Moth Caterpillar on Ash

I didn't see the caterpillar until after I had taken the photo.
Also, I haven't had time to google it so don't know what kind it is yet.

I have however found out some more information about yesterday's blip. My image of a 'steam traction engine' was actually a Fowler Crane Engine, No. 8920 "The Great North" - Built in 1901 by John Fowler & Co of Leeds, Registration Number SG 4713.
The drum of steel cable is visible on the front but the crane itself was not fitted for this rally.