Launch of Indonesia's third Nagapasa-class submarine delayed by silting

The Philippine Navy’s first strategic sealift vessel, seen here while it was fitting out at PT PAL’s dock at Semarang in 2016. This is the approximate spot where PT PAL aims to launch the country’s third Nagapasa-class submarine, Alugoro , given that the original launch location has been affected by silting. (IHS Markit/Ridzwan Rahmat)

The launch of Indonesia’s third Nagapasa (Type 209/1400)-class diesel-electric submarine (SSK) has been delayed, but shipyard officials have devised a workaround to ensure that the vessel will take to the water in the coming weeks.

An industry source who informed Jane’s of the situation has attributed these delays to heavy silting in waters off the Madura Strait, and the Surabaya Western Shipping Route, which is referred to in local navigation maps as the Alur Pelayaran Barat Surabaya (APBS).

“The silting situation was aggravated in recent years by construction work at the Terminal Teluk Lamong,” said the source, in reference to the newly constructed terminal port at Surabaya. “Sediments from the construction have drifted towards the entire Tanjung Perak area, including the PT PAL dock where Alugoro was supposed to be launched. Now the waters are too shallow to safely launch the vessel,” he added.

Alugoro is the third-in-series overall for the Nagapasa class, but the first to be assembled locally at PT PAL’s facilities in Surabaya. Its assembly was done in collaboration with engineers from South Korea’s Daewoo Shipbuilding and Marine Engineering (DSME) as part of a technology transfer programme.