Horsham 10th of January 1972.
4BEP 7004 and Class 73 E6027.
On a dull but clear day, the 12.24 Class 8 engineer's material train from Three Bridges to Chichester, consisting of 12 bogie wagons, one four wheeled wagon and two brakevans, and hauled by two electro-diesel locomotives working in multiple, ran past the Horsham Down Branch Line Home signal at Danger and collided at about 20 m.p.h. with the rear of the 12.02 Victoria to Portsmouth Harbour and Bognor Regis electric multiple-unit passenger train, consisting of 8 coaches, which was standing in the Down Line Platform. The passenger train was pushed forward some 200 feet by the impact and the rear coach was forced up underneath the station footbridge by the leading locomotive of the engineer's train. Both the rear coach and the leading locomotive were derailed and extensively damaged.

The emergency services were promptly alerted and 14 passengers and the guard of the passenger train, who were slightly injured or suffering from shock, were quickly conveyed by ambulance to Crawley Hospital. One of the passengers was detained overnight, but the remaining 14 people were discharged after treatment. The driver and secondman of the engineer's train, who took shelter in the electrical compartment, escaped injury although they were later treated for shock."
Full details from the Railway Archive:-
http://www.railwaysarchive.co.uk/docsummary.php?docID=1121

E6027 was the first class 73 to be withdrawn on 16/7/72 as repairs were deemed not economic.