Diesel subs in the missile age

[Wenatchee Willie]

I am playing Rose Dragonslayer's EXCELLENT missions and rumbling down under. Which means for the first time I'm using diesel subs in the missile age. I've got a couple questions...

1. Do diesel subs during this period still have to go up periodically and raise their snorkel, or has equipment been developed which allows O2 to be regenerated? And if so, how often and for how long do they have to do this?

2. Is there a way in game to determine what the oxygen level is onboard?

Thanks

[drunkblackstar]

I'm also really puzzled by diesel submarines behavior in Sea Power. Frankly, I don't know much about them, so maybe its the way they are supposed to work... But 3 nm per hour most of the time? Really?

And if they move slightly faster, like 5-10 nm\h, they can go only abot 50 nm, and then they need to recharge with snorkel for hours. It juts doesn't add up for me how they can be serious weapon in real life with this characteristics.

I had an impression that they can last about 24 hours minimum with 15-20 nm\h speed under water without need to recharge. Still, haven't find any reliable info on this issue.

So if anybdy has useful links that prove that diesel subs are really THAT bad please share.

[joetrusty2020]

I am not sure that the tactical details of that are included in this game, especially for scenarios shorter than 24 hours, but yes, those diesels would have to snorkel. The alternate technology known as air-independent, non-nuclear propulsion might be available a decade later than the initial time frame for the game.

[joetrusty2020]

Originally posted by drunkblackstar:

I'm also really puzzled by diesel submarines behavior in Sea Power. Frankly, I don't know much about them, so maybe its the way they are supposed to work... But 3 nm per hour most of the time? Really?

And if they move slightly faster, like 5-10 nm\h, they can go only abot 50 nm, and then they need to recharge with snorkel for hours. It juts doesn't add up for me how they can be serious weapon in real life with this characteristics.

I had an impression that they can last about 24 hours minimum with 15-20 nm\h speed under water without need to recharge. Still, haven't find any reliable info on this issue.

So if anybdy has useful links that prove that diesel subs are really THAT bad please share.

Yes, the diesels are better employed in coastal ambushes where they do not really need to move. In WW2, US fleet boats often ran on the surface at night while running two of four engines for propulsion and two for recharging batteries, but in the congested North Atlantic and polar regions with modern ASW radar, that is not a good practice.

[Thewood]

And even radars in late WW2 could detect a snorkel and periscope. Anything faster than 5 knots in proximity to ASW assets can be dangerous. 2000-era diesels are much more stealthy and have better sonars themselves. But its still a dangerous game trying to balance speed/battery/mission.

[Irving Mainway]

Originally posted by joetrusty2020:

Originally posted by drunkblackstar:

I'm also really puzzled by diesel submarines behavior in Sea Power. Frankly, I don't know much about them, so maybe its the way they are supposed to work... But 3 nm per hour most of the time? Really?

And if they move slightly faster, like 5-10 nm\h, they can go only abot 50 nm, and then they need to recharge with snorkel for hours. It juts doesn't add up for me how they can be serious weapon in real life with this characteristics.

I had an impression that they can last about 24 hours minimum with 15-20 nm\h speed under water without need to recharge. Still, haven't find any reliable info on this issue.

So if anybdy has useful links that prove that diesel subs are really THAT bad please share.

Yes, the diesels are better employed in coastal ambushes where they do not really need to move. In WW2, US fleet boats often snorkeled at night while running two of four engines for propulsion and two for recharging batteries, but in the congested North Atlantic and polar regions with modern ASW radar, that is not a good practice.

American Fleetboats didn't get snorkels until after the war, roughly concurrent with the beginnings of the GUPPY program (there was a more austere "Fleet Boat Snorkel" conversion which didn't get into all the streamlining and new gear. Quite a few of these were passed down to various foreign navies, some serving into the 80s (or in the case of Taiwan still being used likely for training).

German U-boats had them in operational use from 44 or so.

[Ole "Slim Jolo" the Hobo Hero]

Originally posted by drunkblackstar:

I'm also really puzzled by diesel submarines behavior in Sea Power. Frankly, I don't know much about them, so maybe its the way they are supposed to work... But 3 nm per hour most of the time? Really?

And if they move slightly faster, like 5-10 nm\h, they can go only abot 50 nm, and then they need to recharge with snorkel for hours. It juts doesn't add up for me how they can be serious weapon in real life with this characteristics.

I had an impression that they can last about 24 hours minimum with 15-20 nm\h speed under water without need to recharge. Still, haven't find any reliable info on this issue.

So if anybdy has useful links that prove that diesel subs are really THAT bad please share.

You'll notice next to the speed in knows there's probably a crossed out little propeller, which tells sub to move at speed they're not otherwise generating noise that'd be picked up on - if you click that off you can go full speed in the sub (same mechanic for nuclear subs too)

As for range, well, I mean I'm pretty sure every diesel sub from 40s-60s was probably in the same boat of having limited underwater operating time, and is why as a whole things shifted to nuclear and the nigh-unlimited range offered by those vs. the previous generation of submarines. You not believing they can't be a serious weapon of war doesn't change the fact that they absolutely were, it just means learning how they were used.

