The Hush Operation
The Hush Operation was a planned Amphibious landing on the coast of Belgium to coincide with the 3rd Ypres offensive. The intention was to open the attack with two British Divisions along the coast near Nieuport then, at 3am the following morning a third Division would pass through the first two and continue the attack whilst the British 1st Division was to be landed in three places to the rear of the German line. The 1st Division was to be split into its three brigades, each of which was to be carried aboard two monitors which were to push one of three 550 foot long pontoons loaded with an eighteen pounder battery and various vehicles including, at the front, three tanks, two males and a female (OH). If it had gone ahead it would have been the first time tanks were used in an amphibious operation.
In addition to their normal role of providing close MG and gun support for the infantry the nine tanks were also to help bridge the sloping sea wall by pushing a portable ramp to the top of it (s13) the female tank was then to use the winch fitted to its right hand side to haul lorries and guns over the top of the wall (s52.p26).
The pontoons were built and successfully tested in the Thames estuary, a section of seawall was constructed at Merlimont and the tanks practised on this (OH) .
The slow progress of the 3rd Ypres offensive eventually doomed the attack and it was finally cancelled on the 14th October 1917 (OH)
To the best of the authors knowledge the first amphibious landing by a tank on a hostile shore would not be made until 1940 when French tanks landed from British landing craft at Narvik in Norway.
Some photos exist of four of the tanks:
A Mk I or II female with special wide wooden spuds on its tracks to help grip the sea wall.
http://en.wikipedia.org/wiki/Operation_Hush,
a Mk IV female with special wide wooden spuds on its tracks to help grip the sea wall. X83.p101
a Mk IV male, also with wooden spuds pushing a ramp and with special wide wooden spuds on its tracks to help grip the sea wall. X11.p92, X52.p26, X83.p101
and a Mk IV (2064) fitted with female sponsons and a winch, photographed later in the war when it was being used as a recovery vehicle. X8.p18, X83.p102
Sources
S8 - British Mark IV Tank (2007) David Fletcher
S11 - The British Tanks (2001) David Fletcher
S13 - The Tank Corps (1919) Maj. Clough Williams Ellis, pg69ff
S52 - Landships (1984) David Fletcher
S83 - Great War Tank (2013) David Fletcher
OH - Official History, 1917, Vol 2, Pg.117