American militarism pre-WW2 and the Ultimate Battleship

[T. A. Gardner]

Why dig a hole?

Good point but the construction shipyard, at the very least, would have to be in the midst of an industrial complex and therefore probably in the ground. To avoid Takao's predicted construction timeline, however, another solution is to build a floating drydock then stick it in a pre-dug hole.

In the meantime, btw, while the drydock was being built, enormous sections of the hull could be constructed elsewhere in existing docks for assembly in the big dock. This is precisely how today's giant ships are built, precisely how American ingenuity solved the WW2 shipping problem, and would make total sense for construction of the mega-BB. One could, for example, assemble sections using the full beam of 360ft transverse in a ~110ft-wide existing construction dock. Build two of those per Iowa-size dock. Later, float the sections together at the mega-dock once it's finished and the hull is already at least one-quarter built-up.

Where were these many Iowa class dry docks?

In the inter-war years, there were only 2 ships of comparable size...Lexington and Saratoga. Three I can think of are Hunter's Point, Pudget Sound, and South Boston.

Drydocks a bit over 1000 feet long and about 150 feet wide were built in the late 30's at virtually every major US Navy shipyard on both coasts.

Construction was begun on the first two superdocks, at Norfolk and Philadelphia, in June 1940. These docks were 1,092 feet long and 150 feet wide. In 1941, a second shipbuilding dock was started at Philadelphia and two similar docks were undertaken at the New York Navy Yard. All these docks were built by the tremie method and were completed, ready for laying of keels, in from 17 to 21 months, as compared with prior times of three to eight years.
Subsequent events in the progress of the war dictated the later abandonment of the program for building these super-battleships and the construction, instead, of aircraft carriers of the Midway class. A large number of carriers and other smaller vessels were built in these docks, in time to play an active part in the Navy's brilliant fleet operations in the last two years of the war.
In August of 1940, the first of two important moves was made to provide adequate ship repair facilities on the West Coast when work was started on the new repair facility at Terminal Island, San Pedro, Calif.
For many years, the Navy had been supporting the fleet in the Pacific from two navy yards, at Puget Sound and Mare Island, with supplementary repair facilities for smaller vessels at the Destroyer Base, San Diego. Puget Sound was the home yard for the capital ships; Mare Island was limited, by shallow water and continuous silting, to vessels of cruiser size and smaller. The facility at Terminal Island was started with the acquisition of land, the enlargement of the area by filling, and the construction of a 1,092-foot drydock and accessory ship, waterfront and weight-handling facilities.
The second move to increase repair facilities on the West Coast was made with the acquisition, in November 1940, of a privately owned ship repair yard at Hunters Point, on San Francisco Bay, within the county limits of San Francisco, with which the Navy had previously had an operating agreement. When taken over, this yard contained two drydocks, one 1,000 feet long. The expansion of this shipyard was initiated in December 1940, when a large assembly shop was started alongside the larger dock.
Development of both Terminal Island and Hunters Point was continued through the entire war period, and both yards, originally designated as naval dry docks, were ultimately elevated to the status of naval shipyards at the same time that the titles of the old navy yards were changed, for organizational reasons, to naval shipyard. Two additional 700-foot docks were built at Terminal Island in 1942-1943, and three drydocks for submarines were built at Hunters Point in 1943-1944.
On the East Coast, ship repair facilities were augmented by the development of a new repair base at Bayonne, N.J., immediately adjacent to the Bayonne Supply Depot. This project included a 1,092-foot drydock, initially conceived for the repair and voyage overhaul of the huge transatlantic liners entering New York harbor, for which there were no existing facilities. This base was developed to a well-integrated small repair facility by the addition of quay walls, shops, and utilities, and ultimately became the Bayonne Annex of the New York Navy Yard.

https://www.ibiblio.org/hyperwar/USN/Bu ... ses-8.html

[Sid Guttridge]

Hi Guys,

The maximum size of US warships was restricted by the size of the locks on the Panama Canal, which allowed quick transfer between Atlantic and Pacific and vice versa.

