I was able to find five HMS Alderney's in the following time frames..... Ketch of 1738,
Frigate of 1742, Sloop of 1755, Submarine of 1945 and Patrol Vessel of 1990 which are all on stamps on Guernsey.
A memorial coin for Dartmouth's Heritage Museum celebration of the 250th year of Dartmouth, N.S. showing the Alderney.(Dartmouth Heritage Museum - Nova Scotia)
Alderney was built at Kingston upon Hull (Yorkshire) England by John Reed in the year 1742. To the drawings or draught H.M.S. Alborough was built at Liverpool and H.M.S. Lowstoft at Deptford. All were ships of the line and carried 22 cannons. The Alderney was a former Naval Vessel and sold to George Heylinger (a London Merchant) after the peace of 1748.
Specifications: Length 112 feet, beam 32 feet x 11 feet (in hold) and had a draft of 10 feet - the lower deck occupied 2,750 square feet and there was 6 feet between decks....she was equipped with the newly invented ventilation system.
Winthrop Bell notes that during the seven years war (1756-63) the Alderney turned up in Nova Scotia waters again serving as a hospital ship to the forces. (Historical Journal of the Campaigns in America Vol. 1. Pg. 23, 65.) But I believe this was the Sloop of 1755.
As shown on http://www.rootsweb.com/~canns/lunenburg/alderney.html "They look to be magnificent ships but looks can deceive, for when it is realized that from the keel to the top deck measured only eleven feet and a lower deck was constructed in between, then it becomes apparent that conditions must have been very cramped indeed for so many people on such a long voyage."
From the scaled plans this statement is misconceiving as the eleven foot measurement was in the hold (bottom) and then there was a six foot high space (probably looks like for cooks mess, and passengers) just below the main deck so the actual measurement from the keel to the main deck was actually seventeen feet - then at the bow and stern there was two enclosed areas measuring 6 feet 6 inches high at the stern and 5 feet high at the bow with decks above each.....
Now with a square footage of 2,750 on the deck for passengers and with 353 passenger on the list this would give each approximately 8 square feet per person - still extremely cramped, so I think that many were also in the top half of the hold area of approx. 2,400 sq. feet. (which scales to 5 ft. 8' high at the lowest point) and thus giving each passenger over 20 sq. ft. of floor area.....and the space at the very bottom of the ship scales from 2' high to 4' clear height (which I believe was probably used for ships supplies).....
