John Fedup
The Bunker Group
It would probably take some serious R&D expenses to do a submarine version. Euro sub vendors will stick with local suppliers and it seems Japan and Australia will go with Li-ion batteries.
Naval Ship & Submarine Propulsion Systems
- Thread starter rockitten
- Start date
Lead acid, at least for the majority of the propulsion. TBH I don't see that changing in the short term.
Even the Lithium subs and designs that exist now, its more about lithium replacing AIP than the entire lead acid battery. If you replace the entire battery with lithium, you might as well throw away your diesels, because you will never be able to charge that battery with the diesels on board. Its more a balance of indiscretion rate and mission. You have also made your conventional submarine 20 times more expensive.
Where as if you look at say enough lithium for several hours of operation, being able to recharge that with a doable indiscretion. Its a small additional cost, you get significant benefit, you maximize lithium advantage, fast charging, fast discharging, heavy cycling, no out gassing etc, while maximizing lead acids cheap bulk storage. Your lead acid battery stays in better condition, you have more operational flexibility, etc. Minimal extra cost.
Fuel cells only fit some mission profiles. For Australia, things with liquid oxygen make no sense. By the time we transit through hot tropical waters, for weeks, there will be nothing left, just from outgasing heating. It would take more to keep it liquid than to propel the submarine. The Japanese made it work because they pretty much on patrol from the time the slip out of their harbor, and they dive deep into the cold and stay there, moving a few knots. But even then, Lithium has provided a better advantage.
Even the Lithium subs and designs that exist now, its more about lithium replacing AIP than the entire lead acid battery. If you replace the entire battery with lithium, you might as well throw away your diesels, because you will never be able to charge that battery with the diesels on board. Its more a balance of indiscretion rate and mission. You have also made your conventional submarine 20 times more expensive.
Where as if you look at say enough lithium for several hours of operation, being able to recharge that with a doable indiscretion. Its a small additional cost, you get significant benefit, you maximize lithium advantage, fast charging, fast discharging, heavy cycling, no out gassing etc, while maximizing lead acids cheap bulk storage. Your lead acid battery stays in better condition, you have more operational flexibility, etc. Minimal extra cost.
Fuel cells only fit some mission profiles. For Australia, things with liquid oxygen make no sense. By the time we transit through hot tropical waters, for weeks, there will be nothing left, just from outgasing heating. It would take more to keep it liquid than to propel the submarine. The Japanese made it work because they pretty much on patrol from the time the slip out of their harbor, and they dive deep into the cold and stay there, moving a few knots. But even then, Lithium has provided a better advantage.
It may not be worth the weight and volume to install an AIP system in certain mission profiles.
Correct me if I am wrong, but I believe out-gasing is not an issue for the first 15 to 20 day period — some AIP submarines can run at a 30-to-45 day patrol cycle.
Cryogenic liquids management using modern vacuum-insulated TEUs can be sold or even rented. These vacuum-insulated pressure vessels will be loaded on a submarine tender, have insulation and pressure management systems to reduce outgas rate but the O2 tank, vaporizer (which is also used for cooling in some Fuel cell AIP submarines) and pressure control manifold do take up volume in a submarine.
There is no need for a liquefaction plant to store at –297°F (–183°C) if the storage period is between 15 to 20 days. But there will be some need to outgas if the storage period is longer — the solution to which is power up the Fuel cell for a few hours every alternate day.
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Well it all depends where you store the liquid oxygen.
Outside: Well making a vacuumed container to go on the outside of the submarine may not be as easy as it first appears. You can have more storage volume, but outgassing is likely to be significant. If you don't have a large transit then this might be fine, operating it continuously.
Inside: You can use vacuum containers, but these take up tremendous amounts of room inside the submarine and will need their own separate bulk headed compartment. Your losses are something like 1% per day. For many that is not a huge amount, for a boat with a 30-40 day transit, its not insignificant. If you have a transit of 1-2 days, then that is insignificant.
Germans have the liquid oxygen and hydrogen storage tanks (not liquid) located essentially at the bottom of the boat replacing the lead acid batteries. Displacing lead acid batteries is not ideal, particularly for a submarine with large transits or that tends to operate at a significant indiscretion rate.
The Japanese have the liquid oxygen and the Stirling engines in a separate bulkheaded section ahead of the engine room. So its more of a complete addition to the original capability.
Then as you said, it also depends on your mission profiles. The Japanese tend to dive deep and go slow under some high traffic areas. Australia probably has a much more varied mission profile doing all sorts of other things in all sorts of other places.
