Für Harald B. von Janwillem Bech
The Dräger Gegenlunge
Counterlung to Swimdive Device
a translation by Joe Bauer
on Hans and Lotte Hass in issue 9 of Historical Diver prompted several
questions regarding the construction and development of the “gegenlunge”
(counterlung) build by the German firm Dräger of Lübeck several decades ago.
Michael Jung, Historical Diver’s German Contributing Editor and author of
the Hass article, now describes the development from “counterlung” to
swimdive device in this short pictorial review
“gegenlunge” or counterlung was so named because the air passes back and
forth the divers lungs to the unit’s air bas as the diver breathes. Dräger’s
Gegenlunge of 1929 (upper left) and the “Badetauchretter”
(“Bathing-dive-rescue device”) of 1915(upper right) unlocked new
applications for oxygen rebreathers. Since the device was very light, it was
possible to use it for small underwater jobs such as the search and recovery
of drowning victims. The diver was held down by heavy weights slung around
his hips and neck, and he walked about on the sea floor in leather sandals.
devices are shown being tested in Dräger’s dive basin, lower left, and the
Bathing-dive-rescue device is seen in use (lower right).
review of patents granted to Drägerwerk provides a guide to the evolution of
the swimdive device from the original Gegenlunge. The origin of the unit is
foun_d in Dräger's 1912 U-Boat escape apparatus. The company first
developed the Bathing-dive-rescue device in 1915 and later introduced the
Gegenlunge in 1928. It is recognizable by the ring-shaped breathing bag
encircling the neck. The circular back was initially to facilitate an
upright posture while walking on the seabed as well as to assure safe
flotation at the surface when used as a rescue device. The Gegenlunge was
patented on Dec 21, 1928 (German Pat. No. 529 399)
In 1942 and
1943, there followed several patents which converted the Gegenlunge to a
swimdive device, mainly by changing the air bag and equipping the diver with
swim fins. Initially, the patent of June 16, 1942 (German Pat. No. 857 753)
relocated the buoyant breathing bag onto the diver’s bag, to facilitate a
proper swimming position. The apparatus could, as desired, be used for
swimdiving or, if special weights were added, to walk on the seabed.
This is the
device which was used by Hans Hass during his Aegean expedition in the
summer of 1942. The standard unit came with a normal automatic oxygen valve
which supplied the diver with a steady volume of fresh oxygen. Hans modified
his unit with a special demand-button ("Zuschuss knopf') which allowed for
an increase in oxygen. If he over exerted himself or had to perform an
emergency ascent, he could push this button and additional oxygen would flow
into the breathing bag.
followed a patent for a "swimdive device with self-contained air supply" on
May 28, 1943 (German Pat. No. 883 100), on which the location of the
breathing hoses and other attachments had a more streamlined arrangement.
This was important in reducing the unit's water resistance while swimdiving.
The next patent, dated Sep. 18, 1943 (German Pat. No. 889 565) describes a
further improvement in which the breathing harness is shaped so that the
midpoint of the lungs and the lower edge of the air bag are very close to
one another. This made breathing easier for the diver. Another patent
further improved the swimdive device and its oxygen recirculation
arrangements, but this patent could not be registered until Oct. 21, 1951
(German Pat. No. 877 868) because of legislative delays after the war.
Dräger mixed gas rebreathers, like the "Atlantis", which use Nitrox as a
breathing gas, are the direct descendents of this first swimdive device.
In 1997 the
Dräger company celebrates its 85th year of building closed circuit
rebreathers - the first, as shown, with oxygen, and nowadays with mixed
End of article Mr Jung.