5:00am - The workday for Simone Fassbender and Karl Heinz Gehring, technicians at Phantasialand, has already begun. Both are sitting in the control room of the coasters. In front of them is a panel with multiple displays, and under the ceiling there are many small black and white screens that observe all important spots of the facility. The central control system is the heart of the roller coasters, here the electronics issue orders to brakes and motors, here the status of the whole ride is shown to the operator. Without powerful computers the highly complex ride wouldn't be serviceable: Brakes are monitored, special effects controlled and the positions of the cars tracked. These tasks are performed by redundant systems represented by a so-called PLC. Its sense organs consist of sensors, switches and contacts. Movements and states of all fixed and moving components are observed and reported to the central control unit. This guarantees that all processes are performed in the determined order and in the correct time slot. Even the position of the freely moving cars is monitored at different spots along the track.

Control room

The Maurer Xtended SC3000, which is the type designation of the two Winja coasters, uses a threefoldly redundant safety concept: Three quasi independent processors make up the heart of the control unit. These differently implemented systems must generate the same result within a tight time span. If this is not the case - for whatever reason - the coaster is automatically shut down and brought to a safe state.

The control unit is informed about every installed mechanism at all times: So for example the state of a brake is constantly controlled , the system is informed about whether it is opened or closed. The three processors are fed with the input from the sensors along the coaster via a fast bus system, then the computers process the data in real time and use them as a basis for controlling all actions of the ride. The necessary wiring is several kilometers long to be able to monitor and address every component. The computers use simple logical principles - "If impulse 1 then close brake 1". Combining such rules leads to a complex structure that can only be handled by a machine.

The output of the control system consists of electric pulses that activate motors or open or close valves in pneumatic circuits. The ride almost runs autonomously. At everyday operation the operator is mainly responsible for the clearance of the cars in the station and monitoring the control screens. A manual operation with riders aboard isn't possible, not even in case of a malfunction. In this case the computer transfers the whole ride into a safe state, too.

Simone Fassbender fetches a printout. It lists all error messages of the previous day. The coaster controls itself, every deviation from the normal case is recognized by the sensors, every fault of a component is detected and leads to a safety shutdown. This is reported to the operator and the cars are stopped by external brakes that are installed throughout the track. Karl Heinz Gehring tells us: "The control system has its own fault diagnostics that proved itself pretty well. Our mobile work group mostly knows instantly which components have to be checked or replaced." Anyway: The red emergency stop button is still there.

A completely new safety concept was designed for Winja's Force and Winja's Fear due to their high complexity and the fact that the track is cut at multiple points, and the TÜV in Munich was involved in this from the beginning. New paths had to be struck in many technical details. Functions and measurement technology that worked well longtime were changed to new ones with an even higher safety level. That is an absolute must to guarantee maximum safety for the riders.

5:15am - The next workstep after the initial system check is inspecting the track. The computer hasn't reported any anomalies during the boot process, and now the visual control of the wearing parts and the security related components begins. These daily routine checks are only a part of the complex inspection procedure. So for example the cars are deconstructed after a specified amount of load cycles to examine the highly stressed components with ultra sound to find micro-cracks inside the material. In addition, TÜV as an independent service provider is consulted once a year for an exhaustive test. There is a huge responsibility on the shoulders of the manufacturer as well as the owner, and they perform uncountable safety measures to meet the demands. This controlled thrill makes roller coasters the safest means of transportation at all.

Car at a block brake

But back to the inspection of the track. To check all components one after the other, the system is switched to a special manual operation mode for the time of the maintenance works. The focus lies on brakes, sensors and the complex special effects. Team leader Werner Kuhl is already on his way, we will meet him later on. Like all staff members, he keeps contact with his colleagues in the control room via voice radio.

The first task is the check of the brake systems. Like every modern roller coaster the two Winjas are based on a block system that allows operation of up to six cars per side. Every course is divided into eight sections to achieve that, and every transition point is equipped with so-called block or check brakes. To prevent collision accidents, there may never be more than one car in each block. The control unit with its body of rules assures that the brakes in front of a block only open when the sensors at the end of the section report that the previous car has passed and the block is empty. So there is always at least one brake section between two cars so they can be be securely stopped.

The brakes at Wuze Town use the principle of Coulomb friction. At the underbody of the cars there is a metallic brake fin that has a special coating on both sides. The active part of the brake is mounted to the track: These brake modules are more than one meter long and have a gap in which the fin immerges into. A mechanism then presses the high-strength brake pads onto the fin just like at a bike and the car slows down.

We are heading towards the brakes of the blue coaster before and after the carousel in the main hall. "We call the coasters the orange and the blue one to clearly distinguish between them", Simone Fassbender explains the color labeling. In this case the blue one is Winja's Fear. Every brake platform can be easily reached even though they are up to twelve meters high. Mostly there are broad staircases built for the access. This is an advantage for the technicians, but also for the riders who can easily leave the coaster in case of a breakdown - block brakes are always used as predefined evacuation spots.

The brake ensures...

Every brake section has at least two independent mechanisms, and each one is operated by an own drive using air pressure. Next to the check brakes - which always exist twofold for redundancy reasons - there sometimes are trim brakes (or scarf brakes), too. The safety brakes used for the block clearance can bring the cars to a stand and keep them in position while the trim brakes fulfill the task of speed control. "The optical difference in the two brake types is most obviously the pattern of the coating", Simone Fassbender tells us. "So it's quite easy to distinguish between them." There are also technical differences that make the security brakes more fail-proof, but the underlying principle is the very same.

... the next block

The matutinal inspection mainly consists of the visual check of the friction pad. The thickness is determined and the position of the brake checked with a gage. The 20 centimeters long pads are replaced as soon as they don't comply with the specification for safe operation anymore. The operativeness of the security brakes is a very relevant criteria. The consequences would be fatal if the cars couldn't be stopped because of a too strong wearout of the pads. To prevent this is the duty of every operator of a roller coaster as well as of the design engineer: One possible solution is redundancy, achieved by the twofold installation of the safety brakes in every section. Another way is fail-safe engineering: In case of a failure the system automatically turns into a safe state. Applied to the brakes this means that the cars come to a complete stop, even if for example the power supply is cut off or the air pressure falls. This is achieved by a simple mechanical component: a spring that is integrated into the adjusting mechanism of the brake. In this so-called spring brake cylinder the compressed spring stores the actual work energy and provides that the brake is closed. The air pressure then opens the brake against the force of the spring. So during the regular operation the control unit has to explicitly give the command to open the brakes, otherwise they remain closed.

A visual control of the mechanical components finishes the check of every brake module. This includes the secure fixing of the proximity switches. Those small turquoise boxes give a signal as soon as a metallic object gets close. They are the sense organs of the control unit and are versatility used: In every brake section they can be found in many spots. They determine the state of the brakes (whether they are open or closed) as well as the position of the car on the track segment. Those data are processed and provoke a reaction within milliseconds: So for example if the speed of a car is determined, the closure time of the trim brake can be calculated. This aims a controlled deceleration to a specified speed. This speed adjustment isn't done in every brake, but it still provides that a fast car can't get too close to a slower one, which would cause the system to completely stop the quicker one for a short time in the next safety brake.