I've never understood this. What does the "mark whatever" mean? And when Lake asks for a second mark he says "no time". How exactly does this work? The tubes don't move, right? The torpedoes go in whatever direction the sub's nose is pointing, don't they? Can any of you ex-navy guys explain it to a land lubber?
Suddenly, LAPD Sgt. Al Powell found himself quite capable of drawing and firing his gun.
Torpedoes don't go in straight lines. Back during WWII torpedoes were programed to follow a course and depth prior to launch. Back then they had to do all the calculations (sub speed, target speed, distance, etc) by hand. They would calculate where the target should be by the time a torpedo fired from the sub would reach it (this is the firing solution). So you shoot where the target is going to be, not where it is now. They can also be fired from both forward and rear torpedo tubes.
Modern subs can get a firing solution with computers almost instantly. Additionally modern torpedoes have wire guided systems so they can be guided even after they've been fired. There's also fire and forget torpedoes that are launched out and it homes in on whatever it hears. Sort of like the underwater equivalent of heat seeking missiles.
PS: This is what part of the alphabet would look like if Q and R didn't exist.share
No the tubes don't move.
But they don't just go straight out from the bow either. They turn to whatever gyro heading is programed into the torpedo on firing. then they run straight out until they run out of fuel.
In order to accurately fire the torpedoes and know what gyro setting to fire the torpedoes on they have to accurately know where the target is in relation to the sub as well as the targets course and speed. They also have to know their own course and speed as well. Normally this will take several sightings through the scope, each time they are marking bearing, range, and angle on the bow. It usually takes several different sets to get an accurate and reliable setup for a good firing solution. Dodge was telling Lake that there was no time for further sets of data to refine the shooting solution. They are basically firing from the hip.
The term "Mark" is used to tell whoever is recording the data to do so "NOW"
Example. The captain is looking through the scope. He will put the crosshairs on the target and call "Bearing... MARK!"
An assistant will read the bearing that is indicated at the moment the captain called "mark"
Assistant "Bearing... 257 degees"
257 will be used in the TDC (Torpedo Data Computer) for this setup
The captain will then use a control to give a split image through the scope. he will adjust the image so that the waterline of the top image lines up with the top of the masts of the bottom image. He will then call "Range... MARK!"
The assistant will then report the stadimeter range that is indicated when the captain calls "Mark"
Here you go: everything you ever wanted to know (and then some) on firing torpedoes from subs.
http://www.hnsa.org/doc/attack/index.htm
I joined the Navy to see the world, only to discover the world is 2/3 water!
At the beginning of WWII they did the torpedo firing calculations "by hand", with a slide-rule type device they called a "banjo" because of its shape. But after the first couple of years, they had Torpedo Data Computers to make the calculations. These were pretty sophisticated electro-mechanical computers, mounted in the conning tower.
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