The Tillman Battleships

0. Abstract

While these studies are just a curiousity to most historians, they are irresistible to battleship fans and wargamers, as they are among the most spectacular battleship designs ever produced by the United States, or any other nation for that matter. These designs can be the used for entertaining wargame scenarios or alternate history speculation. This page also provides some speculation about battlecruisers that might have been developed in parallel. 

1. Introduction

We first learned of the Tillman battleships back in the 1970s, when Stefan Terzibaschitsch's book on US battleships was published. In his notes on the South Dakota (BB-49) class, he mentioned an 80,000 ton preliminary design with fifteen 18 inch guns and a speed of 35 (sic) knots. [1] As you might imagine, this piqued our curiousity, but Terzibaschitsch provided no additional details.

Terzibaschitsch apparently took his data from Sigfried Breyer's book "Battleships and Battlecruisers: 1905-1970", which has a similarly brief mention of these ships, with the same error in the speed figure. [2]

The publication of Friedman's "US Battleships: An Illustrated Design History" made the details of the Tillman battleships available to the general public. Friedman's book is the best reference that we have found for data on the Tillman battleships. [3]

A wargaming friend asked us a number of questions about these spectacular designs. He was looking for a spectacular American battleship design for a wargame. He imagined a "no Washington Treaty" scenario, and wanted American ships to counter the Japanese "13" class. Our discussions lead to the writing of this page.

The intended audience for this page is battleship fans, wargamers, and alternate historians. We thus assume that the readers will have a certain level of knowledge about naval history, American battleships, and the Washington Treaty of 1922.

Since the Tillman battleships were never built, nor even seriously considered, our page contains considerable speculation about what they might have been like. We have tried to label our speculations as such.

One potentially confusing matter in this page is our reference to the South Dakota (BB-49) class battleships. These six battleships were begun in the early 1920s, but were never completed. They should not be confused with the World War II-era South Dakota (BB-57) class, of which four were completed.

2. Senator Benjamin R. Tillman

Tillman was a member of the Senate's Committee on Naval Affairs in the World War I era. Apparently, he grew tired of the Navy requesting ever larger battleships every year. He was also annoyed by the Navy's habit of building battleships that were significantly larger than Congress authorized.  He therefore requested the navy to design "maximum battleships", i.e. the largest battleships that the Navy could practically use.

Nobody is quite sure of what Tillman's motivations were for requesting these ships. There are two schools of thought on what Tillman was thinking:

• He was trying to figure out where the battleship arms race would end. Every year the Navy asked Congress more for money for larger and larger battleships, and when built the ships were frequently larger and more expensive than Congress had authorized. He may have wanted to find out just how bad the situation might get.
• Since battleships were getting bigger every year, the United States would have to build a "maximum battleship" sooner or later, so it might as well be sooner.

3. Maximum Battleships

In 1916, he once again requested a "maximum battleship" study. The US Navy's bureau of Construction and Repair produced a series of interesting design studies, detailed below. Once again, the design studies influenced the design of a succeeding class, the South Dakota (BB-49) class, however once again, the South Dakotas would have been significantly smaller than the ships envisioned in the Tillman design studies, and were in some ways just an enlargement of the previous Colorado (BB-45) class.

The US Navy was not particularly interested in building these "maximum battleships", however after Sen. Tillman requested the designs, the Navy's Bureau of Construction and Repair dutifully did the design studies. They produced a series of four designs late in 1916.

The practical limits on the size of a US Navy battleship were dictated by the dimensions of the locks of the Panama Canal. The locks measure 1000 feet by 110 feet, and so the practical size limit for the ship was 975 feet (297.2 meters) in length, 108 feet (32.9 meters) in beam, and 38 feet (11.6 meters) in draught. Harbor depths further constrained draught to 32.75 feet (10 meters).

After the first four design studies were complete, Design 4 was chosen for further development. Three additional studies, Design IV-1, IV-2, and IV-3 were prepared. At the request of Navy Secretary Josephus Daniels, these designs used 18" guns instead of the 16"/50 used in the earlier studies.

