In 1915, steel producer Worth Brothers of Coatesville, Pennsylvania ordered switchers from Baldwin. These had to fit tight clearances, with a height limit of 7 feet and 9 inches (2,362 mm) and a width limit of 6 feet and 8 inches (2,032 mm). To achieve this, they had small drivers of only 33 inches and a cab mounted low behind the firebox. To fit the largest possible water tanks, these were of rectangular section and filled the loading gauge to the maximum. In the result, water capacity was 800 gallons and coal capacity was 700 pounds. They had outside cylinders and outside Stephenson link motion.

With cylinders of 14 by 16 inches, they produced a starting tractive effort of roughly 13,300 pounds. The first three were delivered in January of 1916 with the works numbers 42777 to 42779. The next two followed in November of the same year with the numbers 44452 and 44453. A final batch of two was delivered in April of 1917 with the numbers 45532 and 45533. Now they made up a total of seven, which were numbered 8 to 14 by their operator.