Abeking & Rasmussen Demonstrates Advantages Over Conventional Hullforms
WARNEMÜNDE, GERMANY 26 June 2013 - The Latvian Navy is receiving five 25m SWATH@A&R patrol boats from Abeking & Rasmussen Shipyard. Three vessels, “Skrunda” (P 05), “Cēsis” (P 06) and “Jelgava” (P 08), were constructed at the shipyard in Lemwerder near Bremen and already delivered to Riga Shipyard in Latvia, while the remaining two vessels, “Viesīte” (P 07) and “Rēzekne” (P 09), are being constructed in Latvia, with Abeking & Rasmussen delivering material packages. One of the principal characteristics of the SWATH-type patrol boat that resulted in the decision by the Latvian Navy to order the five units from Abeking & Rasmussen is its extraordinary seaworthiness, a performance characteristic that has been demonstrated during a series of at-sea live presentations of the fourth unit, “Jelgava”, off Warnemünde Naval Base near Rostock during the last week of June. She was delivered to Latvia on 27 June.
When the first SWATH@A&R vessel ordered by a commercial customer for use in the rough North Sea left Abeking & Rasmussen in 1999, it was clear that the traditional German shipyard was able to generate a riptide in the naval community. Since then, more than 20 vessels of this type with a length of 25m to 60m have been constructed and delivered to various customers, including the Latvian Navy.
Without doubt, the introduction of SWATH@A&R technology also in the military has provided more safety and cost efficiency for the most extreme actions at sea. Boarding operations can be performed at extreme wave heights, Friedrich Jacobi of Abeking & Rasmussen said to NAVAL FORCES. SWATH@A&R vessels cannot easily be ranged with conventional monohull designs in many respects, Abeking & Rasmussen said. Their unique geometry, structure, and hydrodynamics are widely believed as the key advantages this highly modular ship design. The 25.7m long, 125 tons displacement patrol boat designed for the Latvian Navy fulfils a variety of tasks, ranging from patrolling and monitoring of territorial waters to mine countermeasures missions and boarding operations. Significantly, the SWATH@A&R design allows boarding events at a speed of up to 14 knots. The mission modularity is another key design characteristic of the SWATH@A&R patrol boat that will attract the interest of other naval customers.
With the five SWATH@A&R patrol boats, the Latvian Navy receives the appropriate technology at the right time. A crew of up to eight persons can stay for one week at sea even under adverse weather conditions to fulfil critical tasks, including missions together with partners in international assignments. As shown off Warnemünde, the vessel offers sufficient accommodation and additional facilities for up to eight persons that can include Special Forces personnel. The crew will appreciate the low vibrations and noise levels that are well below 65dB(A), the shipyard said. The 13.5m wide vessels are built of aluminium, proving its superior adequacy by high shock resistance, low magnetic and acoustic signature, and low life-cycle costs.
By fitting mission-oriented payloads (e.g. a diving or mine countermeasures module), the vessel’s capability can be significantly enhanced, Karsten Fach, Member of the Board, underlined. A Modular Mission Module similar to a 20-ft ISO container can be mounted between the bows of the two hulls. As said, the vessels built for the Latvian Navy will be fitted for different sensors and weapons, including Rheinmetall Defence's MSP 600 modular optronic multi-sensor platform (to be mounted on top of the vessel’s mast), the same company’s MLG 27 machine gun, a dipping sonar, and up to two .50-calibre machine guns. Additionally, the vessel features a modular installation for carrying oceanographic or hydrographic research equipment. Extensive operational at-sea testing of a 25 m SWATH@A&R demonstrator vessel proved the efficiency and reliability of Abeking & Rasmussen's sophisticated sonar launching and recovery system, enabling the safe and reliable operation of ROV/AUV systems for mine countermeasures operations and hydrographic surveying. The payload capacity is quoted at six tons that will be sufficient to install a 35mm MILLENNIUM gun.
The SWATH technology as an innovative hull concept for smooth service in rough seas revolutionises naval operations. This technology means that the buoyancy of a SWATH-type vessel like the five SWATH@A&R patrol boats designed for Latvia is provided by submerged torpedo-like bodies that are connected to the upper platform by single or twin struts. According to Abeking & Rasmussen, the cross-section at sea surface level is minimised and thus only a small volume of the ship is exposed to the lifting forces of the waves. This technology guarantees an extraordinary comfort during the ride and a secure feeling on-board of a stable platform.
“Almost two years in service, since [the] Latvian Navy received the first SWATH@A&R patrol boat, have shown that the SWATH concept with its multifunction idea in background is a reliable way to go for completing our duties delegated by [the] Latvian government, Cdr. Peteris Subbota, Commanding Officer of the “Skrunda”, the first vessel delivered to the Latvian Navy, said. “The exceptional seakeeping capability never stops surprising even experienced sailors and allows these ships to be first on the line when safety on sea and everyday duties matter. (…) there is still a lot of work to be done to equip these ships with dedicated military and special equipment for specific tasks of [the] Latvian Navy – and this light, economic, and user-friendly ship is just the perfect platform for small Navies”, he said.
The first-of-class SWATH@A&R patrol vessel in a class of five vessels, “Skrunda“, was launched on 20 January 2011 and commissioned into service with the Latvian Navy on 18 April 2011.
(Photo: Courtesy of Latvian Navy)
The SWATH@A&R patrol boat “Jelgava” performs in waves as high as 3,5m.
(Photo: Stefan Nitschke)
Deck handling equipment includes a crane (shown), a small RIB for shallow water operations, and a hydraulic lift on the starboard side for man-over-board or diving missions.
(Photo: Stefan Nitschke)
The vessel’s top speed of 21.4 knots is provided by two MAN D 2842 diesel engines in the lower torpedo hulls (rated at 809kW at 2,100rpm) driving Servogear controllable pitch propellers via Servogear reduction gearboxes.
(Photo: Stefan Nitschke)