Unless this is resolved, all discussion of bigger batteships is moot, unless the USA was prepared to build twice as many of them to cover both oceans or accept the long delay in using Cape Horn.

Cheers,

Sid

[OpanaPointer]

As noted earlier, the Midways and the Montanas (121 ft. 2 in. beam) exceeded PanaMax.

[TheMarcksPlan]

@T.A. Gardiner - thanks for the link, goes into my library. So the USN could build a drydock in 17-21 months...

From the same link,

Between 1938 and 1945, a total of $590,000,000 was expended for construction and improvements at navy yards.

The linked chapter describes myriad improvements that the funds bought - docks, breakwaters, marine rail systems, giant land structures for offices, supplies, construction, etc. This covers facilities for all USN ship-types, including submarines. Given the sheer scale of what $590mil bought, I can't the physical infrastructure for my MegaBB's costing more than $100mil.

[OpanaPointer]

You might want to look at Maury Klein's A Call To Arms: Mobilizing America for World War II. He crushes the topic and there's no end of information in those 897 pages.

[TheMarcksPlan]

A further note on AAA defenses. I'll be referencing the USN's post-war study of AAA effectiveness. http://www.ibiblio.org/hyperwar/USN/rep ... mary-1045/

Per the report, the USN spent 654 5in (non-VT) rounds per aircraft killed. For 40mm, it was 1,1713 rounds.

To translate this into my Mega-BB's performance:

I'll project that the lethal volume of explosion - and thus likelihood of kill - for a time-fuzed AAA round is proportional to the cube of the round's diameter. This is basic physics; the charge of a round expands cubically with diameter. In fact it may underestimate the value of larger rounds in AAA, as larger shell fragments have carrying power that is more-than-linear with their size. The USN for example, found that Japan's 15cm AAA round was more effective than its 12cm round by a greater degree than cubic escalation would predict. https://en.wikipedia.org/wiki/Type_5_15_cm_AA_gun [accurately reproduces chart from the very-long USN study cited therein].

To translate this into 5in shell equivalents, an 18in shell is worth 46.7; a 9.5in worth 6.9.

By these estimates and ww2 average performance, you'd kill one aircraft for every 14 18in shells, and one per 95 9.5in shells.

That seems about right to me intuitively... It would imply that if Yamato fired 2 full broadsides at attacking aircraft it should kill basically one aircraft. OTL the Yamato was using weird shells effective only at 1,000 yards for some reason - despite that fact we can't have expected its 18in guns to fight off hundreds of planes even with good shells.

For MegaBB, however, it's literally different orders of magnitude.
First, the MegaBB has 480 18in guns instead of 9.
Second, these guns can elevate up to 75 degrees as shown in my sketch of a turret mostly "buried" in the hull.
Third, this arrangement enables firing up to 5 shells/minute and loading at 45 degrees due to separation of compartments for powder/shell staging from the gunhouse (again, see sketch - probably needs more explanation though...).
Basically the MegaBB has ~150x the RoF of Yamato.

Returning to our 5in equivalents and implied AAA capability...
The 18 and 9.5in guns would begin engaging targets out to at least 15,000 yards [The 5in/38 DP would engage at ~12,000 yards].
A plane closing at 200kn on a 30kn ship covers ~6,000 yards/minute depending on angle of ship/plane. So ~2.5 minutes engagement time.
In that period, the MegaBB can fire 18/9.5in shells equivalent in lethality to 501,000 5in DP shells, implying 766 aircraft kills. (!)

For light AAA, let's say we have 1,000 40mm barrels. If each fires 100 rounds/min and has 1.5min engagement time, then we have 87 additional aircraft kills - probably those stragglers that survive the heavy-shell aerial holocaust.