Lithium is going to be very attractive to Australia because of our mission profiles. It can assist in transit and on mission. While having some hazards, I would say its safer than having liquid oxygen in the hull of your sub, and much safer than having hydrogen and liquid oxygen in your sub.
While AIP can work for some subs and some mission profiles, Australian subs won't ever be slipping out of port and making their entire mission running off AIP like the Europeans or the Japanese can probably manage.
Outside: Well making a vacuumed container to go on the outside of the submarine may not be as easy as it first appears. You can have more storage volume, but outgassing is likely to be significant. If you don't have a large transit then this might be fine, operating it continuously.
Inside: You can use vacuum containers, but these take up tremendous amounts of room inside the submarine and will need their own separate bulk headed compartment. Your losses are something like 1% per day. For many that is not a huge amount, for a boat with a 30-40 day transit, its not insignificant. If you have a transit of 1-2 days, then that is insignificant.
Germans have the liquid oxygen and hydrogen storage tanks (not liquid) located essentially at the bottom of the boat replacing the lead acid batteries. Displacing lead acid batteries is not ideal, particularly for a submarine with large transits or that tends to operate at a significant indiscretion rate.
The Japanese have the liquid oxygen and the Stirling engines in a separate bulkheaded section ahead of the engine room. So its more of a complete addition to the original capability.
Then as you said, it also depends on your mission profiles. The Japanese tend to dive deep and go slow under some high traffic areas. Australia probably has a much more varied mission profile doing all sorts of other things in all sorts of other places.
Lithium is going to be very attractive to Australia because of our mission profiles. It can assist in transit and on mission. While having some hazards, I would say its safer than having liquid oxygen in the hull of your sub, and much safer than having hydrogen and liquid oxygen in your sub.
While AIP can work for some subs and some mission profiles, Australian subs won't ever be slipping out of port and making their entire mission running off AIP like the Europeans or the Japanese can probably manage.
Unveiled at Euronaval, a concept for a full-electric, all-battery-powered submarine: Euronaval: Naval Group unveils the SMX31E new full electric "Concept Submarine" - Naval News
30 days at 8 knots submerged on batteries alone. That would be pretty phenomenal, and for Canada's desire to have an under-ice patrol capability, a game changer.
30 days at 8 knots submerged on batteries alone. That would be pretty phenomenal, and for Canada's desire to have an under-ice patrol capability, a game changer.
John Fedup
The Bunker Group
Interesting but going up North with no recharging ability seems risky to me. At 8 knots and 30 days running that’s just under 6,000 nm so 3000 nm up and then return. Not sure what range is planned for Arctic sub patrols. In any event something like this with diesels and larger sounds good, perhaps an evolved Attack class with more LIB capacity or future battery technology which no doubt will be even better 20-30 years from now.
Yes, you would definitely need another power source for the transit portion. However, these batteries combined with diesels (or perhaps fuel cells) would definitely allow for under-ice sovereignty patrols. And when I re-read the article it was "more than 30 days at 8 knots".
John Fedup
The Bunker Group
Thirty days at 8 knots or 60 at 5 knots, whatever, the system is theoretical at this point.
Pretty much everything discussed in this thread is theoretical. But we've seen similar estimates made for the Japanese subs (see infographic below), so I think it's pretty safe to say that those kinds of ranges are more than just theoretical.
Image courtesy of SSK Soryu Class Submarines
Attachments
John Fedup
The Bunker Group
Yes, the one way 3000 nm at 8 knots then return likely is more than theoretical but is it sufficient for patrols likely starting from Halifax?
MARKMILES77
Active Member
The new battery chemistry that is most likely next for Australian subs (possibly including Collins) is not Li Ion but Nickel Zinc.
It does not have the ultimate energy density of Li Ion batteries but is superior in pretty much every other way including the most important, safety.
Much cheaper
No need for a complete redesign of the subs electrical systems as there is for Li Ion. Very close to being a drop in replacement for Lead acid.
Zero risk of thermal runaway or fire. unlike Li Ion
No off gasing of Hydrogen unlike lead acid
Long Life
No maintenance
Has a recharging profile which is ideal for submarines. Optimal charging is done in short rapid bursts. They don't like trickle charging.
Energy density approximately 2.5 X lead acid BUT doesn't mind being discharged to zero so effectively has 4 to 5 times the energy density.
AND is being developed for submarine use in Australia by PMB who make the Collins Lead Acid Batteries.
