Class L1s on the Pennsylvania Railroad comprised 574 2-8-2 "Mikado" type steam locomotives constructed between 1914 and 1919 by the railroad's own Juniata Shops (344 examples) as well as the Baldwin Locomotive Works (205) and the Lima Locomotive Works (25).It was the largest class of 2-8-2 locomotives anywhere, although other railroads had more Mikados in total.The L1s shared the boiler and many other components with the K4s 4-6-2 "Pacific" type, giving a total of 999 locomotives with many standard parts.Although the L1s type was quite successful, it was very much eclipsed in PRR service by the larger and more powerful I1s/I1sa 2-10-0 "Decapods", which arrived in service only two years after the L1s and were very suited to the PRR's mountain grades and heavy coal and mineral trains, and by the 1923 introduction of the M1 4-8-2 "Mountains" which took on the best high-speed freight runs.