Bharat Rakshak

Since there is no thread for international naval matters,only a general thread for all military matters,it would be preferable of the frequent posts on naval news is on this thread.

http://www.telegraph.co.uk/news/newstop ... antic.html

I wonder how their paths crossed in the vast ocean. must have been doing some drill together.

This actually proves the limitation of Low Frequency passive sonar when dealing with Very Quite Nuclear submarine.

We have soon reached a stage with major nuclear power where detecting very quite nuclear submarine with passive sonar will be very difficult to impossible , specially when the weather gods are not on your side.

Two gigantic N-subs loaded with BMs collide mid way( they must have been at decent speeds) and neither have any damage?

Would you really expect these countries to admit that their 'security' is compromised in any way ?? even if there WAS a total disaster ? i think their silencing tech are better than their sonars ! or can the high seas affect sonars ..?

Or may be they were engaged in a cat and mouse game to learn about each other and got too hot. NATO camaraderie not withstanding, Royal Navy and Marine Nationale are not exactly chaddi dost, too much history.

Remember reading a newspaper snippet ~10 years back about some Brit leaking some sub info to a French. And the Brits worried about Frenchies improving their system over that of the Brits. Details too hazy to recollect.

Two SSBN wont be playing cat and mouse game against each other , most likely they might be on a patrol in the same area in Atlantic , and since both were deaf and could not hear and knew about the others presence in the area , they simply collided , happens very rarely but it did happen.

Reminds me about similar collision between a US LA class SSN Baton Rouge and Russian Sierra -1 SSN , the damage to LA was bad enough to decommision it quite early.

Since both these submarine were very modern and both would have used passive sonar as a means of detection , it just goes on to show how silent modern submarines have become that they actually realise about the other presence only after a collision.

I am sure bad weather i.e. wind condition and sea state in Atlantic played a major role as well in hiding the subs signature.

In the vastness of the ocean and that too, increasing the "space" since submarines go underwater unlike surface ships, colliding randomly is close to statistically impossible. Well, these two have done the impossible. Collisions of any type happen typically even with surface ships in busy lanes, near ports etc where there is crowding and separation becomes less. But in the middle of the atlantic?. Something very fishy there.

How do wind conditions and bad weather affect submerged sub's signature ?

Weather related ambient noise can be caused by sea state i.e noise caused by surface wave , precipitation , and sound transmission loss in such conditions

Modern submarine have reached a noise level which is equal to less than the noise of ocean , making detection by LF Passive sonar exteremly difficult in favourable weather conditions to almost impossible in bad weather condition.

I remember looking at a figure where a LA submarine would detect a Akula submarine at ~ 10 Km in very favourable weather condition which reached to ~ 0 in adverse weather condition

There is a thinking in USN that to detect modern submarine they may soon have to go active , or end up playing blind man bluff

I think the combination of factors like ambient noise , weather condition , low noise signature of the submarine itself and limitation of LF passive sonar has lead to this accident.

But on a positive note it shows the almost invulnaribility of modern SSBN and its ability to avoid detection as a crucial arm of Nuclear triad .

Where are all the folks cursing the bear for sloppiness when the oh so elegant french and their stiff english cousins manage to do this sort of stuff.

I mean Le Triomphant and Vangaurd colliding... wow... this beats the Russians Nuke sub disasters as simply pedestrian.

what do you mean by "stiff english cousins" ?

You really don't want me to spell that out, do you, and that too to a Mod.

^^^ I think it should be more like 'stiff upper lip' English cousin. Though after this incident many parts of the English anatomy will be stiff.

finding even the quietest sub is most important tech that the future needs to seek after. can any type of underwater optics/laser detection help, in terms of sounding an alarm at least within about 100s of meters.?

Anti sonar tech as in quieting technology or active sonar jamming ? it was not too long that a sub ran into a warship in the malacca straits ! Anyhow this underscores how much countries are willing to go to keep their nuclear subs top secret and their deployments as well.

Lee Willett, of the Royal United Services Institute for Defence and Security Studies, said that Britain and France would be very reticent to share information on what their nuclear submarines were up to. "Despite how close these relations are, they are the ultimate tools of national survival in the event of war," he said.

Maybe they are getting ready for a redux o the Hundred years War!

Huge oil slick from Russian ship heads for British coastline
Few days back middle of Atlantic there is collision of two submarines, now russian leaked oil on
south west or Ireland/wales shores. (cough. Cough may be British or French ducking down for russians?) For these military mights Atlantic is play ground I guess...

French sub unaware it rammed Royal Navy vessel in mid-Atlantic nuclear crash


Despite being allies in NATO members Christan Economic Club(EU), both have no clues whereabouts of each other...

That is the whole idea of having SSBN , nobody has an idea where it is , except for few people on subs

But a a direct collision? Thats something.

It wasnt a direct collision more like they brushed against each other from what has come out until now also it was at very low speed.

http://news.bbc.co.uk/2/hi/uk_news/7892294.stm

Some reports mentioned extensive damage to the sonar dome of "Le Triomphant" . Not sure if "extensive" damage occurs in low speed scrapes....

Frankly speaking it does not matter if they had a head on collision , or a brush , the fact remains that both these modern SSBN ( both these are the newest type from French and British ) could not detect each others presence and the only time they knew about the other is when they hit or scrapped.



We have reached a stage in sub silencing where the noise of submarine at tactical speed is as quite as the Ocean Noise and at very silent speed lower than that , the primary sensors of the subs are the Low Frequency passive sonar , they represent the eyes and ears of the sub , there are other sonars and non-acoustic sensors but they aid the passive sonar specially the non-acoustic sensors.

For obvious reason the sub would not like to go active as it may betray its presence , although they are toying with the idea of using UUV or torpedo with active sensor suite , the non acoustic sensors might be one possible way to detect a submarine presense but they are limited in the scope of use and can be aid the subs primary sensors.

Every sub would like to take cover of natural protection that sea offers and using the temperature variance to mask itself , which limits the enemy sensors in detecting them but also limits their own sensors.

So a combination of factors including the subs own inherent strength and environmental factor will lead to a stage where the sub are almost invisible to a broad range of ASW platforms in open ocean , but at the same time runs a risk of bumping against each other

US Navy orders new electric hyper-kill railgun
http://www.theregister.co.uk/2009/02/18 ... eal_inked/

Low speed also means that they cannot claim that sonars were not effective which happens when the speed goes above 10kts

Raj , both must have been on passive sonar , so lower the speed less is the chance that they might be heard and heard from a good distance , the environment conditions can degrade the capability of passive sonar considerably.

More ever modern SSN like Seawolf and Akula-2 have capability where their passive sonar remain effective at high tactical speeds , which is 25 knots ,before a washout occurs.

OZ;s ne $15 Billion programme to counter Chinese and Indonesian naval sub threats.Good to see that India is not mentioned in the list!

Excerpts:

http://www.smh.com.au/national/jobs-boo ... tml?page=2

Jobs boost from new $15b submarine fleet

Sineva Missile Launch from North Pole
http://www.youtube.com/watch?v=rhI9F0WW3eU

Bulava ground tests, first surfaced and submereged launches
http://www.youtube.com/watch?v=KkKPDSICMQQ

Russian Navy's sub fleet and its current condition as it attempts to reinvigorate its once enormous Cold War nuclear sub fleet.

The Russian Navy Crawls Out Of The Cellar
http://www.strategypage.com/htmw/htsub/ ... 90222.aspx

Stealth Boat to be auctioned off by USN

USN wants to scrap this.. circa 1980 technmology.. Makes you wonder what tech is available now with them..