VietNamNet Bridge – A businessman from the northern province of Thai Binh has announced to test his submarine, named Truong Sa, next week. The submarine has been put into a big tank, to get ready for the test.

According to the manufacturing group, the mini-submarine is designed and manufactured by Mr. Nguyen Quoc Hoa, 56 – director of a mechanic engineering company - and his friends. It is 9m long, 3m high, equipped with two 90 Hp diesel engines and the air-independent propulsion system (AIP). The designed maximum speed is 40km/h, 800km in radius of operation, diving time of 15 hours and the maximum depth of 50m.   

"I and my colleagues have completed the submarine. It was taken out of the factory and put into a tank in the afternoon of January 6," said Hoa.

The manufacturing group is implementing the last tasks for the test next week.

The tank is designed by Hoa, with a depth of 4.5m, 10m long and 3.7m wide. Hoa will sit inside the submarine during the test.

If the test fails, Hoa will continue research, he said.

"I want to remind the younger generation that if the previous generation fails, the next generation should continue that task. Submarines are not something unreachable; there are many things that are more complex than the AIP technology. Vietnamese can do things that others think that they are utopian," said Hoa.

The test run had been delayed several times as the sub failed to pass technical safety tests.

Hoa and his colleagues planned to test the vessel from Thai Binh province’s Diem Dien port to Haiphong city’s Bach Long Vi island. If it proves successful, the vessel would set sail to Truong Sa in the second phase.

The sub was designed to help defend national sovereignty and serve commercial purposes, especially fishing, according to Hoa.

Air-independent propulsion (AIP) is any technology which allows a non-nuclear submarine to operate without the need to access atmospheric oxygen (by surfacing or using a snorkel). AIP can augment or replace the diesel-electric propulsion system of non-nuclear vessels.

Modern non-nuclear submarines are potentially stealthier than nuclear submarines; a nuclear ship's reactor must constantly pump coolant, generating some amount of detectable noise. Non-nuclear submarines running on battery power or AIP, on the other hand, can be virtually silent. While nuclear-powered designs still dominate in terms of submerged endurance and deep-ocean performance, the new breed of small, high-tech non-nuclear attack subs are highly effective in coastal operations and pose a significant threat to less-stealthy and less-maneuverable nuclear subs.

AIP is usually implemented as an auxiliary source, with the traditional diesel engine handling propulsion on the surface. Most such systems generate electricity which in turn drives an electric motor for propulsion or recharges the boat's batteries. The submarine's electrical system is also used for providing "hotel services"—ventilation, lighting, heating etc.—although this consumes a small amount of power compared to that required for propulsion.

A benefit of this approach is it can be retrofitted into existing submarine hulls by inserting an additional hull section. AIP does not normally provide the endurance or power to replace the atmospheric dependent propulsion, but allows it to remain submerged longer than a more conventionally propelled submarine. A typical conventional power plant will provide 3 megawatts maximum, and an AIP source around 10% of that. A nuclear submarine's propulsion plant is usually much greater than 20 megawatts.

Compiled by Na Son

Photo: VNE