Holy Cow Tractor Pulling Team

Sled pulling

In the early days two main techniques were used. Either a dead weight of fixed mass was dragged, or the step-on method was used, where people stood at fixed positions and stepped aboard as the sled passed. Another rule which has now been dropped was that a speed limit should be observed because of injuries resulting from the increased speed at which they boarded. Today's tractors can achieve theoretical speeds over 125 mph. Today's sleds use a complex system of gears to move weights up to 65,000 pounds/29,000 kilograms. Upon starting, all the weights are over the sled's rear axles, to give an effective weight of the sled plus zero. As the tractor travels the course, the weights are pushed forward of the sled's axles, pushing the front of the sled into the ground, synthetically creating a gain in weight until the tractor is no longer able to overcome the force of friction.To help stop the sled some sleds have grouser bars that act like teeth and dig into the soil to stop the sled. Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: Dry friction resists relative lateral motion of two solid surfaces in contact. Dry friction is subdivided into static friction ("stiction") between non-moving surfaces, and kinetic friction between moving surfaces. Fluid fr

ction describes the friction between layers within a viscous fluid that are moving relative to each other.[1][2] Lubricated friction is a case of fluid friction where a fluid separates two solid surfaces.[3][4][5] Skin friction is a component of drag, the force resisting the motion of a solid body through a fluid. Internal friction is the force resisting motion between the elements making up a solid material while it undergoes deformation.[2] When surfaces in contact move relative to each other, the friction between the two surfaces converts kinetic energy into heat. This property can have dramatic consequences, as illustrated by the use of friction created by rubbing pieces of wood together to start a fire. Kinetic energy is converted to heat whenever motion with friction occurs, for example when a viscous fluid is stirred. Another important consequence of many types of friction can be wear, which may lead to performance degradation and/or damage to components. Friction is a component of the science of tribology. Friction is not itself a fundamental force but arises from fundamental electromagnetic forces between the charged particles constituting the two contacting surfaces. The complexity of these interactions makes the calculation of friction from first principles impossible and necessitates the use of empirical methods for analysis and the development of theory.

C.O.W. Systems