This html article is produced from an uncorrected text file through optical character recognition. Prior to 1940 articles all text has been corrected, but from 1940 to the present most still remain uncorrected. Artifacts of the scans are misspellings, out-of-context footnotes and sidebars, and other inconsistencies. Adjacent to each text file is a PDF of the article, which accurately and fully conveys the content as it appeared in the issue. The uncorrected text files have been included to enhance the searchability of our content, on our site and in search engines, for our membership, the research community and media organizations. We are working now to provide clean text files for the entire collection.
Aluminum Surface Ships:
Lightweight Coffins?
We in the surface force have been passive and too uncritical in accepting structural metal other than steel in our ships, a message written in molten aluminum that flowed like ink during the Belknap-Kennedy collision.
I toured the Belknap (CG-26) shortly after the burned-out wreckage was towed home. Steel fragments from exploding three-inch ammunition had ripped through superstructural aluminum, fragments that a lesser thickness of steel would have stopped. Overheads and bulkheads had simply melted away, exposing interior compartments to weather. Globs of resolidified aluminum lay in lava-like relief on intact steel decks. A foot-long metallic stalactite—molten aluminum that had leaked through from the deck above—protruded from the overhead in a compartment. Much of the superstructure was a surrealistic fantasy in metal, tied starkly to reality by the fact that men had died there.
The Belknap tragedy vividly demonstrated what engineers, metallurgists, and aviators have always known: aluminum simply cannot stand up to much energy, whether it be kinetic as from a flying fragment, or thermal as from a fire.
Another problem with using aluminum in the construction of ships is the difficulty of detecting corrosion. Corroding aluminum produces a whitish-gray powder which does not stand out against gray paint. Marrying aluminum deckhouses to steel hulls compounds the problem, and has made “bimetallic corrosion” a common term in the surface warfare lexicon. Too Tequently a ship entering overhaul inds that surprisingly extensive work is needed on the superstructure to repair the ravages of undetected corrosion. In contrast, the ubiquitous, brown rust streak on a steel bulkhead is both an advertisement that corrosion exists and an incentive for its speedy correction.
There are some valid seagoing applications for naval aluminum, such as in small, high-speed combatants. Aluminum was necessary in the FRAM I conversions, which placed bigger, higher superstructures on existing hulls. The surface effect ship certainly will depend on it, but not because of the metal’s military virtues, except for its light weight. Instead, there is no other choice. In this case there is a valid tradeoff between battle- ruggedness and very high speed. But in our recently built, 28-knot frigates, what benefits balance the frailties inherent in their aluminum superstructures?
Unlike the surface effect ship, a displacement hull’s success is not tied to light weight. The design, construction, and propulsion of an all-steel frigate is neither state-of-the art, nor does it run afoul of Archimedes’ principle of buoyancy; the very fast, allsteel warships of World War II did not sink under their own weight or turn turtle when properly ballasted.
The return to steel in our new ships would require greater displacements and modified designs. Is this an unwarranted or unaffordable luxury? In the last two decades we essentially have redesigned our ships in the name of habitability. Cannot an equally compelling case be made for changes that will enhance protection and survival?
Suppose, for a moment, that a naval engineer who knew nothing about the U. S. Navy (or about its potential opponents) were to examine one of our new frigates, and, by evaluating its construction, deduce the threats against which it was designed. The aluminum deckhouse atop the steel hull and the fact that the ship is not weight critical might suggest that underwater damage was of great concern, because the lightweight superstructure is an undeniable plus for righting arm and reserve buoyancy. But then he might question the ship’s antisurface and antiaircraft weapons as a contradiction, because the use of topside structural aluminum (which
he knows is not requisite for a modest 28 knots) suggests that the threat from the air may be little more than wind, rain, and salt spray.
In reality, airborne weapons are the crucial threat. While mines and torpedoes are ever-present dangers, recent advances in surface ASW may force hostile submarines to rely more heavily on standoff weapons, thereby adding their missiles to what already promises to be congested airspace around our task groups and convoys.
The smaller crews of our new, more automated ships mean that each crew member is more precious in terms of his mission contribution. Similarly, survival of the computers and control systems that make manpower reduction possible becomes vital. Today’s combatant, with more complex systems and less human redundancy, needs more—rather than less— protection than its World War II counterpart. But superstructures of lightweight, non-ferrous metal expose the men and equipment within to strafing, shrapnel, and such low-level threats as the rifle and light machine gun, weapons possessed by groups other than military powers.
Since the 1950s, structural aluminum has made slow but steady inroads into our combatants. In fact, the then- technical director for ship design at the Naval Ship Engineering center mentioned in the Proceedings Special Surface Warfare Issue (March 1978) that a design for an all-aluminum frigate was being studied. After all, the use of aluminum is a hard issue to get excited about in peacetime. Aluminum painted gray looks like steel, keeps out the weather equally well, and therefore provides the same sense of protection to those within.
