Keyes Papers. Vol. cxxvii. Origins, plans, and preparation for Operation ZO; 7 May 1917– 6 May 1918, n.d.
1. Contains a memorandum by Cdre Tyrwhitt on attacking Zeebrugge and an extract from a letter from Keyes to the Admiralty on the origins of the operation; 7 May 1917 – 6 May 1918.
2. Contains the Sea Lords’ comments on the plan submitted by Keyes in Feb. 1918, papers on plans for destroying a viaduct as part of Operation ZO and trials of the equipment required, and a list of possible dates with details of tides, phases of the moon, and sunsets and sunrises; 24 Feb. – 28 March 1918.
3. Contains a paper on fitting out the blockships; details of forces required for Operation ZO; papers on smoke and flares; rumours circulating amongst Canadian forces; and details of German guns on the Belgian coast; 11 Jan. – 25 March 1918, n.d.