October 25, 2016: China recently confirmed that final details have been agreed to on the sale of eight Chinese S20 diesel-electric submarines to Pakistan. Four of these will be built in China while at the same time Chinese personnel will assist Pakistan in building another four in Pakistan. Final cost is expected to average somewhere between $500 million and $600 million each.

The S20 is an export version of the Chinese Type 41 (sometimes called Type 39A/B). Thus the S20 lacks the AIP (air independent propulsion system) along with some of the latest electronics and other internal improvements found in the Type 41. China already has 15 Type 41s in service and another five under construction. The Type 41s are basically a clone of the late model Russian Kilo class. China considers it an “improved Kilo” while the Russians consider it IP (Intellectual property) theft and an inferior copy of the original. Neither the Kilo nor the clones have been in combat but Western navies (and those in Asia using similar equipment) report that the Kilo and most of the Chinese clones are quiet and apparently effective subs.

The S20 is a 1,900 ton boat with a cruising speed of 28 kilometers an hour and endurance of 60 days. The crew of 38 operates a highly automated sub that has six torpedo tubes and 16 torpedoes, cruise missiles or mines. The Type 41 is apparently as quiet as the late model Kilos, which were the quietest non-nuclear subs Russia ever built. For about $200 million AIP can be added to an S20, which would involve adding a 12 meter (38 foot) segment to the S20 (which was designed to have such a “module” inserted to the rear portion of the sub).

Since early 2014 China and Pakistan have been negotiating prices and terms for the sale of more advanced Chinese Type 41 subs. At first it was believed that Pakistan wanted six subs, but the final deal specified eight. Currently the Pakistani Navy has five submarines and plans to use all of them against India (which is also considered a Chinese foe).