Progvev-T: The Tank With a Jet Engine for a Turret
The Soviet Union looked at a T-54 tank hull and a surplus MiG-15 jet engine and thought: "Why not combine them?" The Progvev-T (short for "protivogazodinamicheskiy tral," gas-dynamic trawl) replaced the tank's turret with an operational jet engine pointed forward. The concept was to use the engine's superheated exhaust blast to detonate or disable landmines at a safe distance ahead of the vehicle. Turn on the jet, roll forward, and let thermal energy do the mine-clearing work.
Testing in the 1970s showed the concept partially worked. The jet blast could indeed trigger pressure-detonated mines within a narrow strip. But the drawbacks were catastrophic for a military vehicle. The roaring jet engine announced the Progvev-T's presence from miles away, making any element of surprise impossible. Fuel consumption was astronomical, limiting operational range to a few kilometers. The exhaust blast kicked up enormous dust clouds that blinded the crew. And the clearance strip was too narrow for practical use. The project was shelved, but the Progvev-T earned its place in history as the most dramatically over-engineered mine-clearing solution ever attempted.

