The science behind the D-Day landings
6 June 2014 Last updated at 10:54 BST
Seventy years ago one of the greatest amphibious assaults in military history was launched from the south coast of England.
Seven thousand vessels landed 156,000 troops on the beaches of Normandy within a few hours as part of the D-Day landings.
Rob Bell looks at the 'nuts and bolts' which made such a staggering invasion possible from giant troop carrying gliders to tanks that could drive on water.
Major-General Percy Hobart was the man behind many of these unconventional inventions known as 'Hobart's Funnies' including the Sherman Duplex Drive Tank and the flame-throwing Crocodile.
His innovations in engineering and technology changed the course of the war.
Credits: Archive footage is copyright and courtesy of British Pathé. Tank images courtesy of the Tank Museum.
The Science of D-Day is broadcast on Saturday, 7 June on BBC One South at 16:30 BST and nationwide on BBC Four on Sunday 8 June at 19:30 and Monday 9 June at 03:00.