Few sounds arouse more pride and seriousness in a submariner than that of a diving alarm declaring that the boat is once more slipping below the waves. At the same time, every submariner understands the inherent risk of taking ships to sea, no matter what flag they sail under.
Curiously, the same alarm is used when emergency surfacing the boat using compressed air—a last resort when the submarine is in extreme peril. Unfortunately, this system has sometimes been unequal to the severity of the casualty, dragging the crew down to the ocean floor. For those on a submarine, unlike a surface ship, the story does not necessarily end there. For decades, the United States has invested in developing and maintaining the ability to locate and rescue the crew of a downed submarine.
If the submarine was not a complete loss, a specialized team from Undersea Rescue Command (URC) in San Diego, California, will use equally specialized equipment to extract survivors from the ocean bottom. Most nations that operate submarines also have their own submarine rescue capability. By leveraging rising interoperability and coordination among different countries’ rescue commands, URC can increase the potential for an execution of a successful rescue and also build existing alliances, cracking open the hatch to our adversaries. Looking at the U.S. history of submarine rescue can illuminate current engagement and identify gaps that need filling for future success.
U.S. Submarine Rescue History
Undersea rescue as we know it can be traced back to the sinking of the USS Squalus (SS-192) in 1939 off the New England coast and the crew’s subsequent rescue by the fledgling Experimental Diving Unit. Only 39 hours after the submarine had commenced her initial dive, the sailors who survived were safely rescued, although 26 lives were lost.1 Many contemporary submariners had dismissed the idea of rescuing a stricken submarine crew as an impossibility but were proven wrong as each group of survivors made its way to the surface through the frigid New England waters in a cramped rescue chamber. This action would both establish firmly the need for a Navy submarine rescue capability and forever elevate the names Lieutenant Commanders Charles “Swede” Momsen and Charles R. McCann, whose rescue chamber was used to save the lives of the crew.
The loss of the USS Thresher (SSN-593) in 1963 and the Scorpion (SSN-589) in 1968 in extremely deep water—and without possibility of rescue—caused a complete rethinking of submarine design, maintenance, and operations to reduce the number of unrecoverable submarine accidents the United States experiences. This would lead to the Submarine Safety Program (SubSafe), an ongoing effort by sailors and contractors to ensure all submarine construction and operations are executed safely, from welds to operating procedures. Illustrating the magnitude of the effort undertaken to reduce the likelihood of a stricken submarine, several pages of the 2003 Report of [Space Shuttle] Columbia Accident Investigation Board is dedicated to contrasting the Navy’s submarine and reactor safety programs with NASA’s safety programs, with the Navy demonstrating what “right” looks like. The submarine force is not perfect, but its dedicated focus on safety is well known.
The loss of the Thresher would also lead the Navy to reevaluate its submarine rescue programs holistically. As one student of the disaster notes: “Two weeks after the [Thresher] sank, Secretary of the Navy Fred Korth established the Deep Submergence Systems Review Group (DSSRG)” that would conduct a thorough review of submarine rescue capabilities. The McCann Rescue Chamber used in the 1939 rescue of the crew on board the Squalus is only capable of rescues up to 850 feet and was deemed insufficient; although URC still uses two of the devices today, they are not able to operate at modern submarine collapse depths. When the Thresher sank, it was possible for a modern submarine to be at the bottom of the ocean and its crew both alive and unrecoverable.
This shortfall would lead to the Deep Submergence Rescue Vehicle (DSRV) program, the Navy’s first major overhaul of submarine rescue since the 1930s. Originally planned as a 12-vehicle system, it would see the number of planned vehicles drop to 6 and then ultimately to 2. The DSRVs were deep-diving minisubmarines launched from a mother ship—either a large submarine or one of two Pigeon-class surface rescue ships. DSRVs were designed to be rapidly loaded into airplanes, flown to a port, and deployed to rescue a disabled submarine across the world. With the acceptance of the DSRVs Mystic and Avalon in 1977 and 1978, the Navy took possession of a redundant capability to conduct submarine rescue to the crush depths of modern submarines. Both DSRVs remained in service through the end of the Cold War.
The Navy began a replacement program in 1998—the Submarine Rescue Diving Recompression System (SRDRS). Using commercial-off-the-shelf parts where feasible, this system was less militarized than the DSRV and more akin to a deep-diving research submersible. The new design overcame several DSRV shortfalls. It added decompression chambers for survivors, eliminated the need for either a mother submarine or one of the two specialized submarine rescue ships to be present, and overcame general obsolescence concerns. Brought into service in 2008, the SRDRS and its deep diving rescue vehicle, the Pressurized Rescue Module (PRM), allowed the DSRVs to be retired. Unlike the debate that preceded the building of the DSRVs, only one SRDRS was ever proposed and built. Unfortunately, this lack of redundancy carries significant risk—any major material failure or loss in shipping of the SRDRS would eliminate the Navy’s only deep-sea submarine rescue capability.
Successes and Improvements
Submarines provide small nations with limited budgets the seagoing means for coastal defense and holding larger nations’ capital ships at risk. They also allow large countries such as the United States to project stealthy power deep into an adversary’s waters, enabling operational and strategic fires on demand. They are almost ubiquitous because they can scale to a country’s needs quite easily. But manned submarines require a rescue capability that not every submarine operator can afford.