Here is a screen shot from their website:
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MARKMILES77
Active Member
Another big thing some seem to forget or just simply do not take into account and ignore is the thermal efficiency of the different types of batteries, makes a big difference in charging times, capacity and discharge rates.
For a submarine that operates in a given environment with fairly consistent sea temps can be a relatively easy thing to model energy usage, but when you have a Diesel Electric submarine using battery technology operating in a blue ocean capacity such as Australia does, from the frigid waters of the southern oceans to warm tropical and everything in between, and in the one patrol, it adds so much more complexity to the equation !
So to simply say we should have Li-on batteries because of their capacity, discharge rates, etc ignores so much more in actual operational reality and requirements, along with everything else that has been said.
PMB are a great company and do some fantastic work, their knowledge and research is top notch and very highly regarded
Cheers
For a submarine that operates in a given environment with fairly consistent sea temps can be a relatively easy thing to model energy usage, but when you have a Diesel Electric submarine using battery technology operating in a blue ocean capacity such as Australia does, from the frigid waters of the southern oceans to warm tropical and everything in between, and in the one patrol, it adds so much more complexity to the equation !
So to simply say we should have Li-on batteries because of their capacity, discharge rates, etc ignores so much more in actual operational reality and requirements, along with everything else that has been said.
PMB are a great company and do some fantastic work, their knowledge and research is top notch and very highly regarded
Cheers
I think something like or Nickel zinc would be a good fit for an Australian submarine. I don't think Nickel Zinc are quite exactly a drop in replacement, but a much closer to being one in terms of safety and would require less specific design requirements to be considered. Its one of the reason why I don't think we should be too concerned for a submarine that is still being designed around the specifications/requirements of a lead acid battery. That does not mean that lead acid is the only battery technology available to be fitted, and most of the submarine technologies are using lead acid as the key requirements for their solution. There are several battery technologies that would be quite suitable that are cheaper and lower risk than lithium (such as NiZn and NiMH). These would still offer a huge upgrade over traditional lead acid. There are also several advanced lead acid batteries that close the gap between lead acid and more modern chemistries.
Given how large the Attack class will be, displacing over 5000 tons of a particularly low drag design, even a fairly conventional battery will result in very significant performance from the sheer size of it. Quick Charging such a battery will be interesting.
No, not on batteries alone. You would use your diesels to get to the patrol area, and the batteries for the under-ice portion.
John Fedup
The Bunker Group
Here’s an article describing a C-17 deployable fast combat boat for US special forces. The picture shows the boat loaded into the C-17. Although the picture seems to show stern drives, the article claims the boat uses classified surface piercing propellers which were removed. Guessing the drives have been modified somehow for surface piercing propellers. Would be great for the 30,000 island region of Georgian Bay (which probably has 300,000 reefs as well).
www.navalnews.com
USSOCOM Combat Craft Assault Photo Reveals Some Key Features - Naval News
An UNCLASSIFIED November 23, 2020 public domain photo showing the United States Special Forces Command (USSOCOM)’s Combat Craft Assault (CCA), built by United States Marine, Inc.’s (USMI) next to the USS Hershel “Woody” Williams (ESB-4) has revealed some interesting feature information already...
www.navalnews.com
Interesting news from SK on the battery tech for the second batch of their new KSS-III class of 3000t subs: MADEX 2021: Hanwha Defense presents its new technology of lithium-ion battery for submarines
The move away from lead-acid seems to be firmly established in the most leading-edge submarines. It would be interesting to know what exactly is meant by " increase its ability by 300% and economic endurance by 160% ".
The move away from lead-acid seems to be firmly established in the most leading-edge submarines. It would be interesting to know what exactly is meant by " increase its ability by 300% and economic endurance by 160% ".
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Git_Kraken
Active Member
One of the challenges for Li batteries in large packs is that Li batteries are extremely energetic and toxic when burning. This means specialized/robust ventilation and fire suppression systems for spaces with them on warships. Any consideration for Li batteries as a power storage has to take this into account for damage control purposes.
The Chicoutimi submarine fire would have been much different if Li batteries were involved, and the health effects on the crew would have been much worse (both long and short term).
The Chicoutimi submarine fire would have been much different if Li batteries were involved, and the health effects on the crew would have been much worse (both long and short term).
John Fedup
The Bunker Group
True, but the Japanese have enough confidence in their Li-ion tech to use them on their latest subs. The SKoreans’ like the Japanese, have extensive experience with these batteries so they likely are very confident about the safety of their design as well.