THE INVENTION OF THE STEAM ENGINE IN THE 18TH CENTURY made mechanically driven ships fitted with paddle wheels or propellers a viable alternative to sails. Paddle wheels have fixed or feathered floats, and the model shown below features both types. Feathered floats give more propulsive power than fixed floats because they are almost upright at all times in the water. Paddle wheels were superseded by the propeller on oceangoing vessels in the mid-19th century. Propellers are more efficient, work better in rough water, and are less vulnerable in collisions. The first propellers were two-bladed but later threeand four-bladed versions are more powerful; the shape and pitch of blades have also been refined over the years. At the beginning of the 18th century, tillers were superseded on many larger ships by the ship’s wheel as a means of steering.
Paddle wheels and propellers
in
SEA AND AIR
published on 8:40 AM
THE INVENTION OF THE STEAM ENGINE IN THE 18TH CENTURY made mechanically driven ships fitted with paddle wheels or propellers a viable alternative to sails. Paddle wheels have fixed or feathered floats, and the model shown below features both types. Feathered floats give more propulsive power than fixed floats because they are almost upright at all times in the water. Paddle wheels were superseded by the propeller on oceangoing vessels in the mid-19th century. Propellers are more efficient, work better in rough water, and are less vulnerable in collisions. The first propellers were two-bladed but later threeand four-bladed versions are more powerful; the shape and pitch of blades have also been refined over the years. At the beginning of the 18th century, tillers were superseded on many larger ships by the ship’s wheel as a means of steering.
