Quietly and without fanfare, what may be the world’s most advanced diesel-electric submarine visited Norfolk, Virgin-i , d, subsequently, New London, Connecticut this past spring. The undersea craft was the DOLFIJN (Dolphin), the third submarine of the Dutch WALRUS class to be completed.
The Atlantic crossing of DOLFIJN, launched in 1990 and placed in commission in 1992, partially demonstrated the long-range capabilities of this design. These are torpedo-attack submarines, intended specifically to operate in the antisubmarine role against other diesel-electric and nuclear-propelled submarines. The submarine force of the Royal Netherlands Navy is intended to carry out both NATO and national roles. In the NATO context, they are intended to occupy stations in the Barents and Norwegian Sea areas.
The WALRUS design is a refinement of the previous Dutch ZWAARDVIS class, with two submarines built to that design being completed in 1972. The ZWAARDVIS, in tum, was a development of the American BARBEL (SS 580) class, the last diesel-electric combat submarines to be built for the U.S. Navy. (See P.L. van Ewijk, “History of the Dutch Submarine Force,” THE SUBMARINE REVIEW, July 1992.)
The new WALRUS class boats have a standard displacement of 1,970 metric tonnes and are 2,800 metric tonnes submerged (slightly larger than the BARBEL class). The Dutch submarines have an overall length of 222 feet, a beam of 27 feet 7 inches, and are propelled by three SEMT-Pielstick diesel engines with Holec generators that charge batteries for a single Holec electric motor; there is a single propeller shaft. Speeds are 12 knots on the surface and in excess of 20 knots submerged. At slow speeds their non-snorkeling submerged endurance is more than six days; range is estimated at 10,000 nautical miles at nine knots with snorkeling. The submarines have an operating depth considerably in excess of 1,000 feel
While they appear similar to the BARBEL design (including a partial double hull), [Ed. Note: See Figures 1 and 2.] the WALRUS class is fabricated of HY-100 steel and is far more advanced in several respects. First, the Dutch boats are highly automated; that was the first observation to the author by both Vice Admiral Henry G. Chiles, Jr., Commander, Submarine Force, U.S. Atlantic Fleet. and Gerald Cann, the Assistant Secretary of the Navy for Research, Development, and Acquisi-tion, after they went to sea in the DOLFIJN.
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For example, from the submarine’s central operating panel, the propulsion plant, battery charging system, and trim system can be controlled. The trim system has an integrated micropro-cessor and provides real-time recommendations for trim and/or weight corrections.
When at battle stations the submarines-which have three main compartments-have only two men in the forward compart-ment (weapons) with the remainder of the 50-man crew in the amidships compartment (berthing, mess, control); the after (engineering) compartment is normally unmanned, with a sophisticated monitoring and fault correction system being provided. The high degree of automation has led to require-ment for a crew of only seven officers and 43 enlisted men (women do not yet serve in Dutch submarines, although they are embarked in surface combatants).
The WALRUS class requires no hot bunking and stores are carried for 60-day-plus patrols. There are separate officer cabins (three double plus a captain’s cabin), wardroom, general mess, and separate spaces for the four chief petty officers and for the eight senior petty officers.
The design provides an X-tail configuration with four independently controlled rudders with two rudders being sufficient to operate the boal This permits a high degree of control, another feature cited by Admiral Chiles. Also, the rudders do not exceed the circumference of the hull, which is an advantage for shallow-water operations and simplified mooring. (A similar arrangement was evaluated in the USS ALBACORE (AGSS 569).}
If any criticism is to be leveled at the Dutch design it is the fitting of only four Mk 67 21-inch torpedo tubes, a feature copied from later U.S. attack submarines at the suggestion of the U.S. Navy (the BARBELs had six tubes). More tubes would have permitted more weapons launch flexibility, an important factor with the variety of weapons now available to submarines. The boats can carry 22 full-length torpedoes while tube-launche:i mines as well as Harpoon anti-ship missiles can be embarked in place of torpedoes. A rapid, automated reload system is fitted. (The submarines are Harpoon capable, although the Dutch Navy does not now have the submarine version.)
Supporting the design’s ASW mission is a relatively complex sonar suite consisting of the Thomson Sintra TSM 2272 with a bow-mounted Eledon array plus a passive range-finding sonar using three hydrophone arrays on each side of the bull. The submarines are fitted for the Marconi Type 2026 clip-on, towed-array sonar, but this is not normally shipped; rather it is installed (at Faslane, England) when a boat deploys.
All sensors, data analysis, and weapon control systems are integrated in the Signaal Sewaco-VIll Gipsy data complex. All electronics are fully integrated with multi-purpose screens and panels permitting a very high degree of combat systems integra-tion.
TheWALRUS class submarines have encountered some cost overruns while the lead boat was delayed by a fire while under construction, which caused no structural damage but did cause her to be the second boat to enter service. Still, the average cost per submarine was Dfe500 million or $250 million, about one-quarter that of a contemporary LOS ANGELES (SSN 688) class submarine.
Three submarines of this class are in commission: W AL-RUS, ZEELEEUW, and DOLFUN; the BRUINVIS will enter service in 1993. All are constructed by Rotterdamsche Droog-dok Maatschappij (RDM), in Rotterdam, now the only subma-rine construction yard in the Netherlands. RDM has developed
modified WALRUS Mk 2 design with six torpedo tubes and other improvements.
The Dutch Navy had originally envisioned six submarines of this class, to replace all earlier submarines. Financial consider-ations led to only the four being procured, with the two ZWAARDVIS-class submarines now scheduled to remain in service until at least the year 2000.
While RDM has been proposing the construction of WALRUS class boats for other nations, the firm is now marketing a more advanced design-the Moray–that is specifi-cally intended for operations in regional areas. This is a highly innovative design, certainly the next generation in conventional submarine development. The Moray is specifically intended for Air Independent Propulsion (AlP), although the WALRUS design is convertible to AlP.
While the new Swedish Kockum Type 471 design being built for Australia as the COLLINS class will challenge the W AL-RUS design, at the moment the Dutch design appears to be the most advanced non-nuclear submarine afloat, at least outside of Russia. But few Americans have been privy to the secrets of the WALRUS. The DOLFIJN’s trans-Atlantic shakedown cruise was intentionally kept quiet, at the direction of the U.S. Navy. AJ. Plunkett, a top writer at the Norfolk Daily Press, did visit the submarine, but most attempts by journalists and others to see the craft were rejected.
Some U.S. submariners who toured the Dutch boat called her “the wave of the future,” wrote Plunkett. It was pointed out that the DOLFIJN could perform some missions better than larger American SSNs, and other jobs not as well. Plunkett quoted the DOLFIJN’s skipper, LCDR John Weyne, as saying, “The one cannot take the job of the other.” Still, with the increasing U.S. political-military interests in littoral naval operations and potential combat scenarios that will involve Third World submarines, the WALRUS class does offer a valuable look into future undersea combat–a Dutch weapon with an American heritage.