But What About Logistics? USN Surface Combatant Ranges (1939-2021)

There is a cliched saying that, "Amateurs study tactics while professionals study logistics." But as there is growing interest and debate about the future of naval warfare between great powers, the influence of logistics appears to have been relegated to an afterthought. The world has not seen a full-scale naval war for almost 80 years, and technology has changed dramatically since then. In fact, technology continues changing at a breakneck pace, and numerous game-changers currently wait in the wings, ready to take their position on center stage. But as we ponder the ramifications of hypersonics, lasers, railguns, cyberwar, space-based weapons, and the whole gamut of unmanned systems, we need to remember that no amount of future weapons will eliminate the need for logistics.

For the USN, logistics is a particularly critical need given America's chosen strategy of operating forward and challenging the enemy in their own backyard. However, as the number of speeches, reports, articles, and posts advancing a smaller, more affordable, and more distributed fleet grows by the day, mentions of how such a fleet would handle the task of simply getting to the frontlines (much less conducting sustained operations half a world away from American shores) remain shockingly absent. Even the growing concerns about America's understrength sealift force primarily center around the ability to transport and sustain ground forces rather than the ability to supply the fleet itself.

Today, the USN has less ability to conduct sustained combat operations than at any point since WWII. Not only is the fleet train on which it relies a fraction of its former self, but the very endurance of its ships, both in terms of range and magazine depth, is far more limited than before. But if the current fleet architecture already raises serious questions about the USN's ability to effectively fight a new Pacific War, how is the proposed future force of smaller and more distributed vessels supposed to function? It needs to be remembered that the current fleet of large warships was the direct result of the USN's experience in WWII.

Ulithi, the USN's largest forward logistics hub during WWII

While unfortunately left out of most histories of the War in the Pacific, America's victory over Japan was only made possible by a herculean logistics effort. At every step of the advance across the Pacific, American (and Japanese) forces struggled with logistics nearly as much as they struggled with the enemy. The availability of fuel and munitions (as well as the ships to transport them and the depots to store them) did not just shape battles and campaigns, they decided which battles and campaigns were even possible.

The absence of the powerful battleships of Task Force One during the crucial days of the Solomons Campaign is likely the most striking example of the influence of logistics on the War in the Pacific. However, logistic constraints continued to shape fleet deployments right up until the closing days of the war. During the Battle of Leyte Gulf, for instance, Halsey was missing the entirety of Task Group 38.1, as its 5 carriers, 6 cruisers, and 21 destroyers had retired to refuel shortly before the Japanese attacked. Even the late entry of the British Pacific Fleet into the war was driven almost entirely by a lack of slack in American logistics, forcing the British to build their own fleet train before they could contribute meaningful forces against Japan. 

Throughout the war, the USN focused on improving logistics by building more auxiliaries and constructing island bases across the Pacific. Indeed, the entire island-hopping campaign was designed primarily to secure the bases the fleet would require to move across the Pacific. But even with the vast WWII fleet train and massive forward logistics centers like Ulithi, the USN made great efforts to increase the range and endurance of individual warships in order to lighten the burden on the combat logistics force and increase operational flexibility.

USS Gearing (DD-710), the ultimate wartime destroyer with greatly increased range

The push for improved range in surface combatants was most noticeable in the destroyers designed and built during the war. Unlike larger warships, destroyers were small enough that several classes were constructed over the course of the war, incorporating lessons learned during the conflict. As the smallest front-line warships, destroyers were also the weak link logistically, and improvements to their endurance had an outsized effect on fleet logistics.

During the interwar years, when the restrictions of the London Naval Treaty were still in effect, the USN's best destroyers (not counting the limited number of destroyer leaders) were the ships of the Benson and Gleaves classes. Despite being relatively large and capable destroyers for their day, their range of around 3,500 nm at 20 knots proved to be less than desirable. As soon as the treaties lapsed in 1939, the USN began designing a far larger and more capable ship - the Fletcher-class.

