December 20, 2017

The TKMS Type 212CD - MTU12V4000s vs current MTU16V396s

Thanks to Anonymous's 2 comments of 20 December 2017 on which this Submarine Matters article is based. Following a Norway-German government-to-government agreement signed in June 2017 Norway and mainly Germany’s TKMS are producing 6 new Type 212CDs. CD means Common Design. Earlier, in February 2017, the 212CD purchase decison was referred to a Type 212NG.

This article discusses the pros and cons of having an extra diesel engine for the new Type 212CD.

Naval Today, on November 1, 2017 reported “According to TKMS, the class 212CD will combine the low signatures of the class 212A with extended range, speed and endurance to allow worldwide operations.”

A German language Kieler Nachrichten article of December 7, 2017 (once translated) reported “…..it is planned that six identical submarines of the new class 212CD will be procured [4 for Norway and 2 for Germany]. The [German Navy’s] 1st submarine squadron currently has six Class 212A boats. Through the cooperation with the Norwegians, the [German Navy’s numbers will increase] to eight submarines. The first new addition is scheduled for 2027.”

An increase in a submarine's speed may be achieved by reduction of hydrodynamic resistance and increase in propulsive power. As 212CDs are based on 212As (which already have very low hydrodynamic resistance) greater speed can be mainly achieved by increased propulsive power.

Possible propulsive measures include more powerful diesels, motor and lithium-ion batteries (LIBs).
-    The 212CD may use the Type 214's 2 x MTU 16V-396 diesels (amounting to 3.96 MW) much higher than the Type 212A's 1.2MW (see Table page 3) diesel
-   these 2 diesels could work to a Type 214's 2.85MW Siemens Permasyn Motor. This would be an
    increase over the 212A’s existing 1.7MW  Siemens Permasyn Motor, and
-  Lithium Iron Phosphate LIBs may be relied on to give 212CDs high power when fully submerged.
-  A low power fuel cell AIP may be retained or dispensed with.

So, the single diesel generator on the 212A (though it permits miniaturisation in the Baltic) may be replaced by a more powerful two diesel generator arrangement. Favouring two diesels is:
-  Extra power necessary to generate enough electricity for LIBs. 
-  Two diesels are more reliable if one breaks down. 
-  Two also provide the option of servicing one diesel at sea while the other continues to operate.

The trade offs of using different one or two diesel generators arrangements are as follows:
-  Current beam (6.8m)/ one generator [low power] but keeps the 212 usefully compact
-  Current beam (6.8m)/ parallel two generators [lack of repair "elbow" room - bad for
    maintainability]
-  Current beam (6.8m)/ tandem two generators [extends length of whole submarine]
-  Wider beam/ parallel two generators [requires redesign of whole submarine]

Using MTU12V4000 instead of current MTU16V396

Although a major change to two diesels was canvassed above, a less radical solution may be the use of just one MTU12V4000. Just one diesel is an important requirement of the German Navy to keep 212s small enough to handle or exploit Baltic conditions. For example a 212 only 57m long can sit in to smaller holes in the Baltic seafloor than a 214 that is 65m long. A shorter submarine can also turn more sharply on its axis (without hitting rock obstructions) than a longer submarine.

212CD equipped with one MTU12V4000 not two MTU16V396s may be still LIBs capable. Having just one MTU12V4000 diesel also makes it easier to adopt a TKMS's future Methanol Reforming FC AIP. Many common features and spare parts between 212As and 212CDs also means lower through life costs

Comparing the MTU12V4000 and MTU16V396

MTU12V4000s are more powerful than MTU16V396s. Increased power is particularly important given the higher-faster charging capabilities of LIBs.

For the quotes below try opening http://www.tognum.com/fileadmin/fm-dam/tognum/press/2011/MTU_Submarine_Charging_Unit_12V_4000.pdf  which reports:
-  “A submarine charging unit with a 12V4000 submarine engine does have smaller dimensions
    compared to a 16V 396 SE design. However, the mechanical power [of a MTU12V4000] is
    noticeably increased to 1,300 kilowatts (kW) at 1,800 rpm.”
-  “Another major design objective was the reduction of the specific fuel consumption [sfc] 
   [of MTU12V4000s] in combination with greater operating flexibilities for different scenarios.”
-  “The new engine foot for [the MTU12V4000] includes an integrated shock limiter. Its compact and
    easy to install design results in very low effects of the foot’s dynamic behavior on the structure-
   borne noise signature of the engine.”

