Based on the original four-wheel version, this wagon was the modified version (although its previous incarnation latterly carried the fleet numbering W.W.2 erroneously).   It remains in use today and was home to the boiler of No.5 Mona when the asbestos was decontaminated from the boiler in 2020, later being stored at Castletown Station before being moved in early 2023 to Port Erin carriage shed; it has a timber floor and is through-piped for vacuum braking purposes.  Commonly used with a tractor on the flatbed for use with hedge trimming trains each winter.