building concrete crane engineer engineering foundation hard hardness infrastructure maintenance metal progress rubble strong structure tough winch work worker working background gear iron power processing texture backhoe loaders bulldozer carry hard work machine machines maquinas obras work site civil engineer colleagues computer programmer friendly friendship office analysis office meeting office programmer office team office work supervision team work togetherness working together construction fence hat protection sign site warning black smith blacksmith hardwork labour labourer mason toil toiling weld welding brasilia brazil cement fabric high industry manufacture manufacturing men older producing product production sand technology vintage weighed builders crew hard hat Harness safety