AIP module for conventional submarines

Mature technology

Sea proven

Silent in operation

High reliability

Plug-in section

Lowest possible life-cycle cost

MissionBattery charging has always been a key issue for conventional submarines (SSKs) and has led to the development of Air-Independent Propulsion (AIP) systems to extend ships’ submerged endurance. DCNS developed the Mesma® AIP to provide modern navies with enhanced submarine operational capability. Mesma® is a constant output electric generator supplying propulsion, DC network and batteries. It relies on the well-known steam-cycle principle used in nuclear plants (mastered by DCNS in submarines and aircraft carriers for over fifty years) and selection of sea-proven mature technology.

Mesma® guarantees submarines’ safety and discretion. It achieves the best AIP operational performance available today on the market. Its reliability and low maintenance requirements are well proven.

POWER GENERATION & PROPULSION SYSTEMS

Plug-in sectionWithin a sole hull section, Mesma® encompasses:

■■ a tight liquid oxygen compartment without any electrical equipment, cables or lubricants,

■■ a steam module (combustion chamber, steam generator, steam turbine, condenser),

■■ a control system (fully integrated within the vessel management system and remotely operated from the control room).

The Mesma® weight-balanced plug-in section is designed and manufactured to avoid modifying submarine equilibrium. It does not have an impact on living quarters nor affect vessel signature or stealth. No additional manning is required to operate it. After comprehensive onshore validation, a Mesma® section can be incorporated to new submarines, or during submarine upgrades without modifying the rest of the vessel.

characteristicsLife time > 35 years

Output power 200 kW

Submerged endurance > 3 weeks

Maximum operating depth > 350 m

key points key points

Without AIP

With Mesma AIP: on&off running

High-level performanceThe Mesma® AIP system extends submerged endurance reliably and safely, its only limit being the liquid oxygen tank’s capacity: a Mesma® – equipped Scorpene® SSK would remain undetectable for more than three weeks, for instance.

■■ All Mesma® equipment is double-elastic suspended for utmost silence in operation. It is shock-resistant and compliant with submarine warfare environment.

Battery electric power

Low life-cycle cost■■ Mesma®’s low maintenance

requirements are similar to those of any steam machine. Consequently, Mesma®’s maintenance is performed during the normal submarine’s scheduled maintenance without affecting operational availability.

■■ Mesma® is designed and manufactured to last for the ship’s lifetime and uses affordable civilian fuels, which are available all over the world.

This makes Mesma®’s life-cycle cost the lowest of AIP systems’.

Mesma® architecture

Mature technology■■ DCNS has selected proven

technologies featuring high Technology Readiness Levels (TRL) for its AIP systems, limiting customer risks.

■■ Mesma® is based on the well-known steam-cycle principle. DCNS has more than a century’s experience in this field and has been manufacturing steam systems for submarines for more than fifty years.

■■ Mesma®’s reliability figures confirm the wise selection of such mature technology.This provides vessel and crew with optimum safety comparable to that of on-board nuclear power plants.

■■ Mesma® includes maximum operational flexibility to cope with all submarine warfare conditions.

Submerged endurance

> 3 weeks

Civilian consumables

Plug-in section

Submarine operational range.

FuelOxygenCombustion gases

Sea waterElectricitySecondary circuit

Sea water

RecyclingGaseous CO2

Water

Electricalnetwork

CryogenicPump

DIRECTEXHAUST

FUEL TANK

COMBUSTIONCHAMBER

STEAMGENERATOR

OXYGENTANK

ALTERNATOR TURBINE

CONDENSOR

REHEATER

20%

60%

70%

100%

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DCNS40-42, rue du Docteur FinlayF-75732 Paris Cedex 15www.dcnsgroup.com

3 manufactured Mesma®sPakistan’s Navy was the first navy to order an AIP-equipped submarine from a foreign supplier in 1995.

After successful factory acceptance tests in France in 2002, the Mesma® section was tested at sea and commissioned in 2008 further to integration on board Hamza submarine in Pakistan. The trials, including long-lasting endurance tests, demonstrated that the contractual performances level signed in the 1994 contract had been reached.

The second system was delivered in 2012 and the third is due in 2013. Today, PNS Hamza is the first AIP submarine in the Indian Ocean, only to precede two other ones.