Australia’s future Naval Group Attack class submarine design which may be 4,500 tonnes (surfaced) may require diesels with a total electrical output of 6,000kW. This is noting that the 6,000kW is not only for propulsion, but also for the “hotel load” (eg. electrical power for combat system electronics and air-conditioning).
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An MTU 12V4000U83 for submarine. See another view at Penske Power Systems (Australia and New Zealand). ---
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Anonymous
(with some rearranging by Pete)
After SubMatt’sarticle of March 5, 2019 on German (MTU or MAN) diesels for the Attack class Anonymous commentedwith a range of figures to air issues:
To achieve a total 6,000kW electrical output, 6 diesel generators (probably German designed MTU or MAN) are needed [1].
The Attack class design (beam 8.8m) could arrange its 6 x diesel generators in 2 parallel rows of 3 diesel generators [2].
In comparison the length of Japan’s unselected entry (J-SEA1000) for Australia Attack class SEA1000 competition may have involved these measures. J-SEA1000 without AIP but with 4 x higher powered Kawasaki diesel generators would have been 90-92m long. Naval Group’s Attack class design is 97m long so it may possibly have AIP.
The following is just a suggestion. In the case of the Attack class involving AIP totalling 100MW and 6,000kW diesel generators, indiscretion ratio (IR), may all point to a performance index of a submarine is very roughly estimated to be 3% [3],and in the case of non-AIP it may be 4-5%. This is a pretty good performance index.
[1]The MTU V12 4000 U83 (diagram above) has a mechanical output of 1,300kW and electrical output of 1040kW.
The MAN 12 PA4V200 SMDS (diagram below) has a mechanical output of 1330kW and electrical output of 1064kW.
The MAN 12 PA4V200 SMDS (preceding link is about 5MB PDF) submarine diesel. May be used on Australia's future Attack class and the Netherland's Walrus replacement.
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[2]Estimated cross section of Attack-class from various pictures: diameter of pressure hull (d) = 8.8m, thickness of hull steel (a) = 0.05m, thickness of sound absorbing rubber (b)= 0.10 m, width of hull stiffener ring (c) = 0.25m, width of diesel (f) = 1.7m, average distance between diesel-diesel or diesel – hull stiffer (Y). Then, Y=(d-2a-2b-2c-3f)/4= (8.8-2x0.05-2x0.1-2x0.25-3x1.7)/4 =0.72m.
As Y=0.4m for Walrus-class (3 x diesel generators arranged in parallel) and Y=0.5m for SAAB-Damen submarine design (beam 8m, maybe 2,300 tonne surfaced?) (3 x (MTU or MAN(?)) diesel generators arranged in parallel)
The beam of the Australian Collins-class (7.8m) is slightly less than that of SAAB-Damen submarine (8m). I believe diameters of the two submarines are same, and difference in beam is due to position and shape of flank array sonars of the two submarines.
Last year, the Australian Submarine Corporation (ASC) entered into an agreement with SAAB for the provision of a range of services. The experience of ASC with the Collins-class not only supports the A26 Project but also will be useful for design and building of the SAAB-Damen submarine. The future SAAB-Damen submarine design will be based on the existing and reliable submarine (Collins) platform to some extent.
[3]Calculation in the case of 100MW AIP and 6MW GEs
(1) AIP: 100MW
(2) Energy consumption per day ca.6MW =[hotel load (180kW) + propullsion 60kW] x 24 hours
(3) Operation 10 weeks = surveillance 7weeks (ca.50days) + transition 3weeks (ca.20days)
(4) Required battery energy per day for surveillance = Energy consumption per day – energy suppled from AIP = 6MW-100MW/50days = 4MW
(5) Charge period = (4)/electrical output of GEs x 1hour =4MW/6MW x 1hour = 0.67 hours
(6) IR = charge period (hours) / 24 (hours) x100 (%) = 2.8%=0.67/24 x 100 =2.8%
(with some rearranging by Pete)