Naval Analyses: Holland class offshore patrol vessels of the Royal Netherlands Navy

Friday, 14 November 2014

Holland class offshore patrol vessels of the Royal Netherlands Navy

Written by D-Mitch

HNLMS Friesland. Photo: Neil Watkin

The Holland class is a class of four (4) offshore patrol vessels built by Damen Schelde Naval Shipbuilding for the Royal Netherlands Navy (Koninklijke Marine) and they were commissioned in the period 2012-2013. The ships are designed to reduced radar cross section (RDS) and they are painted are painted a new light blue-gray color to improve the camouflage effect. To optimize the seakeeping behavior of the vessels the hull has been stretched, and the bridge and superstructure are located relatively aftwards. Moreover, they are outfitted with ballistic features, blast resistant constructions, redundant and decentralized systems, a gas citadel, extensive fire fighting systems and additional measures to reduce the effects of flooding. Automation level for this vessel is high, and includes a shore support system, a shore management system, a calamity system, a warning system, an overview system and extensive subsystem automation. These patrol vessels are the first vessels of the Royal Netherlands Navy equipped with the Thales Integrated Sensor and Communication Systems (ISCS), an integrated mast module which integrates practically all radio frequency systems, radars as well as communication and optical sensors on board of the ship in one housing. These vessels are without question some of the most modern and well equipped class of offshore patrol vessels worldwide.

Modified photo of HNLMS Zeeland offshore patrol vessel of the Holland class. For high resolution image click here.

The general characteristics of the class is a displacement of 3,750tons, speed of up to 22 knots, length of 108.4 meters and a range of 5,000n.m. with the speed of 15 knots. The endurance is 21 days. The complement is just 52 people while there is additional accommodation for more than 40 in really spacious rooms (it was like.. a floating hotel to me comparing with other ships such as a Type 23 frigate).

Modified photo of HNLMS Holland offshore patrol vessel, lead ship of the Holland class, at the North Sea during the 2014 Nuclear Security Summit. For high resolution image click here.

Each ship carries one Fast Rescue Boat (FRB) and two Fast Raiding Interception and Special Forces Crafts (FRISC) RHIBs. The one RHIB is accommodated in the stern where is launched and recovered via a slipway in the stern while the other one is located at the portside. On the vessels there are are large helideck and hangar to accommodate one NH90 NFH helicopter.

Flightdeck and NH90. Photo: D-Mitch

Rescue boat. Photo: D-Mitch

Large hangar. Photo: D-Mitch

FRISC. Photo: D-Mitch

Marlin WS 30mm. Photo: D-Mitch

Super Rapid 3in gun. Photo: D-Mitch

The ships of the class are armed with the OTO Melara Super Rapido 3in (76.2mm) fully automatic gun installed forward of the bridge. This gun can hit air and surface targets at a distance of 4 km (at 85 degrees) and 16 km (effective 8 km) respectively with a rate of fire approximately 120 rounds per minute and weight of shell greater than 6 kg. Except the main naval gun, the ships are equipped with an OTO Melara Marlin WS fitted with an Mk44 Bushmaster II 30mm chain gun. The Marlin is a highly accurate and reliable multi-role system, particularly effective in the simultaneous engagement of multiple targets such as swarms of Fast Inshore Attack Crafts. Optical sensor suite with day and night vision and laser range finder is mounted independent from the line of fire. The excellent performance provided by the fast and accurate servo systems, are also ensured working either as a stand-alone system with own Remote Control Console or linked to the ship’s Combat Management System. The maximum firing rate is 200rds/min and the effective range is up to 3km.

Hitrole NT 12.7mm. Photo: D-Mitch

The vessels have two OTO Melara Hitrole remote controlled Naval Turrets (NT) with 12.7mm FN M2HB heavy machine guns. The system has a firing rate of 450-550 rds/min and the effective firing range is about 2km. The turret is electrically operated and very accurate due to powerful digital servos. Sighting and tracking actions are performed by means of a high performance day TV camera, IR sensor for night operation, Laser Range Finder and Auto Tracker. The system is linked to other Electro-Optical sensors on board the ship and to ship’s Combat Management System. On the ships there are also several mounts for FN MAG of 7.62mm light machine guns. The FN MAG has a maximum (effective) range of about 1,800m and a cyclical rate of fire of approximately 750-950 rounds per minute.

HNLMS Zeeland. note the water cannon, the mount for FN MAG and the Hitrole NT 12.7mm

IM 400. Image: Thales

IM 400. Photo:Min. van Defensie

All major radars, sensors and communication suite are packed in an advanced mast structure, the so-called Thales Integrated Mast (IM) 400 which is the first member of the I-Mast family. In that way, all radars and antennas not only have a full 360° field of view; they are also developed so as to operate simultaneously without interfering each other. The radars in the Integrated Mast are non-rotating, four-faced active phased array radars, which in itself is a major performance enhancement. As the four faces operate simultaneously, the radars achieve four times the time on target achieved by a rotating radar. The Integrated Mast is simply bolted or welded to the ship, hooked up to the power supply, coolant system and data transmission and is operational in only two or three weeks time. Compared to the one year that is necessary to install, integrate and test all the separate systems, this is a huge time and money saver, for Navy as well as shipyard. A further aspect that reduces costs is the decrease of maintenance. Not only do non-rotating radars require far less maintenance, but the little maintenance that is required can be performed in the protected, sheltered environment of the Mast, meaning that it is no longer necessary to wait for repairs until weather conditions are safe enough.

The IM 400 incorporates the following systems: Sea Master 400, Sea Watcher 100 and the Gatekeeper as well as the Integrated Communications Antenna System (ICAS), a non-rotating identification friend-or-foe (IFF) antenna ring and extensive satellite communications capacity, radar and communications Electronic Support Measures (ESM) and Link 16 capability.

