Spike driver

A spiker (also known as a Spike Driver) is a piece of rail transport maintenance of way equipment. Its purpose is to drive rail spikes into the ties on a rail track to hold the rail in place. Many different sizes of spikers are manufactured and in use around the world.

A BNSF Railway spiker in operation in Prairie du Chien, Wisconsin

Historically, spikers was the slang-name for the rail workers who drove in the spikes after the gandy dancers laid the track on the tie.