5-Inch, 38-Caliber Naval Rifle

[RWK]

Sam,

A couple of follow-on notes for our CVA "pass down the line" thread:

1) In addition to the P-2V, the Midway Class (specifically Coral Sea) was the only F-111B carrier suitability test deck. Roy Buehler (of Strike at Pax) was the project's carrier suit aviator. With the early TF-30's lack of thrust and the F-111B's extended variable geometry wingspan, launch was demanding. Recovery was even worse, due to high Vpa, stability/control/handling issues, wingspan/island clearance, and long momentum-driven engine "spool" times.

2) The Nimitz Class, I believe, has returned to heavily armored flight decks. The 1980 Prowler conflagration on CVN-68 certainly demonstrates real survivability and robust design.

3) One of the CVN-77/CVNX's design primary objectives is the reduction of island/topside weight, through the integration of systems and sensors (as contrasted to today's stand-alone "stovepipe" systems). This is intended to provide margin for further topside/flight deck survivability features. The use of Kevlar-type materials (strong, fire proof and far lighter) is also projected.

Warmest regards -- Roy

PS: Mike, IMHO there is no way CVN-65 could approach 50 knots! Forty knots would be VERY difficult, although perhaps theoretically possible. In my two years in Enterprise, I never saw speeds like 40 knots.

[Cougar]

The 10 "Light" Fleet Carriers of WW II, all built on Cleveland-class cruiser hulls, were the Independence (class leader), Lafayette, Princeton, Beleau Wood, Cowpens, Monterey, Langley, Cabot, Battan, and San Jacinto.

Of those CVLs, only the Cabot is still left, and I think she's headed to the breakers after attempts to preserve her as a museum failed.

I was in New Oreans a few years ago. They had (what was described to me as) one of the last WW2 light aircraft carriers awaiting scrapping. It was going to be towed to India(!) for scrapping 'cause environmental concerns make it cost prohibitive in this country. I'll have to get out the old pictures I took and see if I can discern any identification on it.

Now, back to the original post discussion

I've got a book on the Iowa Class next to me as I write this, and they discribe the muzzle blast of the 5/38s as being more fierce than the main 16/50s. That the 5/38 was a sharp crack compared to the longer period boom of the 16". Kinda like comparing a .223 out of a contender barrel to a black powder 50cal in a long rifle.

[glockten]

I know that some of our flattops during the war started out as cruiser hulls.....was this the Princeton class (was it only USS Princeton or were there others?), and were any built that begin as battleship hulls?

No, but the Lexington and Saratoga were built on battlecruiser hulls. They were originally designed with a 5"-7" armor belt. I don't know how much of that was retained when they were converted to flattops.

[4V50 Gary]

Other BB or CB hulls converted to carriers:

HMS Eagle - former Chile BB (never completed) Admirante Cochrane;
HMS Furious, Courageous, Glorious - former light battlecruiser
IJNS Kaga (former Kaga class BB);
IJNS Akagi (former Amagi class CB);
IJNS Ise & Hyuaga (hybrids w/14" BB guns fore & amidships & flight deck aft);
IJNS Shinano (Yamato class BB - sunk by Joe Enright & Archerfish)
Bearn (former Normandie class BB)

Only the Furious & Bearn survived the war. Of the early conversions from BB/CB hulls, the Kaga, Akagi & Saratoga & Lexington all carried 8" guns for defense against cruisers or raiders. Whereas the Japanese mounted their guns in casemates (in the hull), the USN approach was to place them in dual gun turrets on the flight deck. Of course, while the Sara & Lady Lex guns were drier, the disadvantage was that they couldn't (or shouldn't) fire across their flight decks for fear of blast damage. Both Sara & Lady Lex shipped their guns sometime early in WW II in favor of heavier AA.

Per Breyer, Sara & Lex had 178mm thick armored bulkheads & 152 mm thick side armor

[Mike Irwin]

Cougar,

I don't know if Cabot had ever been in New Orleans, but by the time you were there she was the only Independence-class CVL left.

The Cabot, given her cruiser base hull, is pretty recognizable. This is how she looked in 1997 at Brownsville, Texas.




And another view...

[4V50 Gary]

The U.S.S. Iowa (BB-61) is moored at Suisun Bay with the Reserve Fleet (they don't like being called, "Mothball Fleet"). Saw it the other day when I was on the train. Now, if SF or Berkeley or San Quentin State Prison ever riots, there's firepower out there.

