Roth Develops Sea-Going Accumulator System for Heavy Loads

For precise load handling in maritime applications, Seaqualize in Utrecht, the Netherlands, develops custom-fit solutions. The company is currently working on the Delta600 prototype, an accessory to turn standard heavy-lift cranes into active heave compensated (AHC) machines for use on the world’s oceans. This is the world’s first inline AHC tool for in-air lifting of heavy loads and can compensate heave motions up to 97% using minimal, battery-supplied power. For the development project, Seaqualize is relying on the expertise of Roth Hydraulics in Biedenkopf, the Netherlands. The hydraulic-accumulator specialist developed an ocean-going piston accumulator system for Delta600.

Delta600 is a flexible accessory for any type of loading crane used to move heavy loads in wave action in harbors, on ships, or offshore and that requires lift compensation. The hydraulic unit, with Roth Hydraulics accumulator technology inside, is placed in the crane hook and enables high-precision lifting, moving, and lowering of loads weighing up to 600 tons. In the process, Delta600 compensates for swell and wave motions and controls the load throughout the entire lift. For picking up heavy loads from a heaving ship, the tool’s hydraulics allow gradual build up of the load into the crane wire and automatic lowering at a safe moment. 

The gentle movement controlled by the hydraulic spring prevents heavy loads from breaking away, bouncing, or hitting the ground. The hydraulic unit ensures slow and precise setting-down speeds. The Roth Hydraulics piston accumulator system is around 6 meters (20 feet) tall and has an empty weight of around 20 tons. It consists of several piston accumulators, pressure vessels, and control blocks that have been specially optimized for the application. 

“Particular challenges in the project were the specified installation space and the effect of the dynamic loads on the components of the hydraulic accumulator system,” said Daniel Lauber, design engineer at Roth Hydraulics. 

Piston accumulators
Roth piston accumulators for machinery and equipment are available in sizes from 0.1 to 1,500 liters (0.03 to 396 gallons). Standard units are available with 350 bar (5,076 psi) maximum operating pressure and special versions up to 1,200 bar (17,404 psi), with variable preload pressure. They are used when high withdrawal volumes and withdrawal rates are required. Depending on the application, significant increases in capacity are possible with downstream gas tanks. Even compact, ready-to-connect large-scale systems with a total volume of well over 100 cubic meters (3,531 cubic feet) can be realized by coupling piston accumulators and downstream gas containers in any number. The storage systems are suitable for temperatures from -10 to 80°C (14 to 176°F) and are optionally available for extreme temperatures from -60 to 200°C (-76 to 392°F). 

Roth designs fluid connections and sealing systems of the piston accumulators individually according to customer requirements. Abrupt gas loss to the fluid side is not possible. Friction-minimized sealing systems ensure high efficiency and highly efficient operation. Additional options, such as a built-in stroke limiter or a wide range of measuring and monitoring devices, provide information on the operating status as well as the energy content. The piston accumulators can be installed in any position.

As a full-range supplier, Roth Hydraulics provides a complete technology range with piston, bladder, and diaphragm accumulators as well as accumulator systems for a wide variety of applications. Decades of experience in the development and production of piston accumulators make the company a true specialist. Roth storage systems are designed according to a modular principle. Depending on the requirements, the manufacturer realizes customized and economical solutions.

For more information, visit www.roth-hydraulics.de.