The Navy decided that design IV-2 was the most practical, (or perhaps the least impractical) and this was the design that was ultimately presented to Congress early in 1917. We tend to agree with the Navy's assessment. Design IV-2 should therefore be considered the definitive Tillman battleship design.

3.1 Tillman Battleship Design Studies: Technical Specifications

3.2 Propulsion

• Turbo electric machinery allowed greater subdivision in the machinery spaces, aiding damage control.
• Turbo electric machinery could transfer power from any boiler/turbine to any electric motor in case of emergency.
• Turbo electric machinery eliminated the need for reduction gears, which were difficult and expensive for the US to produce.

3.3 Main Armament

• US Navy 16"/50 Mk 2

These guns were actually produced for the South Dakota (BB-49) class battleships and the Lexington (CC-1) class battlecruisers, however these ships were all cancelled by the Washington Treaty of 1922. The guns themselves were transferred to the US Army where they served for many years as coast defense batteries. It fired a 2100lb (953kg) armor piercing shell at 2800 ft/sec. It presumably would also have been capable of firing later 2240lb (1016kg) shell at lower velocity, probably around 2700ft/sec. [4]

It is quite reasonable to assume had Design 3 been built, the turrets would have been identical to those planned for the South Dakotas. This turret was essentially an enlarged version of the twin turret used on the Colorado class battleships. The more heavily armored turret for Design 1 would certainly have been very similar.

The six-gun turrets in designs 2 and 4 seem quite impractical to us. In reality, the French and British initially had considerable trouble with their four-gun turrets, and so we can only imagine that these six-gun turrets would have been even more troublesome. In any case the six-gun turret was never even reached the design stage.

An example of the 16"/50 Mk 2 apparently survives as a museum piece at the Naval Surface Warfare Center, (Dahlgren Division) in Dahlgren, Virginia. An example of the Army shore battery apparently survives as a museum piece at Aberdeen Proving Ground in Aberdeen, Maryland.

• US Navy 18"/48 Mk 1

The US Navy never produced an 18 inch gun for any real battleship or battlecruiser, however it did design a prototype 18 inch gun in this era: The 18"/48 Mk1. It is more than reasonable to assume that had the Design IV-2 Tillman battleships been built, the main guns would have been quite similar to the 18" prototype gun. Initial design work started in 1916, and construction of a prototype 18"/48 was started around 1920. Had it been completed it would have fired a 2900lb (1315kg) armor piercing shell at 2700 ft/sec. [4a]

After the Washington Treaty went into effect, the 18"/48 prototype was completed as the 16"/56 Mk4. It was found to have little if any advantage over the existing 16"/50 Mk2, and weighed nearly twice as much. In the late 1930s it was reconverted into the 18"/47 Mk A, but it was abandoned because it had little advantage over the the 16"/50 Mk2 or 16"/50 Mk7 firing the new "super heavy" 2700lb (1225kg) shell. An 18" "super heavy" shell weighing 3850lb (1746kg) was designed in the 1930s, but apparently it was never produced. Even if it had been, one could question whether a Tillman battleship could have fired it. The Colorado (BB-45) class could not fire the 16 inch "super heavy" shell because the ships' ammunition hoists could not lift them.

We believe that this prototype gun still exists as a museum piece at the Naval Surface Warfare Center, (Dahlgren Division) in Dahlgren, Virginia.

3.4 Design Notes

3.4.1 Flush Deck

3.4.2 Hull-Mounted Casemate Guns

Perhaps with their huge size and flush decks, the Tillman battleships might have had enough freeboard astern to keep the casemates dry. The casemates would have been one level higher than they had been on earlier American battleships.

Another interesting reversion is the single centerline secondary gun at the tip of the stern. This had been used previously in the Nevada (BB-36) class, but it was subsequently abandoned in the Pennsylvania (BB-38) class. Like all other hull mounted casemates, the Nevada's centerline casemates were removed during refits.

4. Fate of the Tillman Designs and Their Legacy

We don't know exactly what happened after Design IV-2 was presented to Congress early in 1917. Evidently, Senator Tillman was appeased, and no further work was done on these designs. Senator Tillman died on 3 July 1918, and to a certain extent, whatever plans he had for these designs died with him.

