Submarines

doug941 wrote:As for crank powered, those would be harbor defense only. You could size up the Hunley to 150' but you couldn't move it very far.

You couldn't move it very fast, but I don't see any reason it couldn't have nearly unlimited range (limited mainly by consumables and potable water.)

I'm unsure about how the CSN Hunley was geared, but judging by the changes in bicycle gearing and transmission technology in general I'd guess that it could have been much more efficient in transferring the crank power to the propeller -- and presumably any Charisian version would take some advantage of improvements in transmission technology post-Hunley.

Weird Harold wrote:

doug941 wrote:As for crank powered, those would be harbor defense only. You could size up the Hunley to 150' but you couldn't move it very far.

You couldn't move it very fast, but I don't see any reason it couldn't have nearly unlimited range (limited mainly by consumables and potable water.)

I'm unsure about how the CSN Hunley was geared, but judging by the changes in bicycle gearing and transmission technology in general I'd guess that it could have been much more efficient in transferring the crank power to the propeller -- and presumably any Charisian version would take some advantage of improvements in transmission technology post-Hunley.

I'm sure I'm going to miss a lot but here goes. To size up something like the Hunley, you would need to have thicker hull plating and hull framing. Stretch her two or three times without a heavier hull you have a hull waiting to collapse. Larger hull = larger volume of air = more ballast = more weight to move. A larger hull also means more water to displace and greater hull drag. Lastly, weight and drag will increase faster than the increase in power from the crew. In a crank-powered sub, smaller is MUCH better.

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.

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.

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.

Once again a correction. LO2 temperature should have been listed as -297F (-183C)

doug941 wrote: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.

I repeat: the LO2 may be stored for at least some time in Dewar flasks. And even if the LO2 is too hard to store - it's possible to heat the Stirling with simple compressed air. Of course, it wouldn't be as effective as LO2, but it would work. Look at the russian experimental submarine "Pochtovy", build in 1908:

http://en.wikipedia.org/wiki/Russian_submarine_Pochtovy

She udes gasoline engine with compressed air storage. And she was able to go 28 miles underwater (for example, the electirical submarine "Minoga", built in 1908, were able to go only 25 miles underwater)

And we could use shnorkel to save the compressed air supply for the dives.

Dilandu wrote:

doug941 wrote: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.

I repeat: the LO2 may be stored for at least some time in Dewar flasks. And even if the LO2 is too hard to store - it's possible to heat the Stirling with simple compressed air. Of course, it wouldn't be as effective as LO2, but it would work. Look at the russian experimental submarine "Pochtovy", build in 1908:

http://en.wikipedia.org/wiki/Russian_submarine_Pochtovy

She udes gasoline engine with compressed air storage. And she was able to go 28 miles underwater (for example, the electirical submarine "Minoga", built in 1908, were able to go only 25 miles underwater)

And we could use shnorkel to save the compressed air supply for the dives.

What happens if a worker at your LO2 plant is another Temple loyalist? Cryogenic gases such as LO2 can be transported using modern tech but the tech available to Charis, present or future, would require your gas plant be at or very near the combat zone. Cryo gases boil off 1-2% per day by volume using Earth flasks so by the time you made it and transported it you wouldn't have any left to use.

doug941 wrote:What happens if a worker at your LO2 plant is another Temple loyalist?

What happens if a artillery officer onboard KH is another Temple loyalist?

This is the problem of sequirity, not the technology. And i really doubt that some Temple Loyalist would have enough technological knowlege to be premitted to work with liquid oxygen.

And, as i previously pointed out - the submarines would more likely appear in the navy of Dohlar (after current war, of course!), than the ICN.

doug941 wrote:Cryogenic gases such as LO2 can be transported using modern tech but the tech available to Charis, present or future, would require your gas plant be at or very near the combat zone. Cryo gases boil off 1-2% per day by volume using Earth flasks so by the time you made it and transported it you wouldn't have any left to use.

Ok, let's use the compressed air. It's much more simple.

Weird Harold wrote:

Dilandu wrote:We haven't got any real alternative, exep Stirling.

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.

AirTech As long as you went with a direct drive engine that looks like it would sidestep most if not all the tech problems. If you went with batteries, you would still be looking at "Whack a Sub" by way of rakurai.