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higher torques can be provided on custombuilt eSTL systems, which can be scaled up and adapted for specific applications. In a statement at the time, Mr Åberg explained that the STL system allows users to select from its three functions and said that eSTL “will give them even more choice for small and mid-range applications.” He told Marine Propulsion in August that the brakes can be operated remotely via a hand-held controller or even from a smartphone or tablet computer. “Remote operation of our STL systems means operators can stop, turn and lock the ship’s propeller shaft safely from a distance, making working procedures safer and also saving operators’ time,” he said. Dellner has been researching different types of remote controls for around 15 years, he said, describing them as forming part of a wider trend in the industry towards wireless control and monitoring. He believes it is “extremely important to keep pace with the increasing digitisation that’s happening in the world today.”

Its most recent innovations are two heavyduty disc brakes that it has added to its SKD range. They have a modular design which the company believes provides more choice for its customers along with “outstanding stopping power at extremely competitive prices for large industrial, marine and offshore applications,” it said in a statement at the time. Its new SKD 140 brake is suitable for large vessels and delivers a braking force of up to 258kN to stop rotary motion and to hold loads stationary. It has two brake housings, each containing a powerful hydraulic piston. Its other new model is the SKD 4x140 brake, which combines two brake assemblies containing a total of four powerful hydraulic pistons to deliver braking force of up to 516kN, making it Dellner’s most powerful brake yet. Dellner has also developed an offshore version of the brake, with corrosion protection and hard wearing paint and pistons that are specially designed to withstand harsh conditions.

Thanks to the brakes’ modular design, Dellner can also provide larger systems by combining several brake assemblies or by producing customised housings with several pistons to suit specific installations. Manufacturing these brakes benefits from what Åberg described as “new manufacturing processes” that make it possible “to offer these brakes to our customers at extremely competitive prices,” he said. In operation, they use cylindrical guide pins that transmit the tangential braking force from the brake lining to the brake housing and mounting stand, which means that the brake pistons are not subject to any radial forces, which makes the brakes last longer than they would otherwise do, Dellner’s statement explained. Four weeks after Nor-Shipping, the company added two lightweight failsafe brakes to its SKP range. Its SKP 180 weighs 315kg and delivers up to 226kN braking force through two brake housings while the SKP 4 x 180 weighs 630kg and combines two brake assemblies containing a total of four pistons to deliver braking force of up to 453kN.

SHAFT LOAD MEASUREMENTS SAVE FUEL ON DUAL-FUEL ENGINES Accurate torque measurements from an engine’s propeller shaft can help control main engines and lead to considerable fuel savings, according to the German instrumentation specialist, HBM. Its T40MAR torque transducer is certified by a number of class societies for marine use and the company’s business development manager for torque applications, Guy Beaho, referred Marine Propulsion to a case study describing how Wärtsilä is using the transducer with its dual-fuel engines in marine installations with direct driven propulsion. When the engine runs in gas mode, the fuel injection system needs the precise load signal for the engine to work correctly, the case study reports. And to produce a precise load signal, a very accurate torque transducer is needed, it adds. Wärtsilä installed a T40MAR to its engine between the engine flexible coupling and the gearbox hub to measure the output shaft’s torque. Other methods were not accurate enough but T40MAR has an accuracy class of only 0.15 (±0.15 per cent), the study says. It quotes Mr Beaho explaining that the main contribution to this accuracy comes from “the documented

unbroken chain of comparisons tracing back the HBM torque transducers to the reference transducer of the German National Standard.” Direct torque measurements of up to 400 kNm can be made by the T40MAR and its measurement signals – which can be either analogue or digital – are transmitted without needing contacts, which helps make the sensor maintenance-free, the

company suggested. In a paper published on its website in July, HBM reports that accurate shaft torque and load measurements are essential for dual-fuel engines to be able to switch between fuels without losing power. And when an engine is running on LNG, this data is needed to control critical operating modes relating to cylinder pressure, such as knocking, misfiring or overload, the paper says. MP

HBM’s T40MAR fits onto the engine to provide accurate load data (credit: HBM)

Marine Propulsion & Auxiliary Machinery | August/September 2017

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Marine Propulsion & Auxiliary Machinery August/September 2017  

Marine Propulsion & Auxiliary Machinery provides the technical, operational and project teams that work for the ship owner/operator/manager...

Marine Propulsion & Auxiliary Machinery August/September 2017  

Marine Propulsion & Auxiliary Machinery provides the technical, operational and project teams that work for the ship owner/operator/manager...