angles building building construction building site building work cables chains construction construction site construction work crane danger height heights high hoist hoisting hooks lifting metal work pipes railing rails raising safety safety mesh scaffolding security skip steel scaffolding tall work workers working workmen circuit clamps copper current electrical electricity ground power stake wires demining equipment explosive minehunters minesweeper navy sea ship war arm basket cherry-picker cleaning dangerous elevated elevation extension external Harness insulators machinery on-high perspectives power-lines power-pole raised raised-platform risks risky safety-harness surface surfaces up-high washing workman barricade flash flasher lens light safe sicherheit sicurezza sikkerhed texture veiligheid warn warning yellow cool float floater fun lifesaver lifesavers pink sparkling summer water decorative display energy lighting lights outdoor shapes street lights styles