The US owns a fair number of Roll-on/Roll-off ships designed to transport rolling stock (like tanks, trucks and other military vehicles) to various theaters of war. The ships, operated by civilian mariners, have proven to be very useful. Not only that, they’re versatile.
As part of an agreement with the Syrian government brokered by Russia, the US will undertake to destroy Syria’s stockpile of chemical weapons and precursor compounds. To do this, the Military Sealift Command is loading Field Deployable Hydrolysis units on board the M/V Cape Ray.*
But contra ABC News, the Cape Ray isn’t really massive. It’s a middlin’ sized ship. Many of the RO/ROs are much, much bigger.
*many ships of the MSC are prefixed “USNS” for United States Naval Ship, but others use a more civilian prefix. In this case, M/V stands for Motor Vessel. You’ve probably seen a lot of old ships with the designation S.S. Whatever. In those cases, S.S. stood for Steam Ship.