Naval Ship & Submarine Propulsion Systems

rand0m said:

Did anyone else pick up that advertising about the Submarines being built in Adelaide was being aired on TV approximately a week before the announcement...? I found that bizarre!

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Very strange. Trying to assert pressure via public opinion. I'm not sure what it was meant to achieve really.

Sea 5000

Well now that one is ticked off, how does everyone think SEA 5000 will pan out. Which platform entails the most risk and conversely the least? Which suits our conops as we with limited information understand it?

I was just reviewing DCN's early media releases on the original SMX Ocean design, prior to renaming the design to shortfin barracuda - They were actually spruiking the design as having LI batteries!

rand0m said:

Did anyone else pick up that advertising about the Submarines being built in Adelaide was being aired on TV approximately a week before the announcement...? I found that bizarre!

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I saw a TKMS ad 1/2 hour before the announcement, can't for the life of me work out why they were advertising that late. They would have known the descision by that time. Maybe they had paid for it and couldn't get their money back.

gf0012-aust said:

I'll give you one example - there are a myriad more

SB Block 1A is a conventional conversion of the SB nuke
The drivetrain doesn't exist
No western country has used a DE drivetrain on a pumpjet - it has yet to be designed, tested and then developed - and that needs to be done before it goes into the last 3 sections
Look at the pumpjet on a nuke - its able to develop basically instant thrust - ie sprint and surge on demand - the best DE available can't do that - IOW there is an immediate change in performance and handling dynamics
then compare the drivetrain real estate issues on a nuke and compare it to a conventional

.....

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Dumb question here, a pumpjet is basically the same as a waterjet drive on a power boat or jetski, on either they can go from 0 to full tit remarkably quickly, basically within a few boat lengths from when you open up the throttle, surely with the instant torque of an electric driveline the sub with have the same immediate change in performance. Or look at a Tesla, the reason why it has remarkable accleration is because all the engines torque is available right away, it doesn't have to build revs like on a conventional engine. IMO the DE pumpjet should be able to give that instant hit of accleration like an nuke can, so long as there is enough juice in the batteries.

KiwiRob said:

so long as there is enough juice in the batteries.

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And there is the problem right there ! I am sure GF can explain it better than I can, so please expand and correct me if I am wrong GF ?

But essentially it is all about the power, on a DE, you can only store, release, produce and store in the cycle so much energy, you also only have some much energy density based on you fuel used and the storage capacity.

On top of that you can only release stored energy at pretty specific rates, voltage, amperage etc.

Then you have happening in the background what is called the "Hotel Load" this is the absolute base minimum that is required for the submarine to basically survive, CMS, Weapons systems, critical systems, crew etc etc.

You have to manage all of this in very specific ways, you can't just have a reserve in there to jump out of the box like a jack rabbit, just not that simple, and the pumpjet is a very energy intensive form of propulsion.

In a nuke, chalk and cheese, there is a reason why they use them. And there is a reason why no other country has pumpjet propulsion in use for DE's, the Russians tried, so another telling reason why they also only made one

Cheers

KiwiRob said:

Dumb question here, a pumpjet is basically the same as a waterjet drive on a power boat or jetski, on either they can go from 0 to full tit remarkably quickly, basically within a few boat lengths from when you open up the throttle, surely with the instant torque of an electric driveline the sub with have the same immediate change in performance. Or look at a Tesla, the reason why it has remarkable accleration is because all the engines torque is available right away, it doesn't have to build revs like on a conventional engine. IMO the DE pumpjet should be able to give that instant hit of accleration like an nuke can, so long as there is enough juice in the batteries.

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The problem is from 0 to full drained all the juice in the batteries real quick, usually in less than 30 minutes for a SSK.

Everyone are welcomed to point me out if I am wrong:

Taking the Upholder class as an example, the hotel load is about 150ish kw per hr, while the propulsion load is 50ish at 5kt. The rule of thumb for propulsion load increase is about the cubic of the speed, so for a 10kt transit speed, the propulsion load is about 400ish kw per hr.

Now we have a submarine nearly twice the size, with a more power hungry combat system, and you want a higher speed (14+kt) for the pump jet.

Wow........

