architecture background brick bricks decay dirty elements grunge red rust rusty saavem texture urban wall white bark card design floral flower flowers metal nature plant rock stone wood ballast blue metal bolts gravel parallel rail rails secure shine sleepers stable tracks transport triple bucket deep dig digger Dirt earth equipment excavator excavators ground grounded iron scoop abstact boat colors nails pebbles rocks rotten sand sea ship sky textures water bolt corroded corrosion engineering grungy line old plate rivet row series construction drip dripping drips paint rusting splatter splatters surface