gravelling
n.— «Soweto youths aren’t alone in their crazy train-surfing habits.…Typically spurred on by whistles and admiring female looks, young train surfers will variously run against the walls of bridge underpasses (“The Matrix”), drag their feet on the ground (“gravelling”), or run noisily along platforms (“spara-spara”).» —“The Big Picture: Train Surfing” by Sean O’Toole Times (Johannesburg, South Africa) Oct. 28, 2007. (source: Double-Tongued Dictionary)
Further reading
Twice a day the River Thames recedes, revealing a muddy shoreline. Hobbyists known as mudlarks stroll the surface searching for objects that have found their way into the river over the centuries, everything from ancient Roman jewelry to modern...