The Erie's K-5 and K-5-A classes were the only 4-6-2s built to the USRA standard heavy Pacific design, and were the railroad's premium passenger power until the introduction of diesels. The K-5-A class came from Baldwin Locomotive Works in 1923 with many of the same dimensions as the K-5 class. However, their boiler pressure was slightly higher at 210 p.s.i., yielding a greater tractive force of 46,121 pounds, and their engine weight was 323,000 pounds. Near the end of their service life they were upgraded with a multiple-bearing crosshead and disc drivers. In this view an unnamed lensman captured at Youngstown, Ohio, on May 22, 1941, No. 2939 has pulled away from its train to take on water. The image was taken from a Flickr site taken offline in 2008, and also appears in the Railfan.net ABPR Archive, having been uploaded to that massive collection by Bud Laws. For other dimensions of the K-5-A class consult the commentary on No. 2941 following.