Diesel submarines were such a serious weapon of war that that weapons developed solely around countering their threat with such efficiency it began the move of making them obsolete against most of the worlds largest navies because they'd just spent 5 years destroying them with increasing efficiency in the Atlantic during WW2 etc

Read the unit reference in the scenario maybe, it might give you an idea. If the sub only carried Mk48 torpedoes or something, probably it's an older generation diesel submarine meant to infiltrate convoys etc to sink them, not a newer generation nuclear sub that would have a better chance going un noticed and escaping destroyers / etc, have a much wider combat range in general and maybe be ugm-84 capable of using harpoons, etc

[Master Chief]

Originally posted by Wenatchee Willie:

I am playing Rose Dragonslayer's EXCELLENT missions and rumbling down under. Which means for the first time I'm using diesel subs in the missile age. I've got a couple questions...

1. Do diesel subs during this period still have to go up periodically and raise their snorkel, or has equipment been developed which allows O2 to be regenerated? And if so, how often and for how long do they have to do this?

2. Is there a way in game to determine what the oxygen level is onboard?

Thanks

Just perusing through the responses to your question and I didn't notice feedback or answers specifically directed to your question.

1. Submarines of this time period (diesel and nuke) did not need to replenish O2 as often as you might think. For crew consumption, submarines create their own oxygen with O2 generators and they scrub and burn off of excess CO2 and CO with other equipment. However, they all will snorkel from time to time to revitalize air if onboard systems are not keeping up with op tempo demand. Submarines will also snorkel periodically to allow for recharging air banks used to support pneumatic systems and equipment. How often subs snorkel is hard to nail down. For good house keeping sub crews will try and combine all operations requiring snorkeling to limit the amount of trips to periscope depth.

2) As far as ship control is concerned, submerged operations are supported by electric or steam engines. So, tracking of O2 isn't really necessary for this game. If the damage control model for this game ever evolves, it might be a different story.

[Stix_09]

1)yes
2)Not in SP as far as I know

How long a diesel electric can stay submerged mostly related to battery capacity and speed of the sub (power draw from batteries). In SP you can see this range increase at slow speeds underwater. The batteries are more efficient at lower power draw.

The soviet Foxtrot sub had a submerged time of up to 8 days at slow speeds, which was considered a long time for this early period cold war sub, but that would not be typical operations.
REF#
Cold War submarines : the design and construction of U.S. and Soviet submarines
(by Norman Polmar)
Also

Air-independent propulsion (AIP), or air-independent power, is any marine propulsion technology that allows a non-nuclear submarine to operate without access to atmospheric oxygen (by surfacing or using a snorkel). AIP can augment or replace the diesel-electric propulsion system of non-nuclear vessels.

https://en.wikipedia.org/wiki/Air-independent_propulsion

[Wenatchee Willie]

Thanks for the responses everyone.

[drunkblackstar]

Originally posted by Stix_09:

1)yes
2)Not in SP as far as I know

How long a diesel electric can stay submerged mostly related to battery capacity and speed of the sub (power draw from batteries). In SP you can see this range increase at slow speeds underwater. The batteries are more efficient at lower power draw.

The soviet Foxtrot sub had a submerged time of up to 8 days at slow speeds, which was considered a long time for this early period cold war sub, but that would not be typical operations.
REF#
Cold War submarines : the design and construction of U.S. and Soviet submarines
(by Norman Polmar)
Also

Air-independent propulsion (AIP), or air-independent power, is any marine propulsion technology that allows a non-nuclear submarine to operate without access to atmospheric oxygen (by surfacing or using a snorkel). AIP can augment or replace the diesel-electric propulsion system of non-nuclear vessels.

https://en.wikipedia.org/wiki/Air-independent_propulsion

Thank you for the book recomendation!

I've read Norman Polmar's "Cold War Subs", it's one of the best books on the subject, yet I don't recall specific data on diesel subs speed.

[Thewood]

"AIP can augment or replace the diesel-electric propulsion system of non-nuclear vessels."

Does it replace the diesel engine or just supply oxygen to it?

[Semerkhet]

Can I ask you the name of the Mission OP? Mostplayers seem to fanboy around carriers and 80s to 90s stuff, but I really like to see some more earlier cold war missions or to play with DIesel Subs.

[SSG Beard [506 IR]]

Air Independent Propulsion does not require external air at all. There are a few different types but only two are commonly used.

The first is AIP that uses stirling cycle engines that burn diesel with liquid oxygen and this powers generators to keep the batteries topped off.

The second uses fuel cells to generate electricity.

Lithium batteries are also helping to significantly extend submerged endurance.

Nuclear subs have unbelievable ability to stay under water until the food runs out but they need pumps running almost continually to cool the reactor. This means that most Nuc boats are very quiet but not silent. Non nuclear boats usually have the ability to remain totally silent and are the absolute definition of stealth. Ask anyone who operates in any navy about how dangerous diesel boats are and they will tell you. They sit silently in shallow water and ambush anything from other subs to aircraft carriers. They are the primary reason why MAD is still in use. A stationary diesel sub parked silently on the bottom cannot be seen by sonar.