At 171 m long, the USS Pennsylvania is the biggest submarine in the US Navy. It can dive deeper than a thousand feet, sail for 20 years without refuelling, and remain submerged for up to six months. The vessel carries a crew of 155 men and a deadly nuclear arsenal. Uncover the innovations in six landmark submarines, including the tiny Turtle and colossal German U-boats, that made it possible for engineers to incorporate underwater breathing, torpedos, missile launch systems and stealth technology into ever bigger submarines.

Continuing this week is the factual series that examines the evolution of modern engineering. The third instalment explores the leaps in aviation technology that led to the development of the world’s largest cargo plane – the Antonov An-124. Weighing in at 392 tons, the Antonov An-124 can carry tanks, trains and even other aircraft to the farthest corners of the globe. The pinnacle of modern aeronautical engineering, this gigantic cargo plane owes its existence to nearly 100 years of innovation...

Uncover the technological leaps forward that have enabled the world's largest observation wheel - the Singapore Flyer - to be built. The Singapore Flyer is the tallest observation wheel on Earth, rising 165 metres into the sky. It can whisk 1,260 passengers around hourly to see a stunning 45 km panorama of three different countries below. Count down the five major innovations in observation wheels like the original Ferris Wheel and London Eye that have allowed the world's highest observation wheel to be built.

China’s Canton Tower required great leaps in technology to build. Explore the way key historic towers like the Eiffel Tower and Washington Monument made these engineering breakthroughs possible.

France’s TGV has been pushed to 575 kilometres. Examine four iconic trains and the breakthroughs that enabled the development of the fastest train on the planet.