4 … 5 leg derrick,a gin role, a gallows frame,or by hand. Derrick cars have fast become the most popularmeans of erecting plate girders because of their rapidincrease in capacity and esse of travel from one place toanother,because of having their own motive porter.The der-rick car can erect a girder…
Bridges · Theses
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
