Karl´s Rebreather Page

Witchcraft-1 - The perfect Rebreather

• The main unit looks like a collar type livejacket, it carries everything except the tanks and the first stages.
• Where a normal collar jacket carries the emergency tank, the Witchcraft-1 has its cylinder with 2,5l lime, the sensors and solenoids.
• The Witchcraft-1 is optimiced for Buoyancy Mediated Airway Protection, an emergency-inflate kit is available and recommended.
• The exhale path is well isolated and the lime cartridge uses the coaxial countercurrent principle of Justus Liebig (like the IDA71) to achieve a lime temperature of 40C or more, even when the water only has 4C.
• The collar contains two robust counterlungs that also are used as drain-able water traps. This concepts reduces the number specific parts to a minimum and keeps the price that low. The exhale counterlung is small, only 1-2 liter and isolated by thin neoprene.
• The water purge and overpressure valves are the same type that drysuits use.
• The manual inlet valves for O2 and Diluent also come from drysuits, the type and position guarantee hand-free operation by chin or upper arm. As option an also under-pressure triggered diluent valve can be ordered.
• The pressure hoses use identical connectors so that the ppO2 sensors can even be checked during dive, or the diluent valve can be used to add O2 when the other valve system should quit its function.
• The Witchcraft-1 is powered by two controllers: one for the diluent that opens if the ppO2 is (for example) below 0,3bar or above 1,6bar and one for the "Oxygen" that opens if the ppO2 is (for example) below 1,0bar. Under normal conditions both units are active. The "Diluent-Controller" normally only takes care that the ppO2 does not peak too high when descending, the Main-Controller is responsible for the regular Oxygen supply.
• Each controller is fully independent from the other, they share nothing, not even a sensor. Each control unit has its own ppO2-Sensor, its own Display, its own solenoid valve, its own lead-battery and its own pressure housing. The third ppO2-Sensor belongs to the dive computer and a CO2-Sensor is on duty too.
• The tanks depend in number, size and place to the actual needs: from 2x 1Liter to a 2x10 back pack when diving in remote sites or 1x6 where only Nitrox is available or what about 3x4 for Heliox/Nitrox/Oxygen-Switchers.
• The system is able to run with the different gases, in worst case even with "Nitrox-21".
• Witchcraftä sells rebreather lime for a good price to be shure that every user allways changes the lime, even if he only did a short pool-dive. 40kg Witchcraft-Lime are sold for 40Euro, just like cat litter.
• After diving the Witchcraft-1 is separated in 3 parts: the base unit comes in the divebag, just like a normal jacket and for example stays on board, the (expensive, sensitive) lime & electronic unit is taken home by the diver for fresh lime and full batteries and the tanks go to the filling station.
• For the holiday flight Witchcraft-1 is really no problem: the lime & electronic-unit is carried like a part of the photo equipment, the base-unit and the regulators travel in the divebag and the tanks stay at home, the base has own bottles.

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http://Rebreather.de/rebreather/witchcraft-1.htm © Karl Kramer, 19.06.1998