212 U-boat on Future weapons.

Pretty interesting to actually see inside the sub. I was pretty surprise it does not use the pump jet propulsion that the Brits, American and French have put in that supposedly decrease noise.

Man I love this thing! looks great. I was very confused though on one part: the guy in the video was talking about how this sub has a heat sig that makes it easily identifyable, and I didn't catch where he mentions what they use to counter that. I also couldn't understand what role the hydrogen playes...I'm not too good with ships hehe.

Regards,
Maestro

Originally posted by maestro46
Man I love this thing! looks great. I was very confused though on one part: the guy in the video was talking about how this sub has a heat sig that makes it easily identifyable, and I didn't catch where he mentions what they use to counter that. I also couldn't understand what role the hydrogen playes...I'm not too good with ships hehe.

Regards,
Maestro

Maestro,
The heat signature you are describing is from the running of the diesel engine which is turning the a generator or in some cases on a diesel boat also turning the propellor shafting. The diesel exhaust must be sent overboard...this hot exhaust is the heat signature of which they are speaking in the video.

This type of diesel is run on or near the surface....taking in air through a snorkel apparatus and exhausting it out the sail structure..resulting in the heat signature.

YOu counter this by turning your diesel off and taking the boat down to depth where this heat signature cannot be anymore seen.

Thanks,
Orangetom

So what you're saying is this sub is only vulnerable during the time it's getting rid of the exhaust?

Regards,
Maestro

Maestro46,

No I am not just saying that a sub is vulnurable when it is running its diesel though that is one of the times yes...when it is getting rid of its exhaust.

Submarines are vulnurable when they are changing depth...especially going below the surface or when they rise to the surface. They are sometimes blind so to speak at this time. Especially when they are coming to periscope depth. Many submarines have surfaced this way underneath other ships or been run over by large ships who dont see them or even know they are there.
Submarines are very vulnurable in like manner to airplanes..when they change altitude or depth in this case. Many aircraft accidents occur mostly on take off or on landing. Not usually between long distances to destinations...but take offs and landings.

Noise or noise signatures at any depth also make a submarine vulnurable. Either machinery noise or even the act of someone dropping a tool ..to make a noise that can be determined is man made.

Submarines are obviously vulnurable at certain depths. This is why you have operational depths and then crush depths. Obviously one does not want to take ones boat below crush depth. Extreme vulnurability found here below crush depth.

Just some things for you to think about.
Thanks,
Orangetom

orangetom, would it be more appropriate to apply the pump jet propulsor on this submarine instead of the conventional screw, since this technology decrease noise significantly? Why did the Germans not use this technology? Problems applying it to this type of boat?

Deltaboy,

I dont exactly know why they did not incorporate a pump jet propulsor.

I do know that this is not a large submarine as boats go.

I also know that the pump jet propulsor adds alot of weight on the very after end of the boat. This meaning that the boat would have to be redesigned to accomodate this tail heavy weight. A pumpjet propulsor is also an expensive add on compared to regular propellor designs.

I also know that this is not a fast boat as boats go and cannot keep up the speed for any length of time as does a nuclear boat so the advantages of the pump jet propulsor in quietness would not be advantageous in light of the added weight. In otherwords a tradeoff here.
I suspect that much of this boats quietness when submerged below periscope depth is in its not being able operating at a substantial speed as compared to a nuclear boat.

Thanks,
Orangetom

Yeah I don't know of any SSK's that use a pumpjet, I think it's a technology that only offers significant benefits on nuke boats.

Any pump propulsion will be noisier than a quiet propellor. You guys have been watching too much of "Hunt for Red October."

This technology is the same hydrogen fuel cell technology used to power Vancouver's bus fleet.

You take hydrogen and air pass an electric current through a catalyst membrane (thought to be a silver palladium mesh) which burns the hydrogen to produce fresh water and oxygen.

Diesels are only in use for surface running refilling gas bottles and charging batteries. With Hydrogen fuel cells you just dive the boat, crank open the bottled gas and hey presto, electricity for the electric motors and fresh water for the crew. The item says it can go half way around the world, which is about 12,000 nautical miles.

This is brilliant technology.

Originally posted by sy.gunson
Any pump propulsion will be noisier than a quiet propellor. You guys have been watching too much of "Hunt for Red October."

THis is a strange statement to me. I am curioius as to why any nation would install a noisy pumpjet system on a boat and then spent millions on sound mounting systems incorporating the latest very expensive designs..only to use a noisy system for propulsion.

