In 1922, in order to meet the urgent need for additional passenger power, the Burlington received eight locomotives of the 4-8-2 wheel arrangement from the Lima Locomotive Works. The engines were numbered 7000 - 7007 and classed as B-1. They were designed to handle the heaviest trains on the line without doubleheading. To meet this requirement, the B-1 engines were equipped with automatic stokers of the Duplex type. Their total engine weight of 350,000 lb., with 235,500lb. of this carried on the drivers, gave them a tractive force of 52,750 lb. The Lima-built Mountain types were designed to burn lignite ( some were later altered to burn bituminous coal ). Although the engines were delivered without feedwater heaters, they were later equipped with Worthington type systems. The weight of the firebox, which was of the radially stayed design, was supported by a Rushton type trailing truck. Four-wheel trucks of the pedestal design were used on the tenders.