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Updated March 23, 2023
Navy TAGOS-25 (Previously TAGOS[X]) Ocean Surveillance
Shipbuilding Program: Background and Issues for Congress
Introduction
Figure 1. USNS Impeccable (TAGOS-23)
The Navy in FY2022 procured the first of a planned class
of seven new TAGOS-25 class ocean surveillance ships at a
cost of $434.4 million. The Navy’s FY2024 budget
submission shows that the ship’s estimated procurement
cost has since grown to $789.6 million—an increase of
$355.2 million, or 81.8%. The Navy’s proposed FY2024
budget requests $355.2 million in additional cost-to-
complete procurement funding to pay for this cost growth.
The Navy wants to procure the second TAGOS-25 class
ship in FY2025.
Meaning of TAGOS Designation
In the designation TAGOS (also written as T-AGOS), the T
means the ships are operated by the Military Sealift
Command (MSC); the A means they are auxiliary (i.e.,
support) ships; the G means they have a general or
miscellaneous mission; and the OS means the mission is
Source: U.S. Navy photograph accompanying “Ocean Surveil ance
ocean surveillance. The TAGOS-25 program was
Ships,” Military Sealift Command, accessed May 25, 2021.
previously known as the TAGOS(X) program, with the (X)
meaning that the precise design for the ship had not yet
Figure 2. USNS Effective (TAGOS-21) in Dry Dock
been determined. Some Navy budget documents may
continue to refer to the program that way.
TAGOS Ships in the Navy
TAGOS ships (Figure 1 and Figure 2) support Navy
antisubmarine warfare (ASW) operations. As stated in the
Navy’s FY2024 budget submission, TAGOS ships “gather
underwater acoustical data to support the mission of the
Integrated Undersea Surveillance System (IUSS) by
providing a ship platform capable of theater anti-submarine
acoustic passive and active surveillance.... The two current
classes of [TAGOS] surveillance ships use Surveillance
Towed-Array Sensor System (SURTASS) equipment to
gather undersea acoustic data.” Figure 3 shows a simplified
diagram of a TAGOS-25 ship with its SURTASS arrays.
Current TAGOS Ships
Source: U.S. Navy photograph 070913-N-2638R-004 posted at
The Navy’s five aging TAGOS ships include four
Wikimedia Commons, accessed May 25, 2021.
Victorious (TAGOS-19) class ships (TAGOS 19 through
22) that entered service in 1991-1993, and one Impeccable
TAGOS-25 Program
(TAGOS-23) class ship that entered service in 2000. As of
the end of FY2021, all five were homeported at Yokohama,
Quantity, Schedule, and Design
Japan. The ships use a Small Waterplane Area Twin Hull
The Navy wants to procure seven TAGOS-25 class ships as
(SWATH) design, in which the ship’s upper part sits on two
replacements for its five in-service TAGOS ships. The first
struts that extend down to a pair of submerged, submarine-
TAGOS-25 class ship was procured in FY2022. The Navy
like hulls (Figure 2). The struts have a narrow cross section
wants to procure the second through fifth ships in the class
at the waterline (i.e., they have a small waterplane area).
in FY2025-FY2028 at a rate of one ship per year. The
The SWATH design has certain limitations, but it has
Navy’s notional design for the TAGOS-25 class (Figure 4)
features (including very good stability in high seas) that are
employs a SWATH design that would be larger and faster
useful for SURTASS operations.
than the in-service TAGOS ships (see Table 1).
https://crsreports.congress.gov
Navy TAGOS-25 (Previously TAGOS[X]) Ocean Surveillance Shipbuilding Program: Background and Issues for Congress
Figure 3. TAGOS Ship with SURTASS Arrays
Procurement Cost
The Navy estimates in its FY2024 budget submission that
the first ship in the class will cost $789.6 million to procure
and that subsequent ships in the class will cost about $430
million each in then-year dollars to procure. As mentioned
earlier, the estimated procurement cost of the first ship has
grown by $355.2 million, or 81.8%. The Navy’s FY2024
budget submission states that this cost growth is “due to
several factors affecting shipbuilding prices including direct
material inflation, supply chain challenges, and increased
non-recurring engineering costs.”
Acquisition Strategy
The Navy wants to use a single shipbuilder to build all
seven TAGOS-25s. The Navy intends to competitively
Source: Detail from slide 13, entitled “TAGOS(X) Concept of
award in January 2024 a firm fixed-price contract for the
Operations (CONOPS),” in Industry Day briefing for TAGOS(X)
detailed design and construction (DD&C) of the lead ship,
program, June 26, 2019, accessed May 26, 2021, at GovTribe.com.
with options for building up to six additional ships.
Figure 4. Notional Navy Design for TAGOS-25
In January 2020, the Navy released a request for proposals
(RFP) for contracts to perform initial industry studies for
the program. On July 2, 2020, the Navy awarded four
contracts for these studies to BMT Designers and Planners
of Arlington, VA (with a contract value $2.37 million);
Bollinger Shipyards of Lockport, LA ($2.78 million);
Thoma-Sea Marine Constructors of Houma, LA ($2.26
million); and VT Halter Marine of Pascagoula, MS ($2.17
million). In November 2022, VT Halter Marine was
purchased by Bollinger and is now called Bollinger
Mississippi Shipbuilding.
The Navy used the industry studies to inform its
Source: Artist’s rendering accompanying press released entitled
understanding of TAGOS-25 design-cost tradeoffs in
“Halter Marine Secures Contract for Industrial Studies for T-AGOS
support of the RFP for the DD&C contract. The Navy
Program,” Halter Marine, July 20, 2020.
posted the RFP for the DD&C contract on November 19,
2021, and amended it on December 21, 2021. Responses to
Table 1. TAGOS Ship Designs
the RFP were due by April 19, 2022.
TAGOS-
TAGOS-
TAGOS-25
Issues for Congress
19
23
(notional)
Potential issues for Congress for the TAGOS-25 program
Length
235 feet
282 feet
356 feet
include the following:
Maximum speed
10 knots
13 knots
20 knots
the likelihood of further cost growth on the first ship in
Displacement
3,384 tons
5,370 tons
8,500 tons
the class; and
Accommodations
~48
54
68
the accuracy of the Navy’s estimated procurement costs
for the second and subsequent ships in the class,
Sources: “Ocean Surveil ance Ships - T-AGOS,” U.S. Navy, and (for
particularly given the cost growth on the lead ship in the
TAGOS-25) slide 22, entitled “T-AGOS Class Comparison,” from
class.
Industry Day briefing for TAGOS(X) program, June 26, 2019,
accessed May 26, 2021, at GovTribe.com.
FY2024 Procurement Funding
The Navy’s proposed FY2024 budget requests $355.2
The Navy’s desire to replace the five in-service TAGOS
million in cost-to-complete procurement funding for the
ships with seven larger and faster TAGOS-25s can be
first ship in the class.
viewed as a response by the Navy to the submarine
modernization efforts of countries such as China and
Ronald O'Rourke, Specialist in Naval Affairs
Russia. For more on China’s submarine modernization
effort, see CRS Report RL33153, China Naval
IF11838
Modernization: Implications for U.S. Navy Capabilities—
Background and Issues for Congress, by Ronald O'Rourke.
https://crsreports.congress.gov
Navy TAGOS-25 (Previously TAGOS[X]) Ocean Surveillance Shipbuilding Program: Background and Issues for Congress
Disclaimer
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https://crsreports.congress.gov | IF11838 · VERSION 19 · UPDATED