Schottel launches feature-rich propulsion control system

Power is nothing without control, as the saying goes. While this statement was most famously used by an Italian tire manufacturer, it’s applicable to any drive system where power and torque need to be managed with utmost precision.

Schottel is known around the world as a manufacturer of propulsion systems for marine applications. Founded in 1921, the German company is perhaps most famous for its azimuthing propellers. With the ability to rotate through 360 degrees, these systems can steer a vessel without using a rudder.

Today, the company’s power systems are used on a wide range of applications, including ferries and trawlers. They also feature on many tugboats, as these require superior manoeuvrability when guiding larger ships into dock.

New bridge layout

In addition to propulsion solutions, Schottel has a history of developing systems for managing vessel power, with each successive generation looking to achieve the best possible human-machine interface. Launched in September 2026, the latest of these is PropControl4, which Alexander Neideck, Product and Business Intelligence manager, said could be described as the ‘brain and controller interface’ between the crew and the ship’s propulsion hardware.

Christian Böttinger (left) and Alexander Neideck, Schottel (Photo: Power Progress)

“We started with a blank sheet of paper with this new system,” he explained in an interview with Power Progress at the SMM 2026 marine tech trade fair in Hamburg, Germany.

“We have a new bridge layout, combining physical controls and an all-new panel display” he continues. “But all the internal hardware is also new. Central to this is connectivity, so we have designed the system to meet all necessary cybersecurity requirements.”

The bridge controls are presented in a simple layout. Neideck explains that where there were individual screens for each thruster, these are now accessed via a single touch sensitive monitor. “The [panel] layouts are based on the OpenBridge design guidelines, an open-source design system for industrial HMIs,” explains Neideck. “These outline design commonalities across maritime user interfaces, including layout and color schemes. Having a standard layout across different vessels means less operator confusion, less chance someone will make a mistake.”

Expert design

The digital demonstrator on the Schottel stand at SMM featured a tug with two azimuth thrusters, each controlled by a multi-function control lever. “We worked with a specialist company to design the controllers,” says Neideck. “We realized that while we are experts in control systems, we needed a company with expertise in ergonomics to develop a unit which has the right feel.”

“It was interesting to work with an industrial designer, to get their thoughts on the design,” added Christian Böttinger, head of Electronic and Software Engineering. “We also worked with a series of ship captains to watch how they use the controls so we could offer a better solution.”

PropControl4 is a bridge-to-propeller system, but Neideck says that there’s no requirement to install a complete system from Schottel. “An integrator could specify different bridge controls and we could supply just the interface. It would depend really on customer preference.”

Also, he noted, it would be on a case-by-case basis whether it would be possible to use other interfaces when considering remote vessel functionality (outside the bridge). For this, there are specific and unique control functions which might require Schottel-supplied hardware.

Going back to the ‘power is nothing without control’ strapline, while commands are initiated by the bridge, those directions are ultimately delivered to the thruster via onboard switching cabinets. Developed by Schottel, these units have all the hardware and software necessary to deliver the necessary precision needed by working vessels.

“These cabinets are the core of the system, they hold the ‘intelligence’” explained Neideck. “There’s generally one for each thruster and we developed all the related PLC, HMI functions, etc.”

Feature-rich functionality

Digital demonstrater of the PropControl4 system at SMM 2026 (Photo: Power Progress)

The new controls include a series of features and functions to support improved manoeuvring and to help ensure safe operation of the vessel.

On the demonstration panel, Neideck showed how the base of the lever lights up with a blue LED ring to indicate it has control – this is particularly useful when the vessel has multiple control locations.

“Blue means that this is the leading control,” he continued. “The other control lever will follow this unit using the internal motors, they are synchronized.”

The levers also feature haptic feedback. Neideck demonstrates how sending the control lever too far over to the left or right when travelling at speed will trigger vibrations to warn the operator.

Additionally the throttle, operated via a slider on top of the lever, will vibrate when approaching a preset limit to help control vessel speed.

Redundancy builds in safety

The PropControl4 system is fully ‘fly by wire’, with no mechanical connections between any of the individual system components. The setup has required a series of redundancies across the system to ensure safe operation.

Neideck: “The control levers have independent interfaces with the switch cabinets. There is a global bus system that supports communication across the full system.”

In previous versions, a backup system involved separate buttons to control the thrusters. Now, the controls themselves have redundant secondary systems which will switch control over to the working unit. This extends through to there being two PLCs in each switching cabinet for additional safety.

“No one liked the push-button interface,” says Neideck. “So the decision to have redundancy in the control levers is a direct response to customer comments. Of course, if there is an issue the vessel should go back to port, but if a tug is towing a ship that’s a critical manoeuvre, so this allows the task to be completed.”

Application type

Operation of the PropControl4 system can appear complicated at first, but Neideck says this is more to do with control of the azimuth thrusters. Schottel can help with related training, but if an operator is moving directly from a shaftline system, it’s recommended that they receive training on thrusters before going on to learn about PropControl4 setup.

“PropControl4 has been designed for use with tunnel thrusters, shaftlines and azimuth thrusters,” says Böttinger. “We supply all types of drives, so the system had to be capable of working across each of these solutions.”

More importantly, he says, it’s the ability of PropControl4 to scale as needed, either for complex or basic drive systems. “For example, the size of the propeller has no relation to the system, it can be used on leisure craft through to container ships.”