Thunder child boat interior

Thunder Child is an 'XSV 17’ designed and built by Safehaven Marine. The design is a 17m very high speed, wavepiercing, low Interceptor, designed for Naval, law enforcement and offshore patrol  applications, as well as being capable of high speed S.A.R. operations being self-righting and offering fast emergency response times.

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Thunder Child is powered by a pair of Caterpillar C12.9 turbocharged, supercharged and intercooler diesel engines producing 1,000hp each. Propulsion is by Surface drives manufactured by Metamarine in Italy. XSV 17 is capable of a maximum speed of 54kts.

A crew of 10 can be comfortably seated, 6 on shock mitigation seats and 4 on fixed seats in her main cabin, a separate heads and sleeping compartment in her f/wd cabin. 

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Thunder Child is fitted with long range fuel tanks of 5,000+L allowing a range of over 750NM.

Construction and hull design

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The vessel is constructed from advanced lightweight FRP cored composites. XSV has an innovative and unique hull form that allows it to operate in two distinct modes, fully planing and wavepiercing. The hull design hull design combines a constant deadrise deep  V hull form incorporating twin chines capable of 60kts with a wavepiercing bow form. A 24 degree deadrise at the transom transitions to a wave piercing bow, with a super fine wave cutting waterline entry designed to run clear of the water at very high speeds, but which can be bought into dramatic effect with adjustable trim control to very effectively minimizes vertical accelerations at speed in waves, thereby maximizing crew endurance.

The hull provides exceptionally high levels of seakeeping abilities on all courses with its twin chine arrangements providing for high levels of both static and dynamic stability. The design is fully self-righting, capable of recovering after capsize by a large breaking sea and is survivable up to sea state 8, capable of operating effectively in up to sea state 6, and maintain operational speed in sea state 3-4. A unique feature is the bow buoyancy control fins used to increase buoyancy in following seas preventing excessive submersion, the fins are adjustable for wave height and craft speed.

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Thunder Child is fitted with a full array of navigation equipment including HD Radar, VHF radio communications, AIS, and GPS systems displayed on three 15" colour monitors at the helm and navigators station, all supplied by Garmin. FLIR Thermal /night vision infrared camera systems are fitted for night time passage as well as a four zone CCTV covering engine room and external views all displayed at the helm. Dedicated engineers position with dual controls and 15% Cat touchscreen engine monitoring display. The vessel is built to the UK's MCA Cat II commercial work boat regulations.

XSV 17  Principle dimensions / characteristics

L.O.A.                                                   17.8m / 59ft

Hull length                                         16.3m / 53ft 6"

Beam overall                                      4m / 13ft 2"

Beam moulded                                  3.8m / 12ft 6"

Draft                                                    .85m / 2ft 9"

Displacement lightship                    13,900kg

Fully loaded                                       19,500kg

Fuel capacity                                      5,000L

Range                                                  750nm+

Crew capacity                                    10

Engines                                               2x Caterpillar C12.9 1,000hp

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Surface Drive                                     Metamarine

Speed Maximum                                54kts

Cruise speed                                      40-43+kts

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Survivability                                       4x watertight compartments / self- righting / capsize recovery

Launch and performance trials video

Self-righting capsize recovery video

Rough weather winter seakeeping trials video

Construction of Thunder Child, Caterpillar engines and surface drive installation video

Safehaven Marine successfully launched its first-of-class 22-metre high-speed patrol boat demonstrator Thunder Child II earlier this year.

Thunder Child II’s hull design was developed to solve the head sea limitations inherent in traditional catamaran design, where when a sea state exceeds a given size, steepness and frequency, waves, especially in head seas, will inevitably impact on the flat surface of the bridge deck, causing slamming.

She features an innovative hull fusing an asymmetrical catamaran with a wave-piercing mono hull to produce a hull that combines the dynamic and transverse stability of a catamaran with the head sea capabilities of a deep-vee monohull.

The hull design effectively pushes through and splits waves, dampening motions and preventing the flat surface of the bridge deck from ever directly impacting the water surface.