Thales SMILE. Photo: Thales

Thales SMILE (Sea Master 400 the export version) is a non-rotating, four faced S-band (NATO E/F-band) volume search radar designed to simultaneously provide air and surface surveillance, helicopter control and weapon control functions. The range of the radar is 300m - 250 km while the tracking capacity is more than 1000 air and surface tracks. The radar consists of four active phased array panels using Active Electronically Scanning Array (AESA) technology. The new 3D dual axis multi-beam concept enables reliable detection of a broad range of targets in complex environments. The system is almost zero-touch as all operational tasks operate simultaneously and autonomously. Exploiting proven multi-beam and Doppler processing principles, Sea Master 400's advanced system architecture delivers simultaneous functionality at high update rates regardless of environmental and clutter conditions. These include large search volume with high elevation coverage, reliable detection of small targets, rapid automatic track initiation, low false alarm rates, and helicopter detection and approach control. Sea Master 400 is known as SMILE in the IM400 systems contracted by the Royal Netherlands Navy.

Bridge. Photo: D-Mitch

The.. bar! Photo: D-Mitch

A shiny kitchen. Photo: D-Mitch

The large dining room! Photo: D-Mitch

The spacious corridors.Photo: D-Mitch

The SEASTAR is housed between the IFF ring and the
SMILE system. Photo: D-Mitch

The Thales SEASTAR (Sea Watcher 100 is the export version) is a non-rotating active phased array I-band (or X-band) surface surveillance radar for asymmetric threat operations in the littoral, open-ocean and harbour environments with a typical operational range of up to 40 km. Sea Watcher 100 is a 2D radar sensor designed to detect and track even the most difficult of surface targets, such as boats, periscopes, floating mines and swimmers which have a very small radar cross section, that are moving close to the speed of the waves and as such a near-zero Doppler value and that are down at the surface level, sometimes being hidden from view behind wave tops. Typical challenges that Sea Watcher 100 is designed to meet, include multi-path, surface duct propagation and shadowing effects, as well as backscatter and clutter from the sea surface. The non-rotating, staring nature of its antenna arrays allows it to spend more time looking at each possible target, which helps the processing to discriminate real targets from the clutter. Sea Watcher 100 operates using a single-mode concept, which frees the operator from having to select the best possible mode. The system automatically selects the optimum combination of waveforms to provide short-, medium- and long-range coverage, depending on the characteristics of the sea surface as seen from a certain distance. Sea Watcher 100's solid-state active phased array architecture with advanced beam steering and burst scheduling algorithms, ensures both high Doppler resolution and a high update rate, needed to discern small targets that are hidden in clutter. Short- and medium-range search is performed at two-second update rates, while for long-range search an update is provided every five seconds. The radar displays all ranges simultaneously so that the operator does not notice the mode changes and always has a total picture including all close-in, medium-range and long-range targets.

HNLMS Holland just few days after her commission in active service,
during Marinedagen 2012. Photo: D-Mitch

NH-90 NFH helicopter on HNLMS Holland. Photo: D-Mitch

Τhales Gatekeeper

The Thales Gatekeeper offers surround vision for close-in situational awareness up to a distance of 5-8 km, to as close as 15m from the ship, for safe navigation and against asymmetric tactics such as piracy, insurgency and swarm engagements. Gatekeeper is a 360° electro-optical surveillance suite comprising, non-cooled IR cameras and ultra high definition TV cameras mounted in the mast, to provide a continuous un-blocked situational awareness for multiple operating positions. Its main role is to provide security through classification and identification of approaching objects, and target indication to remote controlled small arms. Gatekeeper has also helicopter approach capability. In addition, the system will provide recording of events in order to have legal evidence. It provides 24-hour, day/night surveillance allowing the crew to be deployed more efficiently with personnel being able to stay inside a protected, air-conditioned environment rather than having to stand watch on deck. Gatekeeper also allows the ship to have a relaxed alert state and still be able to respond quickly in case of an emerging threat, Gatekeeper excels in harbours and confined waterways where radar use is restricted and radar performance is limited. The 360°surveillance image is available for multiple operator stations, where each operator has his own 'software controlled window' for amplification of track data and zoom-in without disturbing the 360° view for other users at the bridge, operations room or watch stand. The panoramic view can also be displayed on large screen('s) in the combat information centre.

Zeeland and Groningen. Photo: Ministerie van Defensie

On the top is the radome of the satellite
communication and immediately after
the IFF. Photo: D-Mitch

The Thales Integrated Communications Antenna System (ICAS), provides an integrated communication solution that facilitates the use of standard VHF/UHF communications equipment, is fitted for Link 16 integration, provides excellent transmit/receive isolation, offers estate for auxiliary antennas as GSM/GPS, and is designed for future growth. The ICAS architecture selected for the Royal Netherlands Navy's ships features four flat panel receive antenna arrays and four dual (VHF/UHF) flat panel transmit antenna arrays. These interface to an Antenna Distribution Unit, which in turn interfaces to a Tranceiver Combiner Unit. The Thales Non-rotating IFF Antenna System (NR-IFF) is a circular. L-band array that can be used by both the IFF Interrogator and the IFF Transponder. The system has also capacity for L-band communications. The antenna system consists of four glass fibre radomes covered circular monopulse antenna array's. Each array has two omni channels for use by the IFF transponder and for Link-16 transmissions.

HNLMS Zeeland. Photo: Ministerie van Defensie

HNLMS Groningen. Photo: bobjak

The navigation radars are two Consilium X-band and S-band radars. In their equipment it is included also a TUUM-6, an UnderWater Communication Equipment designed that enables communications between naval actors.