The Problem:

Bucyrus International is one of the world’s leading manufacturers of large-scale excavation equipment used in surface mining. Bucyrus machines are used throughout the world to mine copper, coal, oil sands, iron ore and other minerals. An important part of the company’s business also consists of aftermarket sales in support of its large installed base of machines. The company has produced some of the largest surface mining machines ever manufactured and introduced the first commercially accepted electric rotary blasthole drill in 1952, a product that changed the face of mining forever.

With demand for coal mining equipment on the rise, particularly in China, Bucyrus recently found itself facing a serious capacity issue in its main manufacturing plant in South Milwaukee, Wisconsin. In order to keep up with customer demand, the company launched a three-phase $130 million expansion that included remodeling and re-equipping a new fabrication shop.

A key area of improvement focused on the company’s flame cutting capabilities. Cutting productivity sets the stage for increased productivity down the line. The production of massive mining machines requires the ability to cut and bevel very large parts from plate ranging from half-inch to 12.5 inches thick. Since their products are so highly customized for the capacity of the mines they serve, Bucyrus also rarely cuts more than a few parts that are alike and has no high production runs. They needed a cutting machine that was operator friendly and easy to program that could also increase their overall productivity.

The Solution:

After first purchasing machines from another company that did not work out as well as they hoped, Bucyrus chose new machines from ESAB Cutting Systems. They had an older ESAB machine that they were still using after 17 years. Since their experience with ESAB equipment and service had been very good, they decided to see what new technology ESAB had to offer in oxy-fuel cutting.

They purchased two Avenger X cutting gantries, each equipped with three Flame Control torches, and one Avenger 2 gantry equipped with three Flame Control torches and two Programmable Contour Edge Prep stations.

The fully automated Flame Control system uses flame monitoring technology and electronic proportional valve gas controls to make oxy-fuel cutting easy to set up and use. The Electronic Proportional Valve Gas Control System automatically adjusts the fuel gas low preheat pressure, oxygen low preheat pressure, fuel gas high preheat pressure, oxygen high preheat pressure, cutting oxygen start pressure, cutting oxygen ramp time and cutting oxygen maximum pressure. This makes oxy-fuel gas set up as simple as selecting the material thickness. ESAB’s Vision 55 CNC control uses ESAB’s Programmable Cutting Parameters to fully automate the process set up. The fully integrated process control system automatically sets the cutting speed, kerf offset, preheat time, pierce delay, creep speed, high preheat delay and travel delay. An optional automatic height control system automates the preheat height, pierce height and cutting height.

The Flame Control senses the heat of the flame and sets the temperature consistently. The company found that they could cut with all three torches at the same settings with no need for the operators to intervene, saving approximately 20 percent in production time. The Flame Control torches also use high speed tips so the machine can cut faster, while the sensing technology minimizes problems with flame outs, all contributing to an overall reduction in production time.

The Flame Control torches feature a breakaway torch design. If the torch bumps anything, the machine is shut off. It then resets and is ready to work again. This has significantly reduced maintenance at Bucyrus. With their previous machine, the mounting brackets were frequently damaged in “crashes” and needed to be reset and tested or repaired. These repairs generally resulted in two weeks to a month of downtime. Bucyrus was averaging a month of downtime every other month. This has now been largely eliminated.

The Avenger X gantry is designed with precision linear ways and a high-stiffness beam structure that make the machine ideal for precision cutting, marking and beveling. The fabricated beam is made from two steel tubes with welded stiffener plates to form an extremely stiff welded structure. Avenger X offers positioning accuracy of ±0.015 in. over a 6 ft. x 6 ft. area with a repeatability of ±0.005 in.

Bucyrus uses a great deal of bevel cutting to prep pieces for welding. They needed their need machine to be consistent and reliable in its beveling than their older machines. The programmable beveling stations provided by ESAB consist of three oxy-fuel torches that rotate automatically to cut bevels on carbon steel up to four inches thick. Various geometries can be cut, including X, V, Y and K bevels. A tactile automatic height control maintains the extremely accurate torch height critical to maintain the desired bevel geometry and part accuracy.

Bucyrus bevels parts up to 3 inches thick in various grades of carbon steel. They purchased the Avenger 2 gantry with a 40 ft long x 25 ft. wide cutting capacity so they can turn the plate sideways and cut two parts at the same time. Most of these cut parts go into sections or subassemblies that will be shipped to the mine for final assembly. Some parts can be 12-ft. in diameter. Their largest cut part weighs 20 tons. The contour bevel stations really save time on the large parts.

Another function on the ESAB contour bevel stations is the height control. The dual sensor system freezes the height if it senses that the torch has gone off the plate. Rather than dropping lower as most systems do, the ESAB system maintains the correct torch standoff above the plate surface, which is critically important for accurate bevel cutting.

Bucyrus has seen production demand triple in recent years. To reach these types of production goals, a company has to look for the best technology to do the job. In Bucyrus’s case, ESAB’s advances in automated cutting and beveling technology provide the speed, simplicity and reliability to help this company reach its aggressive goals.