Alternatively open BMT Defence Services Ltd’s “SUBMARINE POWER AND PROPULSION: BALANCING THE ENERGY ELEMENTS” https://www.bmtdsl.co.uk/media/6097995/BMTDSL-Sub-Power-and-Propulsion-Confpaper-Pacific-Jan12.pdf and especially note the tables in the first 3 pages.

Pete Comment

If the MTU12V4000 in operational practice proves as powerful, efficient and reliable as hoped it will be a good replacement for the MTU16V396 and other diesels.

Mainly Anonymous and (a bit) Pete

5 comments:

Anonymous said...

Hi Pete

Norway and Germany are going to product new submarine 212 CD (Common Design) based on 212A.

“According to TKMS, the class 212CD will combine the low signatures of the class 212A with extended range, speed and endurance to allow worldwide operations.” [1]

“…..it is planned that six identical submarines of the new class 212 CD will be procured. Four receive the Norwegians, two the Germans. The 1st submarine squadron currently has six Class 212A boats. Through the cooperation with the Norwegians, the fleet can be increased to eight submarines. The first new addition is scheduled for 2027.” [2]

Increase in speed may be achieved by reduction of hydrodynamic resistance and increase in propulsion power. As 212CD is based on 212A in which reduction of hydrodynamic resistanc has already achieved, propulsion power will increase.

Possible measures are adoption of high power propulsion motor and LIBs. As 212A equips with Siemens Permasyn Motor of 2MW, adoption of more powerfull Premasyn Motor (such as the one of 4MW for 214 subs) may be considered. Because output of fuel cell is low, Lithium Iron Phosphate LIBs may be adopted to supply high power.

One diesel generator system for 212A provides miniaturization of submarine in the Baltic Sea but has issues of low power and failure of diesel for real world wide use. Two diesel generator sytem is better to address these issues. Maintance of diesel is only conducted in dock but also in operation such as snorkeling, maintainability is important. One MUT does not seem to generate enough electricity for LIBs. Trade off of one and two generators system is as follows:

Current beam (6.8m)/ one generator [low power]
Current beam (6.8m)/ parallel two generators [bad maintainability]
Current beam (6.8m)/ tandem two generators [extended length]
Wider beam/ parallel two generators [redesign]

[1] https://navaltoday.com/2017/11/01/tkms-kongsberg-jv-kta-naval-systems-will-be-delivering-new-type-212-cd-submarine-combat-systems/

[2]http://www.kn-online.de/News/Nachrichten-aus-Eckernfoerde/Deutsche-und-norwegische-Marine-beschliessen-U-Boot-Zusammenarbeit

Regards

Anonymous said...

Hi Pete

Former comment on generator of 212CD is reviewed based on the opinion of German Navy that miniaturization is a key concept of German submarine. 212CD will equip with one diesel generator, not two, and it may be LIBs-oriented MTU 12V 4000 instead of current MTU 16V396 [1]. I also expect adoption of methanol reforming fuel cell. Common design and procurement scheme of 212CD will provide reduction in its life long cost.

[1] http://www.tognum.com/fileadmin/fm-dam/tognum/press/2011/MTU_Submarine_Charging_Unit_12V_4000.pdf
“A submarine charging unit with a 12V 4000 submarine engine does have smaller dimensions compared to a 16V 396 SE design. However, the mechanical power is noticeably increased to 1,300 kilowatts (kW) at 1,800 rpm.”
“Another major design objective was the reduction of the specific fuel consumption in combination with greater operating flexibilities for different scenarios.”
“The new engine footfor Series 4000 includes an integrated shock limiter. Its compact and easy to install design results in very low effects of the foot’s dynamic behavior on the structure-borne noise signature of the engine.”

Regards

Anonymous said...

