i was WRONG, appears they DONT have engines, I always thought they had a small one for emergencies like this?! obviously not!
Glider Pilot. co.uk
"Flying a glider is probably the closest thing any human will come to feeling like a bird. Powered only by gravity and air currents, these gliders move silently through the sky, often for hours at a time. Because they have no engines, gliders, or sailplanes, can be thought of as pure flying vehicles, staying aloft by balancing the forces of gravity, lift, drag and thrust."
Glider Pilot. co.uk
"Flying a glider is probably the closest thing any human will come to feeling like a bird. Powered only by gravity and air currents, these gliders move silently through the sky, often for hours at a time. Because they have no engines, gliders, or sailplanes, can be thought of as pure flying vehicles, staying aloft by balancing the forces of gravity, lift, drag and thrust."