I had spotted the 0Z99 working on OpenTrainTimes making its way down the slow on the WCML not knowing quite what it was until a fellow photographer informed me that it was a Class 57 Thunderbird move. However, when it reached Hanslope Junction it was held on a red and looked as if it was going to be put on the fast line thus making a photograph impossible as we were at Milton Malsor on the Northampton loop. Consequently, I set off back to the van to get on with my day. I just so happened to check my phone as I was nearly back and saw that it had reverted back to the slow and that it was just one signal away from where I was! I stopped in the middle of the field that I was crossing, set the camera up, and there it was. The photograph was probably a better one than would have been taken where I was a little earlier as it was a light engine. If anybody has any information as to what this working was please could you get in contact with me. In another guise back in 1980 I photographed this Class 57 as 47225, see.....
https://www.ontheupfast.com/p/21936chg/29477846804/x47225-23-40-glasgow-plymouth-1v57