Research Papers

Drag Sled and Automobile Skidding on Dry Asphalt; An Experimental Relationship

Filename Navin.pdf
Filesize 411 KB
Version 1
Date added June 6, 2010
Downloaded 4 times/fois
Category 2010 CMRSC XX Niagara
Tags Session 4B
Author/Auteur Frank Navin, Eric Brewer, Randy Bearg


This paper presents the results of drag sled research carried on over six years by the authors, the Royal Canadian Mounted Police (RCMP) and the Institute for Police Technology and Management (IPTM). The research presents new experimental data that links the Braker Box drag sled’s coefficient of friction to that of a vehicle’s speed on clean dry asphalt. The research treated the drag sled as a solid tire. A test device was built that used Braker Box drag sleds as the vehicle’s wheels. The test rig’s coefficient of friction was estimated for an increasing load. The pulling force was measured by a load cell and the pulling speed was about 0.48km/h (0.09m/s). An RCMP vehicle was treated as a drag sled and pulled at the same low speed. The same vehicle was used for test skids. Other independent experimental Braker Box drag sled data and vehicles treated as drag sleds were compared to the original data. The two data sets compared well. A third order polynomial equation fit the Braker Box drag sled and vehicle as drag sled coefficient of friction data within the loading range tested. The final conclusion is that the Braker Box drag sleds combined with the new procedure can be used to reliably estimate a skidding vehicle’s speed on clean dry asphalt.

Frank Navin, Eric Brewer and Randy Bearg