submarine

[DuckHunterJon]

Re: submarine

I'll concede to you Bart, you've got much more experience than I do. I was an acoustic engineer working for EB on Seawolf and Virginia class for 4 years. I worked in the acoustic test group that was responsible for all noise testing including sea trials. I agree with the secretive part about the prop, but will hold my ground on the cavitation part - you're almost on the money when you said no one can assume - but it's what I did. Wish I could talk more specifics as these are totally unlike any props we talk about here - but I can't.

I wasn't refering to cavitation affecting noise signature on the surface - as you said, no one cares because there is much more turbulence going on. I was refering to damage that can be done due to cavitation. I know on the sea trials I was on, we had to transit out far enough to dive, and this was always at 5 knots. Maybe this was because these were uncommissioned boats, maybe other reasons. Either way, great discussion. Subs were a passion of mine - I only got out of it as we wanted to move back closer to family.

 

[Home Cookin']

Re: submarine

a retired submariner told me today, "in subs you do all activities in pairs. Like if you dive, you surface." I think there's alot of wisdom to that, in how we approach everything we do. Each act has a necessary follow-up act.

 

[dingbat]

Re: submarine

a retired submariner told me today, "in subs you do all activities in pairs. Like if you dive, you surface." I think there's alot of wisdom to that, in how we approach everything we do. Each act has a necessary follow-up act.

Kind of like "leaving the dock is optional, retuning is not"

 

[AZSenza]

Re: submarine

I was working at NAS North Island last year (Coronado Island) Its HARD to imagine the hardware we have in our military arsenal! I'd drive by the USS Carl Vinson every day to eat lunch. My kids came out to the beach one day and got to see a Nuke sub go by not too far from shore. If you like boats, you've got to go to a Navy Base and watch them operate. Its fantastic!

 

[PiratePast40]

Re: submarine

I agree with the secretive part about the prop, but will hold my ground on the cavitation part - you're almost on the money when you said no one can assume - but it's what I did. Wish I could talk more specifics as these are totally unlike any props we talk about here - but I can't.

Oh come on now Mr. Walker, surely you can tell us just a little more !

Edit: Added a smiley - didn't mean for that to be a personal attack.

 

[hostage]

Re: submarine

Why do subs have a conning tower, doesn't that give it more drag underwater?

 

[PiratePast40]

Re: submarine

Why do subs have a conning tower, doesn't that give it more drag underwater?

On modern submarines, it's called a sail and adds stability. A submarine, like an airplane, operates in a 3 axis environment. Also acts as a storage area for the masts (antennas and periscopes).

On the older boats, the "con" or control room was directly below the "conning tower". This is where most of the commands were given but the actual controls were usually in a room below that. If you have an opportunity to tour any of the diesel boats, or even the Nautilus, you'll see that arrangement.

 

[badkins50]

Re: submarine

Very neat pics. Thanks for sharing. We don't get to see anything that cool on erie.

 

[DuckHunterJon]

Re: submarine

On modern submarines, it's called a sail and adds stability. A submarine, like an airplane, operates in a 3 axis environment. Also acts as a storage area for the masts (antennas and periscopes).

On the older boats, the "con" or control room was directly below the "conning tower". This is where most of the commands were given but the actual controls were usually in a room below that. If you have an opportunity to tour any of the diesel boats, or even the Nautilus, you'll see that arrangement.

In addition to these, one more job of the sail is to provide a hardened structure to punch through ice.

 

[PiratePast40]

Re: submarine

^^^ True but not all boats with sailplanes are equipped to break through the ice. On 637 class boats, the planes could be tilted straight up by by changing the hydraulic valve lineup. Those valves were just forward and to the stbd side of the helm station and just forward of the forward plotting station.

Here's a picture of a boat with the sailplanes in the verticle position:
View attachment 104699

 

[DuckHunterJon]

Re: submarine

I'm not trying to be argumentative either but you are incorrect. The published speed of a Ohio Class Ballistic Missile Submarine depending which Navy, DoD, or civilian website is approx. 12 knots. The submarine pictured above just got underway from Naval Station Norfolk, Va inside of the Thimble Shoals Channel which is dredged to 50 feet so there is no way that submarine is partially submerged. Also, just by looking at the pictures above you can clearly see the bow, sail (conning tower), the hull where the missile tubes are located, and the rudder. Besides the nuclear reactor there is nothing more of a secret than a submarine propeller so no one can assume if or when it will cavitate. The noise of the water moving over the bow and into the sail causes a lot of noise while surfaced so noise is not an issue, only when submerged which is when the secrecy of the propeller comes into play.

