Remote-controlled locomotives make work safer at SSAB

Locomote - SSAB - ctl00_cph1_image

When it comes to successfully managing its continuous operations, railroad and remote control are two key factors for SSAB Tunnplåt AB in Luleå, Sweden. Hundreds of tons of 1500-degree molten steel are transported by rail from the company’s blast furnace to its steel works for further processing. Enormous forces put stringent demands on control and precision of train transports. Åkerströms’ remote control for locomotives accounts for a large part of transport safety.

SSAB Tunnplåt AB is a subsidiary in the SSAB Group and the Nordic region’s largest steel sheet manufacturer. Using its coke oven, blast furnace, and steel works with continuous casting, the Luleå operation takes care of SSAB Tunnplåt’s metallurgical production. Iron pellets from LKAB, a mining company in northern Sweden, are transported to Luleå and transformed into about 200 different types of steel, all with different characteristics, depending on usage needs. SSAB Tunnplåt’s Luleå operation annually delivers about 2-3 million tons of steel slabs to SSAB Tunnplåt in Borlänge for further processing.

Remote control of locomotives enables total control of 300 tons of molten steel in 2000, SSAB invested in a state-of-the-art blast furnace for the Luleå operation. The company wanted even and high production of the greatest quality. It also wanted to improve management of locomotives that transported the molten steel from the blast furnace to the steel works. The Luleå operation has nearly 15 kilometers of railroad on which molten steel and slag are transported.

Locomotives pull torpedo cars—tanks for molten steel that are shaped like torpedoes and lined with 120 tons of refractory bricks to handle the heat. Torpedo cars are filled with 1500-degree molten steel from the blast furnace, which is transported to the Luleå operation’s steel works. A fully loaded torpedo car weighs about 600 tons. Up to the year 2000, locomotives were manually controlled and switched, and this required two persons per locomotive. They also needed to be able to communicate via radio (without misunderstanding) when the locomotive driver controlled the locomotive and the switcher was on the track switching. So after a recommendation from the SSAB operation in Oxelösund, which was already using Åkerströms’ remote control for locomotives, the Luleå operation also went over to remote control.

“We’re incredibly dependent on the railroad, and we want to work in the best way possible,” says Roland Skoog, manager of track-bound transports at SSAB Tunnplåt in Luleå. “That’s why we copied what worked for the Oxelösund operation and added things specific for our needs. Now, thanks to remote control, one person can control and switch the locomotive. The process is more effective and most important of all, much safer. The driver makes the decision and has total control over how the locomotive will be driven and when it will start and brake.”

Using Åkerströms’ transmitter, which is positioned on the front of the operator’s body in a carrying device, the locomotive can be controlled from the ground or from the locomotive. The automatic train control (ATC) unit receives signals from the transmitter. The ATC unit is mounted in each remote-controlled freight locomotive. ATC units are also found in passenger train locomotives. The Swedish Railway Inspectorate totally regulates railroad traffic within SSAB’s facilities, which must comply with the same rules that apply to all other rail traffic in Sweden.

Remote-control switching prevents back and knee injuries
Remote control of locomotives wasn’t the only improvement that SSAB Tunnplåt implemented. Locomotive drivers can also remotely control the switches—thanks to the locomotives’ programmable logic controllers (PLCs) and Trux, Åkerströms’ rugged PCs, which are positioned in the locomotives’ cabs. Via the same transmitter that remotely controls the locomotive, the driver enters a start point and an end point for the route that the locomotive follows as it pulls the torpedo car to the blast furnace to be loaded with molten steel. The PC screen displays the route. The driver can also enter the route and switches directly from the PC’s touch screen. Switching then occurs automatically regardless of whether commands were entered via the transmitter or the touch screen.

“Now, one person can handle the locomotive, enter routes, and drive—without assistance,” says Skoog. “This is a lot safer because the driver has an overview of the traffic at all times and can see what’s happening. Climbing up and down from the locomotive to do strenuous switching is no longer necessary. This prevents damage to drivers’ backs, knees, and elbows. Everyone is very pleased. No one wants to return to the old system. Simply put, it works well.”

Production every hour, year round
After the molten steel is processed into the ordered steel slabs (25-ton pieces), they must cool before being loaded on freight cars for further transport to SSAB Tunnplåt’s rolling mill in Borlänge, Sweden. Four times a day, the slabs are sent via rail to Borlänge. Green Cargo handles the transport.

Today, the Luleå operation has six locomotives, of which three are remote controlled. About 1400 persons work at the steel works; 19 drive locomotives. Since 2001, the SSAB Luleå operation runs 24 hours a day—year round—and has five shifts.

SSAB Tunnplåt employs 4300 persons in foreign subsidiaries and in Sweden at its Borlänge, Luleå, Finspång, and Ronneby sites. The Borlänge operation houses SSAB’s steel sheet production facility; its products consist of hot- and cold-rolled sheet, metal-coated sheet, and painted sheet. The steel is used for many things around us: cars, appliances, ventilation systems, ships, and so on.