A challenge was posted recently in Shipbucket, that drew a lot of criticism for the details for the ship to be produced, with good reason. So far after a week I have been the only person to post a drawing.
It is the consensus of the General Staff that a war with Great Britain is practically inevitable within the next decade. Being an island nation, the UK is a natural fortress that cannot be taken in traditional land offensive, meaning it must instead be starved into submission, via a naval and air campaign. Unfortunately, in the time available to us, we cannot match the strength of the of the Royal Navy, so must concentrate our available resources on destroying British mercantile shipping. Much of this will be accomplished by U-boats and aircraft, but the Reichsmarine is in agreement that a surface component is also needed. Regrettably, large, powerful vessels aren't an option, as these will be too easily countered by the numerically superior Royal Navy. Instead, a new type of vessel is required, a pure raider designed for no other purpose.
Besides having the speed and range required for lengthy operations on the high seas, such a vessel must be inexpensive enough to be built in the required numbers. This means sacrificing such things as armor, complex fire control arrangements, and limiting main armament to produce a reasonably cost effective design that won't tie down too many resources needed elsewhere.
With regard to speed and range, a 39-40 knot top speed is required to ensure being able outrun any RN cruiser by a comfortable margin, while a minimal range of 20,000 nm @ 17kts will be needed for this type of work. All of this needs to go on a hull displacing no more than 3-4,000 tons standard.
Main armament should be sufficient for fending off destroyers, and sinking merchant vessels, but not so heavy as to encourage ship captains to fight when they should run, particularly against enemy cruisers. To this end, an armament of 4x150mm guns in either four single mounts or two twin turrets is judged sufficient for the task. Torpedoes in either twin or quadruple mounts are also considered essential, and provisions for underwater or otherwise concealed tubes should be given consideration. AA armament needs to be sufficient for fending off aerial attack, so at least a moderate suite is required.
Lastly. due consideration should be given to either A: providing some means by which the unit can disguise itself as a merchant ship, preferably being able to appear as a number of different vessels by means of easily erected screens , and dummy funnels and masts, or B: If the latter option is judged impracticable, then reducing visibility via lowering the raider's silhouette, eschewing features such as tall aerial masts or fire control towers. Any measure which will aid in slipping through the British blockade will contribute heavily to the success and survival of the unit!
The initial order will be for 6-12 vessels, and if successful, The Reichsmarine is prepared to look at putting the design into as high production as machinery output will allow for.
Quite a few comments ensued which brought the response:
It might be possible to reduce range a bit, but I'm basing my design requirements off the later British Abdiel Class minelayers, which displaced something like 2,650 or so tons. I'm allowing for up to 4,000 tons, so that should offer enough leeway.
As far as the design being cheap, it's more like cheap as possible under the design requirements. As far as the AU goes, feel free to read my thoughts on the Ardannian AU in the relevant section.
Basing a long range raider off of a short range minelayer is just a bit ridiculous. My final comment and drawing as close to the limits set were:
The biggest problem for a raider adhering to the Geneva Convention is having space for captured crews. Because of this a supply ship for the raider is essential. Capturing and/or sinking half a dozen enemy ships will fill the empty spaces up. What about prize crews? If you capture a merchantman with a valuable cargo. it is not just enough to deny it to your enemy, but if you can get it home it will aid your country as well. What if you fall in with a convoy - your raider would easily be chased off by the escort who would almost be as big as the raider to be designed for this challenge.
The smaller your ship is the less effective as a raider it will be.
Hood's suggestion of the Spahkreuzer is probably ok, but again it is not really big enough to fulfil the job description for a decent raider.
The Graf Spee type were about as small as a raider warship should be. The converted merchantmen were best of all. Those did more damage to the Allies than all the warship raiders put together.
Raiders are expendable. The converted merchantmen were not of use bottled up in port once war began.
