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Rotor Enigma G
The G219 was part of a batch of at least 27 Enigma G
machines sold to the Dutch Navy in 1938 or 1939, just before the outbreak of
World War II.
It was supplied by N.V. voorheen Ruhaak & Co. 1
in The Hague — the Dutch representative of ChiMaAG and
Heimsoeth und Rinke (H&R). 2
The machine surfaced in 2022 without its original wooden transit case
and without a battery compartment, with a makeshift hole at the right side
for connection of an external power source.
It had probably been added by the Dutch Navy in the 1950s or 60s, as more devices
with this type of hole have been found in Dutch museums.
In 2025 an original wooden case for an Enigma G31 was found at an auction
in Germany, after which we were able to restore the machine to its
original condition, as shown on the right.
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The original three cipher rotors (I, II and III) and the reflector (UKW)
were all present and have matching serial numbers.
When the machine was found, it was partially dismantled and some of the screws
were missing from the outer case shell. The machine has meanwhile been
restored, and is fully operational again.
The restoration process is described in greater detail below.
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Translated: Public Limited Company, previously known as Ruhaak & Company.
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When the G31 was introduced in 1931, the name of the company was
Chiffriermaschinen AG (ChiMaAG). It was succeeded
in 1935 by Heimsoeth und Rinke (H&R). Since the G219
was supplied in 1938 or 1939, H&R was its manufacturer.
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The Dutch Navy purchased the first six counter machines
— Enigma model A28 —
in 1928 [1]. These machines had the same size as a
'regular' Enigma
and the rotors were of 'normal' size. In 1931, shortly after ChiMaAG
introduced the Enigma G31,
the Dutch Navy ordered one of the new smaller
machines, G128, probably for evaluation and for testing the compatibility
with the A28.
The image below shows a snippet from an
internal memorandum of H&R from 21 October 1935
in which an overview is given of the sales of commercial
machines between 1926 and 1935 [4].
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It was not until 1938 however, that more Enigma G
machines were ordered.
Divided over several orders, the Dutch Navy purchased at least 81
Enigma G machines between 1938 and 1940.
The last 6 machines
arrived on 9 May 1940,
one day before the German invasion of The Netherlands [5].
It is likely that these 6 machines (G298-G303 and possibly others as well)
were subsequently confiscated by the Germans when they occupied the country
a few days later.
It is known that G209 — part of a batch of 27 machines (G195-G221) that
had been delivered to the Dutch Navy in 1939 — was later used by the
German Abwehr on the Rot (red) nework [1].
During the war, the Dutch Navy operated from the UK, and the
Enigma G machines
were used aboard ships and submarines. After the sinking of two submarines —
O-13 in June 1940 and O-22 in November 1940 — they were no longer
used aboard submarines and were redistributed to other Dutch Naval units
operating in British waters [1]. It is likely that G219 was part of this.
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After the war, the Dutch Navy reused the surviving
Enigma G machines,
as becomes evident from the maintenance booklet of another
Enigma G of the Dutch Navy, with serial number G221 [3]. 1
The machines were used aboard ships for communication with the Dutch Antilles
and the Dutch East Indies.
According to this booklet, the machines were used until at
least 1955, after which they were replaced by modern equipment.
They were retained as spare units until the mid-1960s.
In the mid-1970s, the Dutch Navy ordered all remaining Enigma G
machines to be destroyed and discarded [2].
A few units escaped demolition and ended
up in the collections of the Dutch Naval Museum (MDH)
and the Dutch intelligence service BVD (later: AIVD).
It is unknown how and why the G219 survived,
but it is likely that it was given as a farewell present to a Naval officer
on his retirement. After his death, it eventually became part
of the Crypto Museum Collection (2022).
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The G219 was supplied to the Dutch Navy with the standard commerial
wiring of the rotors and the UKW. For a long time, it was assumed
that the Dutch Navy had rewired the wheels before using the machines
in an operational context, but evidence shows that this was not the case.
So far, all
Zählwerk Enigma machines (A28 and G31)
that were used by the Dutch Navy
had the standard commercial wiring when they surfaced in the post-war
era. This means that the Dutch Navy could have been an easy target
for US and British codebreakers,
both during and after WWII.
It also means that they might have been a target of the German codebreakers
during the war.
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| Wheel | ABCDEFGHIJKLMNOPQRSTUVWXYZ | Notch | Turnover | # |
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| ETW | QWERTZUIOASDFGHJKPYXCVBNML | |
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| I | LPGSZMHAEOQKVXRFYBUTNICJDW | ACDEHIJKMNOQSTWXY | SUVWZABCEFGIKLOPQ | 17 |
| II | SLVGBTFXJQOHEWIRZYAMKPCNDU | ABDGHIKLNOPSUVY | STVYZACDFGHKMNQ | 15 |
| III | CJGDPSHKTURAWZXFMYNQOBVLIE | CEFIMNPSUVZ | UWXAEFHKMNR | 11 |
| UKW | IMETCGFRAYSQBZXWLHKDVUPOJN | |
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Below is a series of photographs that were taken during and after the
restoration of the machine. Considering its age, the G219 is in a remarkably
good condition. The die-cast bottom panel is complete and has not been
'eaten' by moisture or chemicals. Apart from the missing battery compartment
and the lamp panel hold-down nuts, the chassis is complete and all wiring
is intact.
The image above shows the machine as seen from the left rear side. It gives
a clear view of the rotors and the stepping mechanism. Note the large
unused hole in the side of the chassis, just below the rotors. In the
Ch.15b version of the machine,
this hole held a 28 contact socket/switch which could be used
for the connection of a printing device. On the Ch.15a (shown here), this
socket/switch is omitted. For a detailed description of the socket/switch,
refer to our G111 page.
