1864: Screw-powered seamanship

The USS Kanawha, a 691-ton Unadilla-class screw steam gunboat, was commissioned in January 1862. (Navy)

From the archives: August 13, 1864

Effect of the Screw Propeller on Steering

…In our day, when fleets are led into action without a single foot of canvas set, and when so large portion of our Navy consists of screw steamers, it will certainly not be lost time to endeavor to understand all the peculiarities of the effects of the screw in handling this class of vessels.

The art of handling a vessel under canvas has been again and again most elaborately discussed, but there seems to be a deficiency of written instructions in reference to handling screw steamers under steam alone…

In relation to the subject, the first and most important inquiry would be to ascertain whether the ship is propelled by a right or left-handed screw. As the upper blade of a right-handed screw turns from port to starboard when the engine is going ahead, and the reverse of this designates a left-handed screw, the distinction is easily made. Although right-handed screws are most generally used in our Navy, yet a few of the other description are also employed…

We will first find why a right-handed screw steamer should turn with more ease and quickness with her head to port than with her head to starboard…