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Demistifying Service Life ASNE Flagship 18 Jan 2011

Demistifying Service Life ASNE Flagship 18 Jan 2011. Chris Cable Director, Auxiliary and Special Mission Ship Design Division (SEA05D4) Naval Sea Systems Command Christopher.w.cable@navy.mil (202) 781-1943. SERVICE LIFE – Outline. Tell them what you are going to tell them Tell them

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Demistifying Service Life ASNE Flagship 18 Jan 2011

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  1. Demistifying Service LifeASNE Flagship18 Jan 2011 Chris Cable Director, Auxiliary and Special Mission Ship Design Division (SEA05D4) Naval Sea Systems Command Christopher.w.cable@navy.mil (202) 781-1943

  2. SERVICE LIFE – Outline Tell them what you are going to tell them Tell them Terminology Why an understanding of Service Life is important Current ESLs by class Data on ASLs Why do ships get retired before their ESL? So what?? NEEC = Naval Engineering Education Consortium Tell them what you told them! 2

  3. SERVICE LIFE – The Story Tell them what you are going to tell them: An understanding of Service Life is important to all Naval Engineers. Service Life Terminology is often misunderstood. Expected Service Lives change over time. Actual Service Lives seldom equal Expected Service Lives. How we Design ships to meet Expected Service Lives needs more attention. A pressing need is to develop innovative ways to get ships to make it to their Expected Service Lives (NEEC might be able to help). 3

  4. SERVICE LIFE – The Basics Terminology: ESL = Expected Service Life. The number of years ships need to be kept in service to achieve a given force structure. ASL = Actual Service Life. Chronological life from commissioning to decommissioning. CASL = Class Avg. Service Life. Average ASL by class. DSL = Design Service Life. The service life the ship is designed to achieve. SERVICE LIFE REQUIREMENT. ICD, CDD, COR, SPEC, etc. MID-LIFE = Mid life upgrades to get To ESL. SLEP = Service Life Extension Program. Major upgrades to get BEYOND the ESL. 30 YSP = 30 Year Shipbuilding Plan. The Navy tool for projecting force structure. RECAP = Recapitalization. Buying new ships to replace retiring ships and/or to maintain the desired force structure. 4 Ref: Ship Service Life and Naval Force Structure, P. Koenig, D. Nalchajian and J. Hootman, ASNE symposium, Engineering the Total Ship 23-25 Sep 2008

  5. Things you do “in utero” to ensure a healthy start to life and room to grow (need more!!) . THE BASICS - An Irreverent Look Think of a “lifespan” • Normal life expectancy • . • Dad, take your Lipitor! • Time for a quadruple bypass…… • …while Mom thinks about your replacement? • How long did you live? • How long did you family live on average? Only death and taxes are certain. These can change during any period of your lifespan. 5

  6. SERVICE LIFE – Why Important? It is the foundation of the shipbuilding plan, the basis for recapitalization Excerpts from the CNO’s Guidance for 2011 (Oct 2010): (emphasis added) “Continue to be the most dominant, ready and influential naval; force, globally and across all naval missions.” “…conducting essential maintenance and modernization to ensure units reach full service life…” “Build a Navy with appropriate force structure and strategic laydown necessary to implement the Maritime Strategy.” “We must maintain the Fleet we have to the end of its expected service life…” 6

  7. SERVICE LIFE – ESLs by Class Current ESLs by class: 7

  8. SERVICE LIFE – ESLs by Class Current ESLs by class: 8

  9. SERVICE LIFE – ESLs by Class Current ESLs by class: 9

  10. SERVICE LIFE – Why ESLs change over time Why do ESL change over time? Many factors: Force Structure evolving (build up) Force Structure evolving (build down) Stroke of the pen Balance the plan Engineering insight (but not enough of the time!) 10

  11. SERVICE LIFE – CASL info Data on ASLs 11

  12. SERVICE LIFE - Does ASL correlate to displacement? Answer = Yes 12

  13. SERVICE LIFE - Does CASL correlate to Displacement Answer = Yes 13 Note: Includes all decommissioned Cruisers, Destroyers, Frigates, and Patrol Craft built after World War II. Active ships not shown.

