Welcome #71, and some thoughts on the endurance of the DDG51 Class

USS Frank E Petersen, DDG 121 was commissioned on Friday, joining the fleet as the 71st in the class.

It wasn’t clear that the class would be this enduring.  In 1985, the plan was for 29 ships, to (mostly) replace the Charles F Adams and Coontz class.

Construction continued past 29, ending with #112 as the Navy’s interest was shifting towards DDG1000 and LCS.

After several years gap, it became apparent that the DDG1000 and LCS capability was not panning out, and the DDG51 production line restarted.

Current discussion is for production contracts to extend through 2027, some 42 years after the initial contract was signed for DDG51.

So why has the design proved enduring?

There is an old engineering heuristic that all the important design decisions are made on the first day.  And those decisions continue to characterize a program through its lifecycle, be they good or bad.

One of the first good decisions was the old Texas Two Step – the design was achieved in two increments.

  • First, AEGIS was integrated into the existing Spruance hull.  This was not planned, the initial concept was for the larger nuclear strike cruiser.  Dropping back to the smaller Spruance hull form, with a destroyer-sized cruiser, was seen as a compromise.  But this meant the program could focus on AEGIS, with a mature HM&E platform not throwing in complications.
  • Step two was taking the now mature AEGIS design to a new, purpose designed hull, all steel, with a sea-keeping hull form.  While there were lots of advances in the HM&E design, the fundamentals of proven LM2500 and Allison Gas Turbine Generator remained.

The Texas Two Step helped avoid the technology overreach that has plagued more recent ship acquisitions.

Another positive decision was avoiding steam – keeping the design electric based.  Again, this was unplanned.  The original design was for waste heat boilers on the main engines (the RACER system) to “improve” efficiency.  As any veteran (survivor) of an old steam ship, or the 963/993/47 class with waste heat boilers know, the steam system starts eating the maintenance budget the older the ship gets.  I was underway in company with FLETCHER toward the end of her life when the waste heat system just started unzipping.  Didn’t matter how far back from the current leaks the repair started, all the piping was essentially rotten.

The RACER system was demonstrated at NAVSSES Philadephia.  It failed, miserably.  But the failure was at a test site, not holding up ship construction, and was deleted from the design.  You can visit the reduction gears on DDG51 – 53, and see the blank plate where the RACER turbine would tie in.  The concept of the land-based test site paid dividends, continuing through testing of the propulsion plant design, and continuing to support the fleet.

This naturally feeds to the next thought.  One thing RADM Meyer was famous (notorious?) for was sticking with a single contractor, not continually recompeting for short-term savings.

For some reason, some Navy leadership had gotten disfavor with GE and the LM2500, and were pursuing a Rolls Royce solution.  Fortunately, the LM2500 stayed in the design.  Over years, the LM2500 design has matured, maintenance intervals have been extended.  One of DDG51s original LM2500s was just replaced after 31+ years of service (don’t forget precomm trials), and one original engine still remains.  Maybe RACER would have provided some short-term fuel savings, but at the cost of uncountable lifecycle complexity and cost.  The LM2500 just start up and operate, year after year.  And when they don’t it is a process of a few weeks (or less) to replace.

The design was influenced by many decision makers.

Reportedly, SecNav took a sharpie, cut out the helo hanger, one anchor windlass, and put a cap on ship displacement.  A NavSea Admiral thew out the initial highly automated machinery control system design, with orders that he wanted more “men turning valves.”

So to this day, Chief Bosuns bemoan the single anchor windlass, and having to shift the chain, or the infernal chain stopper, or use the forward facing unrep stations.  

But the weight target was achieved by putting spectacle flanges on two main fuel tanks, taking them out of service, and therefore removing the fuel and water impact from displacement calculations.  The day after final contract trials, the flanges were turned, two additional fuel gauges installed, and range extended by the new capacity with no impact on performance.  The hull was NOT changed to reduce displacement, keeping that reserve for the life cycle.

And in many ways, a 1985 highly automated propulsion plant may have had more lifecycle cost than the simpler highly monitored plant that DDG51 started with.  How many thousands of hours did the 963/47 “automated” fuel filter coalescer consume?  (A devilish combination of fuel, electricity, and pneumatic controls).  How many LOEs, OPPEs, and INSURVs came to a dead halt when those controls failed? The DDG51 design had two valves and two pressure switches, with a Sailor dispatched to turn the valves when the alarm sounded.

One more example – INSURV had developed a dislike of Controllable Reversible Propellor Systems, as major portions of the apparatus were in the propellor hub, and not accessible for repair short of a dry dock.  This led to the Reversible Reduction Gear in the USS Supply class, which had an intricate ballet dance of mechanical moves required to slow or stop the ship.  DDG51 instead got the third (or fourth) generation of CRP design, simplifying the mechanical interfaces to make a more reliable system, learning from the prior ship classes with CRP instead of starting with a new, even more complex design.

Fundamentally, the ship design team, led by Andy Summers, NavSea designers, G&C, Rosenblatt, and BIW, made good choices, even when “helped” by senior leadership.  The end result, despite the many hands in the design, ended up maintainable, upgradable, and with Destroyer flexibility, operationally relevant as priorities shifted, and shifted back again.

And somehow the helo hanger eventually got back in the design.

So as the Cruisers fade out, the Destroyers remain RADM Meyer’s true legacy.

But one thing I never understood was FOAs distaste for the Destroyer.  I don’t know if it was the loss of the Nuclear Strike Cruiser, then the consecutive shift to smaller hulls for the CG47 then DDG51.  Or maybe the distaste for Navy leadership at the time of the DDG51 initial decisions, including, as RADM Meyer told it, pushing him out of the program, then out of the Navy, and reportedly blackballing him with industry.  

FOA firmly believed that air defense was an 06 mission.  In his version of the manning plan, the Cruisers had an 05 post command XO (this lasted only two hulls).  Towards the end of his engagement with the BMD program office, he would require charts comparing Cruisers and Destroyers.  But the Destroyers inherited the BMD mission (much to RADM Meyer’s angst), which only served to increase their relevance.  There was a time when USNA Firsties would visit the BMD booth at SNA to see which ships were in the BMD fleet, prior to service selection, with the belief they had more operationally relevant deployments.

I presume that when DDG137 is commissioned, the namesake will not bemoan the reappearance of the helo hanger, or the removal of the spectacle flanges, nor check the inclining data for actual displacement, but appreciate it for the capability it adds to the US Fleet.

So as the 71st ship of the class is commissioned, the first ship, at 31 years old, has recently completed a 44,000 mile deployment, earned another Battle E, remains forward deployed, and there are at least another 18 hulls still in the construction pipeline.

Some of the success comes from the precepts of RADM Meyer, some comes from the experience and vision of ADM Burke as the Destroyer being the workhorse of the fleet.  But that was only the start.  There are untold legions of Navy leaders, civil servants, Industry leaders, engineers, and craftsman, waterfront maintainers, supply support, and ships crews that have kept the DDG51s operationally relevant, capable, and on-duty.  We have started to collect some of the names of the Destroyer Leaders on a page here, but documenting all the heroes and contributors is an impossible task.

So back to where this started – welcome #71. You have some work to do to build on the existing great body of work.  Continue to uphold the legacy of ADM Burke, RADM Meyer, and of course, honor the memory of General Petersen.  Turn to, commence ships work.  We’ll be counting on you for the next 35 or so years.  It is not easy, but as ADM Burke said, you can count on Destroyer Sailors.