The Conical Shock Tube is now operated by the Survivability Test Facility of NUWC Division Newport. 

Contact the program manager at (401) 832-5375 or (401) 832-5372 for more information or to schedule testing.

The Underwater Sound Reference Division has a horizontally mounted, water-filled, Conical Shock Tube (CST) that can be used to test the vulnerability of underwater transducers and associated components and materials to explosive shocks. NUWC Division, Newport can perform the combination of MIL-S-901D (NAVY) Lightweight Shock Tests and CST tests that are the equivalent of the MIL-S-901D (NAVY) Heavyweight Shock Test. The Heavyweight Shock Test produces peak free field pressures up to 18 megapascals and inertial shock motion as the Standard Floating Shock Platform responds to the explosion. The shock tube can simulate both the pressure shock and the inertial shock parallel to the axis of the CST. In operation, a small explosion produces the pressure shock wave, which travels down the tube and strikes the device under test. Lateral hammer blows on the Lightweight Shock Test Machine complete the Heavyweight Shock Test simulation. CST tests can be performed at a rate that is limited only by the mechanics of opening, loading, and filling the tube (usually two or three shots in an 8-hour day).

Testing

The transducer under test is mounted on the face of a piston (see diagram of mounting plate below) free to slide in a cylindrical chamber, which forms the termination of the tube. After the shock wave strikes the transducer, the expanding gas bubble from the explosion accelerates the piston into the chamber, applying the inertial shock to the transducer. Transducers to be tested must fit into the 25 centimeters bore and must be able to be mounted on the face of the piston. The acoustic performance of the transducers can be measured in nearby USRD calibration facilities, both before and after shock test, to determine what changes occurred, if any, due to shock. The configuration of the test region of USRD's shock tube is shown in the diagram.

Key Benefits

The shore based CST facility offers explosive shock testing at a fraction of the cost of open water testing. Use of the CST saves the time, money, and the extensive coordination necessary to perform open water explosive shock testing. NUWC Division, Newport can perform the combination of MIL-S-901D (NAVY) Lightweight Shock Tests and CST tests that are the equivalent of the MIL-S-901D (NAVY) Heavyweight Shock Test. In addition, use of the CST reduces environmental impact by containing all explosions and shock waves generated within the tube.

Diagrams

Shock Tube Test Space                                                                                                        Mounting Plate