Old Steamboats on Display

Old Steamboats on display.

            If your travels ever take you anywhere near Dubuque, Iowa, then do not leave the area without visiting the National Mississippi River Museum and Aquarium.  Located in the Ice Harbor on the Mississippi in Dubuque, this museum has some amazing displays.  There are aquarium specimens of nearly all fresh water fish and amphibians found in the river systems of North America, all shown in a realistic habitat.  There are blue catfish as large as some of the people who come to view them.  And there are displays which re-create the history of this river, and show the part the river played in the early settlement and development of the interior of the continent.

            And they also have on display a 300 ft, steam-powered, side-wheel steamboat, which was used by the Army Corp of Engineers to dredge the channel of the Mississippi.   This boat, the Wm. M. Black, was one of a small group of such dredges built in the 1930s, and used till the early 1970s, when the rising price of crude oil made this kind of unit uneconomical.  (The two boilers on the Wm Black used several thousand gallons of bunker oil per hour.)  This ship is not actually operational. One paddlewheel was removed and placed on display on dry land, so that the public could get a better look at it.  But the ship is mostly intact, and your museum ticket buys you admission to tour this craft at your leisure.  When you walk through the lowest deck, you are surrounded by the working parts.  There are two huge, in-line, double expansion engines, one hooked to the crank pin of each paddle wheel shaft.   These are truly massive engines; the connecting rod is twenty feet long.  A third engine, the one which powers the ten-foot-diameter impeller which sucks water and mud up from the dredge scoop, is a three-cylinder, triple expansion engine.  You can inspect all of this at close range.  When you walk through this area, it’s as though you are actually “in the crankcase of the engine.”  One of the more ingenious things you’ll notice on the engines which power the paddle wheels is the “Stevenson Link.”  This is a simple mechanical linkage which connects two different cam-followers to the valve assembly in such a way that you can reverse the direction of rotation of the engine while it’s running.  There is a 22 inch long yoke which is connected on one end to the rod from the forward cam, and on the other end to the rod from the reverse cam.  The link to the valve box is hooked to a spool that can slide down the yoke, from one end to the other.   The reason that this steam driven, side wheel propulsion system was chosen was extreme maneuverability.  By having one paddlewheel turning forward and the other in reverse, the ship could turn 180 degrees in place.

             The entire museum is well worth seeing.  I’ve lived in the Mississippi valley all of my life, and I know of no tourist attraction more worth seeing—except the Mississippi itself.  If you are visiting the U.S. from some other continent, there are three things you must see before leaving:   The Grand Canyon, The Mississippi, and the fertile farm land found for hundreds of miles on each side of this river.  What is so interesting about driving across fairly flat land and seeing beautiful, green, productive fields of maize for as far as the eye can see, on both sides of the car?  Nothing, except that there is nowhere else on the planet that you can do this continuously for a thousand kilometers.  Just flying over the “corn belt” by jet would take you nearly two hours.  If you are from someplace where a farm field is a narrow strip of land in a valley bounded by mountains on both sides, then perhaps you need to see this.  The upper Midwest not only provides most of the calories consumed in the U.S.,  it also produces a significant fraction of all food consumed anywhere.