The RAN currently has two ships used for afloat support/replenishment at sea; is a fleet oiler, with a limited dry stores capability, while is a general dry stores/fuel replenishment vessel. The navy has initiated a project that will ultimately see two new purpose built vessels enter service by 2020. "Sirius" was purchased second hand (double hulled to meet new international regulations) in 2005 as MT "Delos" and converted to replace in 2006. Then, as "Sirius" reaches the end of its service life around 2018, a new vessel will be purpose built. At around the same time (approximately 2015), a replacement for "Success" will be constructed.