Breasting and Mooring Dolphins
Breasting dolphins carry the fender panel and take the berthing impact; mooring dolphins carry the hooks and the line loads. Why the functions are separated.
A breasting dolphin is a piled structure standing clear of the shore that carries the fender panel, gives the berthing ship something to push against, and transfers the horizontal fender reaction into a pile group. A mooring dolphin is a separate, smaller structure placed forward and aft of the breasting line that carries the bollards or quick release hooks and takes the mooring line loads.
The full article will cover why the two functions are kept apart, so that berthing shock does not pass through the mooring hardware and each structure can sit where its own job requires. It will carry pile group behaviour under horizontal load, the reason groups are battered in opposing pairs so the load is taken as axial compression and tension rather than bending, deck elevation selection against the loaded and light waterlines, and the structural consequence of the PIANC WG 211 doctrine that places the safety margin in the rubber rather than in the supporting structure.
Dolphin berths are also the case that PIANC WG 211 consequence classes A and B are drawn around: a berth with more than two redundant breasting dolphins has functional redundancy, while a berth with two does not, and that distinction changes the partial energy factor the fender is designed to.