British Difficulties in Sustaining a Blockade
The concept of a naval blockade of an adversary is not new. We – the Thirteen Colonies experienced it firsthand during the American Revolution and then again during the War of 1812.
Blockades are simple in concept, i.e., station your warships outside an enemy harbor and prevent warships and merchant vessels from entering or leaving. The goal is to starve the enemy into submission, change their behavior or destroying their will to fight.
Achieving these goals through a blockade is not as easy as it sounds. Geography and the tyranny of distance play a major role. The number of ports a navy has to watch dictates the number of ships needed.
For each ship stationed off a port, the blockading needs three ships. One on station watching the port, one either in transit or undergoing pre-deployment training and the third undergoing a refit.
This does not include the squadrons that support the ships outside the port to deal with any enemy ships that sally forth. Again, the multiple of three applies.
When planning a blockade, admirals must consider either the choke points that have to be watched and/or the number of ports. From there, they can begin to estimate the number and types of warships along with the logistic support needed.
One of the reasons why the Royal Navy had as many frigates as it did was that they were ideal for watching French and Spanish ports. If a merchant ship ventured out, they could take it as a prize, or if squadron departed, they could sail back to a larger force and lead them back to the enemy.
Distance plays a huge role in planning and sustaining a blockade. During the 17th, 18th and 19th centuries, the primary French naval bases were at Brest, Lorient, Nantes and Rochefort on the Atlantic and Toulon in the Mediterranean.
For the Royal Navy, the proximity of these ports to England simplified the logistics issues because even if the frigate was off Rochefort, it was less than 10 days sailing time from Portsmouth. Ships off Toulon could easily rotate back to Gibraltar.
However, during the American Revolution and the War of 1812, the Royal Navy was faced with a much more difficult problem. One, the seaboard of the Thirteen Colonies is 960 nautical miles.
Second, even though the Royal Navy had bases in Halifax, Jamaica and Bermuda, their main supply hub was England, well over 3,100 nautical miles and six to eight weeks of sailing away. Third, the number of ports that the Royal Navy had to watch was far greater than anything it had dealt with in the past.
On both coasts and the Gulf of Mexico, the U.S. is blessed with many deep-water ports. Suddenly, to enforce a blockade during the American Revolution, the Royal Navy had to watch Boston, Providence, New Haven, New York, Delaware Bay (Philadelphia), Chesapeake Bay (Baltimore and Hampton), Wilmington, Charleston and Savannah, just to name a few.
Realizing that the Royal Navy could not sustain a blockade of all the ports on the Eastern Seaboard, part of the British strategy was to seize the major ports – New York, Charleston, Savannah, Wilmington and Newport – in an effort to disrupt U.S. commerce and bottle up the Continental Navy and privateers. History tells us that it was partially effective.
However, between the Continental Navy and privateers, U.S. captains captured between 12 and 15% of His Majesty King Gorge III’s merchant fleet. Their actions forced the Royal Navy to begin convoying ships from the Caribbean headed back to England and those coming to North America to supply the British Army.
The assets used for convoys could not be used to sustain the blockade. In the end, the Royal Navy gave up on a blockade because the level of effort was greater that what it could sustain. By the end of the war, the Royal Navy’s focus was on keeping the British Army supplied, something that it ultimately failed to do when Cornwallis was left trapped at Yorktown in the fall of 1781.
J.B. Elliot’s 2012 painting of Gen. Winfield Scott’s blockade plan to starve the Confederacy.