Swatara Township-based Stephenson Equipment Inc., a heavy-equipment dealer that specializes in construction and road service equipment, had its best year ever last year with $82.4 million in revenue. The Dauphin County company added a four-bay crane shop last year and continues to add employees across its six-branch footprint. SEI fields 140 cranes in its rental business. It also operates a national crane operator certification program offered by the National Commission for the Certification of Crane Operators at three of its facilities. That program trains about 650 to 700 crane operators per year, said Dennis Heller, the company’s president and CEO.