Endurance-class

The Endurance-class was designed and built by ST Engineering (Marine) to replace the Republic of Singapore Navy’s (RSN) former United States Navy County-class tank landing ships. The Singaporean Ministry of Defence announced the program in August 1996, and ST Marine began construction of the lead vessel in 1997. The class consists of five active units, four operated by the RSN and one by the Royal Thai Navy.

While designated as tank landing ships (LST) by the RSN, the vessels feature a well dock and flight deck, characteristics of landing platform docks (LPD). The design emphasizes automation through an integrated bridge system and a Ship Control, Monitoring and Management System, which enables a reduced crew requirement. The ships utilize the Electronic Chart Display and Information System (ECDIS) for navigation. Aviation facilities include an enclosed hangar and a flight deck configured for two medium-lift helicopters. An Aircraft Ship Integrated Secure and Traverse (ASIST) system is used to secure and maneuver aircraft on deck. The well dock and davits support the operation of four 13-meter and two 25-meter landing craft.

Operational service includes sea transportation for Singapore Armed Forces training and midshipman instruction. RSS Endurance performed a circumnavigation of the globe in 2000 while traveling to participate in the International Naval Review in New York. All four Singaporean vessels deployed to the Persian Gulf between 2003 and 2008 to support reconstruction efforts in Iraq. These deployments involved logistics replenishment, maritime presence patrols, and serving as platforms for boarding operations.

The class has been utilized for multinational humanitarian and search and rescue operations. All three then-active RSN ships deployed to Aceh, Indonesia, for relief efforts following the 2004 Indian Ocean tsunami. RSS Persistence participated in the search for Indonesia AirAsia Flight 8501 in 2014. Between 2009 and 2011, the class conducted counter-piracy operations in the Gulf of Aden under Combined Task Force 151.

In 2008, the Royal Thai Navy contracted ST Marine to build one unit. This vessel, HTMS Angthong, features different combat and sensor systems and entered service in 2012. ST Marine has also proposed larger landing helicopter dock (LHD) variants, designated as the Endurance-160 and Endurance-170, featuring full-length flight decks.