The same training benefit can be seen with operators of large cranes. It can perhaps be a common perception that Simulation equipment is an expensive ‘luxury’ – but in reality this is not the case and the benefits far outweigh the costs. According to Bart Williams, Sales Director at US GlobalSim, technical advances over the years have reduced costs and increased functionality. “In the past, only the largest ports could justify simulators, but today prices have dropped to the point where even ports doing under 700 TEU per year are looking at professional crane simulators,” says Williams.
Williams explains that Simulator Training provides the greatest benefit where equipment is:
Complex
Dangerous to operate
Expensive to operate
Not available for training
For simulators, the level of reality equals the level of training benefit. Aspects of good simulation involve the visual model and displays, physics, controls, motion system and the instructor station – these elements are discussed below.
Visuals
The visual model includes the 3D image of the area for the crane simulation. It may be a port with ships and containers or a construction site with partial buildings and vehicles. Visual models of objects should be accurate and should create life-like effects. For example, the loads should cast shadows to aid in realism and depth perception. On the other hand, there should be enough detail to provide realistic images without slowing down the real time computations. The visual refresh rate should be at least 60 times per second. Any slower and the image will be jerky. This would be hard on the operator’s eyes and unrealistic. Each visual channel may be either an LCD display or a projector and screen. Also, each visual channel requires a computer to calculate the images displayed on that channel. The number of visual channels can range from one to over 10.
Software Physics
Simulators must behave in the same way as in real life. Loads must stop or bounce when colliding with other objects. Movement of ships in the water must be natural. Video games with explosions, etc. are for entertainment. Because crane simulators are for training, they might not be as exciting but they provide an invaluable opportunity to train people in a controlled and safe environment.
Controls
Low-level simulators have no motion system and the controls are simple and generic. High-level simulators have controls that look and behave like real crane controls. The picture below shows controls for different types of cranes that can be used on one simulator from GlobalSim. This allows the user to begin with a simulator for STS crane training. But, it takes only a few minutes to exchange the controls for an RTG crane.
Motion Systems – One of the factors that most contribute to the feeling of realism is a motion system. Motion can occur in a number of axes. Flight simulators need to have six degrees of freedom (6 DOF) – roll, pitch, yaw, surge, sway, and heave. But it is important to understand that not all crane simulators need this kind of movement. For example if a STS Quay crane is rotating, then the crane is broken. As shown in the chart below, most cranes only need 3 DOF. It makes no sense to pay for 6 DOF if you don’t need it.
Instructor Station – Professional crane simulators include an instructor station. The instructor can create a range of training scenarios including different weather conditions such as rain or snow. The instructor can establish wind speed and direction. Students can also practice in a day or night time environment. The instructor can also induce failures such as having a spreader getting stuck in the cargo hold. Of course, the instructor software keeps an extensive database of individual students’ performance. The database records contain number of moves per hour, number of collisions, etc. GlobalSim’s, VP of Sales points out that their simulation tools can be applied in a variety of situations. “We have recently installed a system at CSX for use in crane training for intermodal applications. Inland terminals can also benefit from the same technology used for material handling training at ports.” In an age when virtual games and interactive technology is evolving almost on a daily basis it is obvious that simulation will become a necessary tool thereby establishing an increasingly prominent role in the years to come.
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