Such locomotives were designed to run in either direction in commuter service. Their frames were extended for a compact vertical tank for fuel and water behind the cab. They had "cowcatchers" under their rear couplers.
Similar locomotives were built with longer frames for bigger tanks. "Bogies" built by William Mason in Taunton, MA (who also built beautiful 4-4-0 No. 25 in the B&O Museum in Baltimore) and Maine 2-foot-gauge locomotives are examples.