Blow the valves and sit on the bottom

[Thorlifter]

I'm watching the 1943 movie "Crash Dive" with Tyrone Power. Boy that Anne Baxter was a good looking lady.

Anyway a couple things happened that occur in almost all submarine movies that I had questions about.

When they are surfacing they "blew the valves" to surface. To me you would want to keep the air to surface. Why do you get rid of your stored air to surface? That seems backwards to me.

Also, when they were escaping an attacking raider, they sat on the bottom. This happens in a lot of submarine movies. Was it common to sit on the bottom? Seems like a good way to puncture your sub on rocks. If it was common then, is it still common now?

 

[pbehn]

I'm watching the 1943 movie "Crash Dive" with Tyrone Power. Boy that Anne Baxter was a good looking lady.

Anyway a couple things happened that occur in almost all submarine movies that I had questions about.

When they are surfacing they "blew the valves" to surface. To me you would want to keep the air to surface. Why do you get rid of your stored air to surface? That seems backwards to me.

Also, when they were escaping an attacking raider, they sat on the bottom. This happens in a lot of submarine movies. Was it common to sit on the bottom? Seems like a good way to puncture your sub on rocks. If it was common then, is it still common now?

They use compressed air to blow the water out of the ballast tanks. The vocabulary of a movie is sometimes different to real life.

My father was a sailor and he always used to laugh at movies when sailors frantically closed valves to stop leaks. He always said that if that pressure line wasn't needed it would be shut down before any action. Always the leak is behind not in front of the valve too.

 

[Thorlifter]

They use compressed air to blow the water out of the ballast tanks. The vocabulary of a movie is sometimes different to real life.

OK That makes more sense! Thanks!

 

[pbehn]

OK That makes more sense! Thanks!

Ive never been on a sub, but there was a documentary on training submarine commanders in the UK. There are a lot of valves on a submarine, I imagine the person giving the orders would have to say which valves to open or shut as I saw in the documentary. However it doesn't make the stuff of action movies.

 

[fastmongrel]

No experience of subs but it seems to me there are too many quite fragile pieces of equipment sticking out of a sub to risk bumping into the bottom. The only type of bottom I can see a sub sitting on without damage is flat sand. Rocky nope for obvious reasons, muddy could a sub get stuck and as for houses shaped like Pineapples that would be a disaster.

 

[herman1rg]

If you like Anne Baxter, you might like "Sink The Bismark!" with the very lovely Dana Wynter, some planes in it also (Fairey Swordfish)

 

[pbehn]

I believe in the early days of the war German U boats used to "lurk" at or near the bottom in the extremes of the Irish sea before moving towards Liverpool. It was not successful mainly because submarines couldn't remain below for long enough at the time. Also in the Mediterranean subs had problems because so many areas have clear shallow water meaning they were still visible.

 

[mikewint]

Sitting on the bottom is one way to confuse sonar which in those days was sent essentially straight down. The sub was essentially "hidden" by the bottom return echo clutter. Note that today search vessels using sonar to "Search" the bottom for whatever use "Side-Scan" sonar which does exactly what the name implies

 

[XBe02Drvr]

I HAVE experienced sitting on the bottom in a WWII era diesel boat. A boot camp comrade of mine was assigned to one of last diesel boats in USN, and I was invited to an open house which turned into a "visitors cruise" when the local ASW test and evaluation squadron requested a target for an evaluation exercise. After steaming surface and snorkel for about four hours, we dove deep and sat on the bottom of the Gulf of Mexico. Deep for that kind of boat was only 250 ft and our skipper (who had plenty of experience) made a nice soft landing in sand and we adopted about a ten degree list to port. Sweat, stink, mildew, and condensation everywhere, and the hull groaned on the way down. Enforced silence. Twenty minutes after liftoff the P-3 dropped a noisemaker on us. We could hear it hit the surface before it exploded. "Bang, you're dead!"
I later spoke with the techs working with the test equipment, and they said they could see us (in our North Atlantic color scheme) sitting on the white sandy bottom from 100 ft altitude.
Cheers,
Wes

 

[XBe02Drvr]

I believe in the early days of the war German U boats used to "lurk" at or near the bottom

"Operation Drumbeat" in the winter and spring of 1942, U-boats patrolled the Atlantic and Gulf Coasts of US raising havoc with coastwise shipping. Boats assigned to the Gulf of Mexico would pause in mid-Atlantic to paint their dark colored top sides sandy brown. The Gulf has clear water, a mostly sandy bottom, and is mostly pretty shallow. There are few places where a boat with a 400 foot test depth can get in trouble. They would wait out the daytime on the bottom conserving battery, then surface at night to recharge and attack shipping. The sorry state of American ASW at the time left us wide open, with most of the resources we did have dedicated to the North Atlantic and the West Coast. In desperation, the US recruited private pilots, put them in confiscated civil aircraft with depth charges strapped to them, and sent them out sub hunting. Privately owned aircraft were mandated to be "loaned" to the war effort, and a few of them were returned to the civil registry after the war, but seldom to their original owners. Most were disposed of as surplus.
Cheers,
Wes