William Armstrong appeared to have a temporary shipyard at Benwell Boat House, where he constructed 1 schooner for George Tuck of South Shields. This predates the larger Armstrong works on the river, as a naval yard was established in 1883 at the already functioning hydraulic crane and munitions works. Benwell Boat House is shown on the 1858 Ordnance Survey map, though this is 10 years after the vessel was constructed.

The coordinates cited is the most likely location.