True icebergs are galcier fragments that have fallen into the sea. Glaciers are made of compacted smow, which is fresh water. Additionally, “sea ice” that forms from the freezing of sea water is also basically fresh water as well. This is because when saltwater freezes, it excludes salt from the ice crystal lattice.
The record was set on june 21, 2001 in western australia between newman and port headland, a distance of 275km (170 miles) and the train consisted of 682 loaded iron ore wagons and 8 GE AC6000 locomotives giving a gross weight of almost 100,000 tonnes and moved 82,262 tonnes of ore, the train was 7.353 km (4.568 miles)