The Aruba Phosphaat Maatschaapij operated two small tank locomotives. The second one was the “Willem III”, built by Porter in the USA in 1883. Construction lists of Porter indicate a gauge of two feet, while some sources tell that the line was built in a gauge of two and a half feet. Like the first one built in Britain some years earlier, it was a 0-4-2T with side tanks. Unlike the British locomotive, it had its dome above the firebox. The drivers only measured 23 inches and the cylinders were seven inches in diameter and twelve inches in stroke. The company was shut down in World War I due to shipping problems and the availability of large amounts of phosphate elsewhere. Both locomotives were stored in a siding until the thirties and then disposed of in a mine pit.