Task: Text Categorization
Input (English): Text:  The Class E851 was a class of four DC electric locomotives operated by the private railway operator Seibu Railway in Japan between 1969 and 1996.Built in 1969 by Mitsubishi to haul 1000-tonne cement trains the design was based on the JNR Class EF65 and used bogies similar to those used on the JNR Class EF81 locomotives.From 30 November 1990 the discontinuation of freight services to Sayamagaoka eliminated the need for double-heading and the end of all Seibu freight services from 7 March 1996 saw the E851s become surplus to requirements. 
Output (English): 6