The Navy proceeded with the South Dakota (BB-49) class, as they had intended all along. While the South Dakotas began construction, they were all cancelled under the terms of the Washington Treaty of 1922.

Still, the design studies didn't go away completely.

The Tillman design studies influenced the South Dakota (BB-49) design.

The South Dakota class inherited some features from the later Tillman designs, for example the 6" secondary battery. The main armament of the South Dakotas would have closely resembled that proposed for Design #1 and Design #3. The South Dakota class would have had only 13.5 inch belt armor, but that was the most that the Navy's Bureau of Ordinance (BuOrd) thought was practical anyway. At the time the BuOrd suspected armor plates thicker than 13.5" would be metallurgically inferior, and would not be proportionally better than the then standard 13.5" armor plate. The South Dakota's speed would have been only 23.5 knots, but that still would have made them the fastest American battleships to date. Finally, their displacement grew from 41,000 tons to 43,200 tons during the design phase.

In late 1920 and early 1921, the Navy's General Board met to define the characteristics of the battleship class that would follow the South Dakota. The Washington Treaty ended the program before detailed designs were developed, but the alternatives considered were all substantially larger than the South Dakota.

In late 1934, the Navy's Preliminary Design department produced two designs for maximum battleships. In both cases length was 975 ft, and beam was 107 ft. The 25 knot design displaced 66,000 "standard" tons at a draught of 33.5 ft; the 30 knot design displaced 72,500 "standard" tons at a draught of 37 ft. The 72,500 ton ship's dimensions were the largest that could fit through the Panama Canal locks. Main armament was eight 20" guns in four twin turrets. These designs were prepared mainly to study possible responses to a potential Japanese breakout from the Washington and London treaties (which did in fact happen), but the Navy never seriously considered building these ships.

Also, every few years, when new battleship designs were being presented to Congress, some Congressional staffer would dig up the old Tillman design studies and suggest that the new design was not the best it could be. Apparently this happened as late as 1940!

5. Speculation: Construction & Modification of the Tillman Battleships

5.1 Construction

5.1.1 Construction Time

Based on construction times for contemporary American battleships, we speculate that these ships would have taken at least four years each to build. Also, the smaller Iowa (BB-61) class took about 3 years each during wartime. The Forrestal (CV-59) class carriers, which were similar in size to the Tillman battleships, took 3-4 years each during peacetime.

Since the initial design study was not completed until early 1917, we specualte that no Tillman battleship could possibly have been completed before 1921. Even then, it would have been quite a rush! In reality, two ships of the Colorado class were not completed until 1923, so it's likely that no Tillman battleship could have been completed until after that.

This, of course imagines a world with no Washington Treaty.

5.1.2 Cost

5.1.3 Numbers

Had the Tillman battleships been built, it is likely that there would have been five of them. We have three reasons for believing this:

1. Secretary of the Navy Josephus Daniels stated that it would not be worth building any less than five.
2. Prior to the South Dakota (BB-49) class the Navy typically built groups of 4 to 5 battleships with very similar characteristics. (2 Nevada + 2 Pennsylvania; 3 New Mexico + 2 Tennessee; and 4 Colorado, with one discarded under the Washington Treaty.)
3. The USN eventually started construction of six South Dakota (BB-49) class battleships. We assume that the Navy would have had to build fewer Tillman battleships than South Dakota battleships due to their cost.

5.1.4 Names & Hull Numbers

All of the names planned for the South Dakota (BB-49) class were re-used on later battleships. Wargamers might find more practical to re-use pre-dreadnought names that were not re-used later. America's pre-dreadnought era battleships were retired after World War I, and most were scrapped shortly thereafter. Their names would have been available for re-use on Tillman battleships. Reusing pre-dreadnought names would allow the wargamer to design scenarios involving both Tillman battleships and later battleships without name duplication. We suggest such names as Virginia, Nebraska, Georgia, Rhode Island, Connecticut, Vermont, Kansas, and Minnesota.

5.2 Modification

The Colorados received relatively few modifications until the 1940s. They were the newest battleships in the US Navy in the 1920s, and thus required little modification. Money was short in the 1930s due to the Great Depression, and so even if major modifications had been needed, they would not have been made.

