Sternwheel riverboat question

Where were the rudders on those boats? AFAIK, just about every watercraft there is has the rudder(s) at the stern, but on a sternwheeler, the whole back end appears to be taken up with the paddlewheel :confused:
Oh, and Happy Thanksgiving everyone :slight_smile:

It’s not obvious on this picture of a riverboat model, but it looks to me like there’s a rudder at the very end of the hull, just before the paddlewheel.

To me that also seems like the only sensible solution for a shallow draft vessel like that.

On the Natchez in New Orleans, there is a series of long, low rudders in parallel under the wheel.

I was just about to ask a question about the old paddlewheel steamers…I read once , that a stern paddle wheel ahd an efficiency approaching that of a propellor-is this correct? The side paddle type were pretty inefficient-there was a competition held once (a side paddle steamer and a screw driven steamer were tied back-t-back-and the screw drivenship would up pulling the paddle ship in reverse.

IIRC, stern-wheelers were connected to the engine at the center of the boat by a big, long piston arm. This would mean the engine would waste energy just moving it’s own parts, compared to a side-wheeler

If you’ve ever rented a swan boat at the park, you know how frustrating it it to get any kindof speed out fo the damn things, compared to canoes & rowboats. Did anyone ever configure a paddle wheeler with the scoops on a long chain drive, like tank treads, so there’s be as much possible purchase in the water without increasing the how deep in the river the boat sat?

A piston? Meaning a rod that moves back-and-forth? Not likely. I think you mean a rotating connection, a drive axle.

And that’s just the same as most modern propeller-driven ships – the engine connects to an axle that drives the propellers. So why would that be inefficient? The stern wheeler would have to have gearing to change the angle 90º, which a propeller doesn’t need, but that should still not introduce much inefficiency.

My friend has a 100 footer. it has a split paddle . One half can turn one way, the other the opposite it you want. It handles better than you would think for a boat that size. The steering wheel is up front on the 2nd deck. The engine compartment is huge and at the rear. Big diesel engines drive the paddles.

Look at the model picture somebody posted above. It looks like there’s a big reciprocating arm driving the sternwheel, and that’s the arrangement I generally picture, too. Here’s a description, .pdf unfortunately, of the “Belle of Louisville”, constructed in 1914, and still operating today. There’s a diagram showing the “Pitman arm” which turns the sternwheel:

http://files.asme.org/asmeorg/Communities/History/22505.pdf

OTOH, that diagram also shows an engine location which is not that far from the sternwheel. The boilers are in the middle of the vessel, but the engine is in the rear. Admittedly leaving a lot of steam pipe between the boilers and the engine, but I imagine they wanted to have the weight of the boilers in the center.

BTW, the diagram also shows rudders (three) on the back of the hull, ahead of the wheel, just as somebody noted on the picture above.

It seemed to me that another arrangement would be possible - you could mount the rudders behind the sternwheel on the frame containing it. I poked around and found that arrangement as well.

Here’s an unusual one: the Demologos with the paddle wheel in the center of a catamaran. Seems like a good idea. but it was a one-of-a-kind.

BTW, look at the diagram in “anatomy of a sternwheeler” here, also showing a rudder mounted on the hull, boilers in the middle, engine in the rear, and a big reciprocating connecting rod driving the wheel:

http://www.portlandspirit.com/sternwheeler.php

That modern day excursion sternwheeler they are advertising has rudders mounted on the frame behind the wheel, but it’s also diesel powered and appears to have a drive shaft:

http://galenfry.com/OR/stern05.jpg

On a stern wheeler you could have the same piston and piston rod as a screwed ship. But the connecting rod on a stern wheeler is much longer and more massive. Yes a screw ship has a shaft which has more mass but it only rotates there is no change in dorection.

Also most if not all stern wheelers are single expansion. Where as most screw ships were tripple expansion.

Nothing to add except that I’m currently reading The Great Steamboat Race by** John Brunner** and enjoying it a lot. It starts during the Civil War and continues into the 1870s, with most of the scenes so far set in and around New Orleans and on the river.
Obviously Steamboats, their pilots, captains and crew play a major role!

I have traveled on the Delta Queen http://en.wikipedia.org/wiki/Delta_Queen which was built in the 1920s as a sternwheeled steam-powered ferry boat. There are diesel-fired boilers up front beneath the smoke stacks and two pistons in the stern which drive the wheel via a 4-5’ long eccentric crank attached to the paddle barrel.

One of the interesting features of the engine is that it’s a double expansion. High pressure steam drives the port piston and that spent steam is routed to the starboard piston for a second lower-pressure use before being condensed & routed back to the boiler. Unsurprisingly, the two cylinders are different diameters and have different valve timing.

At cruise speeds the engine is running at about 1 stroke per piston per second, so it sounds & feels a lot like a gigantic wheezy grandfather clock. Time truly passed differently in those days, versus the umpteen thousand RPM a modern steam turbine turns.