OSBM Bolt: Waterston, Oil Refinery   

CUT MARK NBM PLATE WKS TP SW SIDE AVENUE B (56.5663m ODN, 0.3m AGL, 3rd order, verified 1971) - what might "plate" mean??

Location
Grid reference: SM 9365 0552.
Landranger 157: St David's & Haverfordwest.
Landranger 158: Tenby & Pembroke.
Structure: Unknown.
Waypoint: OS2877.

Neighbouring Flush Brackets

G5100	Milford Haven, Pill Road 2.79km to the west.
G5099	Steynton, Hayguardhay Farm 2.98km to the northwest.
S7941	Pembroke Dock, Barracks 3.77km to the southeast.
G4919	West Popton Farm 3.79km to the southwest.
S7942	Pembroke Dock, Council Offices 4.22km to the southeast.

The nearest fundamental bench mark is Haverfordwest (1969), 10.67km to the north.