BTW, I don't see those argument regarding to LAB or LiB on SB Block 1A have any point at this stage. It is up to RAN to cherry-pick the best possible gear during the design phase. It is always possible to have a MTU diesel and motor with Japanese battery and British distribution board (ie, nothing french in DT) on the SB, and nothing french (except the kitchen toilet and bunk) in the front sections.........

rockitten said:

BTW, I don't see those argument regarding to LAB or LiB on SB Block 1A have any point at this stage.

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Really ? I beg to differ, and considering your post about power requirements, hotel load etc do you really think the choice of battery type is of not importance ?

The conversion of the sub from Nuke to DE is, I believe, the single most important critical factor. Pick whatever you like, if you do not get this right the sub is history.

BTW "LAB" has a totally different meaning for subs, Large Aperture Bow, type of sonar array

Cheers

As a simple lay person with no sub or defense experience I can offer this discussion.

Tesla can offer mind blowing acceleration and huge range in a vehicle of regular dimensions because of Lithium batteries. They will be lighter, smaller, handle regular deep discharging, supply more current and have significantly more capacity while doing it, charge quicker, than conventional lead acid batteries.

The pumpjet is not as well suited to lead acid battery Diesel electric submarines, because a short sprint will exhaust their charge very quickly, in 10's of km. Lead acid batteries don't actually deliver their best when they are providing huge currents, you actually get significantly less total energy. Many batteries are rated in capacity (Amp hours) and this changes depending how much current you pull out (significantly different at high currents).

Lithium batteries can provide high current with less loss. So Lithium batteries in a car application can deliver a large amount of current and do so more than 3 times more effectively than lead acid batteries could in these high demanding applications.
http://corporate.siemens.com.au/con.../apdr-october-2015-issue-future-submarine.pdf

All three CEP contenders are likely to offer Li-Ion
batteries as an energy cache. Li-Ion batteries have significant advantages over standard submarine lead acid batteries. They have a higher energy-density and much lighter weight; for slow speed operations they offer approximately 1.3 times capacity, but for higher speeds they offer up to three times. It also makes them ideal for pairing with high-powered diesel-generators during rapid transits.
Also more efficient high-speed runs can be conducted deep with regular snorting periods. Li-Ion batteries are also able to take very large charging currents over the
entire charge range of the battery compared to lead acids, which can only be charged at full rates up to about 85% after which time the charging rate must be reduced to avoid a dangerous gassing situation.

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The SB design as it stands now can't really make good use of its pumpjet, nor the most of its 4 diesel engines with conventional lead acid batteries (IMO). However, lithium batteries are coming to subs. Incorporating enough lithium ion batteries to be able to take on propulsion loads would really open up this design (IMO). The french are probably the furthest behind on lithium batteries, as its not critical when you have SSN, and for most SSK's fuel cells will do the job for their CONOPs. Japan with its dated Stirling AIP engines is right on the cusp of deploying lithium ion batteries en mass on sub fleets, so they would be the ones to talk to.

While the SB is much larger than the upholder, I think it would be an interesting exercise to look at hydrodynamic drag compared to say Upholder or Collins. Short fin Barracuda is only 1.6m wider (8.8m) than Upholder, and the drag is probably not a big increase as you may have initially thought (not that frontal area is the only concideration and not that reducing it to a simple cylinder is accurate). With retractable planes, pumpjet and improvements in design and construction I would imagine it would be in the same order of magnitude. I assume the french were pursuing these in trying to reduce noise and also perhaps to extend the time between reactor refits by reducing drag (?).

Its an interesting choice, there is potential, much we don't know about and it seems there may be more that will become clearer in the future. It seems like the RAN really did want a conventional SSN, and the end result of this may be a very different type of sub from what anyone has really built before.

aussienscale said:

Really ? I beg to differ, and considering your post about power requirements, hotel load etc do you really think the choice of battery type is of not importance ?

The conversion of the sub from Nuke to DE is, I believe, the single most important critical factor. Pick whatever you like, if you do not get this right the sub is history.

BTW "LAB" has a totally different meaning for subs, Large Aperture Bow, type of sonar array

Cheers

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Ops, by bad, I should clarify a bit more. What I mean is that there is no point to dig in those french brochure or statements (criticizing Li batteries) and then "assume" our SB will have Li batteries or lead acid batteries.

From my point of view, the Li battery is the way to go regardless it has a pump jst or not. Even if (if!) all suppliers' batteries really catch fire on test lab, there is still a back-up technology called molten salt battery. It has similar power density as Li batteries and the Germans' type 212 already have them on board.

