Though there may have been activity beforehand, this was likely the site of the short-lived J. Knox shipyard at South Hylton. It was a short-lived enterprise first majority-owned by John Knox in 1883 with John Green a senior partner, but converted to a limited company a year later. John built only one vessel, the schooner Margarita, before inviting investors. It was registered on 4 April with a capital of £10,000 in £10 shares with the following as first subscribers: J. Thompson, jun. (timber merchant), R. Richards (iron merchant), J. D. Skinner (ship surveyor), W. Andrew (shipowner), John Knox, E. Thompson (timber merchant), W. Kerr (contractor). It’s clear that, including the famous Thompsons, the venture was meant to be a long-lasting profit boon with the whole supply chain involved.

There is little known about Knox. He was a Scot born in 1842 and worked under Robert Thompson at Southwick. He clearly gained a high regard, enough to set up his own firm by 1883 with his first vessel completed the year after.

They were well regarded and well built for international contracts, and used engines from Doxford’s down the road. The Kingfisher was designed for Ireland’s deep-sea fisheries with other vessels bound for the River Paraná for the Argentinian cargo trade, the Mediterranean trade for an Italian company, as well as service on the River Plate. It’s certain they gained a solid reputation on the South American coast, as this is where the majority of their orders resided.

It should be said this is the most likely of the two potential yards, the other being the ferry yard, which I personally believe would have been far too cramped. This site was not used for building by the 1890s, but there is still a trace of ancillary buildings and a waterfront quay by the 1890s alongside a crane. Most yards had moved eastwards by this stage, so it makes for a reasonably strong assumption.
This company was folded during the depression of 1886, with the final machinery sale in 1887. John went on to be manager of the Priestman yard through to 1909, then had a small shipbreaking yard back at Hylton.