[Mike Irwin]

USS Saratoga survived WW II, as well, only to go down at Bikini.

Saratoga's armor belt was upwards of 6" thick. It was a holdover from the BC days.

As originally constructed, both Sara and Lex had 8 8"/55 cruiser guns in 4 turrets, 2 fore and 2 aft of the island.

Theory was that with her armor and guns she could do a fair job of protecting herself in a sea battle against other cruisers.

Lexington was sunk before those guns could be removed; they were removed from Saratoga in 1942, which were replaced with 5"/38 mounts.

As far as other cruiser-based carriers:

HMS Vindictive started out life intended to be the cruiser Cavendish. She never, as far as I know, saw combat, but like Hermes and Langley, provided much valuable information about the nature of an aircraft carrier.

[C.R.Sam]

5" 54
"The five inch 54 caliber gun may justly be called "Midway Guns", for they were designed and built expressly for the Midway class carrier, and she was the first ship in the navy to carry them." Midway cruise book, 58/59

3" 50
"In case of attack, it would take only sixty seconds for the three-inch battery to hurl over eight hundred projectiles into the air to knock down any plane attempting to penetrate Midway's fire power umbrella.--Each rapid firing twin 3"/50 mount is capable of one hundred rounds of accurate fire per minute." Midway cruise book, 58/59

Mike........during the unpleasantness in Formosa Straits in 58/59 it was nearly routine to conduct flight operations in the 40knot area. Launch with extreme loads, and recover with extreme loads cause the button never got pushed to "light em Up."

Sucks when the boat has to make all the wind over the deck, cause then the wind is straight down the hull line and gives a crosswind for landing on the angle. Plus the approach is through the turbulance caused by the Island structure.

I think the 50+ was logged in Sept 58.

Carlyle.....final at 105 in 737-300 not unusual with light pax load and at least an hour's fuel on board. It will take a 3° landing.

Roy, I forgot about the 111 fiasco. Even worse than the bucks wasted on the Cutlass.

I bounced on the Monterrey....seemed like a postage stamp.

Sam............jeez I feel old.

[Mike Irwin]

Sam,

Sorry, dude, but as far as I know the absolute FASTEST any of the Midways was ever recorded as going was 34.&change knots.

With the hull form and shaft horse power, I don't think they were capable of doing that. Given the hull form, to do 50 kts, they would have needed a SHP of somewhere around 350,000 to 400,000. Not doable with the machinery of the day.

And, no offense to Midway's cruise book, the 5"/54 was NOT designed specifically for the Midway class, they were designed for the Montanas, long before the Midway class was even conceived.

Original design specifications were laid out in 1938/39, initial design/construction/testing took place in 1939/40, concurrently with finalization of plans for the Montanas.

The Midway class was the next logical step in carrier design, and given the nature of BB vs CL in the pre-war years, and the fact that the final design work wasn't done on the Essex ships, and the Essex laid down, until April 1941, the Midway class likely wouldn't have started specific design until mid-1940 to early 1941.

By that time the first 5"/54 mounts and guns had been constructed and, with the cancellation of the Montanas in favor of more Essex-class carriers, had been put into storage.

[RWK]

Quote
3" 50: "In case of attack, it would take only sixty seconds for the three-inch battery to hurl over eight hundred projectiles into the air to knock down any plane attempting to penetrate Midway's fire power umbrella.--Each rapid firing twin 3"/50 mount is capable of one hundred rounds of accurate fire per minute."
Midway cruise book, 58/59
Unquote

Always found the 3/50 to be a waste of weight, people, ammunition, money and so forth. The last of the "eyeball" shooters, my experience is the probability of hitting anything airborne with the darn things approached zero -- plus range was so limited the enemy's weapons were likely "on the way" by the time the 3/50 could engage.

All this said, you "gotta love" cruise book writers; everything on the ship is always superb.

Best regards -- Roy

[Hutch]

I was told by a Navy chopper pilot about a speed run on a CV whose name escapes me. Coulda been the JFK or America. It was not a CVN. Anyway....

A VIP on board has suddenly become very ill, while they're steaming somewhere in the Atlantic. They are in a heavy storm, and it is thought that catapulting the VIP in a COD might kill him, but he needs off the ship and into a hospital ASAP. They brief my acquaintance, and he points to a location on the chart where he thinks it'll be safe to lift off in his chopper, headed for Mayport. He assumes it'll take the ship about 8 hours or so to reach the dparture point and retires to the bunk to be awakened in time for final preps. When he is awakened, much earlier than expected, he checks positions, times etc, and calculates that the ship has been steaming at well over 45 knots (my calculations, I think he said 55MPH) in heavy seas.

