SSBN-726 Ohio-Class FBM Submarines
As of 1995, the Navy was studying an extension from 30 to 40 years for the SSBN-726 class submarines. While 30 years was long the standard number for submarine operating lifetime, the SSBNs would seem to have a rather more benign operating history than the SSNs. They typically operate at somewhat shallower depths, they do not experience nearly as many excursions from their normal operating depth, and they would not operate below their test depth with any degree of freqency. Consequently, it would be expected that they could have a longer operating life than attack submarines [just as fighters wear out so much faster than bombers or transports]. As of late 1998 Navy cost and planning factors assumed that the Ohio-class submarines would have an expected operating lifetime of at least 42 years: two 20-year operating cycles separated by a two-year refueling overhaul.
As part of its long-term plan to divide the Trident fleet equally between the Atlantic and Pacific fleets, beginning in 2002 the Navy will transfer three of the 10 Trident subs now based at King's Bay to Bangor. Of the eight Trident submarines assigned to Bangor -- USS Alaska, USS Nevada, USS Henry M. Jackson and USS Alabama -- will convert from the older Trident I (C-4) missile to the more powerful Trident II (D-5) missile. The Nevada is scheduled to enter the Bremerton shipyard in early 2001 to begin its conversion, and the final pair are scheduled for the refitting in 2005 and 2006.
A key element of the USS OHIO (SSBN 726) Class system maintenance concept is comprehensive life cycle maintenance planning. Each shipboard component or system is subjected to the Logistic Support Analysis (LSA) process to determine Organizational, Intermediate and Depot level maintenance requirements. The maintenance concept also emphasizes design and configuration control, Integrated Logistics Support (ILS), life cycle component and system maintenance planning, dedicated shore facilities with expanded industrial capability, disciplined alteration and modernization programs, and use of a rotatable pool of selected equipment. This rotatable pool is termed the TRIDENT Planned Equipment Replacement (TRIPER) Program.
Removed TRIPER equipments are replaced with fully interchangeable, tested, Ready-for-Issue (RFI) units, which can be rapidly installed and made fully operational within a refit period. Equipment replacement periodicity is determined by maintenance and reliability analysis and engineering judgments intended to preclude equipment failure or significant degradation during operational periods. Removed equipments are refurbished by approved Designated Overhaul Points (DOPs), tested and returned to RFI condition for use on another USS OHIO (SSBN 726) Class submarine. Maintenance planning and scheduling for the USS OHIO Class submarine incorporates workload smoothing techniques designed to maximize work efficiencies and minimize TRIDENT Refit Facility (TRIREFFAC) shop overloads without exceeding periodicity constraints.
In line with OPNAV direction toward implentation of Condition Based Maintenance (CBM), vice traditional time directed maintenance, the TRIDENT Planned Equipment Replacement (TRIPER) Program changed fundamentally to meet the seemingly conflicting intent of both Incremental Overhaul and CBM. The challenge is to accomodate CBM without compromising the Incremental Overhaul process, which has proven so successful in maintaining SSBN 726 Class operational availability, and not to impact planning considerations. To meet this challenge, the Program has been changed to satisfy the diverse demands of both maintenance schemes. These Program changes reinforce the intent of the TRIPER Program to extend service life of components and replace them just prior to failure, to optimize Total Ownership Cost at acceptable material readiness.
With the maturity of the TRIDENT system and the capturing of valuable maintenance history, NAVSEA had assigned TRIPER components to one of three Categories established for scheduling purposes [Category I - Fixed Periodicity; Category II - "Windows" Program (monitored components); and Category III - Unsatisfactory Operation]. Category III components were not expected to be scheduled for routine changeout. This effectively made the overhaul of Category II and III components condition based.
Under the new TRIPER Program structure, Categories I, II and III have been placed into two groups, TRIPER (Scheduled) and TRIPER (CBM). The items formerly in Category I have become the TRIPER (Scheduled) Group, while the former Category II and III components comprise the TRIPER (CBM) Group. TRIPER (CBM) components: a) lend themselves to being accurately monitored, b) have redundancies built in, or c) are less critical. A periodicity is assigned for logistic support, but not for scheduling purposes. Changeout will be based on monitoring and material condition as determined by Ships Force, Squadron and/or Performance Monitoring Team (PMT) input. The SUBMEPP Material Condition Assessment (MCA) Program and/or Reliability Centered Maintenance analyses will continue to assess and adjust periodicities as necessary, including those in the TRIPER (CBM) Group.
The TRIDENT II D-5 life extension (LE) program is required due to the OHIO Class Ballistic Missile Nuclear Submarine (SSBN) service life increasing from 30 years to 45 years. The impact of the SSBN hull life extension is significant in two ways. First, it delays the replacement of these platforms by 15 years, effectively delaying the expenditure of up to $25 billion in current year dollars for follow-on strategic submarine platforms. Second, it requires the service life of the TRIDENT II D-5 Strategic Weapons System (SWS) carried by these ships to also be extended by 15 years. The extended service life requirement affects flight hardware (missile, guidance and reentry) and shipboard hardware (launcher, fire control, navigation and test instrumentation).
