The San Antonio class is a class of amphibious transport docks also called a landing platform/dock (LPD) used by the United States Navy. These warships replace the older Austin-class LPDs (including Cleveland and Trenton sub-classes) as well as the Newport-class tank landing ships and the Charleston-class amphibious cargo ships that have already been retired.
Twelve ships of the San Antonio class were proposed but only eleven were funded. Their original target price was $890 million; as built their average cost is $1.6 billion. Defense Authorization for Fiscal Year 2015 included partial funding for a twelfth San Antonio-class ship. As of January 2018 eleven warships of this class are in service with the U.S. Navy with an additional two ships under construction or authorized.
The LPD17 class of warship for the U.S. Navy.
An amphibious assault ship (also commando carrier or an amphibious assault carrier) is a type of amphibious warfare ship employed to land and support ground forces on enemy territory by an amphibious assault. The design evolved from aircraft carriers converted for use as helicopter carriers (and as a result are often mistaken for conventional fixed-wing aircraft carriers). Modern ships support amphibious landing craft with most designs including a well deck. Coming full circle some amphibious assault ships now have a secondary role as aircraft carriers supporting V/STOL fixed-wing aircraft.
Engineering projects around the globe keep getting bigger and more ambitious. there are structures being designed and built that will dwarf anything that has come before. Plans are on the drawing board for projects so huge not only in scale but in their implications for society they’re almost beyond imagination. This how to build documentary that eyes the largest construction projects ever imagined 'how to build'.
Extreme Engineering' & Megastructures