Forensic Science International
Volume 183, Issue 1 , Pages 54-59, 10 January 2009

Dynamic pressure measurement of cartridge operated vole captive bolt devices

  • M. Frank

      Affiliations

    • Department of Trauma and Orthopedic Surgery, Ernst-Moritz-Arndt-University Greifswald, Sauerbruchstrasse, 17475 Greifswald, Germany
    • Corresponding Author InformationCorresponding author. Tel.: +49 3834 86 22 541.
    • ,
  • K.P. Philipp

      Affiliations

    • Department of Legal Medicine, Ernst-Moritz-Arndt-University Greifswald, Germany
    • ,
  • E. Franke

      Affiliations

    • Working Group 1.33 Dynamic Pressure Measurement, Physikalisch-Technische Bundesanstalt Braunschweig and Berlin, Germany
    • ,
  • N. Frank

      Affiliations

    • Department of Trauma and Orthopedic Surgery, Ernst-Moritz-Arndt-University Greifswald, Sauerbruchstrasse, 17475 Greifswald, Germany
    • ,
  • B. Bockholdt

      Affiliations

    • Department of Legal Medicine, Ernst-Moritz-Arndt-University Greifswald, Germany
    • ,
  • R. Grossjohann

      Affiliations

    • Department of Trauma and Orthopedic Surgery, Ernst-Moritz-Arndt-University Greifswald, Sauerbruchstrasse, 17475 Greifswald, Germany
    • ,
  • A. Ekkernkamp

      Affiliations

    • Department of Trauma and Orthopedic Surgery, Ernst-Moritz-Arndt-University Greifswald, Sauerbruchstrasse, 17475 Greifswald, Germany

Received 16 June 2008; received in revised form 6 October 2008; accepted 7 October 2008. published online 19 November 2008.

Abstract 

Introduction

Vole captive bolt devices are powder actuated spring guns that are used as a pest control mean. After having triggered the explosion of the blank cartridge by touching a metal ring around the muzzle, the vole is killed by the massive propulsion of the gas jet. Improper use and recklessness while handling these devices may cause severe injuries with the hand of the operator at particular risk. Currently, there are no experimental investigations on the ballistic background of these devices.

Methods

An experimental test set-up was designed for measurement of the firing pressure and the dynamic force of the gas jet of a vole captive bolt device. Therefore, a vole captive bolt device was prepared with a pressure take-off channel and a piezoelectric transducer for measurement of the firing pressure. For measurement of the dynamic impact force of the gas jet an annular quartz force sensor was installed on a test bench. Each three simultaneous measurements of the cartridges’ firing pressure and the dynamic force of the blast wave were taken at various distances between muzzle and load washer.

Results

The maximum gas pressure in the explosion chamber was up to 1100bar. The shot development over time showed a typical gas pressure curve. Flow velocity of the gas jet was up to 2000m/s. The maximum impact force of the gas jet at the target showed a strong inverse ratio to the muzzle's distance and was up to 11,500N for the contact shot distance. Energy density of the gas jet for the close contact shot was far beyond the energy density required for skin penetration.

Conclusion

The unique design features (short tube between cartridge mouth and muzzle and narrow diameter of the muzzle) of these gadgets are responsible for the high firing pressure, velocity and force of the gas jet. These findings explain the trauma mechanics of the extensive tissue damage observed in accidental shots of these devices.

Keywords: Trauma mechanics, Industrial blank cartridge, Ballistics, Firing pressure, Working equipment, Vole captive bolt device

 

PII: S0379-0738(08)00391-5

doi:10.1016/j.forsciint.2008.10.007

Forensic Science International
Volume 183, Issue 1 , Pages 54-59, 10 January 2009

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