More pointless running on diesel power under the wires. Travelling noticeably slower than other trains that were using the 25kV overhead, 800005 & 800016 pass Uffington on 29 March 2019 with the 1L42 07:30 Carmarthen to Paddington GWR service. The use of diesel power between Swindon and Didcot is presumably in connection with the dead section at Steventon, but the random nature of which trains are running on diesel or electric is a bit of a mystery.