Dunno if this is true, but I think that modern carriers can hike up the ol' skirts and travel MUCH faster than we are led to believe. Mike, your calculations regarding displacement and SHP may be true, but I wouldn't be surprised if the true available SHP was higher than admitted to.

[C.R.Sam]

Yeah, never see a cruise book speak ill of their boat.

3" ers definately archaic against modern delivery systems.

Not having second sourcing for gun and speed info.....I withdraw my arguments re same.

I will leave this thought tho. Some of these big ships do not fit pure displacement hull calculations. With favorable water density and adequate oomph from the boiler rooms the hulls would rise as much as 18 feet under full tilt. Reduces the power required by a bunch.

With the above in mind, I have no problem with Hutch's post. (48.4Knots = 55mph)

Sam

[Southla1]

Hey Sam, pretty good guess on the 737's speed for not having the flight manual handy . I had guessed about 110 Kts. and added 10 for mama (mama hell ....... more like for mama's oldest bo......... moi!).
I really liked the pictures of the Cabot. I remember back in 72 and 73 I was working on an oil platform off the mouth of the river (The Mississippi) and recall so many times that a Fletcher Class or a Benson Class destroyer was towed by headed for the cutting torches. I know that their times were past but I still hated the idea of them being gone forever except in memory.
I found this great sight on the net, and am going to post it here. In some of the photos of the Iowa firing her main battery the projectiles are visible. The picture also clearly shows the gas jet from the bore overtaking the projectile.

http://www.ussiowa.org/pics/bigguns.htm

This site below is also a good one.If you click through the menu to USS North Carolina, one of the pictures of her firing her main batteries also shows the projectiles after they have traveled away from the bore a bit.

http://www.geocities.com/Pentagon/Quarters/4289/

[Southla1]

Mike, I don't know about USS Midway, but some years ago we had just cleared the sea bouy, at Southwest Pass Mississippi River, in a 65 foot crew boat doing 24 Kts. (as calculated by loran) when USS Enterprise over took us on the STARBOARD beam like a bat out of hell(she had been on a New Orleans visit). We don't know exactly how much he was doing but our skipper, who had been in the USN for 20 before retiring and going to work running crewboats, said she was doing close to 40 Kts. Of course when you clear the sea bouy outbound there you are already in deep water and the only oil platform is our Texaco WD-109 (which was already hit by a Nigerian registered grain carrier........... grain carrier came out second best), so it was not really unsafe to make that speed. By contrast The USS Iowa visited New Orleans once (I got some good pictures of it from our field helicopter) and going up stream was "idling" at an estimated 10 Kts. I estimate this speed because it took him 9 hours from the mouth of the river to New Orleans and it is about 90 Nautical miles in distance. Much slower than the USS Vincinnes that almost swamped a 95 foot crewboat with his stern wake while steaming up river at or about 25 Kts. Boy did that PO the crewboat skipper that was trying to cook some lunch at the time................gumbo all over the galley! I will say this, while I was working at both Texaco South Pass Block 54, and Texaco West Delta 109 oil production platforms I slept with one eye and one ear open because WD-109 is IN the shipping lanes and SP-54 is just barely out of a shipping lane. Makes for interesting times when the fog reduces visibility to 100 feet!

[Mike Irwin]

Guys,

We're talking a hull form that was state of the art 1935-38.

Compared to the Iowas and the Essex class carriers, Midway's hull form was somewhat less capable of high speed mandated by the requirements forced on the design that came with stacking nearly 4 inches of flight-deck armor on top.

The best an Iowa class was ever recorded as doing was about 35.5 knots, and that was after refits in the 1980s with updated machinery and a total load that was a lot less than a WW II-era load out, and that was on an "overload" that produced about 250,000 shaft horse power.

The Iowas weighed about the same as a tricked out Midway, had a much more "aerodynamic" hull shape, and drafted about the same depth (Iowas drafted about 4" more, given their narrow "dart" hulls")

Things only got worse speedwise when the angled decks were installed on carriers in the 1950s. Virtually every WW II-era carrier that had an angled deck installed lost between 1 and 2 knots because of it.

Hull design has come a long way since the 1930s.

