In 1918, the Seaboard Air Line received 16 2-8-8-2 Mallets from ALCO-Richmond to move fast, heavy freights on their main line between Richmond, Virginia and Hamlet, North Carolina. After the wartime traffic had ended, it became clear that the SAL didn't have many uses for them since they were too heavy for many of their secondary lines and didn't fit the clearances in many places.
So all were sold to the B&O in 1920 and only two years later, they were rebuilt to class EL-6a. In this process, they got the wheel arrangement 2-8-8-0 by removing the trailing axle. This considerably increased the adhesive weight and at the same time they were simpled and got a higher boiler pressure, what also increased their starting tractive effort. In this form, they were used until 1954. 