I am aware that there are propellors designed for speed. Others are designed for thrust or working power verses speed, Tugboats for instance. A speed propellor is not necessarily a quiet propellor but designed for speed within a working envelope.
I am also aware of quiet propellors. Designed for quietness within a certain speed envelope. Outside of that envelope they tend to be unquiet.

I just wonder ..as stated why anyone would design a submarine with a noisy propulsion system and then spend huge bucks on extensive sound mounting of equipment. This seems at cross purposes.

Thanks,
Orangetom

Pump Jets

Pump jets are not "always noisier" this depends on depth (pressure) and speed of the blades before the induction of "cavitation".

Pump jets have high blade angles and slow turning speed so are clumsy at slow speeds and in shallow water.

But can run at higher speeds and less noisily than pure blades at depth due to higher internal pressure "within the propulsor" increasing the speed at which cavitation occurs. Remember high angle of attack gives thrust per revolutuion increases over pure "non ducted" blades.

The German boat is a littoral warfare boat not an ocean going attack boat hunting boomers all over the oceans.

If you wish to research this further I suggest you go to the RN website and look up the Astute class of boats. There is a video thread on that very boat in this forum. USS Seawolf uses one as well I believe.

Thanks Deharg, then I'll qualify my objection to the pump jets and agree with you that they do not suit the U-212's environment or purpose.

Other comments about propellors being quieter in their intended revolution range are also quite correct. You wouldn't be pulling thirty knots in shallows either.

EDIT: as an afterthought if the U-212 concept were used in open water no doubt the design could be optimised for higher speeds too, but obviously one has to make a choice which speed range one wishes to optimise. Undoubtedly, range would drop dramatically if the U-212 were intended to charge around at full throttle.

[edit on 24-5-2007 by sy.gunson]

FURIOUS AGREEMENT:

It's still a great boat. I wonder how the good ole "upholders" compare. Maybe Canada did buy lemons(even cheap ones). Can someone with more knowledge than me answer?

Enjoy..

Wouldn't a magnet drive be more stealth than a pump jet?

Don't watch too much t.v.

The Hunt for red october sub in the book had pump jets and for the film this was not considered sexy enough so the magnetic drive featured.

I am sure if could be made quiet and to actually work then yes you could be correct.

Don't forget subs are already stealthy and can hide beneath thermoclines etc so, there is more too it than quiet =stealthy.

Quiet and fast is NOT stealthy. Big boat shallow water is not stealthy.

A lot depends on the skill of the captain and crew. UK subs have been conducting "mock sinkings" of US carrier battle groups for decades.

Enjoy..

Originally posted by Deharg
FURIOUS AGREEMENT:

It's still a great boat. I wonder how the good ole "upholders" compare. Maybe Canada did buy lemons(even cheap ones). Can someone with more knowledge than me answer?

Enjoy..

Weeell... in the strictest sense of the word the Upholders can´t be lemons, since it should have been obvious that they simply are not the most shiny example of engineering art - which was apparent by their lengthy refitting/refurbishing downtime. They more or less continued to show ever new flaws in Canadian service, but that should not have been much of a surprise. Even though they might be good once they DO work, the inherent flaws like using a railroad Diesel will most likely never stop making problems.

The comparison to the U212 howeer would be unfair. Apart from its obvious age advantage, the U212 was from the ground up designed for its characteristics and mission profile - the Upholders however as value alternatives and according to earlier nuclear boat blueprints. These boats are built for monitoring the GIUK gap. The standards to which the U212´s are built were higher as they were needed to become "multipurpose" boats.

Would the german boats have been the better choice, had they been available back then? From a purely technical POV, without a doubt. Upholders´ only advantage would have been a slight longer range. The smaller size, higher maneuverability and lower "draft" (the boats are "baltic-proofed", capable of diving through the shallowest strait of the Baltic Sea), coupled with its unprecented dive length courtesy of the AIP system would have made it far better for patrolling the rugged and remote areas of Newfoundland, Nunavut and the polar circle.

Funny though that, given the follow-on costs of the Upholder boats, the U212s at ~400 mil. €/piece wouldn´t even have been more expensive. As said before, the comparison between the two is a bit unfair, but the U212 stands as the pinnacle of conventionally powered submarines and is likely to continue the export successes of HDW shipyards. They even plan on mounting a 30mm gun on the ship!

Its only downside is the (as of now) somewhat dangerous H² refuelling process.

[edit on 29/5/2007 by Lonestar24]

Thanks Lonestar that was great ....

My father took me to Barrow when I was a little kid and I had the privelige of being allowed onto a real oberon class boat and also got to stand in the bridge simulator .. which was very scary as the thing moved about quite a bit.
Been fascinated ever since..

Enjoy