Press or Industry Publications
Rexroth Bosch Group
11.06.2003
inBRIef 44
The Huber Motion Table
A motion table is a land-based test platform designed to simulate ship motions. In this case, testing the performance of natural gas processing equipment. This motion table is located not far from Birmingham, Alabama and was built for the Huber Company. Their client is El Paso Energy, who owns the drilling platforms through which natural gas will be drilled far out in the ocean.
To replicate sea state conditions, the table is pitched and rolled around a single swivel point. The motion table is 110 feet long, 14 feet wide and 29 feet off of the ground when level. It weighs approximately 500,000 lbs.
The Bosch Rexroth hydraulic/electronic control system provides the pitch and roll axes motions. The system consists of a 6,000 gallon/1700 horsepower hydraulic power unit, two 720 gallon accumulator stands, several large manifold blocks, Hydraulyne cylinders and pipe swivel assemblies, and a complete electronic control system from operator interface to closed loop position control.
 Bosch Rexroth was involved very early during the conceptual design of the motion table. Engineers from S&E and Technology Marketing worked with the naval architects designing the motion table to assure the table design would allow for the best orientation of hydraulic cylinders and axis control. This early involvement in the design gave the customer confidence that Bosch Rexroth is a very technically capable company that would work with them to reach the best possible design. Like many of the systems S&E sells, this was a one-of-a-kind project. It required a lot of up-front engineering to establish the systems requirements before the details of the design could begin. For final confirmation of the system design, the services of the Lohr simulation group were required. They simulated the integrated motion table and the hydraulic system using the customer's ADAMS model, coupled to Bosch Rexroth's MOHIS simulation software.
Se state is simulated using a sinusoidal motion profile cycling +/- 6.2 degrees every 13.7 degrees for pitch. Roll cycles simultaneously at +/- 6.3 degrees every 12.1 seconds. Six degrees may not sound like a lot. But this huge platform is also pitching up and down 24 feet at speed of up to 47 inches per second while the roll is cycling. That is very impressive
The customer's requirement for this entire system was to run several short tests of the gas processing equipment with the table moving at sea state conditions. The customer's testing was complete after about two and a half hours. The Bosch Rexroth system performed flawlessly. With testing complete, the system is currently being decommissioned. It will be disassembled and put in storage. The current site is rented and the owner requires that it be returned to a green field condition. |
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