It is likely that the Tillman battleships would have received similarly few modifications through the 1920s and 1930s. We speculate that the following modifications would have been made:

• Addition of aircraft catapults. If standard US practice were followed, two catapults would have been installed: one on the main deck on the centerline behind the turret 5, and one on top of turret 4. An aircraft handling crane would have been installed at the tip of the stern. These would probably have been added in the 1920s.
• Slight improvement of anti-aircraft guns. The original Tillman designs indicate only a few 3 inch anti-aircraft guns. It is likely that some 5 inch/25 guns would have been added.
• Improvement of splinter shielding. Splinter shields would have been added around the anti-aircraft guns sometime in the 1930s.
• Removal of hull-mounted casemate guns. Depending on experience, it is likely that the hull mounted casemate guns would have been removed. The Colorado class did not have hull-mounted casemates to remove, but several earlier classes did, and in all cases, they were removed. While it is imaginable that the Tillmans' hull-mounted casemate guns would have been "dry" enough to be functional in bad weather, they were not that useful. The weight saved by their removal no doubt would have been used for anti-aircraft guns. The guns probably would have been removed in the 1920s.

One Colorado class battleship, the USS West Virginia (BB-48), was extensively damaged at Pearl Harbor on 7 Dec 1941. She was extensively reconstructed with large hull bulges, a modern dual purpose secondary battery similar to that on the North Carolina (BB-55) and later classes, a modern superstructure, (once again, similar to those on the newer battleships) and modern electronics. Both Tennessee (BB-43) class battleships were reconstructed in this manner as well. If a Tillman battleship had been similarly damaged in the 1940s, one could imagine that she might have been similarly reconstructed, and emerged as a very formidable warship.

6. Speculation: A Tillman Battlecruiser?

Many nations, including the United States, were designing battlecruisers in this era to compliment their battleship fleets. The American battlecruiser design contemporary to the South Dakota (BB-49) class was the Lexington (CC-1) class. This lead to some speculation on our part on what a "Tillman Battlecruiser" might have looked like.

Unlike Great Britain and Germany, the United States, by and large, did not design battlecruisers. The Lexington (CC-1) class was the United States' first foray into this realm. The Lexingtons were intended to be used as scouts rather than as members of the battle fleet. They were designed more like cruisers than like battleships, and would not have been particularly well armored. The General Board, which had great influence over ship design, wanted very fast scouts, and thought that armor protection was not terribly useful for these ships. They thought that scouts would not fight against ships armed with more than six inch guns. The General Board actually rejected numerous designs with better armor than the Lexington class.

The Lexingtons were designed independently of the South Dakota class battleships, however they would have had eight of the same powerful 16"/50 Mk 2 guns that would have been used on the South Dakotas. They also would have used the same type of 6" secondary guns.

6.1 Speculation #1: Battlecruiser based on Tillman Design #3

6.1.1 18 inch guns?

• A preliminary sketch dated 14 August 1919 shows a battship very similar to the South Dakota with eight 18 inch guns.
• In late 1920 and early 1921, the General Board defined characteristics for "Battleship 1922". They produced a design which was very similar to the South Dakota class, but about 1300 tons larger, and was armed with eight 18" guns.
• Also, some of the Tillman designs featured twin 18 inch guns.

6.1.2 Faster and lighter?

6.2 Speculation #2: Battlecruiser based on Design C

Design C also had somewhat less armor than Tillman design #3: 8 to 12 inches on the belt, 12 inches on the barbettes, 16, 9, 6 and 11 inches on the turrets, and 2 to 3 inches on the armored deck.

Design C had at least one unusual charateristic: the placement of the two forward turrets. They were mounted significantly higher than one might have expected. Turret 1 was above the first superstructure level! Turret 2 was superimposed above it, and was thus very high up. This probably would have given the ships a high center of gravity, which could have caused operational problems.

The General Board rejected Design C, and its slightly smaller companion Design D in June 1918, on the grounds that they

"embody radical departures from existing designs and ideas." [7]

The General Board instead adopted Design B, an 850 foot design with eight 16 inch guns, which eventually evolved into the Lexington.

