Caption: About a mile east of London station, GOT 908 APCU leads 3 GO Transit bilevel coaches eastbound on the Dundas Sub, a long way from their usual territory. F40PH VIA 6447 is on the back providing all of the motive power.

Looks to me like a scheduled VIA train operating with borrowed GO Transit equipment, perhaps because of a shortage of operational VIA coaches - maybe the LRC coach fleet was "grounded"? Since GO Transit's coaches use a higher HEP voltage than VIA for HVAC & lighting, a GO Transit APCU, APU, or locomotive has to provide the Head End Power.

My other GO train in London pictures from March and April 1992 mostly consist of an F59ph and three bilevel coaches. APCU's were little used once GO had enough F59ph's. GP40 GOT 720 was trailing unit of a CP freight train through London on 1992/4/17.