Angled flight decks on aircraft carriers enable modern aircraft carriers to simultaneously conduct takeoffs and landings by aircraft. Previously, in the 1910s till about 1945, aircraft carrier flight decks were “axial” flight decks with no special angled area with which to manage aircraft. In this case “go-arounds” were much more difficult and in the event of a landing accident, the aircraft was caught by a barricade stretched across the width of the flight deck. Flight operations consisted on either takeoffs/launches OR landings. After landing, the aircraft would taxi forward out of the landing area, to clear it for the next aircraft. Parking the aircraft was typically done in the forward portion of the flight deck.

Naval Historians credit the Royal Navy, and specifically Rear Admiral Dennis Cambell with the invention of the angled flight deck:

The angled flight deck was invented by Royal Navy Captain (later Rear Admiral) Dennis Cambell, as an outgrowth of design study initially begun in the winter of 1944-1945 when a committee of senior Royal Navy officers decided that the future of naval aviation was in jets, whose higher speeds required that the carriers be modified to “fit” the needs of jets.^[13][14][15] With this type of deck — also called a “skewed deck”, “canted deck”, “waste angle deck”, or the “angle” — the aft part of the deck is widened and a separate runway is positioned at an angle from the centreline.^[16] The angled flight deck was designed with the higher landing speeds of jet aircraft in mind, which would have required the entire length of a centreline flight deck to stop.^[16] The design also allowed for concurrent launch and recovery operations, and allowed aircraft failing to connect with thearrestor cables to abort the landing, accelerate, and relaunch (or “bolter“) without risk to other parked or launching aircraft.

The angled desk indeed allowed for the simultaneous launch and recovery of aircraft. The first aircraft carrier with the angled flight deck was the HMS Triumph (R16) which was tested in 1952:

In 1952, HMS Triumph was used for the first trials of an angled flight deck. Her original deck markings were obliterated and replaced with new ones at an angle to the long axis of the ship. The success of these trials led to the development of the now standard design, with additional areas of the flight deck added to the port side of the ship

The US Navy tested the markings for an angled flight deck on the USS Midway (CV-41) in 1952. “However the orientation of the arresting gear and barriers remained oriented to the axial flightdeck.”

The USS Antietam (CV-3) had the first “true” angled flight deck, as structural changes to the ship were made to accommodate that feature.

However upon reading Dr. John T Kuehn’s Agents of Innovation: The General Board and the Design of the Fleet That Defeated the Japanese Navy, it seems that the angled flight deck is a United States Navy invention, not as always thought, a British invention.

Before I get to that a bit about the General Board and flying deck cruisers. The General Board was established in 1900 to play a critical role in linking the Washington Naval Treaty and innovation in the fleet. “Particularly astonishing, given the hierarchical nature of the U.S. Navy, was the General Board’s tolerant and consensus-driven process which led to an environment highly favorable to creativity and innovation.”

The flying deck cruiser was an attempt by the General Board to use remaing Washington Treaty warship tonnage allocation to meet the perceived aviation needs for the Navy war plan in the Pacific, unknown as War Plan Orange.

During one particularly interesting meeting of the Board in December 1930 a design for a ship called the “flying deck cruiser” was undergoing review by the general board which lead to a very interesting discussion:

The refined design included one feature in particular that had received little discussion during the hearings but was an outgrowth of them. During the December 1930 hearings, the Board had questioned the BuAer (Bureau of Aeronautics, the part of the Navy responsible for Naval Aviation) officers at length regarding launching and recovering aircraft on the shortened deck of some of the designs. The aviators had brought up the technique of taking off at an angle in order in order to avoid the island, or perhaps a forward superstructure, as well as to get a longer deck run. Evidently, the BuC&R officers has paid close attention because they included and angled flightdeck in the design. It was offset to the port (left) side of the ship in order to give the aviators more usable deck space for spotting (parking) and flight operations (Kuehn, p.118).

If the US Navy had built this ship they would have learned the same lessons we now know about angled flight decks about a generation before the angled deck carrier.

Here’s a line drawing of what she may have looked like:

The 1920s and 1930s represent a period of unparalleled and rapid technical innovation in the US Navy and the angled flight deck is only one example (even if the CF was never built).
There were quite a few Naval innovations that took place as a result of the Washington Naval Treaty, the Fleet Problem exercises and War Plan Orange and I’ll be posting more about those in the future.

Sources (you can buy all these books by using the Amazon Store link to the right):

Wings of the Navy: Testing British and US Carrier Aircraft by Captain Eric “Winkle” Brown

US Aircraft Carriers: An Illustrated Design HIstory by Norman Polmar

Agents of Innovation: The General Board and the Design of the Fleet That Defeated the Japanese Navy (make sure that you buy this book (through the Amazon link right). It’s an excellent and interesting read).