6.2.1 Changes in Profile and Propulsion?

6.2.2 Faster and lighter?

Once again, more speed and less armor might have satisfied the General Board, so one might have to imagine a faster variant of this design with more power and less protection. Like Tillman design #3, one might also imagine a variant with eight 18 inch guns.

6.3 Maximum Battlecruisers: Technical Specifications

Design	Speculative Maximum Battlecruisers						Lexington (CC-1) class (For comparison)
	Tillman Design #3	Design C	Design D	DRW Speculative #1	DRW Speculative #2	DRW Speculative #3
Date	13 Dec 1916	16 May 1918	8 May 1918	N/A	N/A	N/A	14 Jun 1919
Displacement, in tons	63,500	54,500	54,500	63,500	54,500	63,500	43,500
Waterline Length, in feet (meters)	975 (297.2)	900 (274.3)	880 (268.2)	975 (297.2)	900 (274.3)	975 (297.2)	850 (208.5)
Beam, in feet (meters)	108 (32.9)	106 (32.3)	106 (32.3)	108 (32.9)	106 (32.3)	108 (32.9)	101 (30.8)
Draught, in feet (meters)	32.75 (10.0)	32.25 (9.85)	32.25 (9.85)	32.75 (10.0)	32.25 (9.85)	32.75 (10.0)	31.0 (9.45.0)
Max. Speed, in knots	30.0	30.0	29.5	30.0	30.0	30+	33.25
Max. Power, in EHP (SHP)	90,000 EHP (180,000 SHP)	90,000 EHP (180,000 SHP)	90,000 EHP (180,000 SHP)	180,000 SHP	180,000 SHP	218,000 SHP	180,000 SHP
Number of Boilers	24	17	17	24	17	13?	16
Main Battery	Twelve 16"/50 in four 3-gun turrets			Eight 18"/48 in four 2-gun turrets			Eight 16"/50 in four 2-gun turrets
Belt Armor	13"/7"	12"/8"	12"/8"	13"/7"	12"/8"	13"/7"	7"/5"
Barbette Armor	12.5"/4"	12"/4"	12"/4"	12.5"/4"	12"/4"	12.5"/4"	9"/7"/5"
Turret Armor	18"/10"/5"/9"	16"/9"/6/"11"	16"/9"/6/"11"	18"/10"/5"/9"	16"/9"/6/"11"	18"/10"/5"/9"	11"/6"/5"/8"
Deck Armor	3""	3"/2"	3"/2"	3"	3"/2"	3"	1.75"/1.5"/1.5"
Notes	Tillman "Fast Battleship" Design #3, exactly the same as above.		Similar to Design C, but slightly shorter and slightly slower.	A variation on Tillman Design #3 with 18 inch guns	A variation on Design C with 18 inch guns	A variation on Tillman Design #3 with more power and 18 inch guns

7. Footnotes

[1] Terzibaschitsch, pg 110.

[2] Breyer, pg 252.

[3] Friedman Battleships, pg 148-153.

[4] Friedman Naval Weapons, pg 21.

[4a] Friedman Naval Weapons, loc. cit.

[5] Friedman Cruisers, pg 76.

[6] Friedman Cruisers, pg 84.

[7] Friedman Cruisers, pg 98.

8. References

1. Battleships of the U.S. Navy in World War II by Stefan Terzibaschitsch, 1976, Bonanza Book, New York NY
2. Schlachtschiffe und Schlachtkreuzer 1905-1970 by Sigfried Breyer, 1972, Karl Müller Verlag, ISBN 3-86070-044-8
3. U.S. Cruisers: An Illustrated Design History by Norman Friedman, 1984, Naval Institute Press, Annapolis MD. ISBN 0-87021-718-6
4. U.S. Battleships: An Illustrated Design History by Norman Friedman, Naval Institute Press, Annapolis, MD 1985 ISBN 0-87021-715-1
5. US Naval Weapons by Norman Friedman, Naval Institute Press, Annapolis MD. ISBN 0-87021-735-6
    

Copyright ©2001 Lawrence H. Wells and David R. Wells. All rights reserved.