Consider for a moment the force required to do what this machine is doing. It's one of perhaps 9 different specialized vehicles in a line progressing down the track. The first vehicle in front pulls the fastening bolts from the old rail road ties. The second vehicle follows with a large magnet, attracting the discarded bolts strewn about the track. Then this machine follows, third in line. Its hydraulic arm attaches to each railroad tie, and as the weight and pressure of the vehicle sits atop the rail - pulls the buried tie out of its rocky resting place - where it has sat for many years. It yanks it out like a toy and flings it out to the side (seen just below the men in the background). Then a forth vehicle (see in the distance) follows with a articulated arm to lift discarded ties and insert new ones. It's amazing to me, what we as humans are capable of engineering and building. Union Pacific Track maintenance, Fort Collins, Colorado (2016).