Freight action on Hatton Bank and 66014 approaches making a fuss with a long rake of vehicle carriers conveying Ford cars and vans. The working is 6M58 1410 Southampton Western Docks to Bescot.
I'm guessing this was the early running 6M28 Hinksey VQ to Bescot Departmental.
It has been put inside the loop to allow another train to pass or to await its booked path. The driver opens up the power handle to keep the train moving on the rising curved gradient.