Interestingly, the greater size of the new destroyer was not driven by a larger armament (the Fletcher-class carried the same number of guns and torpedoes as its predecessors), and early proposals actually called for a smaller ship than the Benson and Gleaves classes. But requirements for deeper magazines, improved seakeeping, and enhanced survivability drove up the displacement. Capable of 4,000 nm at 20 knots, the Fletcher-class was an upgrade when it came to endurance, but wartime experience demanded even greater range.

For the final wartime destroyer class, increasing range became the primary goal. In fact, a longer hull and greater bunkerage were the main distinctions between the Gearing and Allen M Sumner classes (which was little more than an upgunned Fletcher). With a range of approximately 4,400 nm at 20 knots, the Gearing-class was a substantial improvement over the prewar destroyers. 

For more details, this document from HyperWar has full wartime fuel curves for all USN destroyer classes.

The triumph of logistics, USS Bainbridge (DLGN-25) the USN's first nuclear-powered destroyer

As the USN continued to expand its global presence during the Cold War, the size and range of its warships continued to increase. The Leahy-class frigates of the 1960s offered an impressive 8,000 nm at 20 knots - slightly more range than a WWII heavy cruiser. There was even considerable interest in nuclear-powered destroyers, as they eliminated the need to refuel entirely (nuclear power was actually considered more valuable in smaller ships than in carriers, which already had sufficient range).

By the height of the Cold War, the USN operated surface combatants that fell into two general levels of endurance. At the top were the fast carrier escorts, designed to keep up with their larger charges over immense distances without stopping to refuel. This segment of warships included 9 nuclear-powered cruisers with effectively unlimited range, 18 steam-powered cruisers that could travel over 7,000 nm at 20 knots, and the dozens of ships of the Spruance, Kidd, and Ticonderoga classes with their ranges of 6,000 nm at 20 knots.

The second level of endurance included virtually every other surface combatant in the fleet, from older destroyers down to the Knox-class and Oliver Hazard Perry-class frigates. Despite relatively large variations in size and capability, all of these ships possessed a range of roughly 4,500 nm at 20 knots - effectively identical to the Gearing-class destroyers of WWII. Given that these ships were intended primarily for second-line duties such as convoy escort, this was not a terrible limitation.

Today, the critical class of high-endurance carrier escorts has almost completely vanished, with only the 22 aging members of the Ticonderoga-class remaining (as an aside, the impressive range of these ships is arguably their most valuable characteristic, not their additional VLS cells or command spaces). And while little discussed, the Arleigh Burke-class achieves the same 4,500 nm at 20 knots as the second-line ships of the Cold War. This does not bode well for potential fleet operations during a future Pacific War, especially as the combat logistics force is also a fraction of its former size.

The future USS Constellation (FFG-62), the future of the USN surface fleet

As the USN explores a future fleet architecture that embraces the principles of distributed maritime operations, the logistics implications of moving towards smaller hulls must be carefully examined. Currently, the exact specifications of the proposed large and medium unmanned surface vehicles remain unclear as the programs are still highly experimental and far from producing an operational ship. However, the specifications of the Constellation-class frigates currently under construction have been released and are not reassuring.

While the Constellation-class is advertised as offering an improved range of 6,000 nm, digging into the details reveals a ship optimized for peacetime cruising rather than wartime operations. The stated 6,000 nm figure is achieved at a slow speed of just 16 knots, and the ship's combined diesel and gas propulsion means that fuel consumption will increase dramatically at higher speeds (assuming the maximum range is achieved on diesel power alone). This means the Constellation-class may very well offer less wartime range than the Gearing-class destroyer from WWII.

However, unlike the USN of WWII or the Cold War, the USN of the near future will not have any fast long-range escorts to fill the gaps when the short-ranged Arleigh Burke-class and Constellation-class ships prove insufficient. So far, it appears that the proposed fleet of smaller ships is poised to dramatically increase the USN's' logistics requirements and render a potential Pacific War more difficult. While the tactical benefits of distributed lethality (and the budgetary benefits of less expensive ships) are persuasive, perfecting tactics while ignoring logistics is not the secret to success in a global conflict.