November 6, 2014

DCNS' new submerged SSK solution - Lithium-ion battery and 2 AIPs

Presented on the DCNS Group' website on 29 October 2014 is

Three technologies to improve submerged endurance [for the proposed DCNS SMX Ocean]

"To meet demand from customers for improved submerged endurance of conventional-propulsion submarines (SSKs), DCNS now offers dedicated hull sections known as Autonomy Boosting Sections. Whereas SSKs typically have a submerged endurance of about three days, DCNS now proposes three new technologies to extend this critical parameter to three weeks.

The first is a hull plug equipped with new-generation high-capacity lithium-ion batteries. Easy to operate, the technology offers high submerged speeds on demand and improved response to power ramp-up and variations. Lithium-ion batteries can also be recharged at sea. The endurance of a Scorpene-type submarine is increased to seven days resulting in a significantly enhanced tactical capability.

The second solution, the Mesma air-independent propulsion (AIP) system, is packaged as a compact dedicated hull section. Mesma’s steam turbine-based technology uses a fuel that is readily available in ports and is ideal for extending an SSK’s endurance at patrol speeds. The sea-proven Mesma system increases the submerged endurance of a Scorpene-type submarine to two weeks.

The third solution, a second-generation fuel-cell AIP, represents a technological breakthrough compared to current-generation AIPs in terms of performance, safety, flexibility and maintenance. This solution combines several key DCNS innovations in fuel cell technology. Hydrogen is produced from diesel fuel by hydrocarbon reforming as required, overcoming the need to store hydrogen on board the submarine.

This revolutionary technology increases submerged endurance to three weeks; a capability that confers a decisive advantage in certain theatres of operations."

DCNS second-generation fuel-cell AIP.


The complexity of two AIPs and one not fully mature battery type means some years of testing under  operational conditions would be required prior to purchase. Three weeks submerged within what speed limitations? Fire risks of Lithium-ion batteries and large stores of oxygen, ethanol and hydrogen within the one submarine? Reliability, cost, safety and speed comparisons may beg the question (or produce the reply) why not go the tried and tested nuclear reactor route?

For a description of existing AIPs (and Spain's proposed AIP as well as Russia's) see AIP Technologies and Section, August 5, 2014 .

Also connect with France's DCNS announces the SMX OCEAN large conventional submarine


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