My father worked at the Boston Navy Shipyard during WWII and was on the USS Massachusetts on it’s shakeout cruise and described how it was thrown sideways for a couple of hundred yards when it fired all of it’s guns broadside.
People forget Massachusetts once was a significant manufacturer of many things. West of 495 is littered with shut down factories; every little town seems to have one. Now I think our primary product is idiots.
The battleships are “pushed sideways” by the blast of their cannon (if fired at right angles to the hull), but not that much. Look at a photo taken in calm water: it shows the waves of the impact, some of the movement, and much of the blast effect.
http://www.navweaps.com/index_tech/tech-022.php
Do Battleships move sideways when they fire?
What looks like a side-ways wake is just the water being broiled up by the muzzle blasts. The ship doesn’t move an inch or even heel from a broadside.
The guns have a recoil slide of up to 48 inches and the shock is distributed evenly through the turret foundation and the hull structure. The mass of a 57,000 ton ship is just too great for the recoil of the guns to move it. Well, theoretically, a fraction of a millimeter.
But because of the expansive range of the overpressure (muzzle blast), a lot of the rapidly displaced air presses against the bulkheads and decks. Those structures that are not armored actually flex inwards just a bit, thus displacing air quickly inside the ship and causing loose items to fly around. Sort of like having your house sealed up with all windows and vents closed and when you slam the front door quickly the displaced air pops open the kitchen cabinets.
R. A. Landgraff
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To calculate the velocity of the USS New Jersey moving sideways, what you need to consider is conservation of momentum. A 16” Mark 8 APC shell weighs 2,700 lbs. and the muzzle velocity when fired is 2,500 feet per second (new gun).
The USS New Jersey weighs about 58,000 tons fully loaded (for ships, a ton is 2,240 lbs.) - Emphasis added on 16 June 2006 in an effort to stop vision-impaired individuals from sending Emails about the “missing” 2,000 in the equations below.
All weights must be divided by 32.17 to convert them to mass.
If the battleship were standing on ice, then:
Mass of broadside * Velocity of broadside = Mass of ship * Velocity of ship
9 * (2,700 / 32.17) * 2,500 = 58,000 * (2,240 / 32.17) * Velocity of ship
Solving for the ship’s velocity:
Velocity of ship = [9 * (2,700 / 32.17) * 2,500] / [58,000 * (2,240 / 32.17)] = 0.46 feet per second
So, ship’s velocity would be less than 6 inches per second, ON ICE.
This analysis excludes effects such as (1) roll of the ship, (2) elevation of the guns (3) offset of the line of action of the shell from the centre of gravity of the ship and (4) forces imposed by the water on the ship. These are variously significant, and will all tend to reduce the velocity calculated above.
Greg Locock
I think your old man was telling you navy stories - Do Battleships move sideways when they fire?
“Thrown sideways a couple of hundred yards”.....really?