Warship Technology: March 2017
Well known as a designer and builder of FRP pilot boats, patrol boats, crew transfer vessels and naval and military craft, Safehaven Marine was earlier profiled in Warship Technology (July/August 2015 issue) for its SV 11 high-speed Inteceptor craft or ‘Barracuda’ as it was dubbed. More recently it has launched a new unit which is a development of the Barracuda range of high-speed, low radar cross-section (RCS) units for patrol/naval operations, which it has dubbed ‘Thunder Child.’ It says the new design is even faster than the Barracuda, has greater range, a large crew capacity and an even lower RCS.
Thunder Child is an undeniably striking and stylish design, however, the resulting sleek profile is purely as a result of form following function in the vessel, which the Irish company says combines a high-speed wave-piercing hull with a low radar signature superstructure. The new unit is 18m length overall (17.3m moulded) with a 4m beam and a draught of 0.85m.
Typical operational roles for the new version of the XSV would include patrol and surveillance around port and harbour infrastructure as well as coastal and offshore installations and anchorages. “XSV 17 is also eminently capable of very high-speed pursuit and apprehension of those engaged in illegal waterborne activities such as drug trafficking,” says the company. “Her long range and crew facilities allow extended offshore operations”. From a naval perspective potential deployment scenarios are far reaching, and include covert surveillance, which could be undertaken with a greatly reduced risk of detection thanks to the new unit’s low RCS.
The XSV has an innovative hullform that allows it to operate in two distinct modes: fully planing and wave-piercing. The hull combines a deep V hullform with a 24degree transom deadrise for the aft planning area with a wave-piercing bow which is designed to run clear of the water at high speed, reducing drag and maximising speed, but which can be bought into dynamic effect with running trim control from large hydraulic trim tabs. This allows the bow to become wave-piercing and dramatically reduce slamming in head seas, maximising endurance for her crew when operating in rough conditions.
Anti-submersion fins
Another unique feature claimed by Safehaven Marine is adjustable anti-submersion fins at the vessel’s bow. Hydraulic in operation, they can be adjusted for speed and wave height and prevent excessive submersion in large following seas in very rough conditions when speed inevitably must be reduced. “The hull provides high levels of seakeeping on all courses,” Safehaven says, “with its twin chine arrangements providing for high levels of static and dynamic stability.”
The design allows for maximum speeds of in excess of 60knots with propulsion either by surface drives or hybrid waterjets, the latter allowing speeds of 50knots plus. The first example of the new design has surface drive propulsion supplied by Metamarine of Italy and is powered by a pair of Caterpillar C12.9 1,000hp engines. “It is achieving more than 56knots at present with more to come, and has a 45knot plus cruise speed,” said the company, with fuel tanks that can provide a range of in excess of 700nm.
12-person capacity
This particular version of the XSV 17 has capacity for 12 people to be seated, all on shock-mitigation seating in a climate-controlled main cabin, which has been designed to offer maximum visibility and situational awareness in a comfortable, secure environment for multirole operations, offering up to four individual command positions with their own consoles. The seats fitted on Thunder Child are ‘Wavebreaker’ shock mitigation suspension units with carbon race bucket developed and supplied by AMP Power in Holland, which dramatically increase crew endurance in rough seas. The design of the large forward cabin allows a modular configuration and has been configured so that it can function in three operational roles with conversion undertaken quickly and easily between pursuit and interception, in which case a modular self-contained weapon deployment system incorporating a 12.7mm gyroscopically stabilised, remote-controlled machine gun can be raised above deck through watertight hatches. “In this way, when the vessel is in engaged in surveillance or patrol, the main weapons are concealed and the vessel’s RCS signature is reduced,” said the company.
When the vessel is engaged in pursuit or ‘apprehend’ modes, the weapons are raised for deployment, another advantage of this being that the weapons are hidden when not in use, reducing the vessels VCG, which is beneficial in heavy weather.
Another role anticipated for the new version of the XSV 17 is extended offshore patrol, in which case full live-aboard accommodation is provided in the forward cabin. A third role is search and rescue (SAR) operations or troop deployment. In this role an additional 16 survivors/combatants can be carried. The design is fully self-righting and able to recover after capsize by a large breaking wave.
Faster reponse times
Safehaven Marine says it believes that the performance of the new unit enables much faster emergency response times than conventional SAR designs, “virtually doubling their speed.” “With statistics indicating that more than 90% of incidents occur in fair to moderate conditions where the XSV’s higher speeds could be utilised, the ability to offer faster response times can make a significant difference saving lives,” said the company. “In extreme conditions the design still offers a high degree of survivability, albeit at reduced speeds.”
Light weight, high strength
The XSV 17 is built using advanced lightweight cored composite for its hull and superstructure, offering light weight and high strength. The windows were specially developed by Safehaven Marine for maximum strength and lightness, utilising hard-coated 12mm polycarbonate with an additional outer protective film for the side windows, embedded directly in the FRP structure, with 18mm laminated glass steeply raked to minimise pressure loadings from green seas utilised for the forward screens.
In addition to a full array of navigation equipment including radar, radio communications, AIS, CCTV and GPS systems – all supplied by Garmin on Thunder Child – a range of specialised sensors are also offered. These include FLIR thermal/night vision infrared camera systems for surveillance and night-time operations. A Hyperspike and rapid obscuring system can be integrated concealed below decks and remotely raised through watertight hatches.
