Built for John P.Turnbull of 50 South Kinning Place, Glasgow. There are no records of her in service up until her final voyage in 1890.
On March 23rd she sailed from Glasgow with a cargo of 80 tons of coal for Campbeltown under the command of her master, Captain McCulloch. The voyage via the Kyles of Bute was uneventful in good weather and the crew anticipated an early morning arrival in Campbeltown. However, as she cleared Kildonald Point and Ross Island in darkness, the light north east wind veered steadily to the south west and the sea became progressively rougher. In the early hours of the 24th, when she was within one mile of Davaar Lighthouse she was struck on the port side by a large wave, and capsized and sank within three minutes. Fortunately her crew made it ashore at Ardnacross in "Glenhead's" small boat and arrived safely in Campbeltown by foot at 7am that morning.
As I've recorded above, the contemporary records mention good weather, the wind veering, followed by a rapid capsize and sinking. Could this have been another case of the seemingly not uncommon pufferman's malaise of setting off on a sheltered water voyage in good weather and deciding not to bother battening down the hatch? With their very low freeboards, the steam lighters of this generation were very vulnerable to the conditions which overcame "Glenhead". I do have to stress that I am only speculating here as there is no evidence as to what did cause her very rapid demise.
Link to RCHMS wreck record here