The hull will, by design, fully wave pierce, the level to which is speed dependent, but in general wave height needs to exceed 2.5 to three metres before this begins to occasionally occur.

Thunder Child II has a length overall of 23 metres, a beam of 5.2 metres and a lightship displacement of 24,000kg, featuring a fully cored FRP hull and superstructure in vinylester and E-glass.

Kevlar and carbon fibre is incorporated as reinforcement within the structure, which has been over engineered to provide the necessary strength for heavy weather operation and designed to a six-gee operational envelope.

During development, Thunder Child II underwent extensive sea trials during which she reached a maximum speed of 54 knots, fully tested in a range of trials in varying sea states right up to extreme conditions of Force 10 and in six-metre seas off the Atlantic coast of Ireland.

Another benefit of the design concept is the high transverse stability provided by the catamaran aft sections, which minimise the rolling that traditional-vee hulls can suffer from when operating in rough conditions. Heavy heeling, often as a result of wind or chop influence at the moment of becoming airborne off the crest of a wave can, in extremis, cause high impact loadings when the hull impacts the water heeled over, on what is then, in effect, a flat surface.

The catamaran hulls offer greater initial transverse stability and resistance to wave-induced heel in the first instance, and by virtue of their slim body nature offer less surface area to wave impact in these situations, allowing a softer entry.

Integral to the design is the incorporation of a hydrofoil system. FASTcc ran the design of the Hysucraft foil system and supplied the workshop drawings to foil builder Hydrofoil Manufacturers, which shipped the foil system over to Safehaven in Cork in mid-August 2019. The system is installed between the asymmetrical catamaran hull, the asymmetrical form being particularly advantageous in this respect.

This lifts the hull some 400mm out of the water at higher speeds, allowing the forward monohull section to run mostly dry and clear of the water with very little wetted area, greatly reducing resistance. The monohull sections only come into significant effect in larger sized wave encounters, allowing the hull to cut through waves. The hydrofoil also very effectively damps motions especially in respect of pitching.

Thunder Child II’s hull also incorporates twin transverse steps, which at higher speeds reduce the wetted area on the hull bottom as well as increasing lift and stabilising running trim. The steps, working in conjunction with her hydrofoil, allow Thunder Child II to run at high speed with very low drag and resistance, maximising speed and efficiency. According to Safehaven, at higher cruising speeds of 34 to 40 knots, she has a 20 per cent greater range and better fuel economy than that of a typical planing hull.

The design allows for wider load variations as the monohull section supports a significant percentage of the vessel’s overall displacement, and by virtue of its steep deadrise, buoyancy rises exponentially. This supports increases in displacement, thereby preventing excessive hull sinkage, which on a pure catamaran hull design results in a significantly reduced bridge deck clearance when heavily loaded.

Seakeeping in large waves at displacement speed when inevitably forced to slow down is thus improved, with slamming never occurring on the bridge deck.

Thunder Child II is fitted with quad Caterpillar C8.7 650hp (480 kW) engines coupled to France Helices SD3L surface drives in a staggered arrangement. This setup provides the desirable redundancy for her planned upcoming trans-Atlantic record attempt, as should one engine fail she will still be able to maintain planning speed.

She is fitted with an 8,000-litre fuel capacity, allowing for a 750nm+ range at her cruise speed of between 32 and 40 knots (depending on fuel load), and is capable of altering her LCG to prevailing sea conditions via a fuel transfer arrangement to a 2,000-litre forward ballast tank.

Thunder Child II has been fitted out to a practical and purposeful standard and also to provide a comfortable environment, with her main remit being fast offshore passage making. She has a crew capacity for five, all on military spec shock mitigation seating supplied by the Canadian company SHOXS, with four additional reclining suspension seats aft in her main cabin for passengers.

A basic galley is also provided aft in the spacious main cabin fitted with sink, 240V hob, microwave and fridge. Her lower forward cabin offers a comfortable living area with full sleeping and live-aboard facilities for her crew featuring five berths in four cabins, including a master’s cabin.

