Submarines

If you went with batteries, you would still be looking at "Whack a Sub" by way of rakurai.

I think that misses the point a little. The EM emissions from running a system on a battery would be undetectable from orbit. It's the fact that you're messing with electricity, which is explicitly prohibited by the Writ, that makes it not kosher.

Hi Aitech,

I can find only 40 IJA supply subs actually listed on the net, but that number includes a dozen built for the IJN of 28, while those that actually completed a successful supply sortie were far fewer.

Erminio Bagnasco's book "Submarines of WW2" only lists 52 purpose built for both the IJN [26] and IJA [26], but identifies 27 completed for the IJN, while the IJN operated many others submarines in the supply role and lost dozens doing so.

Most of these small unarmed subs were designed to deliver only 40 tons of supplies with a range of only 1500 nm at 8kts surfaced [less than 8 days round trip!] and only 8 hours of underwater endurance; they were a pathetic desperate attempt to stave off starvation, even assuming the sub was able to keep an 8 day round trip schedule [!] and the soldiers only ate 2 pounds per day, supplementing that with what they caught fishing etc, the submarine could support only 5500 soldiers over those unlikely assumed 8 days, at a time when the Japanese Home islands themselves were increasingly short of food.

Besides the handful [if that] that actually succeeded in making a single supply run, most were still under construction or training when the war ended and were quickly scrapped.

These posts seem more for the hobbyists than any serious suggestion for RFC, who I'm sure has a better design in mind if the story requires it, which it doesn't appear to need at this time.

L

AirTech wrote:*quote="Weird Harold"*[quote="Dilandu"]We haven't got any real alternative, exep Stirling.*quote*

Charis (aka Howsmyn Industries) have extensive experience with pneumatic tools and motors; It wouldn't be particularly stealthy to anyone in a position to see the bubble trail, but a pneumatic drive would be within Charis' known capabilities.

An alternative may be to take a couple of leaves out of the Japanese Imperial forces play book.
The Japanese navy used a compressed oxygen / alcohol reciprocating engine in the Long Lance torpedo's giving them a range of 40km. A larger sub operating at a slower speed should be able to increase this by an order of magnitude. (As the exhaust is CO2 and water very little of the gas would reach the surface unlike a compressed air torpedo). The engines used in the Long Lances was very similar to that used in air tools, just larger and operating at 400C (for more efficiency, a turbine would be a logical next step).
Whilst the Japanese navy didn't operate cargo subs, the Japanese Army (yes Army) had a fleet of several hundred being used as submersible landing craft and supply lighters under the nose of the American forces in the Pacific. For a submersible to be effective it just has to be below the surface - a snorkel is very useful and batteries are optional as there is no need to dive deep if you are just trying to not be observed and not attacking anything.
For a steam system I can see an option of going to a high pressure oxidizer system with a supercharger compressing combustion air for a fluidized bed combustor - with a corresponding reduction in boiler size. That said diesel systems are within reach and are an obvious next step.[/quote]

Duckk wrote:

If you went with batteries, you would still be looking at "Whack a Sub" by way of rakurai.

I think that misses the point a little. The EM emissions from running a system on a battery would be undetectable from orbit. It's the fact that you're messing with electricity, which is explicitly prohibited by the Writ, that makes it not kosher.

Most likely you are correct, but MERLIN doesn't know for sure. And first generation electric motors would tend to be "noisy" in the EM sense, instead of the batteries. If the Empire were to tinker with them, don't you think they would keep them a long way from Tellesberg or Cherayth, just in case?

Duckk's point is that even Loyal Charisians would see batteries as violating the Writ.

doug941 wrote:

Duckk wrote:I think that misses the point a little. The EM emissions from running a system on a battery would be undetectable from orbit. It's the fact that you're messing with electricity, which is explicitly prohibited by the Writ, that makes it not kosher.

Most likely you are correct, but MERLIN doesn't know for sure. And first generation electric motors would tend to be "noisy" in the EM sense, instead of the batteries. If the Empire were to tinker with them, don't you think they would keep them a long way from Tellesberg or Cherayth, just in case?

doug941 wrote:

Dilandu wrote:Well, there is nothing impossible in the submarine with Stirling engine, heated by stored oil & oxygen (in large Dewar flasks) for submerged propulsion. It would have characteristics at least not much worse than ocean-going subs of WW1.

Not impossible but functional unworkable. A true Stirling engine uses heat to move pistons, meaning a heat source inside somewhere. Current subs that use LO2 are actually either a hybrid Stirling or a closed cycle diesel. If a Stirling was to be used, you would have to come up with an alternative to the electric motors now used. Either way, you need to store and use a liquid at -362F (-223C) Possible in lab setting, VERY unlikely in the field.

