The world’s first realistic fast small ship simulator, a prototype of which will be delivered next month to the Royal Netherlands Navy (RNLN), could revolutionise the training of fast-boat crews and influence the design of the boats themselves.

A technology demonstrator, built by Netherlands-headquartered simulation specialist Cruden, that was shown at the High Speed Boat Operations Fora in Lisbon and Gothenburg, has performed so well in preliminary trials that the Netherlands Defence Academy at Den Helder has initiated an extensive test program on the prototype and expressed interest in acquiring three full scale units.

The new Fast Small Ship Simulator (FSSS) is similar to large-vessel bridge simulators in that it provides a working replica of a real boat’s controls and navigation systems, but it differs in one crucial respect: the boat’s cockpit and crew are located on top of a motion platform. This moveable base adds a new dimension to training by physically cueing the body forces coming from acceleration, rocking and slamming etc. The ability to actually feel relevant hydrodynamic effects brings unprecedented authenticity to the rehearsal of critical handling situations and could help boat manufacturers accelerate their R&D programmes.

The latest offering has been developed in collaboration with the independent Maritime Research Institute Netherlands (MARIN), which has vast experience of developing complex simulation environments for the maritime industry; Tree C Technology, software developers well-known in the world of offshore simulation; and Cruden, the world-leaders in automotive and motorsport driving simulators.

At Cruden’s headquarters in Amsterdam, 30 engineers possess expertise in every aspect of simulator hardware, software, motion cueing, vehicle dynamics, rendering, and content. This collective knowledge has produced automotive simulators capable of mimicking real cars’ behaviour so precisely that manufacturers such as Audi, Porsche and Jaguar Land Rover use them for vehicle development and several Formula 1 teams rely on them for driver training and chassis development. By carrying-over much of the technology developed for automotive clients and combining it with MARIN’s detailed knowledge about hydrodynamics, Cruden has been able to bring new realism to marine simulators.

Cruden’s FSSS can be fine-tuned to replicate the behaviour of almost any small fast-boat or motor yacht. The first one to be built is modelled on the MST FRISC 1200, the 12-metre long Rigid Hull Inflatable Boat the RNLN deploys all over the world on anti-piracy, counter-drugs, and rescue missions. To reproduce the FRISC’s performance and handing characteristics, Cruden started with detailed data provided by the boat’s manufacturer, MST, meshed this with hydrodynamic modelling from MARIN, and made fine-tuning adjustments after running validation trials at sea in one of the 48 FRISCs owned by the Royal Dutch Navy.

Ahead of going to Den Helder, the FSSS currently sits inside a purpose-built room at MARIN’s vast R&D centre in Wageningen, near Arnhem. Here visitors are greeted by the odd spectacle of what looks like a FRISC cockpit being carried away on the back of a gigantic metallic spider with six legs. The spider is a Hexapod motion platform known as ‘6DOF’ because it can move in all six degrees of freedom; In addition to surge, heave and sway, the platform can also rotate for yaw, pitch and roll. On top of the prototype’s platform, the scene is rendered on five 42” screens providing over 180° horizontal field of view where the full-mission units will have 8 m diameter screens with 360° field of view and visuals provided by a cluster of projectors. The console holds fully operational OEM navigation-, radar- and communication-equipment (SeaCross, SIMRAD, Raymarine, Furuno, Garmin and iCOM are supported), so that the simulator can not only be used to train for seakeeping or docking but it is capable of simulating full missions.

Movements only feel realistic if the motion platform responds realistically to control inputs and in sync with the visuals. In a Formula One simulator, if the delay between driver input and vehicle response is more than 30 milliseconds longer than in real life, the simulator is worthless. In a fast small ship simulator, these responses must be nearly as fast. If you’ve hit a wave you cannot wait 30 milliseconds to feel it because at 65 knots you will already have travelled another meter and piercing that wave would feel unrealistic. This presents a challenge because there is unavoidable time-lags in sending information from one point in a simulator’s system to another. The main causes of this are sampling delays, processing time, and data transfer, all of which Cruden has worked hard to iron-out. Cruden’s pioneering solution, which synchronises and minimises latency to an unrivalled degree, enables the simulator to anticipate how to react by building predictive algorithms into its calculations. The result is zero simulator-induced latency: the totally convincing impression that the simulated boat behaves in exactly the same way as on the water.

When simulating rough seas, the FSSS convincingly cues slamming up to 1.6g where in real life, FRISC crews are subjected to up to 9 g in Sea State 2 and in higher Sea States they come crashing back down on deck with over 15g. 1.6g has proven to be violent enough to be a believable experience. In real life, it takes only one such impact to cause knee or spine injuries, and yet the FRISC instructors, expensively trained and in limited supply, were typically having to ride-out the ocean waves for 1,000 to 1,400 hours every year.

It was this injury risk which first inspired the Netherlands Ministry of Defence to propose the building of a fast small ship simulator and to commission Cruden to help turn the idea into reality.

By Jake Frith