From World War II at Sea, by Craig L. Symonds (Oxford U. Press, 2018), Kindle pp. 335-337):
The Allies’ material shortages, especially in shipping, compelled them to improvise. The British had three full-sized aircraft carriers and three smaller ones to cover their assigned targets, but the Americans had only the Ranger. To supplement her, they constructed flight decks atop four oilers and redesignated them as auxiliary carriers. Significantly smaller than regular carriers, and lacking a hangar deck, they could still embark thirty planes each, though all of them had to be carried on the flight deck.
Troop transports were another problem. What few landing ships the British possessed had been lost at Narvik and Dunkirk, and many of the American transports were half a world away, running supplies into Guadalcanal. It was a zero-sum game: ships needed for one undertaking necessarily had to come from someplace else. As the official British history of the campaign puts it, “The transports, store-ships, and auxiliaries of all sorts which had to be taken out of circulation seriously upset the Allied shipping programme throughout the world.” The Allies cobbled together what they could. To carry soldiers to North Africa, they relied heavily on prewar cruise ships; the British even commandeered ferryboats from the Glasgow-Belfast run. Similarly, American civilian cargo vessels metamorphosed into “attack transports.” In effect, the invasion fleets for Torch were jury-rigged (as the Americans put it); in the British idiom, they were “lash-ups.”
Of course, the packed troopships and laden cargo vessels required a substantial escort in order to cross the several thousand miles of hostile ocean to the invasion beaches, and that, too, meant withdrawing forces from other theaters. Britain could escort its contingent only by relying heavily on the Home Fleet, as it had for Pedestal, committing three battleships (Duke of York, Nelson, and Rodney), the battlecruiser Renown, five cruisers, and all five of the Royal Navy’s aircraft carriers plus thirty-one destroyers. To obtain them, the Royal Navy reduced the escorts for the transatlantic convoys and suspended convoys to Russia altogether. The escorts for the American troopships, which would sail directly to North Africa from the East Coast of the United States, included three battleships (Massachusetts, New York, and Texas), seven cruisers, and thirty-eight destroyers. More destroyers would have been desirable, but in the late summer of 1942, destroyers were in demand everywhere, including the Solomon Islands.
Once the troopships and cargo vessels arrived at the target beaches, there was the additional problem of getting the men, their equipment, and their vehicles from the transports to the beach. The Marines who had landed at Guadalcanal had benefited from years of practice landings during the 1930s, and their assault on Guadalcanal had been almost routine; they merely had to climb over the sides of their landing boats and wade ashore. The assault in North Africa, however, would involve soldiers, not Marines, and on a much larger scale. To get them from ship to shore, they would have to climb down rope or chain nets from the transports into small plywood boats that would carry them several miles to the beach.
The vessels needed to accomplish that were also in short supply. The British version of this type of small landing boat was called “landing craft, assault” (LCA), and the American version was called “landing craft, personnel” (LCP). Each was capable of carrying thirty-six soldiers at a time, and their navy crewmen were to shuttle back and forth between ship and shore until the landing force was established. Because the American LCPs had been designed and built by Andrew Jackson Higgins, nearly everyone called them Higgins boats (a practice that will be followed here). Later in the war, both the British and American versions would have armored drop-front bows that would enable the soldiers to run directly from the boat out onto the beach, but the early models were simply rectangular plywood boxes with a motor on the back, and when they ground up onto the sand, the men, each of them carrying between sixty and ninety pounds of gear plus their rifle, had to climb out over the sides into waist-deep water before making their way to the beach, as the Marines had done at Guadalcanal.
Getting armored vehicles ashore was a bigger problem. The campaigns in France and Flanders in 1940 had demonstrated that ground combat in the Second World War meant the use of armored vehicles, specifically tanks. Getting tanks from ship to shore was a far more difficult problem than carrying soldiers. The British had experimented with tank-carrying ships that were converted from shallow-draft oil tankers used on Venezuela’s Lake Maracaibo. Like so many innovations, this one had originated in the fertile mind of the prime minister, and the vessels were dubbed “Winstons” (smaller versions were called “Winettes”). What made them distinctive was their massive bow doors, which opened like a giant cupboard. After running up as close to the beach as they could get, they opened their big bow doors and deployed a long ramp. In theory, tanks and trucks could then drive out from their commodious hold directly onto the beach. The concept was certainly valid, as later models of such ships demonstrated. The early versions, however, were cumbersome and difficult to unload, and they had proved disappointing, and nearly disastrous, during the ill-fated raid on Dieppe.
The Americans attacked the problem differently, appropriating a large cargo ship, the Seatrain New Jersey, that had been designed to carry railroad cars from New York to Cuba, and modifying it to carry tanks. She was not a true amphibious ship, however, since her deep V-shaped hull did not allow her to steam up onto a beach, and she could unload her cargo of tanks only if she had access to a working harbor.
Carriers, battleships, cruisers, troopships, cargo ships, destroyers, and landing craft: altogether, the British and Americans employed nearly six hundred ships, plus the small Higgins boats, to execute this first major strategic counteroffensive of the war. From the start, the commanders had to scramble to find the manpower, the equipment, and especially the shipping to make it happen. The nickname “Operation Shoestring” that had been used to describe the Guadalcanal landing might just as easily have been applied to Torch.