Foreign Relations of the United States, Conferences at Washington and Quebec, 1943

J.C.S. Files

Memorandum by the British Chiefs of Staff¹

most secret
Enclosure to C.C.S. 315

[Quebec,] 18 August 1943.

“ Habbakuks”

1. We are impressed with the possibilities of constructing “floating airfields” as a type of aircraft carrier, and we are of the opinion that, research and design have now reached a stage when we should proceed with the production of certain types. A Technical Note is given in Annex I.²

2. Three types of vessel have been designed on paper by naval architects:

Habbakuk I

3. A vessel made of wood was designed in the hope that it could be ready in 1944 and would not use much strategic material. This, we have learned is not the case, as there is a shortage of timber. Consequently in view of the limited requirement for this type, it has been decided not to proceed with it.

Habbakuk II

4. This vessel could be made of steel but would require about 150,000 tons per vessel as well as a great deal of shipyard space and skilled labor. Alternatively, it could be made of pykrete (frozen pulp and water), but the feasibility of this depends on the completion of full-scale tests during the winter 1943–44. These experiments have been in progress in England and Canada since December 1942. The proposed design has a speed of about seven knots; is self-propelled; and has a length of 1,700–2,200 feet; the beam would be sufficient to operate and park medium bombers and transport aircraft and, if assisted take off could be employed, heavy bombers. If orders for the above full-scale tests are given immediately, and if these are successful, the first pykrete Habbakuk might be operational by the middle of 1945, but there are a large number of constructional and operational problems to be overcome.

Habbakuk III

5. This would be a smaller and faster type made of steel; about 70,000 tons per vessel; speed 12 knots; self-propelled; length 1,000–1,200 feet; beam sufficient to operate fighters, naval aircraft and light twin engine bombers. If a definite order is given in the near future, and if the material can be made available, the first could be operational by the spring of 1945. The construction of this type would, however, conflict with other ship construction, e.g. escort carriers.

6. Arrester gear will be necessary on all types and the employment of assisted take-off methods would be of great value.

7. In the war against Japan, we see considerable possibilities in Types II and III, particularly the latter. They could not, of course, in any way fulfill the functions of an aircraft carrier operating with the fleet, but there are a number of other ways, details of which are described in Annex II² in which we think they would be of great value. Indeed, we feel that after a certain number of escort carriers have been constructed, it would probably be better to build a few of these Habbakuks rather than devote all our efforts to further escort carriers. (See paragraphs 40 and 41 of Annex II.)

Recommendations

8. We suggest that we should now take steps as follows:

a. To construct at least two Habbakuks III , which is the more promising type for use both in the Pacific and the Indian Ocean;

b. To continue experiments and construct during the coming winter sections of pykrete for Habbakuk II ’s for experimental purposes. Subject to success in this, we should construct a number of Habbakuk II ’s in pykrete during the following winter for use in the Pacific.

9. We cannot undertake construction in the United Kingdom because neither labor nor the material can be made available. If, therefore, the Combined Chiefs of Staff agree in principle with our proposals, we suggest that they should invite the appropriate United States and Canadian authorities to set up a board forthwith to press on with this matter. We shall be glad to place British experts at the disposal of both.

1. Circulated under cover of the following note by the Secretaries of the Combined Chiefs of Staff (C.C.S. 315), August 18, 1943: “In order to save delay, the enclosure, prepared by the Chief of Combined Operations [Vice Admiral Mountbatten], in consultation with the British Joint Planning Staff, is presented direct to the Combined Chiefs of Staff for their consideration.”

   For the discussion of this paper at the 112th Meeting of the Combined Chiefs of Staff, August 19, 1943, see ante, p. 890.

2. Not printed.
2. Not printed.