It is also important to note the materials and machining is VERY important in Sterling engines. For the most part, since their invention, they have been little more than a curiousity and science demonstration due to these factors. The energy output is so low, that the mass of the engine's moving parts and their friction must be kept kept as low as possible to make the engine's output significant and viable. Only in the last 20 years has material science allowed Sterling engines to be viable industrial hardware. Can you make a Sterling engine with usable energy output with 1890s steel and no plastics industry? Something tells me no.

Is it possible to build a small sub that attaches to other ships or is that just something used in stories?
Say some of these subs were latched onto merchant ships, and when raiders came along, they detach and deal with the enemy. The ships are the bait, and the sub could simply be dedicated to launching and using its weapons against targets.

I have not read 90% of this topic, but here is my 2¢ anyway...

Something like a more seaworthy version of the civil war era USS Monitor could serve much of the tactical and/or strategic uses that a submarine would be used for.

It would also fit better within the storyline that DW/RFC has set up.

ERR

doug941 wrote:
I think that misses the point a little. The EM emissions from running a system on a battery would be undetectable from orbit. It's the fact that you're messing with electricity, which is explicitly prohibited by the Writ, that makes it not kosher.

Most likely you are correct, but MERLIN doesn't know for sure. And first generation electric motors would tend to be "noisy" in the EM sense, instead of the batteries. If the Empire were to tinker with them, don't you think they would keep them a long way from Tellesberg or Cherayth, just in case?[/quote]

I think you missed my entire point - batteries are OPTIONAL. For a covert submersible assault vehicle you just have to be below water level with just a snorkel and periscope showing (with the possibility of going to bottled air for short periods). This would permit the covert insertion of medium sized assault forces (AKA Charisian SEAL teams) just like the US Navy does with swimmer delivery vehicles but without the drawback of inventing SCUBA systems needed for a wet submarine. Think of it as a submersible landing craft / assault boat (with a bow ramp as well if you want one..).
BTW the Japanese army built a lot of submarines for supply delivery in the field out of scrap steel before the General Staff caught on and started building properly engineered subs in Japan for this purpose. (There are photo's taken by the US army of these lashed up subs, they are much rougher than the navy versions).
Since the opponents don't even know how to build a surface motorized ship, a submarine of any sort will mess with there minds. (The Japanese also built submersible tanks and then screwed them up by getting them to carry a pair of torpedo's...)
If you can think of it, someone will try it....

AirTech wrote:

doug941 wrote:
I think that misses the point a little. The EM emissions from running a system on a battery would be undetectable from orbit. It's the fact that you're messing with electricity, which is explicitly prohibited by the Writ, that makes it not kosher.

Most likely you are correct, but MERLIN doesn't know for sure. And first generation electric motors would tend to be "noisy" in the EM sense, instead of the batteries. If the Empire were to tinker with them, don't you think they would keep them a long way from Tellesberg or Cherayth, just in case?

I think you missed my entire point - batteries are OPTIONAL. For a covert submersible assault vehicle you just have to be below water level with just a snorkel and periscope showing (with the possibility of going to bottled air for short periods). This would permit the covert insertion of medium sized assault forces (AKA Charisian SEAL teams) just like the US Navy does with swimmer delivery vehicles but without the drawback of inventing SCUBA systems needed for a wet submarine. Think of it as a submersible landing craft / assault boat (with a bow ramp as well if you want one..).
BTW the Japanese army built a lot of submarines for supply delivery in the field out of scrap steel before the General Staff caught on and started building properly engineered subs in Japan for this purpose. (There are photo's taken by the US army of these lashed up subs, they are much rougher than the navy versions).
Since the opponents don't even know how to build a surface motorized ship, a submarine of any sort will mess with there minds. (The Japanese also built submersible tanks and then screwed them up by getting them to carry a pair of torpedo's...)
If you can think of it, someone will try it....[/quote]


What you are describing would be closer to a Civil War David than to a sub. Easier to build AND use. Also fits story line better.

doug941 wrote:[quote/]
What you are describing would be closer to a Civil War David than to a sub. Easier to build AND use. Also fits story line better.

The Davids were not sea boats by any stretch of the imagination. I was thinking of something closer to the Colombian narco subs which operate at periscope depth with a snorkel, the ability to drop completely under water for short periods (in rough weather for example)and capable of making ocean passages.
A mother ship could drop the boat a couple of hundred miles offshore and use the sub to ferry small teams ashore and retrieve both them and any other passengers (involuntary and otherwise) without exposing higher level technologies.
If nothing else this would provide cover for Merlin's less conventional activities.