The success of the amphibious assault at Inchon during the Korean War showed the utility of LSTs once again. This was in contrast with the earlier opinion expressed by many military authorities that the advent of the atomic bomb had relegated amphibious landings to a thing of the past. During the Korean War a number of LSTs were converted to transport the much needed, but slow and short range LSU from the United States to the Korean theater of war using the piggy-back method. After arrival the LSU was slid off sideways from the LST. Additionally, LSTs were used for transport in the building of an Air Force base at Thule, Greenland during the Korean War. Fifteen LSTs of what were later to be known as the "Terrebonne Parish" class were constructed in the early 1950s. These new LSTs were longer and were equipped with four, rather than two, diesel engines, which increased their speed to . &lt;a href="3%26quot%3B/50%20caliber%20gun"&gt;Three-inch / 50-caliber&lt;/a&gt; twin mounts replaced the old twin 40 mm guns, and controllable pitch propellers improved the ship's backing power. On 1 July 1955, county or, in the case of Louisiana, parish names were assigned to many LSTs, which up to then had borne only a letter-number hull designation.