Of all the programmes scheduled to commemorate the 70th anniversary of D-Day, this little gem is arguably the most revealing. It follows affable engineer and broadcaster Rob Bell as he pays tribute to the technical innovations that led to Allied victory.He uncovers the complex, risky logistics of launching a mammoth attack from the sea, with all the tragic trial and error it entailed. His awe is understandable when he encounters engineering marvels such as the Sherman Duplex Drive tank, otherwise known as the Donald Duck. Thirty tonnes of iron and steel adapted to float in water, it played a vital role in storming the beaches of Normandy.He also speaks to war veterans with vivid memories of the landings. Says one man who was there that day: “The carnage on that beach... thank God they never show pictures of it.” Informative and respectful, it's a humbling slice of history.