3G 4G abstract background blue chip communication computer connect connection digital electronic equipment futuristic green illustration mobile motherboard PC photography program programme red rgb SIM.card smart technology telecommunication telephone vector wallpaper wifi wireless accident alarm burn caution chemical device emergency extinguish extinguisher fire firefighter fireman flame foam handle hazard heat help hydrant nozzle object powder precaution property protection rescue safe sign spray warning white work bricks brickwork builder builder’s trestles building construction development home house partial construction preparation real estate safety sand sand pile secure solid structure suburban tools tradesman trailer urban vehicles wall worker working workman appearance confined display displayed engines heavy heavy-duty historical history locomotives machinery machines mobility power powerful rails railway railway-yard restoration restoration-yard restored steam-engines steam-locomotives steam-trains strength trains transportation