機器
abandoned
black
broken
brown
burnt
business
cable
circle
closeup
color image
crawling
curve
damaged
danger
dirty
electric plug
engine
engineering
equipment
glass
green
grunge
headlight
industry
iron
lamp
locomotive
macro
material
metal
obsolete
old
orange
part of
pipe
railroad track
rough
rusty
steam train
steel
technology
train
transportation
travel
yellow