The short answer is that containers are standardized and universalThere are a few sizes, and all trucks, trains, and ships are designed and built to work with those sizes For example, when a container is loaded at a factory in China full of goods bound for the USA, you can use crane to put it on a truck or a train, which will take it to a port, where the container gets unlocked and lifted off the truck chassis onto a ship, which can be stacked with thousands more containers on top of each other, in rows and columnsThe ship will then take it by water to a port in the USA, where the container is loaded onto another truck or train, which takes it to its final destinationThe main advantage of using container modules is that you only pack the goods once, and container itself is intermodal, that is, it can be moved using various modes of transportation, and the mode can be switched at any point and time.
the pipes were old radiant heating pipesand yes they were sometimes installed in attic ceilings.(your ground floor could be concrete making it difficult to install there)after looking at your link , the old pipes are definitely dead as there is a hole in onejust ignore them or rip them out and sell the scrap coppershould be worth a few $ as scrap metal is at all time high.