Efficiencies often form as scale increases, in submarine rescue as in much else. Whereas a single rescue chamber may be an appropriate system for ten submarines, it may be an outsized cost for a country with just 5 boats. Leveraging international partnerships allows these nations to outsize their organic capabilities. International cooperation and standards become crucial for these countries. It is in the United States’ interest that these nations seek out either our standards or those international ones to which the Navy adheres to increase interoperability. A hatch of a custom size or shape, unique tap signal codes, or incompatible doctrine will surely delay, if not outright inhibit, a successful rescue. Just as these nations may lean on us in a time on need, we may need them to assist us as we continue to deploy our submarines all over the world – both partners stand to gain by working together. A significant effort was made to this end with the formation of the International Submarine Escape and Rescue Liaison Office (ISMERLO) in the aftermath of the 2000 sinking of the Russian Oscar II submarine Kursk in the Barents Sea.
ISMERLO was the brainchild of NATO’s Submarine Escape and Rescue Working Group (SMERWG) and was designed to “facilitate the rescue response for a distressed submarine . . . and to improve the ability to respond to a call for assistance.”2 For the first time a full-time organization to facilitate international standards and cooperation was built for submarine rescue. Initially located in Norfolk, Virginia, ISMERLO was recently moved to its current home in NATO’s Allied Maritime Command located in Northwood, England.
Figure 2 provides an illustration of major exercises, real world rescue/search operations, and delegation visits with URC active participation in the past five years. Almost all the larger exercises in undersea rescue took place under the auspices of ISMERLO, and the active participants are predominately NATO countries building depth and skill at rescuing western-built submarines. In addition, Bold Monarch 2011 and Rim of the Pacific (RimPac) 2016 had significant Russian and Chinese participation, respectively.
Bold Monarch 2011 may have been the largest and most widely attended submarine exercise in the past decade, with some 2,000 participants from more than 20 countries involved in the 12-day exercise. Submarines from Spain, Turkey, Portugal, and Russia demonstrated true interoperability. In many ways it was the culmination of the efforts of the international community following the loss of the Kursk and the improvements made to Russian submarine rescue capabilities. Unfortunately, this was the last year the United States and Russia would conduct a submarine rescue exercise together, as a result of the annexation of Crimea. Only the actual search-and-rescue effort for the Argentinian submarine San Juan in 2017 brought the two submarine rescue forces back together, albeit briefly.
RimPac 2016 was much like its predecessors in its grand scale of maneuver. What was different was that in this year the People’s Liberation Army Navy (PLAN) attended and also integrated its submarine rescue capabilities. China deployed its LR-7 rescue vehicle to Hawaii and conducted successful mating with a submerged training rescue seat—demonstrating its ability to rescue the crew of a bottomed western submarine.3 The Chinese military has historically been inspired by the capabilities of the U.S. Navy’s URC, both in terms of its ability to effect a real world rescue and how it has used this capability as a mechanism of soft power to strengthen alliances.4 The PLAN’s attendance in this exercise, especially in the capacity of a rescue force, was in line with China’s political goals and demonstrated its rising subsurface capabilities to the world.
Other recent exercises unfortunately demonstrate that the memory of the Kursk and other submarine accidents has begun to fade. For example, Submarine Escape and Rescue Exercise (SMEREX) 2018 was an Italian-led escape exercise with support from ISMERLO and representatives from more than a dozen nations. Based around rescuing the crew from a Greek Type 214 diesel submarine, the nine-day exercise involved major submarine operators such as Russia and Turkey participating alongside nations such as Brazil, Chile, and Ecuador. Absent, however, was the United States; the Navy did not even provide a nonparticipating observer. With only one submarine rescue system now in operation, the SRDRS, the U.S. Navy would have to depend on the international community if any casualty occurs to SRDRS. At the height of the Cold War, the United States and the Soviet Union found a way to have astronauts meet in space and demonstrate interoperability, but it appears this level of good will has faded since Russia annexation of part of Crimea.
Vision for the Future
Development of submarine rescue capabilities—particularly the U.S. Navy’s—have been driven by accidents, and such development often loses focus as the memory of those accidents fades. Today’s limited budgets and renewed focus on great power competition are combining with fading memories of major submarine disasters to cause just such a loss of focus. It took the sinking of the Thresher for the United States to create a deep-water rescue capability and the loss of the Kursk to generate ISMERLO. Justifying financial expenditure to ensure the United States is a leader in international submarine rescue capabilities is challenging, especially for those unaware of the capability’s on-again/off-again history. Without action, the Navy risks finding itself surprised by capability gaps in the coming decade and witnessing its leadership role diminish. International partners could easily become the only possible option for rescue.
The Navy should take the following actions over the coming decade to reduce or eliminate this risk:
- Acquire a second SRDRS to increase URC’s resiliency and enable exercises and training to be conducted without reducing readiness.
- Increase attendance of URC personnel in international submarine rescue exercises and coordination events. URC must have uniformed experts (reservists where appropriate) in the room to both absorb and shape the conversations.
- Work with political leaders to support exercises involving Russia and China for the purposes of submarine rescue. U.S. allies should not be forced to pick which country will attend their exercise—all can be there to save lives.
The U.S. commitment to the sailors that take submarines to sea is to maintain a ready rescue status every hour of every day to execute the zero-fail mission of rescuing the crews of downed submarines wherever possible. The United States has shared its knowledge and expertise freely with partner nations and even potential adversaries. Continued investment in the training and development of URC’s capabilities is and will continue to be a critical part of the ongoing development of submarine operations for the United States and all who sail beneath the waves.
1. Peter Maas, The Terrible Hours: The Greatest Submarine Rescue in History (New York: Perennial, 2001), 182.
2. Submarine Escape and Rescue Working Group, “International Submarine Escape and Rescue Liaison Office Concept,” 13 June 2003, 1.
3. Frederick J. “Fritz” Roegge, “RimPac 2016: An Exercise in Response and Interoperability,” Ho’okele, August 5, 2016, sec. A.
4. Gabriel Collins et al., “Chinese Evaluations of the U.S. Navy Submarine Force,” Naval War College Review 61, no. 1 (Winter 2008): 71.