Determining the Pull-Forces Required to Extricate a Victim Entrapped at Various Angles in a Grain Mass

Prior research on extrication of victims entrapped in stored grain has measured the vertical forces applied to a representative victim (i.e., mannequin) using an anchor point that is mounted directly overhead. However, primarily because of how most grain storage structures are designed, the forces applied would more likely be coming from an angle. This is due to the victim typically being entrapped in the center of the grain mass while the access point is at the perimeter of the roof. The objective of this study was to measure the peak forces required to pull a mannequin at an angle and compare it to vertical pull. An adult-size mannequin was pulled out of dry corn and soybean masses from various depths and at various angles. It was found that both corn and soybeans were comparable regardless of depth or angle with the exception of 15◦ angle. It was also found that, at pulling angles of 60◦ and 75◦, the loads were comparable to those required at 90◦ or directly overhead. Only at the sharper angles of 15◦ and 30◦ did the peak forces significantly increase. The results highlight that there is some flexibility in the placement of the anchor point and that extrication forces on the body will increase at sharper pull angles.