Using a derrick to raise marble for a building on Trinity Place, 1906
A derrick is non-motorized machine for raising iron and stone. Derricks are visible on every level of this 1906 building site, being used to raise the stone for building the walls. Note the workers standing to receive the stone.
The men on this job were members of the Stone Derrickmen and Riggers Union, Ironworkers Local 197, which still exists today.
Men called riggers erected the derricks to raise both stone and steel using the same principles as a mast on a sailing ship; a stationery pole stabilized with guy wires (as a mast on a sailing ship might be stabilized) had a moveable boom allowing workers to raise heavy materials using ropes or wire cable and pulleys.