Dancing manhole covers are an intriguing and curious phenomenon but extremely dangerous for road vehicles as well as pedestrians. They are reported worldwide after heavy rainfall in urban environment. Stormwater systems are overloaded with running water containing large entrapped air pockets for which manholes form an escape route. However, heavy lids cover the manholes and they are supposed not to move.
An attempt is made to understand the physics behind dancing manhole covers by means of simple spring-mass-dashpot modeling. The ingredients are liquid slugs, air pockets, and fluid-structure interaction.