Do any of you think that the commitee that decided the French option was the best, forgot to ask DCNS if a conventional could use the pump? Do you think they might have asked them to prove it? Do you think they might have more info about what it will and wont be able to do than you do? Fair dinkum, im about to toss this forum and go to a sensible one...like the Pakistan defence forum, the quality is almost the same at the moment.

old faithful said:

Do any of you think that the commitee that decided the French option was the best, forgot to ask DCNS if a conventional could use the pump? Do you think they might have asked them to prove it? Do you think they might have more info about what it will and wont be able to do than you do? Fair dinkum, im about to toss this forum and go to a sensible one...like the Pakistan defence forum, the quality is almost the same at the moment.

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I'm hearing you, the negativity is almost surreal. I'm certain some are upset that their pet didn't get up. Perhaps some just didn't see DCNS coming and think they are looking a little silly. Perhaps, perhaps not. I'm sure that with in excess of 50 billion of tax payers dollars at stake some of the more basic questions being thrown around here have indeed been answered. Most people here do not know because they aren't in the loop. If some people are in the loop they would if there is any level of intelligence be laying very low. Have a great night.

old faithful said:

Do any of you think that the commitee that decided the French option was the best, forgot to ask DCNS if a conventional could use the pump? Do you think they might have asked them to prove it? Do you think they might have more info about what it will and wont be able to do than you do? Fair dinkum, im about to toss this forum and go to a sensible one...like the Pakistan defence forum, the quality is almost the same at the moment.

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the problem is that you might have had a similar mindset to the teams that assessed Tiger, NH90, MU90, HQJOC, etc etc..... and the end state is that until they release it in 30 years we won't publicly know whether the CAT was gazumped by the NSC.

out of all the progs I know where there was Govt intervention as opposed to taking the defence selection, it was only Bushmaster that ended up successful and low on the radar for steering group reviews etc...- and even then it was canned (and I worked at the time for Cambridge who were supplying the harnesses, so we got a stay on the contract - only to have it lazarused as the Govt realised that Bendigo was a seat at risk, so needed to shore it up)

As it was it was a good bit of gear - but it was about to be cancelled until the seat crunchers stepped in.

The other thing to be aware of is that the AIC side would have had a lot of weight in the assessment matrix - and everyone has seen how quickly all 3 scrabbled to lift local production as a selling point.

AIC plus full ToT would have had enormous weight as the latter is one of the things that contractually the CoA wants to secure so as to not end up with a Kockums repeat.

All in all, my sense of this is that the ADO are expected to negotiate protection into the contract because none of the technical detail would have been finessed for that CEP. The CEP is basically stage 1 of risk mitigation. Prior to Abbott and Abe, we never had CEP's as part of a formal eval anyway. Its entered the procurement lexicon for ever and a day now however.....

knightrider4 said:

I'm hearing you, the negativity is almost surreal. I'm certain some are upset that their pet didn't get up. Perhaps some just didn't see DCNS coming and think they are looking a little silly. Perhaps, perhaps not. I'm sure that with in excess of 50 billion of tax payers dollars at stake some of the more basic questions being thrown around here have indeed been answered. Most people here do not know because they aren't in the loop. If some people are in the loop they would if there is any level of intelligence be laying very low. Have a great night.

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I get really pissed off at snippy comments like that

we are professionals whose job is to protect the commonwealth - we're not warhammer players.

if you have some tech responses that counter what I've said feel free to come back with some coherent responses other than fan clubbing comments on the current decision

btw this is the first stage of negotiation - so NONE of the specific requirements have been scoped and agreed upon - so your comment about the $50bn and considered thought being used to get to this point does not accord with how projects and these platforms are assessed

lose the attitude btw, as sensible discussion around important issues such as this should be the norm

I'd suggest that you read why the concerns have been raised and then do some research a response

when you find out that whats been said is true and of concern, then maybe start engaging against minus the churlish comments

if you believe that whats been said is inaccurate then come back with facts and maybe those who have actually worked on major maritime projectssuch as subs will detect that your questions are genuine rather than more gilded and tart responses to things that you obviously take issue with

its a fair battlefield when it comes to technical debate - like it or lump it

gf0012-aust said:

I get really pissed off at snippy comments like that

we are professionals whose job is to protect the commonwealth - we're not warhammer players

