Singapore to begin local sea trials of Type 218SG submarine

Impeccable sailing into RSS Singapura – Changi Naval Base. (Singapore Ministry of Defence)

One of the four Invincible (Type 218SG)-class diesel-electric submarines (SSKs) acquired for the Republic of Singapore Navy (RSN) has arrived in the country, and the vessel will be undergoing local sea trials.

The trials are being conducted ahead of the boat's commissioning and are done as part of efforts to eventually operationalise the vessel, the country's Ministry of Defence (MINDEF) announced on 20 July.

MINDEF did not disclose when the boat, which will be in service as RSS Impeccable , arrived in the country. However, Janes understands that it reached Changi Naval Base on 7 July and was fully unloaded from its carrier, the heavy-lift transport ship Rolldock Storm , on the day after.

As reported by Janes in June 2023, Impeccable was loaded onto Rolldock Storm in May 2023 at ThyssenKrupp Marine Systems (TKMS) facility in Kiel, Germany. At the time of that report, the ship and its cargo were on passage along the western seaboard of Southern Africa, according to automatic identification system (AIS) data.

Impeccable is one of four Type 218SG SSKs ordered under two separate contracts signed between TKMS and the Singaporean government in 2013 and 2017.

The submarine can attain maximum speeds in excess of 15 kt when surfaced and 10 kt when dived. With an overall length of 70 m and a pressure hull diameter of 6.3 m, the air independent propulsion (AIP)-capable boat displaces 2,200 tonnes when submerged and 2,000 tonnes when surfaced. Each SSK is armed with eight tubes.