) at Teltow. However, H & R has delayed this
due to the uncertainties about the exact numbers to be rewired and confusion
about the payments. H & R now asks about immediate clarifications as they
have been informed that all UKW A must be rewired to UKW C before 31 March
1939.

None of the documents explains why it was decided to withdraw UKW A, nor why
it was decided to rewired it to UKW C. However, knowing that the price of a
single Enigma wheel was 54.50 RM in 1930 it seems that the rewiring was
largely governed by economical considerations. From Nr. A 7501 all Army
Enigma machines were automatically delivered with UKW C, however it is not
known if this remained the case for machines produced after 1940.

I hope you have found some of this of interest. There is a lot more to the
Enigma story than this.

Frode Weierud