anchored climb climbing danger dangerous dangers grip gripping Harness height high hoisted hold holding immobilised immobilized lines maintenance maritime mast plank repairs rigger rigging risk risks risky rope ropes safety safety-equipment safety-harness sailing seat seated seaworthy secured securing security ship stop stopped suspend suspended tall-ship tough transport vessel work workman above angles antenna appearance architectural attached attachments building colored colors coloured colours communication concave cover covering dark dish edges edging electrical-signals electromagnetic elements exterior external feedhorn light parabolic parabolic-reflector perspectives radio-waves ridges rooftop round satellite-dish shapes sunlight sunshine surface surfaces technology television textures turbine-ventilator ventilate ventilation abstract angle angled architecture ceiling clouds color colour frame framed glass linear long metal metal-framework metal-work perspective rectangular shaded shadows shaped sky sky-light skylight skylight-windows structure structured style support supporting visibility visible window window-frame windows