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Denmark’s Iver Huitfeldt-class Frigates

For Denmark, commonality and modular techniques yield affordable, flexible frigates

Denmark’s Iver Huitfeldt-class frigates may be state-of-the-art combatants. But they share much in common with previous Danish naval ships – literally.

The larger Iver Huitfeldts and Absalons are designed to operate on extended deployments far from home. This global outlook is a paradigm shift for Denmark.

According to Cmdr. Senior Grade Per Hesselberg, who is in charge of the Danish frigate program, the frigates and Absalon-class flexible support ships are very similar. In fact, the two classes have 80 percent commonality. “The frigates have twice the power, a better radar, a more sophisticated AAW capability, and are quieter for ASW, but otherwise they are much the same.”

Both classes of ship have the same MTU 8000 20V M70 engines. The frigates have four, and can achieve 28 knots. The two engines on the flexible support ships can propel them to speeds of 24 knots. Both ships have plenty of power margin for future growth.  “We can’t predict the future,” Hesselberg says.

Iver Huitfeldt

The Royal Danish Navy frigate HDMS Iver Huitfeldt (F361) transits in the Arabian Sea, Jan. 2, 2013. Iver Huitfeldt was assigned to Commander, NATO Task Force 508 supporting Operation Ocean Shield, maritime interception operations and counterpiracy missions in the U.S. 5th Fleet area of responsibility. U.S. Navy photo by Mass Communication Specialist 2nd Class Deven B. King

Both ships take advantage of Denmark’s experience with warship modularity gained with its StandardFlex (StanFlex) ships and containerized capability packages.

Denmark has two Absalons, and one of three Iver Huitfeldts in the fleet. “We will deliver the second frigate, in mid-2014, and at end of 2014 we will deliver the third frigate,” says Hesselberg.

Modularity and the COTS (commercial-off-the-shelf)-based system with an open architecture-approach (OA) makes these ships easy to modify and less time consuming to upgrade. “We use  civilian standards whenever possible, especially with IT,” says Hesselberg. “We can configure the network for whatever capability we need. We can attach any system in any compartment to the network.”

Absalon

The Royal Danish Navy flexible support ship HDMS Absalon (L16). The Absalon class flexible support ships share 80 percent commonality with the Iver Huitfeldt-class frigates. NATO photo

The 14 Cold War-era  Flyvefisken-class StandardFlex ships could be equipped with various modules to give each ship the desired capabilities. Where those StandardFlex ships were built to operate in Danish waters, and have since been retired, the larger Iver Huitfeldts and Absalons are designed to operate on extended deployments far from home. This global outlook is a paradigm shift for Denmark.

But here’s where it all fits together. “With standardized modularized systems, we are able to reuse design elements,” Hesselberg says. “The stainless steel containers have standardized interface panels so a container can go on any ship in the Danish Navy, plug in and operate.”

“Modularity makes ships easier and more economical to build,” Hesselberg says. “It also makes them more efficient to operate, less expensive to maintain and to modernize.”

The Iver Huitfeldt-class frigates have a vertical launch system with 32 cells for SM-2 missiles (and possibly Tactical Tomahawk in the future) in addition to the containers for 24 ESSMs,  and provision for two 76mm, although only one is shipped aboard the class ship at the moment, as well as a 35mm Oerlikon close in weapon system, MU 90 torpedoes, and the embarked EH 101 helicopter, making for a truly potent frigate. The 76 mm gun, ESSM (the NATO Evolved SeaSparrow missile) and Harpoon (anti-ship missile) modules actually came from the earlier generation Flyvefiskens.

Peter Willemoes

The Royal Danish Navy frigate HDMS Peter Willemoes (F362) makes its way to San Juan, Puerto Rico for climate testing, Nov. 17, 2011. Denmark’s Iver Huitfeldt-class frigates and Absalon-class flexible support ships give the Danish Navy an unprecedented global naval capability. Royal Danish Navy photo

“We have the same Integrated Platform Management System (IPMS) on the frigates and flexible support ships. We use the same Terma C-Flex combat management system (CMS) network on our frigates and flexible support ships as well as our Arctic Offshore Patrol Vessels (AOPVs). We have a very large, redundant fiber network on these ships. The system is divided into layers. The frigate uses more of the combat management system’s different applications, and the AOPV uses less.  But they both have basically the same C-Flex software architecture,” Hesselberg says.

“We use standard civilian 19-inch racks for our electronics,” he says. “To upgrade the weapons, sensor, communications and IT systems, we just put new gear in the racks. We’re upgrading our C-Flex system from Windows XP to Windows 7 this summer.”

“We have built in flexibility from the beginning. It’s not that much more expensive in the beginning, but easier to update later on. It’s the safe, low-risk option,” Hesselberg says.

Iver Huitfeldt

Members of the boarding team from HDMS Iver Huitfeldt (F361) aboard the MV Torm Kristina, after they had searched to ensure no pirates were on board. The Iver Huitfeldt-class frigates give Denmark the ability to protect her interests around the globe. NATO photo

The containers can be stored when not used, and can be reequipped or updated. They are not universally interoperable. “Our boxes cannot be adapted by someone else unless they are using the C-Flex CMS, or another CMS that can adapt our container interfaces,” Hesselberg says.

“We learned from our flexible support ships to have extra space for containers on the frigates,” he says.

“Modularity makes ships easier and more economical to build,” Hesselberg says. “It also makes them more efficient to operate, less expensive to maintain and to modernize.”

It all fits together.

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Capt. Edward H. Lundquist, U.S. Navy (Ret.) is a senior-level communications professional with more than...