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Sorry old mate I have no idea what warhammer is? No need to get aggravated. If I may I imply that the very questions raised on this forum regarding pump jet propulsion would not have been asked by those conducting the CEP. So what we know about the limitations of pump jet propulsion on DE drivetrains as explained by various members of this forum, has eluded those who conducted the CEP. In essence it appears that against all advice provided by those who conducted the CEP as they surely would relate to government what has been stated here as it appears to be common knowledge, the AI involment has totally overiden the advice of the CEP panel and process.

knightrider4 said:

Sorry old mate I have no idea what warhammer is? No need to get aggravated. If I may I imply that the very questions raised on this forum regarding pump jet propulsion would not have been asked by those conducting the CEP. So what we know about the limitations of pump jet propulsion on DE drivetrains as explained by various members of this forum, has eluded those who conducted the CEP. In essence it appears that against all advice provided by those who conducted the CEP as they surely would relate to government what has been stated here as it appears to be common knowledge, the AI involment has totally overiden the advice of the CEP panel and process.

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err no.

this process was about selecting a prime based on a broad selection matrix - none of the technical specifics or the IP issues would have been considered in detail - thats left to the next stage

if the prime can't build to the spec sought and contractual constraints set by the CoA then the contract can still get cancelled and default to the next best choice.

NONE of the technical specifics would have been reviewed in detail

some of us actually do this for a job and have done this before

gf0012-aust said:

err no.

this process was about selecting a prime based on a broad selection matrix - none of the technical specifics or the IP issues would have been considered in detail - thats left to the next stage

if the prime can't build to the spec sought and contractual constraints set by the CoA then the contract can still get cancelled and default to the next best choice.

NONE of the technical specifics would have been reviewed in detail

some of us actually do this for a job and have done this before

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I do not doubt for one minute your professional qualifications and experience in procurement. Simply seeking clarification on the process and how a decision is made. But surely the CEP would over the 15 months addressed some of the issues raised here.

knightrider4 said:

Sorry old mate I have no idea what warhammer is? No need to get aggravated. If I may I imply that the very questions raised on this forum regarding pump jet propulsion would not have been asked by those conducting the CEP. So what we know about the limitations of pump jet propulsion on DE drivetrains as explained by various members of this forum, has eluded those who conducted the CEP. In essence it appears that against all advice provided by those who conducted the CEP as they surely would relate to government what has been stated here as it appears to be common knowledge, the AI involment has totally overiden the advice of the CEP panel and process.

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Commander Sub Sqdn told industry that the RAN wasn't there to build their sub around industry - the RANs requirement is to get the best capability that they can

Govt in case you haven't picked it up has made decisions based on political demands - ie protection of a voting base. or have you not paid attention to what weatherill, edwards, xenophon have been doing for the last 9 months?

the AIC weighting therefore is highly significant - and that means that it runs counter to what the Commander Sub Sqdn said to industry reps at the SIA meetings

IOW, like all the other examples I have given, there would be some pretty significant evidence that Govt priorities have had a different complexion to what CMDR SS said....

the CEP is not about confirming whats on the powerpoint demo

aussienscale said:

And there is the problem right there ! I am sure GF can explain it better than I can, so please expand and correct me if I am wrong GF ?

But essentially it is all about the power, on a DE, you can only store, release, produce and store in the cycle so much energy, you also only have some much energy density based on you fuel used and the storage capacity.


Cheers

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Ok I see, I don't know anything and just assumed that going full tit would only be for a short distance to get out of harms way, not something you would do over distance's more than a few KM.So in my uneducated mind a battery producing instant torque from 0 rpm allied to the fast reacting pump jet would be a great idea.

gf0012-aust said:

Commander Sub Sqdn told industry that the RAN wasn't there to build their sub around industry - the RANs requirement is to get the best capability that they can

Govt in case you haven't picked it up has made decisions based on political demands - ie protection of a voting base. or have you not paid attention to what weatherill, edwards, xenophon have been doing for the last 9 months?

the AIC weighting therefore is highly significant - and that means that it runs counter to what the Commander Sub Sqdn said to industry reps at the SIA meetings

IOW, like all the other examples I have given, there would be some pretty significant evidence that Govt priorities have had a different complexion to what CMDR SS said....

the CEP is not about confirming whats on the powerpoint demo

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I'm fully aware of the political implications of the decision. I did not think that Australian industry involvement would have that much influence to preclude us getting the most capable boat.