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15 October 2022
When we received the G219 in September 2022, it was in reasonable cosmetic
condition. The exterior was dusty but largely undamaged, the rotors were
present and, given its age, the lamp film was in reasonable condition.
Apparently the machine had been stored in a humid place for many years,
as there were signs of corrosion on the case shell and on the shiny metal parts.
After opening the top lid, it became clear that in the past the machine had
been taken apart. The battery compartment was missing and the wiring harness
to the lamp panel was rotated by 360°. There were no lamps present on the lamp
panel, which is usually a good thing. Over the years we've seen many lamp films
that had been damaged by installing the wrong type of lightbulbs.
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We first removed the three rotors and cleaned their exterior and contacts
thoroughly. We then traced the wiring of the rotors, to confirm that they
had not been rewired by the Dutch Navy. All rotors have the
original (commmercial) wiring.
Next, we cleaned the contacts of the entry disc (ETW) and the reflector
(UKW). We also traced the wiring of the latter and confirmed that – like
the rotors – it had not been rewired. In the next step the levers, pawls,
pinions and cogwheels of the stepping mechanism were cleaned and oiled,
after which the mechanism could be tested.
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This was done by typing on the keyboard and observing the advancement of the
three rotors and the UKW. Everthing worked as expected. Although the
original crank was missing, we checked whether it was possible to rewind the
mechanism by one or more steps, but this didn't work.
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26 lightbulbs of the correct specifications
were installed on the lamp panel, and an external PSU was connected to
the machine, so that a first test could be conducted.
Only a few lamps lit up, indicating problems with the keyboard switches.
The keyboard was then dismounted from the chassis,
so that the individual switches could be inspected.
Some of the switches were misaligned and some of the
rubber pushers at the end of a key shaft were
missing or worn out. They were subsequently
replaced by new rubber pushers
that are fixated with a tiny drop of superglue.
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The rubber pushers operate the large seesaw
at the bottom of the chassis, which in turn actuates the
stepping mechanism at the rear. After mounting the keyboard back in place,
the rubber pads at the front corners of the seesaw were adjusted for
proper operation of all keys and switches.
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The sloped lamp panel is hinged and is held in place by
two screws located at the front edges of the lid.
These screws mate with a treaded brass block that is fitted to a flange on
the chassis. On the G219 these
threaded blocks were missing, as a result of which
the lid was not held in place.
It is unknown why these blocks had been removed.
Suitable replacements were made from a solid piece of brass, and mounted in
place as shown in the image on the right. The hole at the centre has 4 mm thread. The top lid is now properly
retained when the machine is moved around.
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In the next step, the wiring for connection of a battery was restored.
Two era-correct wires were added:
one was connected to the lamp panel (visible
in the image above) and the other one was connected to the common rail of the
nearest switch below the keyboard.
For the time being, the two wires will be fed out through the
makeshift hole
at the right side of the machine. They will later be connected to a
replacement battery compartment as and when it becomes available.
Update 30 November 2025
Earlier this year we found an original wooden transport case for the
Enigma G31 at an auction in Germany. When it arrived, we noticed that
the four holes – needed for fitting the Enigma G31 – were missing from
the bottom.
This means that it was a new-old-stock (NOS) replacement unit.
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Unfortunately, it also means that all of the other parts, such as the
crank, the spare lamps holder, the enigma shield and the manufacturer's
name late were also missing and had to be sourced.
Luckily, the hinges, the lock and the lid retaining brackets were present,
although the rightmost one was bended. The case was first cleaned and
then oiled, to preserve its texture and to protect it against drying out.
The retaining bracket was repaired and four large recessed holes
were drilled into the bottom, so that the G219 could be mounted in place
with contemporary bolts.
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Wooden case missing - Battery compartment missing
Crank missing All lightbulbs missing Mechanism misadjusted Rubber pushers in keyboard worn out or missing Crank won't turn mechanism back - Celluloid windows above rotors missing
Lamp panel hold-down nuts missing Several screws missing from the outer case Lamp film badly damaged Holder for spare light bulbs missing Decals missing
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Device Rotor-based cipher machine Purpose Naval message encryption Brand Enigma Type G Model G31 Designator Ch.15a Serial number G219 Manufacturer H&R Country Germany Year 1939 (est.) Customer Dutch Navy Rotors 3 (I, II and III), S/N G219 Turnovers 17, 15, 11 Reflector Settable and driven, S/N G219 Wiring Standard commercial wiring Stepping Irregular (cogwheel gear) Plugboard No Extras Crank, green sunlight filter (option) Dimensions (HWD) 160 × 250 × 275 mm Opened (HWD) 345 × 250 × 410 mm Weight 9.4 kg (7.2 kg without the wooden case)
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The serial number of this machine (G219) was found at the following locations:
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Wooden transit case Decals (Enigma shield and H&R address plate) Spare lamp holder - Battery compartment
Crank - Green filter
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Zählwerk machines sold to the Netherlands
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The following Zählwerk machines were sold to the Netherlands
and were used by the Dutch Navy. Note that the first 6 machines
were the older model A28, which is interoprable with model G31.
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Of this batch (G195-G221), G209 was delivered to the Dutch Navy, but was later
used by the German Abwehr on the Rot (red) network.
The machine had been captured after the German invasion of the Netherlands.
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This batch of 6 machines (G298-G303) was delivered to the Netherlands on 9 May 1940,
and was confiscated by the Germans after the German invasion of the
Netherlands on 10 May 1940.
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Surviving Dutch Naval machines
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Document kindly provided by Frode Weierud.
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© Crypto Museum. Created: Sunday 18 September 2022. Last changed: Wednesday, 10 December 2025 - 21:29 CET.
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