But much more should be added (below) including Singaporean submarines defending against and monitoring Chinese ship, submarine and land targets.
The emphasis given to AIP in Singapore's current 2 x Archer class (Stirling AIP) and 4 future 218SGs (fuel cell AIP) suggest short to medium range missions will be common. This is because AIP is heavy and of diminishing utlilty on longer range missions.
The 218SG's Atlas Elektronik combat system, with some US add-ons, will retain many existing capabilities and add new ones. Many missions around Singapore Island (map below) and the Malacca Strait will be on AIP (for around 2 weeks) only. Much of this short range work is (will be) for electronic warfare (eg. signals interception). Such interception "targets" can more publically include the non-state actors (eg. detecting short range terrorist/pirate/smuggler radio signals).
Once a submarine senses a target a submarines weapons are too heavy and expensive (more than
US$1 million per torpedo or missile) to destroy a small boat. Also you'd blow up people who may only be suspects and blow up all evidence! Instead a submarine (using tethered signal buoy beaming to satellite?) may alert a Singapore Police Coast Guard boat or Navy patrol vessel (maybe launching a smaller rigid hulled boat) to deal with the target boat more "gently".
With only 28 officers-sailors needing accommodation on 218SGs, on special missions there may be space for:
- around 6 intercept operators/linguists with 6 work stations
- around 10 divers-special forces and their equipment (one mission fighting terrorists).
Networked with Singapore's submarines in combatting and monitoring threats includes other Singaporean, US and other allied platforms. Platforms include land based or connected sensors, seabed (long range SOSUS) broader ocean sensors and shorter range (RAP/FDS) sensors strung across the Malacca Strait seabed and nodes on/near Singapore main island and islets. On seabed sensors see https://gentleseas.blogspot.com/2019/01/possible-sosus-rapfds-arrays-western.html .
Possibly networked with and informing subs are human intelligence/police/border/customs, overt press, patrol boats, frigates, LCSs, aircraft/UAVs, land-based radar and intercept stations and satellites.
PATROLS - TAILING
All these networked sensors can help cue submarines to tail Chinese submarines on surfaced "innocent passage" through the Malacca Strait and more so Chinese subs who decide to pass through submerged.
SSKs like the 218SG are too slow to shadow Chinese SSNs and SSBNs. But (with Japanese submarines doing the northern leg shadow) 218SGs could do the southern leg shadow of Chinese Song and AIP Yuan class SSKs.
Only at long ranges into the Pacific (including South China Sea) and Indian Ocean would Singapore's submarines be a little more autonomous of all this network help. Looking at Germany's Type 212A as a minimum, the 218SG may have a range of around 8,000nm at around 4 to 8 knots combined snorting and surfaced. Such a range would allow a 218SG to:
- patrol oil strategic lines of communication (SLOCs) between the mid-Indian Ocean
(eg. Diego Garcia or India's east coast bases) and Singapore.
- Singapore to Taiwan and return (maybe keeping an eye on the southern China
coast) using aerials extended from the fin/sail, tethered buoys or work-to-submarine UUVs.
Singapore's submarines (as with the surface navy) all the way to the Persian Gulf oil area, can contribute to longer range protection of the oil/gas/chemical tanker route. This includes tankers eastwards across the Indian Ocean to Singapore's refinery/chemical facilities.
Another way to estimate what the 218SG may be used for is to look at the Combat System - Weapons suite.
Singapore does not appear to be using the submarine weapons of its main ally, the US, other than possibly the US made Harpoon anti-ship and land attack missile. Singapore’s Air Force and Navy use the Harpoon. In the submarine launch mode the Harpoon is called UGM-84 with a range of up to 140 km (75 nm) against ship and land targets.
-Sebastien Roblin at The National Interest. March 2, 2019, with cited halfway down Sebastien's
- Singapore's Straits Times, Feb 18-20, 2019.
- The Independent, Feb 19, 2019.