Forty-nine 2-car units were built , numbered E50001-49 for driving motors ( later renumbered 53001-49 ) and E56001-49 for driving trailers ( later renumbered 54001-49 ) .
Forty-nine 2-car units were built , numbered 50001-49 for driving motors ( later renumbered 53001-49 ) and 56001-49 for driving trailers ( later renumbered 54001-49 ) .