close...its called a weight transfer sled and it doesn't "dig" into the ground. it has hydraulic cylinders that move the weights from the back of the sled to the front which builds resistance as they pull it down the track. its linked to the sled's wheels. so the further they pull it the harder it gets. the track is 35 ft wide 300ft long. if more than one tractor fom the same class gets a full pull then they will add more weight and pull again furthest being the winner
Perhaps the cameraperson pulls back so far on the un-zoom when the runs start, in order to catch all the parts which might fly through the air if the engine explodes. None did, but it interfered with appreciating the runs.
Its a test to see who has the best pulling tractor. That thing they are towing digs into the ground more and more as they move down the track. The tractor with the best torque and traction will be able to pull it the furthest.