U212A

Type 9b 1939

212A Class

Overall length: approx. 57 m

Height: approx. 11.5 m

Max diameter: approx. 7 m

Surface displacement: approx. 1550 t

Crew: 27

Pressure hull material: non-magnetic steel

Integrated control and monitoring system

CWCS (Command and weapons Control System)

X-rudder

Diesel generator

Propulsion motor: Permasyn motor

Fuel cell plant: 9 modules

Propulsion battery: voltage range 300 - 600 V

Noise-optimized propeller

Heavyweight torpedoes

Weapon tubes with water dischange system

Reserve torpedoes in rapod reload position

Surfaced

• all boat structures above water

  • by radar or optical detection

Submerged in shallow water

• by radar

• by IR

• by optical detection in waters with good visibility

Submerged in deep water

• underwater detection by sonar only (active or passive)

  • 212A class or comparable submarines are only detectable by active sonar

Only navies with state-of-the-art equipment have sensors capable of detecting submerged submarines….but only at close range.

Underwater sensors

• different systems for different frequency ragnes from 10Hz to 100kHz

• different detection ranges

Above-water sensors

• periscope (a few nautical miles)

• optronic mast (a few nautical miles)

• radar

• ESM

Submarines are able to cover a larger detection area with their passive sensor than surface units (TAS 50 to 60 km)

Transit range

• submarines are capable of travelling long distances without external support

Mission duration

• long endurance periods of several weeks without external support

Required water depth

• capable of deep water operation

• capable of shallow water operation (up to 20 m depth contour)

Threat aspects

• due to thier low detectability in submerged condition, submarines are almost completely untraceable by surface threats while, in addition, being highly mobile

Submarines can be deployed undeteced worldwide even in high-threat areas, and can remain there for prolonged periods.

Communication capabilities of submarines

• communication in various frequency ranges: VLF, HF, VHF, UHF

  • with command centres ashore

  • with surface units

  • with divers or commands ashore

Image and data transmission capabilities

• SATCOM

• HF, VHF, UHF

• UT, Underwater Telephone

• INMARSAT-C

• GMDSS, Global Maritime Distress Safety System

• AIS

Communication is also possible in submerged condition via hoistable masts and buoys

During operations, submarines can communicate worldwirde and transmit current situation reports to toher units or an HQ almost unnoticed.

Problem: Low mast height above water surface

Classical tasks

• anti-surface warfare

• anti-submarine warfare

• minelaying

Additional tasks

• intelligence, surveillance, reconnaissance

• combat diver operations

• peacekeeping activities at sea

• shore and air target engagement

• covert preparation of amphibious operations

• covert mine reconnaissance

• special operations

• Implementation of specific customer requests and requirements

• Short lead times

• Small boats (low propulsion power, low signatures) with a maximum set of capabilities, e.g. in terms of sensor systems, automation, armament, …

• Minimum signatures

  (acoustics, magnetics, hydrodynamic pressure field, heat emision, radar and sonar signatures)

• Long underwater range

  (Air Independent Propulsion, AIP: Fuel Cell (FC), Stirling Engine, Closed Cycle Diesel (CCD))

• High survivability

  (diving depth, cruising range, snorkeling / indiscretion rate, shock resistance, crew concept, ergonomics, environmental conditions on board)

• Integration into a logistics concept

  (communication / information, documentation, supplies)

• Long service life (> 20, up to 30 years) combined with the option of a midlife conversion

Constraints due to “Archimedes’ Principle”:

Weight, displacement and the corresponding centres of gravity already have to be defined very precisely at the project planning stage and these values must be adhered to during the detailed engineering phase.

(ballast < 3% of displacement)

Additional systems needed for operating in the “third dimension”:

• Auxiliary systems: main ballast tanks, trimming, regulating, emergency blowing, boat’s atmosphere, steering system, hoistable masts, lifesaving equipment, batteries, systems for AIP operation

• Command and Weapons Control Systems: sonar systems, underwater communication and navigation, torpedo defense, weapon embarkation, stowage and ejection systems

• For safety reasons, systems are designed with a higher level of redundancy than is common on surface vessels

• All systems have to be integrated within an extremely confined space while paying due regard to functional and operational requirements and maintainability and observing Archimedes’ principle

• The high component density inside the submarine requires the construction documentation to be very detailed, which means that all construction activities are predetermined to a large degree

Extremely high demands with regard to signatures

-> fulfilling contractual requirements requires special measures, such as:

• Selection of acoustically optimized components

• Double-resilient mounting of noise sources

• Acoustic enclosures, sound shields

• Suppression of transient noise (e.g. switching noise of propulsion control system, operation of hoistable masts and rudders)

• Magnetic signature reduction by way of using non-magnetic steels, magnetic ranging of components and installing degaussing systems

• Reduction of radar and sonar signatures by appropriately designed hull shapes and by coating the hull with absorbent material

• Hydrodynamic optimization (cavitation noise of the propeller, flow noise)

Simulation procedures for submarine-specific physical processes:

• Hydrodynamic seagoing performance (depth keeping, depth change, turning circles, emergency surfacing)

• Signatures (acoustic, target strength, magnetics, infrared)

• The submarine industry largely shapes and maintains guidelines and regulations concerning submarines.

• Only a small share of standard components from commercial shipbuilding can be used; many complex submarine components have to be specifically designed.

• Submarine-specific key components are to be developed by the yard, either on its own or in cooperation with key suppliers. In order to minimize risks, prior efforts are required (R&D projects) and advance trials in test facilities have to be performed.

• Yard’s own submarine crew required for sea trials

• Safety ship including personnel to be provided

• Extensive documentation (“operator manuals”) to be prepared, today “Interactive Electronic Technical Documentation”

• Training of customers’ operating crews

• Customer-specific training, simulators built and operated in customers country

• Submarine construction requires a broad system capability, i.e. expertise and sufficient capacity in all technical fields relevant to the submarine

• This system capability is to be maintained throughout

• Information is exchanged in a highly interconnected network between a large number of different parties, which requires careful engineering planning and progress control. It is therefore crucial to establish:

  • common information and organization systems

  • close coordination between the parties

  Using CAD in submarine contruction is the most demanding application of CAD due to the multitude of components.