Engines of Our Ingenuity

No. 2954: A SINGULAR FLOATPLANE

by John H. Lienhard

Today, a singular floatplane. The University of Houston's College of Engineering presents this series about the machines that make our civilization run and about the people whose ingenuity created them.

Think about the light floatplanes that carry a few passengers and freight from lake to lake in the Alaskan outback. Most are high-winged planes that ride on two pontoons. Sometimes the body rides in the water like a boat, with an engine up on the wing.

Conventional float plane
A conventional float plane in service in western Canada. (Photo by John Lienhard)

But the old US Navy floatplane was quite different. Consider this: We entered WW-II with only seven aircraft carriers among hundreds of major naval vessels. Radar was embryonic. But ships had to know what lurked in the large oceans around them.

The solution, evolving since WW-I, was that cruisers, battleships, and even some destroyers, carried their own airplanes - ones that could take off and land while the ship was moving. If that sounds tricky - well, more on that in a moment.

Four models, all pretty similar, had evolved by WW-II. All took off and landed on a single large pontoon, with stabilizing floats under each wingtip. Three companies made them: Curtiss, Vought, and the Navy (which had its own factory in Philadelphia.)

Curtiss SOC Seagull
Curtiss SOC Seagull, the earliest Navy floatplane still being used in WW-II. It was one of the few American biplanes that saw action throughout the war. (Image courtesy Wikimedia Commons.)

Most WW-II airplanes changed in form as the war ground on. But these hardly did. A few early two-winged floatplanes served for the entire war. The rest had a single low wing. And all but the last version had a 2-man crew. You had to know what to look for to tell them apart. They typically cruised at around 125 miles-an-hour. They were not made for aerial combat.

The last of the lot, the single seat Seahawk, had one major advantage. It had the same sedate cruising speed. But it could get away at over 300 miles-an-hour in a pinch. That was important. You see, those Navy floatplanes were vulnerable and they suffered severe losses. Staying alive was a big problem for their pilots.

OS2U Kingfisher
The Vought OS2U Kingfisher was a mainstay during most of the War. (Photo by John Lienhard at the National Naval Aviation Museum in Pensacola.)

Now: the moving ship problem: The planes were flung from a catapult rail that ran their speed from 0 to 70 miles-an-hour at release. Returning, they landed beside the ship and ran into a mesh sled in the water. The mesh snared the pontoon, then dragged the plane along while the ship's crane picked it up.

Seahalk on retrieval sled
This Curtiss Seahawk has caught its pontoon in its mesh retrieval sled and is awaiting the ship's crane to lift it aboard, while it's being towed. (Image courtesy Wikimedia Commons)

So how did these planes perform? Well, beyond spotting enemy ship movements, they picked up downed airmen, ferried the wounded and ferried admirals. They did anti-submarine work, strafed enemy troops during landings, and spotted targets for their own ships' guns - though that was tricky and their information could be iffy.

In fact, warships often flew them away during naval battles - or even just dumped them in the sea - since they were dangerously flammable. By the war's end, ships had workable radar as well as the new helicopters. New technology made that last fast-moving Seahawk obsolete on arrival.

And those odd, single-pontoon floatplanes vanished. I finally got to see one at the Pensacola Naval Air Museum - hanging from a ceiling - lost among sexier jet fighters and bombers. Today, it is as though those pretty old airplanes had hardly existed.

I'm John Lienhard at the University of Houston, where we’re interested in the way inventive minds work.

(Theme music)


Al Adcock, U.S. Navy Floatplanes of World War II in Action. (Color by Don Greer) (Carrolton, TX: Squadron/Signal Pubs., Inc., 2006): Aircraft No. 203.

See also, the Avalanche Press floatplane site, this You-Tube movie about the Seahawk in action, and the Pacific Aviation Museum floatplane site.

See also, the Wikipedia sites for Curtiss SOC Seagull, for the Vought OS2U Kingfisher, for the Curtiss SO3C Seamew, and for the Curtiss SC Seahawk

This episode was first aired on June 30, 2014



The Engines of Our Ingenuity is Copyright © 1988-2014 by John H. Lienhard.