I'm trying to get in touch with a friend of a friend who is a naval architect to see if he can shed some light on this.

[Mike Irwin]

Carlyle,

Enterprise's top speed is still, as far as I know, classified, but a lot of people claim that she's capable of 40+ knots.

Given the fact that she was built with extreme redundancy in the reactors (she's supposed to be able to make "fleet" speed on 3 of her 8 reactors), she very likely has a LOT of spare power.

She's rated at 280,000 shp, but I've seen speculations that she can dump nearly 330,000 shp into the water.

She was also, I believe, the first ship with a hull-form designed with the aid of computers, so she's a lot more "aerodynamic" than earlier ships.

[RWK]

IMHO, the question with Enterprise (and others, for that matter) is not power per se. Hull shape and fluid dynamics are such that a point of extremely margin return is reached at approximately 35 knots. This means a VERY marginal velocity increases -- eventually approaching zero -- for each incremental power increase.

Regards.

[4V50 Gary]

The Lexington shipped her 8" guns in 1942 before she was sunk. See Stern The Lexington Class Carriers & Breyer Battleships & Battlecruisers - 1905 to 1970. There is some dispute as to whether it was in March or April. Both Stern & Breyer claim March but noted naval historian Friedman gives April (see Friedman: U.S. Aircraft Carriers: An Illustrated Design History).

[Mike Irwin]

Regarding speed, here's another thing that I forgot...

Just about any ship will "rise" out of the water when at speed.

Unfortunatly, the more a ship "rises," the less efficient the screws become at driving her forward due to increased wake turbulence, which causes increasing cavitation.

[Mike Irwin]

RWK,

Yep, that's certainly true, but I think you'll find that the return point is somewhat higher than 35 knots given increasingly efficient hull designs.

While it's a whole different set of dynamics, of course, a good example of increasing efficiency of hull design allowing greater terminal speeds is with submarines.

Submarines these days are so highly refined that they actually have higher submerged speeds, sometimes significantly higher, then when running on the surface.

[Mike Irwin]

Cougar,

I got the e-mail with the pix, and I tried to e-mail you back, but it came back with "fatal errors" in the address.

Anyway, I'd lay good money that the ship in your photo is, in fact, Cabot. I had never heard of her being in Nawleans, but I'm not at all surprised, given the fact that she was headed to Brownsville, Texas, around that time to give given to the Cabot Association, which tried to preserve her as a museum. Unfortunatly, they ran into money problems and couldn't make a go of it.

As far as I've been able to tell, Cabot's now history, literally.

[bruels]

Regarding hull speed and horsepower:

I was Air Operations Officer on USS Enterprise from 1985 to 1987. After an overhaul period that included drydocking, scraping and painting her bottom, the fastest I ever saw her go after the overhaul was 33 knots during the post overhaul trials.

From my meager naval engineering course in NROTC, I remember that a displacement hull achieves 50% of its maximum speed on only 12.5% of her power, and 80% of its speed on 50% of its power. This was shown to be true during one of my midshipman summer cruises where I saw my destroyer capable of 24-25 knots on only two of her four boilers lit off and on the line.

Horsepower has little to do with maximum speed. Hull length to beam ratio is more important. Again, my naval engineering text showed that the horsepower to ton ratio for destroyers was 16 to one. Cruisers was about 5 to one. Battle ships was about 3 to one. And carriers was a little over 2 to one. All of them had top speeds of 32-34 knots. The only difference was the destroyers could get to top speed quicker than the larger ships.

[CGGunner]

I was on the USCGC Duane we had one 5/38 MK30 Mods It was great weapon and very reliable and fairly easy to work on. We did'nt have a Fire control system on my ship onlt sights and radar range

[TexasVet]

I was on a Sumner class DD in the late sixties, and have been case loader in the lower ready room, case loader in mount 53, gun 1 and hot case man in mount 51. Hated being down below the guns at GQ, loved being hot case man. When I changed to FTG striker, I couldn't believe the analog computer (Ford, no, not that Ford) used to aim the 5"38s. Most complicated piece of gearing and potentiometers I ever saw in my life. But it worked.
Saw an F-111 land on the Forest Fire (Forrestal) in the Med and thought it was NEVER going to stop. Strechted the cables all the way to the island! Dumbest thing the Navy ever tried. WAY too heavy for carriers.
Don't know how fast for sure the Big E would go, but saw her pass us when we were doing 32 knots like we were standing still. Impressive.