fuel. The sea trials were held outside the Heads on 12–13 July 1921 with the tanker performing satisfactorily. Upon completion of the twelve hour long trial run, the ship returned to port and after applying final touches was handed over to the USSB. Operational history Following the delivery to her owners the tanker was laid up in Benicia due to scarcity of cargo and overabundance of tonnage. Hammac remained idle until the end of January 1922 when demand picked up and it appeared the recession was easing. After undergoing maintenance, the ship was chartered for one trip by Union Oil to deliver gasoline to United Kingdom. At the time there was widespread confusion as to why the delivery was effected from the West Coast when it was cheaper and quicker to do the same from the East Coast of the United States. Nevertheless, after loading over 3,000,000 gallons of gasoline the tanker departed San Francisco on 14 March 1922 bound for Thames Haven. Hammac passed through the Panama Canal on 28–30 March and reached her destination on 21 April. After unloading her cargo, the tanker left England on 27 April and arrived at Port Eads on 19 May, successfully concluding her maiden voyage. The tanker conducted one more trip carrying oil for Union Oil from the Gulf ports to Philadelphia before being switched to molasses trade. In that role Hammac carried molasses in bulk from Cuba to Gulf ports or Europe. For example, in December 1922 she brought in approximately 9,500 tons of molasses to Rotterdam. On her next trip the ship brought in a cargo of beet molasses from Holland to Baltimore. Due to lack of storage space for this type of cargo, it had to be unloaded into a discarded tanker Brindina. In March 1923 several tankers including Hammac, still in the USSB possession were sold to Union Oil and General Petroleum Corporation. Following the tanker's arrival in Baltimore she was inspected and transferred to her new owners and departed for West Coast on 26 May reaching San Francisco on 15 June. Under new ownership, Hammac conducted one trip with a cargo of gasoline to Philadelphia in July 1923 before returning to West Coast where she was renamed Emidio after the San Emidio oil fields. In 1923-1924 the tanker was largely involved in transportation of gasoline from General Petroleum refineries on California to London, with occasional trips up