And all these projections assume that the planes come in a single wave timed all to arrive on target at once. Reality would be different. At Pearl Harbor, for example, Nagumo's carriers had 414 planes but launched 183 (44%) in the first wave. It takes time to get a lot of planes aloft and they don't have the endurance to fly around and wait for everyone to form up.

Furthermore, this calc ignores plane losses when flying away from the ship.

So realistically the MegaBB could meet a 1,000-plane single-wave attack and splash 80+% of the attackers. To launch such an attack would require ~30 fleet carriers carrying ~80 planes apiece. The MegaBB would survive the attack; the carrier's air arm would be devastated. The conventional fleet could then destroy the enemy carriers.

One further note: As the study notes, most AAA kills were by the ships targeted by the planes rather than nearby supporting ships. The study doesn't break down shells/kill for targeted vs. non-targeted ships, however. The takeaway is that targeted ships would have lower shells/kill rates than reflected in these statistics.

A further further note: Many of the shells in the OTL WW2 sample were fired from lighter ships that were pitching/rolling violently (Atlanta-class, DD's). Many were fired by ships lacking the most-sophisticated fire-control systems. Neither would be true of MegaBB.

For these reasons, the sample is somewhat biased against the MegaBB and it isn't a stretch to suggest it could shoot down >1,000 planes before they even reached her.

If that seems implausible, consider the fact that MegaBB's 501,000 5in-equivalents is over twice the number of normal-fused 5in AA shells fired by the USN during the entire war (223,000).

No aerial attack force in either naval or land-based warfare has ever encountered an AA artillery barrage on even the same order of magnitude as that which MegaBB could throw up.

[Takao]

Why dig a hole?

Good point but the construction shipyard, at the very least, would have to be in the midst of an industrial complex and therefore probably in the ground. To avoid Takao's predicted construction timeline, however, another solution is to build a floating drydock then stick it in a pre-dug hole.

In the meantime, btw, while the drydock was being built, enormous sections of the hull could be constructed elsewhere in existing docks for assembly in the big dock. This is precisely how today's giant ships are built, precisely how American ingenuity solved the WW2 shipping problem, and would make total sense for construction of the mega-BB. One could, for example, assemble sections using the full beam of 360ft transverse in a ~110ft-wide existing construction dock. Build two of those per Iowa-size dock. Later, float the sections together at the mega-dock once it's finished and the hull is already at least one-quarter built-up.

Where were these many Iowa class dry docks?

In the inter-war years, there were only 2 ships of comparable size...Lexington and Saratoga. Three I can think of are Hunter's Point, Pudget Sound, and South Boston.

Drydocks a bit over 1000 feet long and about 150 feet wide were built in the late 30's at virtually every major US Navy shipyard on both coasts.

