Wells Brothers' Battleship Index
The Tillman Battleships
|German (HSF & KM)|
|Russian & Soviet|
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.
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.  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. 
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. 
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.
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:
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.
|Design||Tillman Battleships||South Dakota (BB-49) class (For comparison)|
|Date||13 Dec 1916||13 Dec 1916||13 Dec 1916||29 Dec 1916||30 Jan 1917||30 Jan 1917||8 Jul 1918|
|Displacement, in tons||70,000||70,000||63,500||80,000||80,000||80,000||43,200|
|Waterline Length, in feet (meters)||975 (297.2)||660 (201.2)|
|Overall Length, in feet (meters)||998 (304.3)||684 (208.5)|
|Beam, in feet (meters)||108 (32.9)||106 (32.3)|
|Draught, in feet (meters)||32.75 (10.0)||32.75 (10.0)|
|Max. Speed, in knots||26.5||26.5||30||25.2||25.2||25.2||23.5|
|Max. Power, in EHP (SHP)||65,000 EHP (130,000 SHP)||65,000 EHP (130,000 SHP)||90,000 EHP (180,000 SHP)||90,000 EHP (180,000 SHP)||90,000 EHP (180,000 SHP)||90,000 EHP (180,000 SHP)||60,000 SHP|
|Number of Boilers||18||24||12|
|Main Battery||Twelve 16"/50 in four 3-gun turrets||Twenty-four 16"/50 in four 6-gun turrets||twelve 16"/50 in four 3-gun turrets||Twenty-four 16"/50 in four 6-gun turrets||Thirteen 18"/50 in five 2-gun turrets and one 3-gun turret||Fifteen 18"/50 in five 3-gun turrets||Twelve 16"/50 in four 3-gun turrets|
|Images||Click Here||Click Here||Click Here||Click Here||Click Here||Click Here||Click Here|
|Notes||In some ways, this is a greatly enlarged South Dakota (BB-49) class battleship. While the South Dakota design was not finalized until 1918, design work was well under way at this point.||Similar to design #1, but trades off some armor for increased armament. (BuOrd considered 13.5" to be the practical limit for armor plate thickness.)||Design 3 was a "fast battleship". At the time, the General Board was not particularly interested in fast battleship designs.||Adding 10,000 tons to the displacement allowed the armor of Design #1 to be combined with the main battery of Design #2.||Had these ships actually been built, the guns probably would have been 18"/48 Mk1|
It is quite reasonable to assume that if Design 3 had 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.
Evidently, the Navy was not satisfied with the original 2900 lb. shell. In 1921, the Navy produced ten "Type B" shells, which weighed 3330 lbs. (1514 kg) Apparently, at least one of these shells survives at Naval Surface Warfare Center in Dahlgren, Virginia. [4b]
In 1927, 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.
In the late 1930s, the Navy designed an 18" "super heavy" shell weighing 3850lb (1746kg) . Several examples were built, and the gun was test fired with these shells at Aberdeen in 1942. [4c] The muzzle velocity was 2400 feet per second, with a range of 43,000 yards at 45 degrees of elevation. Two examples of the "super heavy" shell survive near Building 1 at Naval Surface Warfare Center in Crane, Indiana.
We do not know whether a Tillman battleship, built in the 1920s, could have fired the "super heavy" shell. 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.
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.
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!
Based on construction times for contemporary American battleships, we speculate that these ships would have taken at least four years each to build. The Tennessee and Colorado classes (much smaller than the Tillman battleships) took 3-4 years to build. Also, the Iowa (BB-61) class (still significantly smaller than the Tillman battleships) 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.
Had the Tillman battleships been built, it is likely that there would have been five of them. We have three reasons for believing this:
|Class||Pennant Number||Ship Name||Keel Laid||Shipyard|
|South Dakota||BB-49||South Dakota||15 Mar 1920||New York Navy Yard|
|BB-50||Indiana||1 Nov 1920||New York Navy Yard|
|BB-51||Montana||1 Sep 1920||Mare Island|
|BB-52||North Carolina||12 Jan 1920||Norfolk Navy Yard|
|BB-53||Iowa||17 May 1920||Newport News|
|BB-54||Massachusetts||4 Apr 1921||Fore River|
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.
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:
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.
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 thus designed to be 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.
In order to make up the 1632 ton difference in the boiler weights, it is possible to consider a thinner armor belt. Reducing the belt to 9.5 inches (a little over 24 cm) and tapering down to 3.5 inches (8.9 cm) at the bottom would probably save enough weight. (based on assumptions of steel weighing 490 lbs/cubic foot) While this is substantially less than other battlecruiser designs shown here, it is still thicker than the armor belt ultimately chosen for the Lexington-class, and probably more in keeping with the General Board's scout concept. If lighter machinery could indeed have been built by 1918-1919, some of the belt armor could certainly have been restored.
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." 
The General Board instead adopted Design B, an 850 foot design with eight 16 inch guns, which eventually evolved into the Lexington.
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.
|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)||860 (262.2)||975 (297.2)||900 (274.3)||975 (297.2)||850 (259.1)|
|Overall Length, in feet (meters)||998 (304.3)||924 (281.7)||884 (269.5)||998 (304.3)||924 (281.7)||998 (304.3)||874 (259.1)|
|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|
|Images||Click Here||Click Here||Click Here|
|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|
|1.0||1 January 2002|
|2.0||1 March 2014|
 Terzibaschitsch, pg 110.
 Breyer, pg 252.
 Friedman Battleships, pg 148-153.
 Friedman Naval Weapons, pg 21.
[4a] Friedman Naval Weapons, loc. cit.
[4b] Dulin & Garzke, pg 282-283
[4c] Dulin & Garzke, pg 110-111
 Friedman Cruisers, pg 76.
 Friedman Cruisers, pg 84.
 Friedman Cruisers, pg 98.
Copyright ©2001 Lawrence H. Wells and David R. Wells. All rights reserved.