Roll-on/roll-off (RORO or ro-ro) ships are ferries designed to carry wheeled cargo such as automobiles, trucks, semi-trailer trucks, trailers or railroad carsThis is in contrast to lo-lo (lift on-lift off) vessels which use a crane to load and unload cargoRORO vessels have built-in ramps which allow the cargo to be efficiently rolled on and rolled off the vessel when in portWhile smaller ferries that operate across rivers and other short distances still often have built-in ramps, the term RORO is generally reserved for larger ocean-going vesselsThe ramps and doors may be stern-only, or bow and stern for quick loadingHave a nice day !
I would guess there is a zone valve in that line somewhere preventing the flow of hot water.Could be anywhere in the line there and even located in the baseboardA thermostat would control it.
