Are groins constructed for the purpose of maintaining or widening beaches that are losing sand?

No, groins are not constructed for the purpose of maintaining or widening beaches that are losing sand. Groins are actually designed to prevent or reduce the loss of sand from a beach. They are usually constructed perpendicular to the shoreline and extend into the water. Groins work by trapping sand that is being carried along the shoreline by waves and currents. This helps to maintain or even increase the width of the beach in the area behind the groin.