But a combatant must absorb punishment as well as dish it out. While we cannot afford to design a destroyer capable of shrugging off a hit from a cruise missile, the protection afforded by steel would pay handsome dividends against the near-miss. Consider other threats: the frigate’s
involvement in the rescue of the Mayaguez reminds us that our ships, even in the missile age, may still confront such unsophisticated violence as the strafing aircraft, the artillery air- burst, and the shoulder-fired weapon.
Programs currently exist to lessen the vulnerability of aluminum structures by the addition of protective thermal insulation, synthetic armor, and the like. While these measures may offer partial relief, as long as aluminum remains at the heart of the structure are we not attempting to pull ourselves up by our bootstraps from a questionable base? Perhaps refits of this nature are the best that can be done to existing ships; fot future designs, however, we should increase and improve our options until we are
assured that the “Belknap deficiencies” have been overcome.
Now is the time to reflect on the vital military differences among structural materials, rather than after battle damage or another disastrous fire. The Belknap tragedy was an unplanned operational evaluation of aluminum on combatants, and we cannot afford to ignore the results.
Nobody asked me either, but . . .
Captain Carl A. Nelson, U. S. Navy
The Unrestricted Line Officer And Ship Maintenance
Over the years the Navy has vacillated in its emphasis on ship maintenance. In the “good years,” when the beat was off ship maintenance, the front-running unrestricted line officer Was in the “gun club” or was a tactics-oriented operator. Although ernphasis on postgraduate education bas consistently been on technical curricula, assignment practices were such that these officers didn’t get their hands dirty.
On the other hand, the Navy has generally been consistent in entrusting a very able but small community of restricted line engineering specialists tvith the maintenance and engineering problems of the Navy. Yet, because the Navy would appear to be in the bad years,” the credibility of this community is now being questioned—not because of lack of ability hut rather because its people have been stretched so thinly throughout the complex engineering and maintenance organization that their effectiveness to control any given set of problems has been weakened. To compound this problem, the number of officers from which to sustain a viable promotion flow pattern has been Aversely affected in terms of quality as well as quantity. The result is that professional respect of the past is being eroded under a veil of suspicion of mismanagement.
The outgrowth has been free and open discussion on how to reconcile the situation. How much engineering and maintenance should all unrestricted line officers know? Where do
we best use the few members of the engineering duty officer (EDO) community?
The EDO’s role and responsibilities have only recently been defined as a naval officer first, a community of professional engineers specializing in ship’s and combat systems second, and an individual accepting responsibility for technical matters in all assignments last.
Many have argued that our Navy should imitate some of the world’s other navies by expanding the role of the engineering duty officer and assigning the unrestricted line officer to an exclusive operator role. Recent studies indicate, however, that the U.S. Navy’s long-range intentions are to strengthen the unrestricted line officer's role in engineering and assign the EDO to essentially a technical role.
Hence, unrestricted line officers are hitching up their belts and marching off to become better engineers. Officers assigned to conventional surface ships are being exposed to significantly more rigorous engineering and maintenance training. New officers receive similar instruction at our surface warfare division officers’ school. Middle-grade officers undergo department head engineering and combat systems curriculum, and selected officers attend a prospective engineer officer course at the naval reactor facility in Idaho. Senior officers en route to major surface commands are being subjected to a demanding engineering course under such rigorous conditions that some selectees have quit.
As more and more of the EDO community are reassigned out of maintenance management duties and
into more technical responsibilities, the void must be filled by unrestricted line officers. The field is fertile, and, although complex, it is not beyond the ken of subspecialists. To a certain extent, maintenance management is ready for “new blood.”
Officers fresh from CO, XO, and department head tours where they were on the “deck plates” during light-off exams and operational propulsion plant exams can bring a fresh insight into the maintenance needs of the fleet. This conversion cannot be complete, however, unless key jobs in the EDO-dominated supervisors of shipbuilding as well as naval shipyards are opened to assignment rotation of unrestricted line maintenance managers. These billets, replete with union problems and the inertia of Program Evaluation Review Technique/Cost- Performance Report planning, could just as well benefit from the balance provided by a fresh “point of view.”
Critical to the success of this change in emphasis will be the priorities placed on these duties by the BuPers officer detailers. Officers who have served both in the Bureau of Naval Personnel and in key maintenance management assignments seem to equate the two in terms of “demanding duties.” We must be careful to recognize the importance of vigorous maintenance management to the readiness of our weapon systems and continue to assign top-notch competitive officers to this vital field.
It’s not enough to pass a propulsion examination. We need to get the unrestricted line officer into ship maintenance.