  14. SERVICE LIFE - Does ASL correlate to multi-mission vs. single-mission Answer = Maybe 14 Single mission ships Multi-mission ships

  15. SERVICE LIFE - “Birth date” matters because of external events

  16. SERVICE LIFE – Factors for Early Retirement Why do ships get retired before their ESL? Many possible factors: Treaties Stability issues Mission system unable to meet threat Material Condition Damage (grounding, fire, high sea state structural damage, etc) Loss (wartime) Business Case (cheaper to build new??) Industrial Base considerations Environmental Considerations (ex: double hulling) Changes in the nature of the threat (Littorals, BMD, etc) Costs to operate (Fuel Efficiency, Manning costs, etc) Cost to get to ESL are prohibitive Mission goes away 16

  17. Same ship, two missions Then as Indonesian DE 342, served 1974-2007+ = 33+ more years as gunboat DE 1035 USN 1958-1974 = only 16 years due to being ineffective against nuclear submarines 17

  18. SERVICE LIFE – DSL info 1970’s to Early 1990’s GENSPEC was not specific about Design Service Life. Some editions made oblique reference to a presumption that ships generally would be in service for 25 years. Thus the assumption of a 25 year life for surface ships (with no growth or mods occurring in the last five years). Some of our margin policies (e.g., required electric plant service life allowance) have been indexed to that number for many ship classes. With respect to the hull, fatigue life was not a controlling factor. Structures folks assumed their designs had enough margin that, provided you repaired any degradation as it occurred, the hull would last an unlimited duration. 18

  19. SERVICE LIFE – DSL info (cont.) LPD 17 (early 1990s) onward LPD 17 = 1st program where we dealt with DSL meaningfully. Requirement was set for a 40-year ship life. Whole ship FEM models have been built for LPD 17, but in terms of validation to demonstrate that the hull meets the fatigue requirement, the methods used there were simplified in comparison to the process used today. All ships (except JHSV) after LPD 17 had OPNAV-specified ESL requirement. On JHSV they said essentially "I'll let that float in the interests of cost and will take what I get.” Though OPNAV typically uses ESLs as "planning numbers" to guide a range of activities, few people understand that they have no direct basis in engineering for older ships. 19

  20. SERVICE LIFE – Service Life Allowance Service Life Allowances (SLAs) – when delivered each ship shall be capable of accommodating growth during its service life w/o compromise of hull strength, reserve buoyancy and stability characteristics. Anticipated growth consists of authorized changes (like ship alts and mission upgrades) as well as unauthorized changes (like too much paint and extra coke machines). SLA NOT THE SAME AS DESIGN MARGINS SLAs for Weight, KG, Electrical, A/C, Hull Strength, Accommodations, Fatigue Life Notes: As SLA consumed, performance characteristics degrade (speed is at delivery). Major modification / conversions typically account for providing SLA compensation. When SLA fully consumed, may need Weight and Moment Compensation. 20

  21. SERVICE LIFE – So What? So What? Excerpts from the CNO’s Guidance for 2011 (Oct 2010): (emphasis added) “We will continue to pursue affordable warfighting solutions that emphasize evolutionary vice revolutionary capabilities, common hulls and airframes, open architecture, modularity, lower energy footprint, and reduced manpower.” Design ships to meet their ESLs -- develop the engineering understanding of the technical underpinnings to Design Service Life. SFA Corrosion Allowance / high performance materials. More mission modular – maybe. Business case? Nobody doing it commercially? Open architecture (broadly) – probably. Aircraft Carrier example – you can argue that Carriers have such long lives because the aircraft are the modular mission packages. Innovate with new ways to help existing ships meet their ESLs (Goal: ASL=ESL) 21

  22. Modular combat system?? 1945 prop Hellcats 1991 supersonic Hornets USS Midway, 1945-1992, 47 years

  23. SERVICE LIFE – So What? (cont’d) So What? Excerpt from the CNO’s Guidance for 2011 (Oct 2010): (emphasis added) “We will lead Science, Technology, Engineering, and Math (STEM) education and outreach to grow top technical talent to lead tomorrow’s Navy…” NEEC – Project based education – we need to get SUSTAINMENT projects in front of the students Contact for Project ideas: NEEC Director = Mr. Steve Ceccio (possibly develop the course: what every Naval Engineer Needs to Know About Service Life) Contact for Mentoring : Mr. Bob Keane Innovate with new ways to help existing ships meet their ESLs Predictive Tool. Project Ideas. “What every Naval Engineer needs to know about service life” 23

  24. SERVICE LIFE – Summary Tell them what you told them! An understanding of Service Life is important to all Naval Engineers. Service Life Terminology is often misunderstood. Expected Service Lives change over time. Actual Service Lives seldom equal Expected Service Lives. How to Design ships to meet Expected Service Lives needs more attention. A pressing need is to develop innovative ways to get ships to make it to their Expected Service Lives (NEEC might be able to help!). 24

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