Real Submarine Technology & History Q&A

[DaveyJ576]

Originally Posted by Platapus

Anyway, about 2/3rds though the book, Beach makes a comment that the Negative Tank, unlike the other tanks is vented directly into the submarine. In the story he relates a circumstance where during an emergency dive, the negative tank was not blown when it should have been and when they blew it at a deeper depth it caused discomfort in the submarine.

Beach is pretty accurate in his books. But is this true?

Negative Tank vents only into the Submarine?

Why? is this to help conceal the submarine during the dive?

It is my understanding/(misunderstanding?) that during a normal dive, the negative tank is flooded, but when the submarine is on the way down, it is blown at a relatively shallow depth. The purpose of the negative tank is to give the submarine that extra kick to get under faster.

By venting the Negative tank into the submarine, there would not be a big sub fart of air telling the enemy where the sub is.

Is this correct or do I need to go back to lubbing land again?

Platapus:

You answered all of your own questions, and accurately I might add! When surfaced, the negative tank is kept full (or nearly so depending on the calculated state of the boat's buoyancy). You do this for the very reason you mentioned: it provides that extra amount of negative buoyancy needed to submerged the boat fast on a crash dive. Once under, the tank is blown to a pre-calculated "mark" that will restore (when combined with adjusting the amount of water ballast in the trim tanks) the desired neutral buoyancy. If circumstances prevented you from blowing the tank at periscope depth, you would obviously have to use increasing amounts of air pressure to empty the tank the deeper you were at the time. You eventually have to vent this air if you want to refill the tank and the air has to go somewhere. Venting it over the side would give off telltale bubbles so it is vented inboard. This would raise the internal air pressure and after a while this gets very uncomfortable for the crew.

BTW, Ned Beach wrote two sequels to "Run Silent, Run Deep", and are both excellent reads in their own right. "Dust on the Sea" picks up where the first book leaves off and completes the WWII portion of the trilogy. "Cold is the Sea" jumps to the Cold War era and follows Richardson after his promotion to a nuclear submarine squadron commander and deals with a Soviet submarine incursion to the Arctic.

Beach wrote the original RSRD in his off time while serving as a naval aide to President Eisenhower. It was a best seller and turned Beach into a semi-celebrity while still serving in the Navy. He also wrote several non-fiction books, one of his best being "The Wreck of the Memphis". This is the story of his father's command, the armored cruiser USS Memphis (ACR-10) and how it was wrecked by a freak tsunami while in harbor in the Dominican Republic. This was a gripping, thrilling tale and Beach did a masterful job of writing. I highly recommend any of this books.

[sharkbit]

Originally Posted by DaveyJ576

Platapus:


BTW, Ned Beach wrote two sequels to "Run Silent, Run Deep", and are both excellent reads in their own right. "Dust on the Sea" picks up where the first book leaves off and completes the WWII portion of the trilogy. "Cold is the Sea" jumps to the Cold War era and follows Richardson after his promotion to a nuclear submarine squadron commander and deals with a Soviet submarine incursion to the Arctic.

Just curious-What do you think of Beach's accuracy?

I always felt they were extremely detailed and accurate, as well they should be considering his service. His narrative of approaches and attacks, especially in "Dust on the Sea", seem extremely detailed and very realistic. I've learned a ton just from those books as opposed to the 30 second approaches depicted in movies or the glossed over attacks in some books.

I'll definitely second your recommendation on the trilogy . I've read all three countless times. In fact, I had to replace my copy of "Dust on the Sea" last year-it was falling apart. "Run Silent, Run Deep" isn't to far from falling apart as well.

[DaveyJ576]

Originally Posted by sharkbit

Just curious-What do you think of Beach's accuracy?

The accuracy of his novels is top notch. Beach is an incredible writer and his narrative brings everything to life without overwhelming you with technical minutiae.

Beach and most of the other good authors will sometimes downplay the technical side because of the necessity of writing for a wide audience, an audience that may not know the difference between a TDC and an SJ. Beach did a great job of balancing the somewhat conflicting desires of writing a technically and historically accurate novel while at the same time appealing to a wide and only partially informed audience.

The ultimate edition of RSRD is in the U.S. Naval Institute's Classics of Naval Literature series. It is a finely crafted hard bound edition and should last for decades. It comes with a ribbon page marker. "The Wreck of the Memphis" is also available in this series. I have both books and they are true treasures of my collection. See this link for more info:

http://www.usni.org/store/books/clas...ilent-run-deep

[Rip]

Originally Posted by DaveyJ576

The accuracy of his novels is top notch. Beach is an incredible writer and his narrative brings everything to life without overwhelming you with technical minutiae.

Beach and most of the other good authors will sometimes downplay the technical side because of the necessity of writing for a wide audience, an audience that may not know the difference between a TDC and an SJ. Beach did a great job of balancing the somewhat conflicting desires of writing a technically and historically accurate novel while at the same time appealing to a wide and only partially informed audience.

