Royal Caribbean Cruises has ordered new ships that will be powered by liquefied natural gas (LNG) and introduce the use of fuel cell technology, the company said in a statement. The ships will join the fleet of Royal Caribbean International. The company said it signed a memorandum of understanding with shipbuilder Meyer Turku for the new class of vessel under the project name "Icon." The vessels will be delivered in the second quarters of 2022 and 2024. The company also said it will begin testing…