Heavy loads under control

When a large object is moved, stresses are placed on the object due to uneven weight distribution or load-shifts between the lift points. If the mover is not careful, the object can bend or twist creating a stress riser that can cause hundreds of thousands - or in the worst cases - millions of dollars in damage.

However, to counter this, SPX Power Team developed a programmable logic controller (PLC) synchronised lifting and lowering Motion Control System (MCS) to reduce the risk of bending, twisting or tilting. The Motion Control System operates by digitally controlling the movement of an object, keeping it safely level within parameters specified by the user.

SPX Power Team's Motion Control System hardware and software was tested recently by its Norway distributor, SP Tools AS, for Radøygruppen AS, a developer and manufacturer of advanced steel structures and their client an oil and gas structure company.

Radøygruppen AS' client developed a subsea wet gas compressor station comprised of a subsea steel structure frame with two sensitive wet gas compressors inside, weighing a total of 650 tonnes.

Radøygruppen AS needed an accurate synchronised pump to help lift their client's wet gas compressor station and transport it from production to shipping more quickly and accurately. Initial tests revealed that improvements could be made to the Motion Control System to help achieve this," said Stig Pisani,SP Tools AS, CEO/Manager .

"We needed to find a solution for Radøygruppen AS, an experienced engineering services supplier, to measure the centre of gravity. This was very important to help them correctly load the subsea structure on to the supply ship and achieve accurate control when moving the large frame. They also needed to increase the speed for the pump to lift the structure 4 times so it would be high enough to measure the centre of gravity," said Sven-Erik Torstensson, SPX Hydraulic Technologies, Territory Manager.

The Motion Control System software was improved to allow SP Tools AS/Radøygruppen AS to measure the centre of gravity, and the pump was also upgraded to the SPX Power Team PQ120 electric pump to synchronise the lift and increase the flow rate to 120in3/min.

The upgraded Motion Control System software, the synchronised faster flow rate pump and four 280 high-tonnage, low cycle, hydraulic return cylinders (SPX Power Team R2806D) were all used to quickly, safely and accurately transport the two 650 tonne compressors for the subsea wet gas compressor station.

"SP tools chose SPX Power Team's Motion Control System because its technology is very reliable and simple and allows for the customer to safely transport a large 400-650 tonne structure," said Pisani.

After these improvements were made, Radøygruppen AS bought a second unit. The improved features are now included as standard in all SPX Power Team Motion Control System units.

"This is a great example of the power of collaboration to enhance and refine our products and provide solutions tailored to meet our customers' specific needs and the improvements made to the Motion Control System means all our customers benefit," said Torstensson.

The SPX Power Team Motion Control System can be used for lifting or maintaining bridges, moving heavy equipment and buildings, structural testing in civil engineering, lifting, weighing, determining the centre of gravity (for example, of oil platforms), structure raising, levelling and shoring. It is said to allow for synchronised lifting, lowering, pushing, pulling, tilting or positioning heavy loads automatically with great accuracy.