Construction was begun on the first two superdocks, at Norfolk and Philadelphia, in June 1940. These docks were 1,092 feet long and 150 feet wide. In 1941, a second shipbuilding dock was started at Philadelphia and two similar docks were undertaken at the New York Navy Yard. All these docks were built by the tremie method and were completed, ready for laying of keels, in from 17 to 21 months, as compared with prior times of three to eight years.
Subsequent events in the progress of the war dictated the later abandonment of the program for building these super-battleships and the construction, instead, of aircraft carriers of the Midway class. A large number of carriers and other smaller vessels were built in these docks, in time to play an active part in the Navy's brilliant fleet operations in the last two years of the war.
In August of 1940, the first of two important moves was made to provide adequate ship repair facilities on the West Coast when work was started on the new repair facility at Terminal Island, San Pedro, Calif.
For many years, the Navy had been supporting the fleet in the Pacific from two navy yards, at Puget Sound and Mare Island, with supplementary repair facilities for smaller vessels at the Destroyer Base, San Diego. Puget Sound was the home yard for the capital ships; Mare Island was limited, by shallow water and continuous silting, to vessels of cruiser size and smaller. The facility at Terminal Island was started with the acquisition of land, the enlargement of the area by filling, and the construction of a 1,092-foot drydock and accessory ship, waterfront and weight-handling facilities.
The second move to increase repair facilities on the West Coast was made with the acquisition, in November 1940, of a privately owned ship repair yard at Hunters Point, on San Francisco Bay, within the county limits of San Francisco, with which the Navy had previously had an operating agreement. When taken over, this yard contained two drydocks, one 1,000 feet long. The expansion of this shipyard was initiated in December 1940, when a large assembly shop was started alongside the larger dock.
Development of both Terminal Island and Hunters Point was continued through the entire war period, and both yards, originally designated as naval dry docks, were ultimately elevated to the status of naval shipyards at the same time that the titles of the old navy yards were changed, for organizational reasons, to naval shipyard. Two additional 700-foot docks were built at Terminal Island in 1942-1943, and three drydocks for submarines were built at Hunters Point in 1943-1944.
On the East Coast, ship repair facilities were augmented by the development of a new repair base at Bayonne, N.J., immediately adjacent to the Bayonne Supply Depot. This project included a 1,092-foot drydock, initially conceived for the repair and voyage overhaul of the huge transatlantic liners entering New York harbor, for which there were no existing facilities. This base was developed to a well-integrated small repair facility by the addition of quay walls, shops, and utilities, and ultimately became the Bayonne Annex of the New York Navy Yard.

https://www.ibiblio.org/hyperwar/USN/Bu ... ses-8.html

Respectfully, June, 1940 is not June, 1930.

Further, if construction of superdocks only began in June, 1940...How does this put one in every major ship yard in the late 1930s?

[TheMarcksPlan]

Further, if construction of superdocks only began in June, 1940

Your last reminder that the TITLE OF THE THREAD includes earlier U.S. militarization, not the anomalous situation of interwar America where the world's largest economy agreed that its navy would be only tied for first and barely half-again as large as a country with ~8% of American economic might.

[OpanaPointer]

IRL the US didn't even build up to the levels allowed by the Washington Naval Treaty.

[TheMarcksPlan]

STRATEGIC VERSATILITY AND POWER-PROJECTION: The clincher for why the pre-war U.S. should have built mega-ships.

So far I've been discussing Mega-BB's battle-worthiness.
That's only half the picture of the ship's true benefit.

The MegaBB's empty draft is ~40ft; its hull depth is 140ft. To maintain 20ft of freeboard, we could load the megaBB to 120ft draft or ~2.1mn displacement. Given an empty displacement of ~700k, that's 1.4mn tons of potential deadweight cargo capacity. Take off the gun barrels for cargo duty and free up another 100k tons.

Or look at volume: The ship's hull alone encloses ~860,000 GRT volume or about 10 RMS Queen Mary's (inclusive of QM's propulsion apparatus). In battle configuration much of that is reserved for ballast and, functionally, for reserve buoyancy. As a troopship, however, it should easily be able to accommodate 10x the QM's max pax load of 16,683 souls. https://www.queenmary.com/history/timel ... war-years/ And temporary housing (marine Quonset huts) on-deck would be easily accommodated.

More likely, do a combination of the foregoing: The ship carries ~500k ammo/powder in magazines and tanks/trucks on deck to the UK for the war buildup, ~500k tons of oil, and ~100k soldiers. At ~30kn eastbound and loaded, ~35kn westbound and light, it could easily make 30 such round-trips over a year - delivering 30mil tons of cargo and 3mil troops. Both figures substantially exceed the grand total cargo and troops moved to the UK from the U.S. by July 1944. https://www.ibiblio.org/hyperwar/USA/US ... cs1-6.html

What ports could support such movement?
I've already discussed that Provincetown Harbor could support a mega-wharf with depths of over 100ft.

On the UK side of the pond the Firth of Clyde is perfect. Today it supports a mega-port with >100ft draft.