Hi Pete

Recently, Penske Power Systems unvealed MTU 12V4000U83 submarine engine which may be used for Collins and Shortfin submarines. This engine is possible alternative for MTU 16V396SE83. According to Penske Power Systems, maximum power of 12V4000U83 is 1500kW [1].

I hope that Canberra Connection does not adversely affect on purchasing from Penske Power Systems.

[1]http://penske.com.au/2017/09/27/penske-power-systems-reveal-mtus-next-generation-submarine-charging-engine-pacific-2017/
Notice: diesel generator consists of diesel engine and alternator, and diesel generator is not presented in this picture. Output of generator is engine output x power facor (eg, 1500kW x 0.8 = 1200kW).

Regards

Anonymous said...


Hi Pete

Both MAN 12PA4 V 200 SMDS [1] and MTU 12V4000U83 [2] show same performance, but piston speed of MAN (9.1m/s) is lower than that of MTU (11.4m/s). Lower piston speed is favorable to reduce vibration.

1000kW-class generator can satisfy performance of small AIP submarine for short period (few weeks) patrol, and 212A or CD is invincible convensional submarine in the Baltic Sea if the budget is sufficient.

For large submarine, more powerful generator such as 2000kW-class is desirable to reduce number of generators, i.e., length of submarine. For example, four KAWASAKI 12V/25/25SBs with output of 6800kW are nearly equivalent to six 12PA4200SMDSs or six 12V4000U83s.


[1] MAN 12 PA4 V 200 SMDS: Bore 200 mm, Stroke 210 mm, Mechanical output 1330kW at 1300 rpm (=Piston speed 9.1m/s) , Generator output 1064kW
(http://www.marine.man.eu/docs/default-source/shopwaredocuments/pa4-sm-smdsfba3ca1740b144429518d4e002fd7d6f.pdf?sfvrsn=3)

[2] MTU 12V4000U83: Bore 170 mm, Stroke 190 mm, Mechanical output 1300kW at 1800 rpm (=Piston speed 11.4m/s), Generator output 1040kW
(http://www.tognum.com/fileadmin/fm-dam/tognum/press/2011/MTU_Submarine_Charging_Unit_12V_4000.pdf)


Regards

Anonymous said...

Hi Pete

Happy New Year!

Combined turbocharger and supercharger system, which is superior to single turbocharger or supercharger system and is patent of MAN, is adoped for 12PA4V200SMDS, while twin turbochargers system is adopted for MTU 12V4000U83 [1,2].

Common Rail (CR) system [3], which is latest fuel injection system for diesel engine and prodives optimal condition of combustion, is adopted MTU and reduction of vibration, is adopted for 12V4000U83, but, its adoption for PAV200SMDS is not clear. Issues of CR system are fuel lubrication, fouling deposit by fuel degradation and high sensibility of bad influence [4].

Diesel fuel for submarine contains trace amount of sea water which does not seem to affect on CR at ambient temperature. But it may provide issues as corrosion or erosion or combination of both at high pressure and temperatue, because reaction rate between sea water and metal will significantly increase at high temperature and high pressure cause mechanical stress on metal or combination of erosion and corrosion. Presumably, manufacturer of CR conduct degradation test by using real/simulated fuel including trace sea water to access durability of CR, but, durability of CR under the real operlation is not estabilished yet.


[1] http://www.marine.man.eu/docs/default-source/shopwaredocuments/pa4-sm-smdsfba3ca1740b144429518d4e002fd7d6f.pdf?sfvrsn=3 (MAN 12 PA4 V 200 SMDS)

[2] http://www.tognum.com/fileadmin/fm-dam/tognum/press/2011/MTU_Submarine_Charging_Unit_12V_4000.pdf (MTU 12V4000U83)

[3]http://www.marine.man.eu/docs/default-source/shopwaredocuments/common-rail6d4a00a89677406b92e2a18b9edb80a2.pdf?sfvrsn=3 (Common rail marine diesel for MAN Diesel and turbo)

[4] https://costeffective.com.au/2017/03/05/solving-common-rail-diesel-problems/
(Solving Common Rail Diesel Problems)

Regards