 The U.S. Army issued extended end connectors ("duckbills") to add width to the standard tracks as a stopgap solution.Duckbills began to reach front-line tank battalions in fall 1944, but were original factory equipment for the heavy M4A3E2 Jumbo to compensate for the extra weight of armor.The M4A3(76)W HVSS Shermans and other late models with wider-tracked suspensions corrected these problems, but formed only a small proportion of the tanks in service even in 1945.