The Kleintauchgerät 138 is a further development of the Gegenlung, which, similar to the Bade-tauchretter, is intended for water rescue and light work under water. A catalog from 1933 mentions for the first time a version of the counterlung with a larger alkaline cartridge and a larger oxygen cylinder of 0.6 1 instead of 0.4 l. The oxygen supply is continuous. The small diving apparatus is first advertised in 1940. The device resembles the modified form of the counterlung as mentioned above. Due to the enlarged alkaline cartridge and oxygen cylinder, the dive time is given as 40 min at light work or one hour at rest. The small diving apparatus weighs 3.7 kg.The counter lung is described in the operating instructions of the Kleintauchgerät as unsuitable for light underwater work due to its limited capacity. It is only used for rescue from sunken submarines. This statement contradicts the older instructions for the counter lung, which state that diving for light underwater work is the primary function of the device. The term “small diving device” is also used in some publications for other Dräger products, such as the bathing diver rescuer.
I have read a lot about the famous Dräger Model 138. This old oxygen rebreather is not easy to find. The famous Hass rebreather is 83 years old now after it was developed bij Hermann Stelzner and Hans Hass in beginning of the 40 ‘s. Now I am very pleased to have my own a Model 138. After years I finally managed to buy a 138 in the beginning of 2010. Here you find detailed pictures of the unit.
I would like to thank Ing. Michael Jung of the Hans Hass Institute for his kind permission to use the shown photos
The Draeger manual has a nice workingprinciple drawing:
You might notice that the inhale hose is on the divers right shoulder.The unit was sold with mouthpiece or Full face mask.
The use of oxygen rebreathers showed the changing view on the exposure to high levels of oxygen. In 1942 the user of the gegenlunge was advised:
They could use the rebreather during 25 minutes in 15 MSW
Then in 1952 when the Modell 138 was realeased they advised:
The unit could be used at 25 meters of Depth during 10 minutes!
Accidents must have caused the factory to give a more moderate adviceIn 1961 the factory adviced the diver not to dive deeper than 10 meters, although, according to the handbook of the 138, hyperoxia was not so dangereous as hypoxia. The depth however was limited to 10 meters because there seem to be people who do not perceive muscle twisting arround the mouth and eyes…..Here you find the Barakuda logo on a sportdivers Modell 138 (not on mine)
OK, now let us have a closer look at my unit 138 – 1228
Clearly visible the letter (1) 38 – 1228 It seems to me that this is production unit 1228A complete 138 on my table ……Overpressure valve on the outsideOverpressure valve on the inside. You are actually looking on the inside of the counterlung. This 60 year old material is of a unbelievable quality!Top of the scrubber. There are some blue particles (origin?)The valves are near the scrubber and in the hose.Here you see the mouthpiece. It has an small eye on it. Guess were it was used for….Unfortunately some parts show the marks of there age…. This oxygenbottle was not the original one. The original one was a 0,6 ltr bottle filled with 150 bar. With 90 ltr of oxygen the diving time was limited to 40 minutes. One of the main differences between this 138 and the rebreather of Hans Hass is that the 138 had a constant oxygen flow of 0,9 ltr/min and a manual bypass. The oxygen was injected directly into the counterlung and the unit was provided with a non return valve. Dräger K-valvePressure reducer with bypass valveThe inside of the pressure reducer shows the adjustable flow screw Oxygen is added directly into the counterlung on the inhale side of the loop Here you see the complete oxygen feed assembly Lock assembly for the srubber, one screw !Here you can see how the scrubber fits into the counterlung and uses two seals heavy duty clamping deviceSpring loaded scrubber. The scrubber should be filled and tapped until the lime is 10 mm underneath the edge.bottom of the scrubber The complete unit, a gem in the collection..Copyright Hans-Hass-Institut für Submarine Forschung und Tauchtechnik
Hans Hass with the unit between the Gegenlung and the Model 138 in a mirrored view as printed in many books!
I hope you enjoyed the small journey in time!
This page was only possible with the help of M. Jung and J. HarjuPicture Courtesy of Helmut Knufermann, thanks Helmut!
The above paper was compiled by Michael Müller (Oxydiver) who granted me the much-appreciated permission to publish his work. The article was published in German and is now also available as a translated English article on the following page LINK
This page was first published 09-05-2010, if you have additional information please let me know!
Therebreathersite was founded by Jan Willem Bech in 1999. After a diving career of many years, he decided to start technical diving in 1999. He immediately noticed that at that time there was almost no website that contained the history of closed breathing systems. The start for the website led to a huge collection that offered about 1,300 pages of information until 2019. In 2019, a fresh start was made with the website now freely available online for everyone. Therebreathersite is a source of information for divers, researchers, technicians and students. I hope you enjoy browsing the content!
