The Lionel Lines Berkshire Type 2-8-4-Locomotive No. 726RR was available only in 1952. This locomotive is virtually identical to the A Variation of the No. 736 that was available in 1950 and 1951. The difference is that due to the shortage of magnetic material during the Korean War that resulted in this engine not having Magnatraction. The BLACK painted die-cast metal boiler is found with both three and four pane cab windows. Equipped with a three position directional unit, smoke, lighted headlight behind a hinge re-enforced boiler front, ornamental bell and whistle, and a complete set drive rods, this locomotive came with a No. 2046W Tender that has bar-end trucks with one magnetic coupler. There are two variations:

Variation A: SILVER rubber-stamped cab number "726" only in larger printing.

Variation B: SILVER rubber-stamped cab number "726 / RR" in smaller printing.

All of the Berkshires that Lionel produced were designed to run on O Gauge tubular track of the post war period and will not operate properly on the tighter curves of O27 Gauge track.