On December 18, 2003, the US Navy announced that General Dynamics Electric Boat Corp. (GD/EB) had been awarded a cost plus incentive fee contract worth $222 million for the conversion of the first Ohio Class Guided Missile Submarine (SSGN), USS Ohio (SSGN 726), and for Long Lead Time Material (LLTM) and Conversion Installation Planning for the Conversion of Ohio Class Ballistic Missile Submarines (SSBNs), the USS Michigan (SSBN 727) and the USS Georgia (SSBN 729), to SSGN 727 and SSGN 729. The award modified a contract with GD/EB originally awarded on Sept. 26, 2002, for SSGN detail design, long lead time material, and conversion planning. The contract modification included a cost plus incentive fee contract for the conversion of SSGN 726 and a cost plus fixed fee contract with performance incentive fee for the installation planning and LLTM for SSGN 727 and SSGN 729. The contract also provided priced options totaling $152 million for the fiscal 2004 Conversion of SSBN 728, the USS Florida to SSGN 728 and for the completion of Conversion Installation Planning for SSGN 729.
Upon completion of their conversions, the SSGNs will be able to carry up to 154 Tomahawk missiles and to function as the host platform for 66 special operations forces (SOF). SSGN 726 began its ERO at Puget Sound Naval Shipyard in November 2002, and began conversion work in November 2003. SSGN 728 began its ERO at Norfolk Naval Shipyard in August 2003, with conversion start planned in April 2004. Both the SSGN 726 and the SSGN 728 will complete conversion in fiscal 2006.
Engineered Refueling Overhauls of OHIO Class (TRIDENT, SSBN 726) Strategic Missile Submarines is a major overhaul performed near the mid-point of the submarine's service life to re- capitalize the vessel and extend the useful life to maintain the required SSBN force level. Work performed includes: refueling of the reactor; major propulsion plant and ship equipments are repaired or upgraded; obsolete equipments are replaced; ballistic missile systems are repaired or upgraded; limited alterations to provide for reliable operations during the remaining operational life of the submarines and the ship is re-certified for Unrestricted Operations (SUBSAFE URO).
The upgrade of USS HENRY M. JACKSON (SSBN 730) and USS ALABAMA (SSBN 731) strategic weapons systems from TRIDENT I (C4) to TRIDENT II (D5) to achieve the President's Nuclear Posture goal of 14 TRIDENT D-5 equipped SSBN. This upgrade will be performed concurrently with their EROs in FY 2005 and FY 2006, respectively.
The Program of Record calls for a post- START II Submarine- Launched Ballistic Missile (SLBM) force of 14 TRIDENT SSBNs, all equipped with TRIDENT II (D5) missiles and based at two homeports (Kings Bay, GA, and Bangor, WA). This mandated 14- boat, all- D5 force breaks down as follows:
- 10 SCN- Funded, New- Construction TRIDENT II Submarines: SSBNs 734 - 743, the last of which deployed in FY 1998.
- 2 OPN- Funded, TRIDENT I (C4) Equipped Submarines Being Backfitted to TRIDENT II (D5) Capability : SSBN 732, which completed its concurrent Engineered Overhaul (EOH) and D5 Backfit at Puget Sound Naval Shipyard (PSNS) and was deployed as of 2005, and SSBN 733, which as of 2005 was undergoing its own EOH/ D5 Backfit at PSNS.
- 2 SCN- Funded, TRIDENT I (C4) Equipped Submarines to be Backfitted to TRIDENT II (D5) Capability: SSBNs 730 and 731, which commence their concurrent Refueling Overhauls and D5 Backfits in FY 2005 and FY 2006, respectively.
In FY99 and again in FY06 a NUWC KEYPORT study identified a number of obsolete electronic components in the Ship Control Station (27 out of 107) that are no longer available. The FY06 study recommended that the Ship Control ISEA develop and execute a program that would address the near term obsolescence issues and ensure the continued availability of the subsystem in the out years. Alterations and actions are done at the lowest practicable and authorized level (taking into consideration urgency, priority, capability, capacity and cost). Alterations to SSBN 726 Class Submarines are scheduled for accomplishment at the TRIREFFAC, Kings Bay and NAVIMFAC, Bangor. This requires equipment procurement and installation, technical planning, training, and associated resources. This line provides for material procurement necessary to install the required alterations to SSBN 726 Class Submarines at the NAVIMFAC, Bangor, and the TRIREFFAC, Kings Bay. Additionally, this line provides for the utilization of specially trained and dedicated installation teams to ensure accelerated and correct installation of complex and high priority alterations within specific time frames. Provided are comprehensive program management and execution, including planning, direction, control, installation, integration, and coordination of specifically selected safety related, mission enhancement or technical HM&E alterations.
Starting in FY12, SSBN SWSS OER Upgrades are planned for Ventilation Alarm Monitoring Panel (VAMP) and the Missile Heating and Cooling Proportional Controllers. Both upgrades are required to support Strategic Programs' SWS Integration program (Mod6/Mod7) which replaces the current Launcher, Fire Control and Weapons Support electronics.
Engineered Refueling Overhauls (EROs) shifted from SCN funded to O&MN, OPN, and WPN funded beginning in FY10. Installations of this ShipAlt are accomplished during SSBN refits, SSBN Extended Refit Periods (ERP), SSGN Major Maintenance Periods (MMP), and SSBN Engineered Refueling Overhauls (ERO). Installation do not complete until the availability completes. Thus the installation duration ranges from 90 days for refit installations to 821 days for ERO installations.
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