Good automation runs deep

Bauer Maschinen GmbH has automated a unique research drill rig for exploring the seabed. It was made possible by B&R automation components that function reliably, even 2,500 meters below the surface of the ocean.

Descending through the darkness, four plate-footed legs extend in preparation for contact with the landscape below and ensure the ten-ton apparatus comes to rest in a solid stance. A robotic drill extends to probe the layers of sediment and rock below.

What sounds like a landing on a distant planet is actually mission much closer to home, though the terrain is almost equally unexplored. It is a research drill rig taking samples from the ocean floor at depths of nearly 3,000 meters.

The rig is called MeBo 200, and it is the result of a joint development project by MARUM – the Center for Marine Environmental Sciences at the University of Bremen – and Bauer Maschinen GmbH. MeBo 200 is capable of working at depths of up to 2,500 meters, where it can drill 200 meters into the seabed. The core samples it obtains provide valuable insight into the sediment structure and geology of the seabed.

MeBo 200 is mounted in a frame that fits nicely into a 20-foot container and is carried by a research vessel to the location that is to be studied. When it arrives, the exploratory drill rig is lowered to the seabed by 2,700 meters of steel-armored cable. The cable is MeBo 200's lifeline to the ship, supplying it with both power and control commands.

The first two MeBo generations were used successfully in research projects for many years. For commercial use around the world, Bauer wanted to make further improvements and equip it with the following elements:

• State-of-the-art control technology
• An extended communication network
• Interfaces for external automation components
• An updated diagnostics and maintenance system

As its partner for upgrading the automation architecture, Bauer relied on B&R. "We've been working successfully with B&R for a very long time, and have been using their technology in our deep drilling rigs for decades," says Bauer's Lothar Schirmel.

In order to reliably collect data from the seabed and send it to the ship, kilometers above, MeBo 200 requires extremely resilient technology. "At 2,500 meters below sea level, conditions are extreme," says Schirmel, "so all the components used must be robust and reliable. That's why we chose B&R's X90 mobile control system, which easily withstands these extreme conditions."

The X90 controllers are easy to adapt to different requirements using option modules. For the MeBo 200, they were configured as intelligent POWERLINK bus controllers with numerous integrated I/O connections. The POWERLINK protocol is transmitted on single-mode fiber cable via wave-division multiplexing media converters and converted back when it reaches the ship.

"Operating a reliably functioning real-time network under these extreme conditions is a major challenge," says Schirmel. But together with B&R it was one Bauer was able to solve. "They provided expert guidance in the selection of converters, and they knew just how to tweak the network settings to get the initial communication interruptions under control. That's exactly what you want from an automation partner."

All the data comes together in the B&R APROL process control system, which runs on two redundant Automation PC 910 units. Three more industrial PCs from the Automation PC 3100 series are used as remote HMI servers.

"We've been using APROL as a powerful HMI, data acquisition and data management solution in our oil and gas deep drilling rigs since 2005," Schirmel explains. "A key element is the high-performance data storage and long-term archiving that APROL offers. That includes the Trend Viewer, which lets us visualize the recorded data and analyze error causes."

Author: Franz Rossmann, technology journalist from near Munich