ex. Dräger Travox 120

I got a Draeger Travox 120 and modified it into a "river diving" rebreather.

It needed some modifications to become a safe manual mode CCR

The original Draeger Travox 120 is a fire fighter device. Exhale is going directly into the scrubber. Also the direction valves are far away from the mouthpiece.
And there is no mouthpiece but a mask. As the mask has a rounded pane, its working like a lenses, making it unsuitable for use in water.
Without mouthpiece, there is no closing valve. The device originally works with pure oxygen, with a fixed flow of 1.5 liters/min.

First tests, with only small modifications.

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The way it looks today.

I reversed the breathing loop direction. That way, exhales go directly into the counterlung, with also works as a water trap for quite a large amount of water.
I took out the old direction valves and made some new housings, placing the new valves in the new mouthpiece.
For less water current resistance, the tubes are only placed asymetrically on the left side, nearer to the mouthpiece center than in normal configs.
Lastly a smale 1 liter steel bootle as diluent and some holes to avoid bubbles collection in the case completes the CCR modifications.

Mouthpiece modifications

Based on Draeger Ray flapper valves I turned two housings and connected them between the tubes and the original mask connector.
Mouthpiece is a military version that can be closed as usual and is connected only on the left side.
Instead of two tubes over the shoulder the two original tubes "hang down". In stronger currents causes less annoying flutter.

ADV valve modifications

. The 2.stage is now connected to switchable diluent.
Additional push buttion alows manual diluent injection .
The inhale vale is changed to work at a higher suction by a stronger spring.
The original overpressure valve is not good for underwater usage. It's closed by a screwed plate.

Overpressure valve and sensor box

The snot locker box is moved from the tube to the exit of the sorb housing and a modified Apeks valve is fitted.
The valve must be modified to have less leakage after strong ventilations. In the same box there is place for the O2 sensor.

Modifications of a second Travox

Learning by the expiriences of mine, here are some enhancements we made for a good friend.

Direction valves

Much better solution of the valves, includet directly in the tubes.

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Sensor and overpressure valve

The OVP is a safety valve, in case O2 source is not closed and mouthpiece is closed.
My newest design incorporates that functionality with the O2 sensor housung. The housing is fixed in the counterlung via normal p-connector.

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ADV

The ADV has a connction to a normal inflator nipple. That way it's easy to use a stage as diluent.

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Divers

Some snapshots of minor details.

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Type Modified Draeger Travox 120 -> mCCR

Size 550 x 400 x 210 mm

Weight empty 13 kg --> full equipped 18 kg

Jacket None

Breathing bag volume > 7 liter

Scrubber 2.4 Kg Dive Sorb

Bypass Modified Draeger Travox

Over pressure valve Modified APEKS

Breathing hose Modified Draeger Travox

Diluent tank 1 liter steel

Regulator Diluent Alysee, modified

O2 tank 1 liter steel

Regulator O2 Draeger travox

O2 gauge computer HS Explorer or Air-Z O2, MeOxy, ...

Dosage constant Draeger travox 0.8 l/min

Dosage manual injection O2 and diluent

Specialties Light, easy diving device.
Goals: 20m depth, max 2.5m/sec current.
5 minutes cleaning / preparation.

Idea of an alternative mouthpiece

MeTravox Mouthpiece variant

Type	Modified Draeger Travox 120 -> mCCR
Size	550 x 400 x 210 mm
Weight	empty 13 kg --> full equipped 18 kg
Jacket	None
Breathing bag volume	> 7 liter
Scrubber	2.4 Kg Dive Sorb
Bypass	Modified Draeger Travox
Over pressure valve	Modified APEKS
Breathing hose	Modified Draeger Travox
Diluent tank	1 liter steel
Regulator Diluent	Alysee, modified
O2 tank	1 liter steel
Regulator O2	Draeger travox
O2 gauge computer	HS Explorer or Air-Z O2, MeOxy, ...
Dosage constant	Draeger travox 0.8 l/min
Dosage manual injection	O2 and diluent
Specialties	Light, easy diving device. Goals: 20m depth, max 2.5m/sec current. 5 minutes cleaning / preparation.