By: Robert Brown12th Aug 2022 12:37PMThis comment is an observation only and may assist others in finding further information; this is a winching unit, which is what the stationary engine unit is and confirmed by the fairlead on the left end. The “bogies” may be the frames of mine skips which is why the main frame sits on timbers; probably there are no conventional bogie pivots. Note that there appears to be a bar of some sort connecting the “bogies” and a thin rod (towbar?) at left end of left “bogie”. The use of mine skip frames would explain the large frame overhang past the wheelsets. The wheelsets may be close together to allow the skips to manoeuvre around tight bends, possibly underground. There does not appear to be any anchor attachment, ie whatever it is winching requires less force than the handbrakes on both “bogies” and the mass of the entire unit can exert in braking. The handbrakes would be awkward to reapply frequently as the main frame overhangs the “bogies” by more than may be apparent, judging by the angle of shadows compared to the roof on the boiler. Gauge is unclear, and is probably smaller than standard as it seems unlikely that such a small boiler would occupy such a large part of the loading gauge.