In April 2019, GB Railfreight announced that sixteen locomotives would be rebuilt as Class 69s by Progress Rail, with the existing Ruston-Paxman engine replaced by an EMD 710 12 cylinder powerplant, with updated electronic controls based on those used in the Class 66 also due to be installed. The prototype locomotive, 69001, is due for delivery in May 2020.
GBRFs engineering director, Bob Tiller, stated that a complete rebuild and re-engine of each locomotive would be cheaper than buying brand new locomotives and shipping them in from abroad. Tiller also highlighted the EMD 710 engines' environmentally friendly emission status as compared to some older locomotives, including the Class 66, which at the time of the announcement were over 20 years old.
The new engine will be an EMD 710A, as fitted to Class 66 locomotives numbers 66752-66779, which is IIIa emission-compliant. The original underframe, bogies, traction motors and brake system will be retained and overhauled. New compressors, blower motors and electronic cubicles will be fitted. The AAR multiple unit system will be used.