The design has a high level of survivability, with multiple watertight compartments complying with commercial standards of safety and engineering, and she also has EU RCD Category A certification.

A Humphree interceptor trim control system is integrated, allowing fine control and adjustability of her running trim. A four-kW AC generator provides 240V onboard and a Dometic 27,000btu air-conditioning unit provides climate control.

A full suite of electronic navigation equipment is integrated with four 19” monitors in a “glass helm” design for radar, GPS chart plotting, VHF, forward-looking sonar and a FLIR thermal camera. A dedicated engineer’s station allows monitoring of the engines and multiple-angle CCTV coverage of the craft.

Satellite communication is provided by Sailor ensuring the crew can be in contact in remote regions above the Arctic circle. Thunder Child II also carries a three-metre RIB.

See all the other news, reviews and features of this month’s Maritime Security Week right here

XSV 20 Principle dimensions / characteristics

L.O.A.                                                   23m / 75ft

Hull length                                         21.4m / 67ft

Beam overall                                      5.4m / 17ft 7"

Draft                                                    .85m / 2ft 9"

Displacement lightship                    24,000kg

Fully loaded                                       29,000kg

Fuel capacity                                      4,000L

Range                                                  400nm+

Crew capacity                                     12

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Seating                                                SHOXS  Shock mitigation seats 

Engines                                              2 x 1,500hp MAN

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Gearboxes                                          ZF

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Surface Drive                                     France Helices SDS5L

Waterjets                                            Marine Jet Power / Hamilton

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Trim control/stabilization                Humphree

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Air-Conditioning                                 Dometic 2X 2,7000BTU

Speed Maximum                                50kts+

Cruise speed                                      40+kts

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Survivability                                       8x watertight compartments

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Construction                                       FRP Composite

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Horizon Yacht Sales is pleased to present you with ‘Thunderchild.’ A 2017 Barracuda XSV 17 designed & built by Safehaven Marine.

If you are looking for a boat that is capable of going fast for long distances, in any weather, this semi-custom design from Safehaven Marine may be the ultimate answer. Cruising at 45mph, topping out at 64 mph, Thunderchild is adaptable across a range of applications; a mega yacht tender, an offshore support vessel, a patrol boat, offshore search, and rescue….this boat has an enviable track record that attests to her pedigree.

The XSV 17 is a sophisticated hull design, driven by twin C12.9 Caterpillar turbocharged, supercharged, and intercooler engines with heavily upgraded Meta Marine Surface drives. In calm to moderate sea states, she is a planing hull, but when conditions deteriorate, she can shift to wave-piercing mode with a very fine entry and a deep V deadrise at the transom minimizing pitch, yaw, and pounding. Twin chines afford excellent dynamic and static stability. Built with advanced lightweight Fiber-reinforced polymer (FRP), enables the XSV 17 ‘Thunder Child’ to survive in sea state 8, when her proven self-righting capability might be called upon.

The XSV 17 design was focused on development for naval and law enforcement applications, so she benefits from a low RCS (radar cross-section), due to her hull and deck design, as well as her outfitting.

‘Thunder child’ has six shock mitigation seats for extreme condition comfort and a further four seats for moderate conditions. With a head and shower, and accommodation forward and air-conditioning at a total of 50,000 BTU. The helm boasts three large 15” Garmin GPSs displays with HD radar, VHF, AIS, FLIR Thermal /night vision, and an onboard CCTV monitoring system for engines and equipment.

In 2017 Thunderchild made history and became the world record holder for the fastest circumnavigation of Ireland via Rockall. Thunderchild covered 1347 miles to circumnavigate Ireland, counterclockwise in just over 34 hours, at an average speed of 39mph. With 1320 gallons of fuel, giving a range of up to 750nm, she only had to refuel twice en-route.

If you would like to enquire into this excellent example of an XSV 17 ‘Thunder Child’, then please contact the Horizon Yacht Sales broker team today.