The convict ships were ordinary British merchantmen that might appear at any port throughout the known world. No ship was specifically designed as a convict ship. Sometimes a ship may make several trips as a convict vessel and then be used as a store ship or passenger ship and then may once again be used to carry convicts. Whenever possible contractors of convict ships organised to collect cargo from China or India on the voyage back home.
Vessels chartered for carrying convicts were square rigged, were normally ships or barques and sometimes brigs and normally smaller vessels between 200 and 400 tons. Chartered vessels were hired at the lowest rate per ton provided that they were seaworthy. The number of convicts to be carried was normally based on an allowance of two tons for each convict. If there was surplus tonnage civilian or military personnel could also be carried as well as additional provisions and stores for the colony.
Ship owners usually only tendered their smaller vessels as it was more profitable to use the larger vessels for other purposes and on shorter routes. The voyage to Australia involved navigational challenges, many months at sea going to and returning from Australia and it could not always be guaranteed that there would be a return cargo to make the voyage worth while.
The chartering of convict ships was always by tender. Shipowners determined the hiring rates and they varied with each trip. No vessel was accepted until it had passed an inspection by naval authorities.
The best ships were the East Indiamen which were strong ships and the largest class of merchantmen. Only the finest materials were used in building them. The West Indiamen was a smaller version of the East Indiamen with a slightly different deck design. These ships tended to be well cared for unlike many other ships that could have rotten timbers and rigging and were unseaworthy. The crew of the East Indiamen were as strictly disciplined and well turned out as the crews of the Royal Navy. The crew on other ships was often made up 'from the very dregs of society' (p86) often recruited from waterside taverns, often illiterate, heavy drinkers and unskilled in navigation and seamanship. Musters of crews often showed that ships arrived minus crew members who had abandoned the ship at a port.
The majority of convict ships had three officers as well as the master and some had a fourth mate. The carpenter was an important crew member and sometimes he had an assistant. Some ships had a boatswain and some had a sail maker. Most ships had a cook to prepare food for the officers and crew.
Naval authorities thoroughly examined ships to ensure that seaworthy ships carried convicts. Although some of the convict ships were suspect they all safely made the voyage to Australia.
- Bateson, Charles: The convict ships 1797-1868. Sydney, Library of Australian history, 2004 (originally published 1950)