The ultimate edition of RSRD is in the U.S. Naval Institute's Classics of Naval Literature series. It is a finely crafted hard bound edition and should last for decades. It comes with a ribbon page marker. "The Wreck of the Memphis" is also available in this series. I have both books and they are true treasures of my collection. See this link for more info:

http://www.usni.org/store/books/clas...ilent-run-deep

That is the version I have, and I got it for a song on amazon. My first try to get it resulted in finding out the book store didn't actually have it anymore. But like Mush I was persistent and got the *%#*% thing eventually. To be passed on to my son when he is old enough.

[DaveyJ576]

When the USS Nautilus (SSN-571) first went to sea for exercises with the fleet in 1955-56 the incredible performance advantage she enjoyed over a conventional diesel-electric GUPPY boat shocked many naval strategists. The sudden realization that she nearly rendered all existing anti-submarine warfare (ASW) techniques obsolete hit the establishment like a ton of bricks. A conference was called together in the late summer of 1956 at Nobska, Massachusetts to study the problem. One of the main issues the attendees tackled was how to hunt and destroy a high speed, high endurance, deep diving nuclear submarine.

One of the solutions they came up with was (predictably for the 1950's) to nuke it. A developmental outgrowth of the Nobska study was the Mk 45 ASTOR (anti-submarine torpedo). With an 11 kiloton yield W34 fission warhead, the Mk 45 would overcome the limitations of the existing sonar and tracking systems and largely negate the speed and depth advantages of a nuclear submarine through good old fashioned brute force.

The Mk 45 was a 19 inch diameter swim out weapon that was 19 feet long and weighed in at a 2300 lbs. It was an electric torpedo of a relatively simple design. It had a range of approximately 7 nautical miles (14000 yards) and ran at a speed of 40 knots. It had no internal guidance or sonar systems other than a gyro. It was guided to the target via a control wire back to the firing sub. U.S. nuclear weapons doctrine of the day dictated that the weapon could not be allowed to auto-burst via it's own systems. It had to be detonated by the firing sub's crew at the appropriate moment (hence the control wire). The 11 kT warhead had a hard kill radius of 8000 yards. In other words, if your target was within that radius when the weapon detonated, it was dead, no joke. At 12000 yards the weapon could still be lethal, although the probability of a kill dropped quite a bit. At 16000 yards the target stood a reasonably good chance of surviving. It entered service in 1963 and was finally retired for good in the 1979 as the highly capable Mk 48 came on line.

There was a bit of gallows humor amongst the submarine crews that carried this weapon to sea. It was said you were assured of two kills anytime you used a Mk 45, your target and yourself. Remember that in the early 1960's the vast majority of the USN submarine force was still made up of diesel-electric GUPPIES and the new Tang, Darter, and Barbel class diesel "fast" attack boats. The maximum speed of these boats varied between 15 and 18 knots. At those speeds the battery would be completely dead in about a half hour. The concern was that if you fired a Mk 45 at an enemy it would be virtually a suicide shot. You wouldn't be able to get away from it fast enough to survive the detonation of your own weapon.

The hard kill radius of the weapon was 8000 yards, with a good probability of a kill out to 12000 yards. Let's assume best case scenario and say you obtain a firing solution on your target at 14000 yards. You fire your Mk 45 and she is running to your target at 40 knots. It will take about 10 1/2 minutes for the weapon to run that far. You can't maneuver and run away to increase the range. Remember the weapon has no internal sonars or guidance, you have to guide it to the target with your boat's own sonars, meaning you have to keep pointed at the target and stay slow and quiet. You send the command for the weapon to burst when it hits the calcuated range of 14000 yards and you wait for the shock wave to hit, fingers crossed.

Accurately tracking a submerged target at 14000 yards was problematic at best in those days. You wanted to rely on passive sonar so that you wouldn't give away your presence with active sonar pings. This made accurate ranging very difficult. Tracking ranges of 9 to 11000 yards were more realistic, and often it was less than that. This gave you precious little room for error when using this weapon. Later advances in sonar increased detection and tracking ranges and made the use of the Mk 45 a bit safer, but the submarine crews never really liked it and always viewed it with a great deal of justified trepidation. No one was sad to see it go when it was finally pulled from service.

If you want to see a Mk 45 torpedo, the USS Torsk (SS-423) museum has one on display on board the boat in Baltimore, Maryland, minus the warhead of course! The Torsk herself never carried the Mk 45 while in service as she did not have the proper sonars or fire control systems.

[Ducimus]

12 minute Declassified navy film about the MK 45 torpedo:

[DaveyJ576]

Originally Posted by Ducimus

12 minute Declassified navy film about the MK 45 torpedo:

Great stuff Ducimus! Thanks! Notice how the vid said 12000 yards max range? That's even worse! Almost within the kill zone!

[Platapus]

Originally Posted by DaveyJ576

You answered all of your own questions, and accurately I might add!

Thank you for your kind words. I try to figure things out before posting here. I greatly appreciate your contributions to this thread. You give the straight poop and your are patient with lubbers like me.

This is one of my favourite threads on this site.

[Sgt Hotcliff]

Hey mates!

just want to say I just found this thread and will have trouble playing SH4 now, with all this info to read!

Also found an interesting Manual of Mk14 and 23 Torpedoes at
http://www.hnsa.org/doc/torpedo/index.htm

Thk's
Hotcliff