Built Adrossan 1847 by John Barr and James Shearer; three masts, two decks and a poop deck, fixed bowsprit, woman figurehead, carvel-built, square stern; 127.4 x 26.9 x 20 feet; 619 gross tons. Registered to Greenock, owned by Thomas Hamlin & Company, the senior partner being John Hercus who had earlier married Isabella Gowan of Whitehaven and appears to have named the ship in her honour.
Between 1847 and 1849, the Isabella Hercus sailed under Captain Peter Houston between the Clyde and Calcutta, then in August 1850, she sailed for the West India Docks, London, where a month later her agents Filby & Company chartered her to the Canterbury Association. There had been ownership changes too. In August 1850, John Hercus sold his 16/64 share to North Shields merchant Robert Pow. In September 1850, peter Houston sold his 8/64 share to her Ardrossan builders Barr and Shearer. Her new owners now held between them 32/64ths with minor shareholding from George Dalgleish, James Prentice, Mrs William Burns and Mrs Hugh Hercus.
The Isabella Hercus tender document notes further dimensions: height between decks 6.6 feet, length of lower deck 131 feet. She was to be purified every fourth week with a solution of chloride of zinc.