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View Full Version : Do BB's Move When They Fire a Broadside?



Kaleun1961
07-17-2006, 03:53 PM
For some time the idea has persisted that when big ships like USS Iowa fired their guns in a full broadside that they actually moved sideways due to the recoil. This site refutes that idea and uses mathematics to assist in doing so. I'll have to leave the calculations to someone else; I forgot most of what I learned in high school.

Broadside Math (http://www.navweaps.com/index_tech/tech-022.htm)

P.S. There are a couple of nice colour photos of broadsides, as viewed from above.

cwhense
07-17-2006, 05:35 PM
dont know if they actually moves sideways in the water, I do know they will rock the boat with a full broadside, saw some footage from an Iowa class ship firing its full broadside and it rocked back a bit.

hueywolf123
07-17-2006, 05:50 PM
The problem with being academically inclined is you tend to miss obvious points. One is that in none of those calculations do they mention water density. I won't dispute the mathematics involved, but the ship is in water (funnily enough), there fore I wouldhave considered both relative density + surface tension of the water to be two of the most telling factors. Neither are mentioned. Yes the recoil is allowed for on the muzzles of these guns, a 48" slide. Have these guys ever fired rifles, mine allowed for recoil, but still pushed me. In physics, all factors must be equated, these guys have not done that

Silva_Bullet
07-18-2006, 02:54 AM
I would tend to agree that the ships would perhaps rock from the recoil... MASSIVE recoil http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif... but ships were simply not designed to move sideways. The length of the keel would present too much surface area to move through the water density, wheras the underside of the bow (excuse my inept terminology here) was designed specifically to 'cut' through resistance offered by water density.

So, in my opinion, the ship wouldn't move to the side, but a full broadside would certainly rock the hell out of the ship.

Bucketlung
07-18-2006, 06:17 AM
Perhaps we should move one of these babies to the coast of Lebanon and run some definitive tests? http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif Nobody would notice.

LoboWolf
07-18-2006, 07:35 AM
I can solve this mystery for you. My brother served on the USS Wisconsin (the longest of the Iowa class BB's) for 3 years upon her recommission 1988 and I am a retired Chief Petty Officer with over 20 years active duty. I served aboard the USS Iowa for 2 years as an SKC (Storekeeper, Chief).

These big boys do not move when firing a full broadside. If the force was strong enough to make that happen it would split the ship at the keel! The "recoil" is not what you would expect either. You can certainly feel the guns when they are fired but it does not "rock" the boat significantly; it's more of a very quick vibrating "jolt" that you feel in your bones sort of. Very hard to describe the actual sensation.

And yes, I agree, we should park one off the coast of Lebanon. From around 23-25 miles offshore, the Iowa class can drop a 2400 pound projectile (or nine of em) within a 50 yard radius area if needed. It plows up some dirt to be sure.

Just for further note, the Iowa class was finally retired from service because they just were not cost effective. Yes, they packed a punch, but at a very high $$$ rate. Just too damned expensive to operate when we have so many other platforms in our arsenal that can do a better job of tearing stuff up at a much lower cost.

Kaleun1961
07-18-2006, 07:52 AM
Are the Iowas fully retired or just in mothballs? Could they come out of retirement again if needed?

WilhelmSchulz.
07-18-2006, 10:16 AM
Originally posted by Kaleun1961:
Are the Iowas fully retired or just in mothballs? Could they come out of retirement again if needed? Yes they are mothballed, but due for srtiking.

UF_Excalibur_D
07-18-2006, 10:56 AM
Originally posted by WilhelmSchulz.:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kaleun1961:
Are the Iowas fully retired or just in mothballs? Could they come out of retirement again if needed? Yes they are mothballed, but due for srtiking. </div></BLOCKQUOTE>

The IOWA, and ALABAMA are musuems, the MISSOURI is moored next to the ARIZONA memorial at Pearl Harbor and the TEXAS I belive is also a memorial dunno where though. The WISCONSIN and the MISSOURI are the only ships that can be brought back to active duty. The WISCONSIN is downtown Norfolk, seen her myself...only weather deck tours because the ship is on reserve status. There is a marine patrol on board and she can be reinstated and rearmed in under a month. Only ships that were being built or partly built were struck the rest were donated to thier sponsor state or put on reserve.

LoboWolf
07-18-2006, 01:18 PM
Originally posted by Kaleun1961:
Are the Iowas fully retired or just in mothballs? Could they come out of retirement again if needed?

The Department of the Navy has made it pretty clear however that the Iowa Class Battleships won't see action again. Again, they are just too expensive to operate and they don't provide any real support that cannot be achieved via other platforms. During the first gulf war they were indeed used for indirect fire-support and (more often) they were used to coordinate Tomahawk Cruise missile shoots (SLCM...when u care enough to send the very best..ha)..until the Aegis Cruiser platforms could arrive on station.

The Iowa classes carried Surface Launched Cruise Missiles, Harpoon Anti-ship missiles, and of course the three batteries of sixteen inchers. All of these, except the 16's are more functional and better outfitted on newer vessels.