The ship could cross the pond at 120ft draft but lighten to 90ft at the wharves by offloading oil to waiting tankers/barges.
The 100k soldiers would be impressed into temporary longshoreman service at both ends to unload ammo, vehicles, and other miscellanea of war by hand.

-----------------

Then there's shore bombardment. Obviously D-Day is the big event but with the ship's amplification of U.S. build-up in England this could easily occur in 1943 instead of 1944. OTL D-Day had the support of 7 old battleships; one MegaBB would have 70-80x the firepower. MegaBB usage in Europe could have allowed capture of Brest and/or Cherbourg late in 1942, allowing for a full-fledged, port-supported army group operating in France during 1943.

Or consider El-Alamein: Rommel was pinned on a 40-mile strip between the Mediterranean and the Qatarra Depression during June-November 1942. The MegaBB could annihilate 60% of Rommel's battle line with a "Surprise!" million-tons of shells in a single morning, after which Monty pins the stunned remnants of the Afrika Korps against the Depression and ends the North African campaign months earlier than OTL. Then again, maybe the MegaBB runs 100k soldiers and weapons past Sicily to Monty during Summer 1942 instead, sealing Rommel's fate much earlier than OTL where Monty had to wait for slow and vulnerable cargo convoys to go around Africa.

Likewise for the Italian campaign, where Anzio/Salerno are far easier after the Germans eat another million tons of shells.

[T. A. Gardner]

Respectfully, June, 1940 is not June, 1930.

Further, if construction of superdocks only began in June, 1940...How does this put one in every major ship yard in the late 1930s?

Construction of these drydocks started with the "Two Ocean Navy" plan in about 1938. The drydocks were built to a standard design and could be completed in about 18 to 24 months versus 3 to 6 years previously required because of changes in construction techniques.

It just shows that these drydocks weren't big enough for the ship in this thread and if they had to be they would have taken longer to build and cost more.

[T. A. Gardner]

As to carrying 100,000 troops on this ship, as Markus suggests...

It isn't happening. Even today, with more room per person that number couldn't be reached. You don't have the space to dedicate to berthing, the means to feed these men, or anything else.

Here's a realistic look at today's Navy berthing.



You aren't going to be able to run what would be a slave ship transporting these troops.

[Robert Rojas]

Greetings to both brother Takao and the community as a whole. Howdy Takao! Well sir, in reference to your posting of Wednesday - October 23, 2019 - 11:51am, old yours truly rather suspected that my utterly hairbrained scheme for the S.S. Normandie would not go unnoticed by yourself. And yes, there would be no practical way for the glorious S.S. Normandie to do with your quite rightful criticism of the technical suggestion in the first place. On the other hand, this whole ersatz creation of brother "THE-MARCKS-PLAN" is nothing but an utterly hairbrained scheme. This thread, from my perspective anyway, is only worthy of parody. It's right up there with the thread entitled as ITALIAN INVASION OF MALTA in year 1940. Now, in defense of our brother Erich Marcks, I must duly concede that it is quite a radical leap to transition from the role of Strategic Planner of the Eastern Front to that of an American Industrialist akin to HENRY JOHN KAISER. Well, that's my latest two Yankee cents worth on this wanting topic of interest - for now anyway. As always, I would like to bid you an especially copacetic day over in your corner of the Commonwealth of Pennsylvania.

Best Regards,
Uncle Bob

[Richard Anderson]

I recall a friend of mine who was an excellent draftsman and used to while away his time by drawing up plans for just such vessels. He enjoyed detailing the attributes of these for the KM and IJN as well...oh, wait, we were in seventh grade...

[Takao]

I recall a friend of mine who was an excellent draftsman and used to while away his time by drawing up plans for just such vessels. He enjoyed detailing the attributes of these for the KM and IJN as well...oh, wait, we were in seventh grade...

Did the same thing, just not that good a draftsman.

Stillb there is a program out there that lets you create your own what if warships. Its called Springsharp.