Actuator Technology from Pfaff-silberblau Moves Vessels Safely Through Locks in Rivers and Canals

Worm gear screw jacks also work impressively in steel structures for hydraulic engineering: Electromechanical lock drives for inland waterway transportation.

Friedberg and Hannover, Germany, April 11, 2005 – Pfaff-silberblau Hebezeugfabrik GmbH & Co. KG (of Friedberg/Derching, Germany) is more than just a leading supplier of solutions for actuator technology when it comes to custom requirements for the manufacturing of (special-purpose) machines, for lifting and material handling technology, for stage technology or medical devices. For a customer in France, Pfaff-silberblau has developed a special construction for steel structures in hydraulic engineering based on the Pfaff-silberblau modular system for worm gear screw jacks. The system is impressive from a technological and economical perspective: Using electromechanical lock drives, inland vessels can maneuver themselves through Northern France’s system of rivers and canals per remote control. The company that manages traffic on the Sambre and Scarpe rivers in Northern France needed a solution that enables vessels to independently activate the controllers for lock systems via local control centers. Using monitors, the command centers can keep track of the current water levels and the lifting position of the individual lock systems, and thus ensure a smooth flow of vessel traffic. Pfaff-silberblau supplied the high-performance drive technology for these systems: The locks are opened and closed using size 25 worm gear screw jacks with Tr 90 x 16 trapezoidal spindles. Here, the lifting elements handle a dynamic tensile load of 75 kN for maximum lifting lengths of a good 7,000 mm, or a static load of 250 kN. Pfaff-silberblau’s design is particularly impressive when it comes to its hardiness, even when subjected to harsh weather and tough environmental conditions. Regardless of the source of the challenge (ice, frost, pieces of wood or grime), the worm-gear screw jacks are up to the test. Thanks to their robust design and reliable travel and position measuring system that is directly mounted on the screw jacks, the lock system is always ready for operation. There is even emergency manual operation available for the drive units in the event of a power failure. Moreover, for safety-related reasons, the wear of the movement thread for the threaded, self-locking trapezoidal spindle is displayed visually and recorded regularly. Should a foreign object in the water cause a blockage, this would reverse the load on the spindles from a tensile load to a compression load. Sensors are used to reliably register this critical situation and report it to the control system, which prevents further stroke movement that could cause the spindles to destroy themselves. The drive units are submersible and are equipped with telescoping, rust-resistant protective covers for the lifting screws as well as an anti-rotation device that uses precision square tube. In order to realize the required swivel movements, the lifting units have a rotating bolt in the direction of one axis. The actuator specialists from Pfaff-silberblau were particularly careful when it came to the selection of materials and to their protection against corrosion. All bare parts are either equipped with durable protective coats or were made out of rust-resistant materials. The electronic components have an IP-67 protection rating and additional protection against mechanical damage. Thus, the lifting units working in these French lock systems are nearly maintenance free and only require an annual check.

About Pfaff-silberblau Pfaff-silberblau Hebezeugfabrik & Co. – which was established over 135 years ago – currently has 360 employees and a group turnover in excess of 62 million euros (2004 fiscal year). The company is a leader in the fields of hoisting machinery and materials handling equipment, actuator technology/worm-gear screw jacks, stage technology, road & rail, and materials handling technology. Pfaff-silberblau is an experienced partner for solving any problem related to moving (turning, lifting, lowering, pushing, shunting) loads of up to 1,000 tons in any direction. The company has factories in Friedberg and Heilbronn (Germany), and is represented by its own national companies in Switzerland as well as Austria, England, the Benelux countries, Poland and Hungary. Beyond that, more than 40 affiliated representative offices are active for Pfaff-silberblau around the world.