<page_title> British Rail Class 317 </page_title> <section_title> Fleet details </section_title> <table> <cell> Class 317/7 <col_header> Class </col_header> </cell> <cell> 317722 (Demonstrator unit) <col_header> Cars per Set </col_header> </cell> </table>
British Rail Class 317's class 317/7 Demonstrator unit is number 317722.