The PRR M1 4-8-2 when first produced had a tender similar to the one used on K4 steamers, a 110-P-75. This tender carried 11,980 gallons of water and 18.5 tones of coal.
Apparently this proved too small for the big 4-8-2, and bigger tenders soon replaced the smaller K4 style tender. There were at least three types used, but the one seen most often was the 210-F-75, a 22,090 gallons of water/31.5 tons of coal behemoth with dog house. The original 210-F-75 had 6-wheel truck. In later years the tender received 8-wheel trucks and renamed 210-F-75B.