The other problem is that the ordanance for the 16 inchers is all old old stuff (and was determined to be one possible contributor to the disaster we had on the Iowa).

Anyway, there just is not any concievable reason the Navy would bring these old warhorses out of retirement again. Technology has outpaced them, and the simple fact is that the US Navy (our entire military actually) is being required more and more to do a bigger, further reaching mission with fewer and fewer dollars. Every dollar is so valuable that we just cannot afford to spend them on such old technology.

They have earned their place in history, and are finally enjoying their long due retirement!

BTW...for those of you in the South...the USS Alabama is a great ship to visit. She is berthed as a floating museum in Mobile, AL. A real bonus is that the USS Drum is moored alonside her as a floating museum as well. My dad served on the USS Bergall (SS 328 I believe) in WWII and she was the same class as the Drum. Very cool tour. Don't miss them if you have a chance.

cwhense
07-18-2006, 06:28 PM
the rest were donated to thier sponsor state or put on reserve.


I wish we had the Iowa here in Iowa, but CA got it, we didnt have a place big enough nor was the river deep enough for it to travel this far north. It would have been A sight to see though.

UF_Excalibur_D
07-19-2006, 06:36 AM
Yeah it would have been a sight to see for sure...The USS ALABAMA is closed right now for a long while...Hurricane Katrina really pounded her. If you have kids in the Scouts (boys or cubs) you can plan an overnight stay on the BB's or Carriers, I have some info here and can't wait for my son to get old enough...lol.

macker33
07-20-2006, 08:23 AM
Yeah they did,thats what made the bismarck such a threat in its day,the bismark was able to fire 3 salvos a minute while all the best of the rest could manage was 2 salvos a minute.

The bismark was able to self right itself quicker and as a consequence could find the range of the enemy ship quicker.

blastomatic1759
07-20-2006, 09:04 AM
i actually liked the ALabama , even though it was a South Dakota class, kinda sad its closed. but running around on that ship was kinda cool , even though they wouldnt let me in the engine room , that whole museum they have their in Mobile is kinda neat . The USS Drum was an ok exhibit as well , but the think i couldnt staring at was the A-12 Blackbird they have in there , that thing was way cool .

cpt_Alex2006
07-20-2006, 11:25 AM
Something to think about, the guns are some distance above the waterline and the boats c of g is someways under the waterline so most energy from he recoil is atemting to rotate the boat about its c of g, hence the boat doesnt try to move lateraly.

alex

Kaleun1961
07-20-2006, 11:39 AM
I've read a similar thing about the P-47 Thunderbolt fighter in WW2. It was armed with 8 X .50 caliber machine guns. When it fired, the combined recoil of the guns had the effect of slowing down the plane. Anybody know if this is true or another myth?

Even though the Fifties weren't cannons, they were armour piercing and could shred any plane in the air. As I said, the P-47 had eight of them; the P-51 had six, one quarter less firepower. The Mustang was more maneuverable than the Thunderbolt and thus more likely to end up on the tail of a German plane. Even so, six of those Fifties still packed a good punch.

AO1_AW_SW_USN
07-21-2006, 04:00 AM
Originally posted by LoboWolf:
I can solve this mystery for you. My brother served on the USS Wisconsin (the longest of the Iowa class BB's) for 3 years upon her recommission 1988 and I am a retired Chief Petty Officer with over 20 years active duty. I served aboard the USS Iowa for 2 years as an SKC (Storekeeper, Chief).

These big boys do not move when firing a full broadside. If the force was strong enough to make that happen it would split the ship at the keel! The "recoil" is not what you would expect either. You can certainly feel the guns when they are fired but it does not "rock" the boat significantly; it's more of a very quick vibrating "jolt" that you feel in your bones sort of. Very hard to describe the actual sensation.

And yes, I agree, we should park one off the coast of Lebanon. From around 23-25 miles offshore, the Iowa class can drop a 2400 pound projectile (or nine of em) within a 50 yard radius area if needed. It plows up some dirt to be sure.

Just for further note, the Iowa class was finally retired from service because they just were not cost effective. Yes, they packed a punch, but at a very high $$$ rate. Just too damned expensive to operate when we have so many other platforms in our arsenal that can do a better job of tearing stuff up at a much lower cost.


Haven't met you before Chief. I was a former AO1 (Aviation Ordnanceman) Airdale, now medically retired. So here's my belated "Welcome Aboard" message to you.

BTW, how did you feel about the merger of all AK rates to SK from a few years back?

Baldricks_Mate
07-21-2006, 04:33 AM
Don't know about BB's, RAN has'nt ever had any but...what else might move on a ship while firing?

I was crook as a dog, sitting on the head during the wait for an Ikara missile fire exercise on HMAS Perth. I was too crook to listen to the pipes. They decided...right...NOW (Bang!) was a good time to let fly.

Aft torpedos away Skipper!