How do I know - I am a active duty Chief Petty Officer in the United States Navy with over 15 years of active service. I have spent 12 of my 15 years of duty in Norfolk and I worked for 3 years on both Los Angeles and Ohio Class submarines.

Disclaimer - All of this info is on Navy, DoD, and public websites and also goes more into detail on History Channel's Modern Marvels.

Just a follow up Bart. I was wrong. I emailed a friend of mine who retired after 42 years (mostly in the acoustic test group I was in). He reminded me (funny how memory fades after 11 years) that my first sea trial was on a Los Angeles class - and that 24 hour transit was after a failure of the port side bow plane. That was why we were limited to 5 knots. First time out and puking for a straight day must have clouded my memory (that, or I'm just getting old!)

Also, 5 knots was the limit in the river, where many of our overnight trials were. He confirmed normal surface speed once out of the channel is 15 - 20 knots for all the above mentioned subs. Unclassified underwater speed (for Seawolf) is "in excess of 35 knots".

 

[Boobie Trap]

Re: submarine

a retired submariner told me today, "in subs you do all activities in pairs. Like if you dive, you surface." I think there's alot of wisdom to that, in how we approach everything we do. Each act has a necessary follow-up act.

Kind of like flying.....

Take offs are optional, landings mandatory:!!

 

[phonfish]

Re: submarine

On any given day here in the Hampton Roads area, you can see our great military in action. You might see submarines, carriers, destroyers coming in or out port. You may see jets practicing takeoff and landing manuvers at Oceana. The Coast Guard boats are everywhere on patrol. Go up the Elizabeth River and see workers repairing Navy ships or go up the James to Northrup Grumman and see the newest Carrier being built. In my opinion, there is no better place to live and enjoy the water, under the watchfull eyes of the greatest miliary power in the world.

 

[Home Cookin']

Re: submarine

so I went out Friday evening and there ws all kinds of security going on at the base, and saw a sub coming in--this time it was lashed to a commercial tugboat and being dragged into the pen. I don't think it was the same one; looked smaller. Didn't look as proud, either, as the one heading out under its own power.

Today the Navy copters were doing drills nearby.

 

[jim765]

Re: submarine

I was working at NAS North Island last year (Coronado Island) Its HARD to imagine the hardware we have in our military arsenal! I'd drive by the USS Carl Vinson every day to eat lunch. My kids came out to the beach one day and got to see a Nuke sub go by not too far from shore. If you like boats, you've got to go to a Navy Base and watch them operate. Its fantastic!

i hate the color of navy gray lol spent 3 very enjoyable year on uss forestal, and man ,liberty was great lol

 

[sschefer]

Re: submarine

Not trying to be argumentative, but something's not right. Sub's can't run fast on the surface. 5 knot max. Any faster and they risk cavitating. Cavitation on that big of a prop can tear them apart, or at a minimum change their noise signature. You didn't say how much of the con tower was visible, so there's a chance they were partially submerged, but still couldn't go that fast.

How do I know - spend 24 hours on surface transit through a storm just once and you'll know exactly how subs travel on the surface! Never been that seasick in all my life.

Previous home was Groton CT.

Try running from a typhoon in a ARS (USS Deliver). 47 deg rolls, never puked but I was pretty green. The mine sweeper (USS Enhance) I was on was no joy either. The USS New Jersey was a Cadillac. The USNS Bowditch was no fun up in the North Atlantic and that flat bottom LPD (USS Juneau) was no joy ride either. The USS Mars was another Caddy as well as the USNS Kawishiwi.. Quick, how long was I in the Navy..

 

[baylake]

Re: submarine

Thanks for the pictures. Never saw them in action. I wish I will see them like you.

 

[kfa4303]

Re: submarine

On modern submarines, it's called a sail and adds stability. A submarine, like an airplane, operates in a 3 axis environment. Also acts as a storage area for the masts (antennas and periscopes).

On the older boats, the "con" or control room was directly below the "conning tower". This is where most of the commands were given but the actual controls were usually in a room below that. If you have an opportunity to tour any of the diesel boats, or even the Nautilus, you'll see that arrangement.

My uncle was ship's surgeon on Nautilus. Great name for a boat. Good to know the silent service is out there......somewhere.