I was just curious about the crew sizes for ships from the 1700's. How many people were required to operate it? I couldn't seem to find a source that told me straight out.
For sailing the ship, the number of crew needed is largely determined by the number of masts and the type of rig. (Also, the details of the rig had some bearing as, generally, later in history, advances in rig efficiency such as divided tops’ls and to’gallants, brace winches, etc., allowed crew efficiency to increase).
Square rig required more crew per mast than fore and aft rig. Chapman reckons that a 4 masted full rigged merchant ship (late in the age of sail) required a crew of 48. (p. xvi) He reports that the 7 masted schooner “Thomas W. Lawson” (5,200 tons gross) operated with a crew of 16 men.
“Chapman, Great Sailing Ships of the World”, https://books.google.no/books?id=QgMRudqoLGQC&pg=PR15&lpg=PR15&dq=size+of+crew+on+sailing+ships&source=bl&ots=9TyCVTDP9f&sig=E-s9V33IaacETh-vr8BoM_9cJno&hl=en&sa=X&ei=5DwJVcrrDsf4OraggeAG&redir_esc=y#v=onepage&q=size%20of%20crew%20on%20sailing%20ships&f=false
I have sailed a 100 foot brigantine (square rigged on the foremast, fore and aft rigged on the main mast) perfectly well with a captain and 4 sailors. (Of course some evolutions, like setting and taking sail would have been faster with a larger crew, and others such as weighing anchor (man-powered windlass on this ship), would have been easier.)
This was day sailing. On a longer voyage, where 24 hour coverage was required, the same ship, on a 2 watch system, would have worked well with an 11 man crew (Captain, mate, 8 seamen, 1 cook).
Warships, of course, needed far larger crews than merchant ships. This was primarily due to the number of men needed to operate the cannon. A training manual for the French revolutionary navy specifies that a 36pdr cannon should have a crew of 15 men, an 18pdr cannon should have a crew of 11 men, and an 8pdr cannon should have a crew of 7 men.
(Note: the cannon could probably be operated by fewer men, but the rate of fire would be slower, and the French navy may have made allowances for some redundancy in order to keep operating when some of the gun crew were killed or wounded.)
Chris Henry, “Napoleonic Naval Armaments 1792-1815”,
Warships only rarely carried enough men to man all their cannon at once (usually only one broadside).
Besides the number of men needed to operate cannon, warships also carried marines, specialist petty officers, larger numbers of able seamen, so that sail handling could be carried out more rapidly, which would be an advantage in combat.
The Queen Anne's Revenge, was a 3 masted, full rigged ship, said to mount 40 guns (though only 31 have been found at the wreck site - she may not have had 40 guns mounted).
(In a letter to the Lords of Admiralty written 12 July, 1718, Captain Ellis Brand of HMS Lyme wrote, "On the 10th of June or thereabouts a large pyrate Ship of forty Guns with three Sloops in her company came upon the coast of North carolina ware they endeavour'd To goe in to a harbour, call'd Topsail Inlet, the Ship Stuck upon the barr att the entrance of the harbour and is lost; as is one of the sloops".)
http://www.qaronline.org/History/Story-of-Blackbeard
The cannon mounted on the Queen Anne's Revenge were a mix of sizes and types.
To sail the ship (using a two watch system) the minimum crew needed might have been about 25 men (this would not have been enough to sail the ship and fight the cannon).
Clipper ships, (also three masted, square rigged ships, like the Queen Anne's Revenge (though 150 years or so later in history)) on the California run, generally carried a crew of 50-60. These ships carried proportionally much more sail area than Blackbeard's. They valued speed much more highly. They knew they would need to sail through the extreme and dangerous conditions round Cape Horn (where a larger crew which could take sails rapidly might contribute greatly to the safety of the ship). So they were willing to invest in a larger crew in order to gain "high efficiency" rather than "fair efficiency". Different ship owners in all eras might value sailing efficiency differently. The more they valued this, the more they would be inclined to ship a larger crew.)
(Rough estimate for number of crew required to provide various "efficiency levels" for a three masted, full rigged, ship on a two watch system: "Fair efficiency" - 25-30 men; "Good efficiency" - 30-40 men; "High efficiency" - 40-60 men.)
So, I think the *Queen Anne's Revenge might well have carried a crew of 30-40 men to sail the ship, plus enough others to man the cannon. If we estimate that she might have carried the crew to man one broadside, that the average cannon were 8 pounders (I know that some of the cannon recovered from the wreck were 6 pounders, but I think she had some larger guns as well), and guess that she was mounting perhaps 34 guns, then she would have wanted to carry 119 men to man the guns.
When the pirates captured the Queen Anne's Revenge (she was being employed as a French slave ship), they reportedly had 150 men (in two sloops). Now we know they had picked up some crew since then (14 from the French crew, for example) and probably lost some here and there. When the Queen Anne's Revenge was wrecked, accompanying her were three smaller pirate sloops (one was also wrecked on the sandbar, and the pirates sailed away in the other two).
If we estimate that a good sized crew for the Queen Anne's Revenge, would have been 30-40 sailors and 119 gunners, for a total of 150-160 men, it might have been possible that Blackbeard had crewed her with that many. I suspect however, that she was undermanned, and the size of his crew was less.