'NOVA: Bombing Hitler's Supergun'
(DVD / NR / 2016 / PBS)
Overview: In 1943, Hitler hatches a diabolical weapon: a bank of superguns housed in a massive underground complex in Nazi-occupied northern France. Together, the guns would be able to pump 600 high explosive shells 100 miles to London each hour, spelling doom for the Allies. Join NOVA as engineers, archaeologists, and WWII historians investigate this fearsome weapon and two audacious missions designed to destroy it.
DVD Verdict: The V-3 (Vergeltungswaffe 3) was a German World War II supergun working on the multi-charge principle whereby secondary propellant charges are fired to add velocity to a projectile.
The weapon was planned to be used to bombard London from two large bunkers in the Pas-de-Calais region of northern France, but they were rendered unusable by Allied bombing raids before completion. Two similar guns were used to bombard Luxembourg from December 1944 to February 1945.
The V-3 was also known as the Hochdruckpumpe ("High Pressure Pump," HDP for short), which was a code name intended to hide the real purpose of the project. It was also known as Fleißiges Lieschen ("Busy Lizzie").
Although the plot to use these weapons failed, this NOVA in depth documentary is as fascinating a reveal about the mind of Hitler today as I'm sure it was back then. A man who would stop at nothing to win the war, a man whose minions kept creating new and bigger and better weapons of war seemingly each month, the Supergun used multiple propellant charges placed along the barrel's length and timed to fire as soon as the projectile passed them in order to provide an additional boost.
Solid-fuel rocket boosters were used instead of explosive charges because of their greater suitability and ease of use. These were arranged in symmetrical pairs along the length of the barrel, angled to project their thrust against the base of the projectile as it passed. This layout spawned the German codename Tausendfüßler ("millipede").
The barrel and side chambers were designed as identical sections to simplify production and allow damaged sections to be replaced. The entire gun would use multiple such sections bolted together. The smoothbore gun fired a fin-stabilized shell that depended upon aerodynamic forces rather than gyroscopic forces to prevent tumbling (distinct from conventional rifled weapons which cause the projectile to spin); this resulted in a lower drag coefficient.
Not that they ever got further than the testing stage, for as we now know, the Allies stopped these Superguns in their tracks (quite literally!). The V-3 “supergun” was meant to win the war for Germany, because for the first time since World War II began, Hitler was on the back foot. Luckily for the British, that's exactly where he stayed. This is a Widescreen Presentation (1.85:1) enhanced for 16x9 TVs.