Water Activated Buckle

The Water Activated Buckle (WAB) has been designed to offer a secondary egress/release option for occupants under water.  The WAB functions like any normal rotary buckle and can be opened at any time by rotating the cover. In the event that the submerged occupant cannot open the buckle, it will release automatically after a pre-determined time period allowing for egress or extraction from the vehicle.

The "over water safety solution" for:

  • Military
  • Search and Rescue
  • Coast Guards
  • Off Shore Operations
  • Rotor Wing Applications
  • Fixed Wing Applications
  • Amphibious Vehicles

System Design and Integration

The SCHROTH RFR buckle technology uses a tilt member to translate the rotary function of the actuator into the linear movement required to release the buckle. The tilt members are positioned between the rotating actuator and the release plate, as the actuator is rotated the tilt member rotates about a floating axis causing the load plate to depress the pins releasing the latches. The design frees the buckle from the need of lubricants making it maintenance free and highly durable even in the most adverse environmental conditions.

The RFR buckle is assembled using a single centrally positioned bolt; it is the feature which allows it to so readily incorporate the water initiated actuator. The center bolt has been redesigned to incorporate the detection and initiator circuit board, the battery, the initiator and the actuator piston. Instead of moving the tilt members as in normal operation, the piston impinges directly upon the release plate moving the latch pins into a permanently open position. This provides for a safe release of the entire restraint.


The WAB is an electrically operated mechanical system, which remains passive until immersed in water.

On immersion a circuit is made between the water probes and the batteries are connected to the timing and initiation circuits.  After a pre determined period of time the initiator circuit operates the actuator depressing the release plate and withdrawing the latch pins and releasing the harness.

The timing and initiation circuit is unaffected by the salinity of the water into which it has been immersed. Careful circuit design ensures that the conductivity of the water does not affect the balance maintaining a measured time constant.

Safety Design Features

The water probes are arranged in a way that accidental completion of the timing and initiation circuit is prevented. This feature also ensures that condensation and / or water spray will not form in sufficient amounts to complete the initiation circuit.

In the event the buckle is immersed in water it must remain immersed for the full pre-determined period of time, as defined by the operator’s specification, before it will release automatically. Withdrawing the buckle from the water prior to the specified time will break the circuit and the timing circuit will be reset to zero. This feature avoids the triggering of the device by potential liquid spillages such as coffee or water.

Any failure of the water activation sensor will not inhibit the normal manual operation. The electrical circuitry is immune to external radiated energy.

Technical Features

  • Buckle weight only 202g / 7.1 OZ.
  • Fresh or salt water activation
  • 5-year battery life guaranteed
  • Resistant to humidity, rain, fungus and other environmental conditions
  • No special support equipment required
  • Buckle can be installed in a matter of seconds
  • Single simple actuator for total harness release
  • Regressive Force Release (RFR™) technology

Pro-Tip: The menu can also be openend and closed with the m key.