Motorkreuzer 1938 is part of a design competition that is held in July 1937 in order to succeed the M-class. The original requirement were for a displacement of less than 8,000t with similar capabilities to the M-class (namely armament and protection). MK38 is the largest entry, displacing 8,959t with pure diesel propulsion and proposing the use of three 15 cm triple turrets two fore and one aft. The armament layout would have raised dissension at a later stage and the use of only two shafts was rejected as being overtaxing on a ship of this size. The machinery space needed increased the length and thus weight of armor required, and the shaft-propeller layout would inevitably resulted in excessive vibration and vulnerability to shock damage. In the end, none of the designs were was considered superior to the M-class and any hope of them being laid down were gone with the outbreak of WWII.
Original blueprint scan
PNG version
Specification:
[Displacement - 8,959 tonnes
Length - 191 m (oa) / 186 m (wl)
Beam - 17 m
Draft - 5.3 m
Speed - 35.1-35.7 knots
Machinery - Two shaft, 59,000bhp each
Armament -
- 9x 15 cm SK C/25 in triple turrets
- 4x 8.8 cm SK C/32 in twin mountings
- 8x 3.7 cm SK C/30 in twin mountings
- 4x 2 cm SK C/30 in single mountings
- 8x 53.3 cm torpedo tubes in quadruple set
Protection -
- Belt - 30+50 mm over magazines and boilers
- Deck - 20 mm, 25 mm slope
- Turrets - 80 mm face, 20 mm sides
Of note, despite the usage of 15 cm SK C/28 on M-class and other entries, a closer look on the blueprint reveal a longer-barreled 15 cm SK C/25 of the Königsberg and Leipzig class being used. This might imply the use of same turret of the Nürnberg, which has similar level of turret armor found on M-class. Moreover, the secondary/heavy AA battery is depicted with Dop. L. C/32 mount as per the blueprint, however it is likely it would be replaced with Dop. L. C/37 mount instead like the final M-class design.
Open to feedback and criticism