When Andy and I surveyed this line two years ago, see....
https://www.ontheupfast.com/p/21936chg/C328046004/x1-journey-there-via-ecml-hull-to for some unknown reason we missed this box. I persuaded my travelling companion to turn off the A64 and take the lanes in order to reach this very isolated box. Whilst it operates some semaphores it is not a block box merely operating some manual gates. The box was opened by the North Eastern Railway circa 1873 and is of its type S1b design.