Plug-and-play electrohydraulic braking systems from Dellner Brakes were introduced to the US market at this year’s International Workboat Show in New Orleans.
Combining the very best of Swedish and German engineering from Dellner Brakes and sister company Pintsch Bubenzer, the new BUEL STL system provides a compact, self-contained solution for stopping, turning and locking ship propeller shafts on vessels of all sizes, as well as for industrial applications.
As the name suggests, the system combines elements from Dellner Brakes’ stopping, turning and locking (STL) systems with Pintsch Bubenzer’s patented BUEL electrohydraulic thruster/power package. According to Edgar Roca, VP for Dellner Brakes, “It functions as an HPU, but it requires about 70% less hydraulic oil than an HPU. It’s fully enclosed; therefore, we do not have to have any external hydraulic lines running to the system. And it allows us to power a complete stop, turning and locking system with a full enclosed hydraulic thruster.”
Because it needs no external piping, the system is compact, easy to install and, with the BUEL using only half a liter of high-performance synthetic oil (compared to as much as 30 l of hydraulic oil in standard hydraulic power units), it is cheaper to run and environmentally-friendly too.
“You don’t have to worry about any hydraulic fluid leaking. In the marine industry there’s a lot of concern, normally a lot of the brakes take their fluid from the water system, and there’s a concern there that they think the brake might take too much fluid and then you’re having a steering problem,” Roca said. “So this really just eliminates that, cuts out the concern, and you have a fully enclosed hydraulic system directly to our braking.”
At its simplest, the new system combines a Pintsch Bubenzer BUEL Model G, delivering up to 240 bar of pressure, with a powerful Dellner disc brake offering stopping force of up to 517 kN per unit. Customers can then choose to add a Dellner locking device that, available with hydraulic, electric or manual power, can deliver locking force of up to 1,300 kN. Customers requiring a full STL system can then also add a Dellner electrical continuous turning device, which uses an electric gear wheel to move the brake disc and attached shaft to any position – forwards and backwards – or turn the disc continuously, all with variable speed and turning force of up to 157 kN. A system with the above configuration and a 2.25m diameter brake disc will provide 550 kNm stopping torque, 1,450 kNm locking torque and 155 kNm continuous turning torque (intermittent breakaway 233 kNm).
The stopping, turning and locking functions can be operated individually or as a fully automated system. There is also a wide range of options for the system interface, from manual hand operation to electronic control panels and even remote wireless operation through a smartphone or tablet — whatever the customer needs.
Roca said the BUEL STL is ideal for workboats, such as tugboats, icebreakers, and military vessels. “We really see it being a game changer for us on the work boats because of the fact they want small, compact shaft braking systems, yet they don’t want to do any modifications to the external hydraulic system,” he said. “They want to have a fully enclosed system, without having to take fluid and pressure from the motor system.”
Dellner Brakes’ STL systems fit around the ship propeller shaft to enable faster directional changes with maximum maneuverability. They also help lower fuel consumption, reduce the load on propulsion systems and make routine maintenance quicker, easier and safer. Securing the propeller prevents damage to the shaft and bearings if the vessel is drifting or buffeted by waves.
It also allows ROVs and divers to operate around, the propeller blades in safety. When in the harbor, using the turning function to rotate the propeller can also help to reduce marine growth on the blades and lubricated shaft bearings. Roca said the BUEL STL can also be used in oil and gas, mining, port, and paper as well as any other type of industry that might require any type of emergency stopping, braking, turning solutions.
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