Complex sentence: Engineers at Caterpillar's Mining & Construction Equipment Division in Decatur, Illinois designed the 797 using CAD technology, the first time computer-aided design tools had been used extensively to design a Caterpillar truck.
Split into simpler sentences: Engineers at Caterpillar's Mining & Construction Equipment Division in Decatur, Illinois created a new design for the 797 using computer-aided design technology. This was first time CAD tools had been used extensively to design a Caterpillar truck.