Boatnerd Discussion Forum

With the sternwheel design also gave the paddlewheel a greater measure of protection when running in shallow, swift, or snag-infested waters, except of course when running astern. That's one of the main reasons they became so popular on the Mississippi and its tributaries, as well as the western rivers.

Sidewheelers generally found their niche in relatively protected waters where draft was less of an issue. The combination of a speedy narrow hull with abundant deck space from the wide overhanging paddle guards was particularly well suited for passenger ships. In calm waters a pair of sidewheels (especially with feathering blades that remained vertical while they were in the water) could be a very efficient way to propel the ship. In heavy seas, however, a fully-submerged screw propeller quickly proved to be superior to paddle wheels of any configuration. That's why deep sea paddle steamers were pretty much extinct by the 1880s, while they were still building coastal, lake, and river sidewheelers in some parts of the world into the 1950s.

Stern wheelers were designed to be very shallow draft so they could navigate the un dredged rivers and landings. A good may towns that the river boats stopped at didn't have docks, or if they did they were not much more then some planks laying on the muddy bank. The shallow draft allowed the stern wheeler to push up to the bank and drop the gang planks and off load leaving the stern wheel in deeper water.

The side wheeler had a deeper draft as needed on the lakes for stability, which also allowed cargo to be stowed in the holds (hull) where as the stern wheeler in most cases had the cargo stowed n deck. The side wheels also had a deeper bite in the water which worked better in a seaway and gave better control.

I should have added that for any given power requirement, a stern wheel would be easier to design and construct since it has a support bearing on both ends of the wheel. Also a stern wheel can use the entire width of the vessel for power transmission, without adding to the width of the vessel. To get the same power out of narrower side wheels, the wheels had to be a larger diameter and be submerged deeper. I think these are some of the reasons stern wheels were popular on rivers.

There are some excellent books that cover the development of river boats on the "Western Rivers", as the Mississippi River system was once called.

The sternwheel systems cannot push a ship in rough open water and they were also limited in their maneuverability. A sidewheel system was very useful in small harbors and kept a ship stable in storms.

I think it may have had to do with the fact that side wheels worked better in heavier seas. With the stern moving up and down in heavy seas, the depth of the paddles submerged in the water would be highly variable on a stern wheel, which would in turn put a lot of stain on the engine and drive train. Side wheels would be much less affected by this and would provide more constant power in heavy seas.

You are correct that there weren't many stern wheelers on the Lakes. But there were a lot of side wheel boats on the Mississippi and other rivers. Many of the early line haul towboats were side wheel as well as many of the big railroad transfer ferries across the Mississipi and Missouri. Their side wheels and engines were often placed well aft of midship, with the boilers placed quite a ways forward.

I have been trying for years to find out why lake steamers were sidewheelers but river steamers were sternwheelers. So far, no luck. Can anyone help ?