Cross compound engines were used on other boats besides the Delta King and Queen. Capt. Frederick Way's famous Betsy Ann also used a cross compound engine.

Sternwheelers are actually much easier to steer in reverse. The wheel wash acts directly against the rudders when moving astern.

A slight correction: the high-pressure cylinder on the Delta Queen has a bore of 26" and the low-pressure cylinder is 52" bore, both with a 10-foot stroke. The boiler pressure is 200 PSI and the engine is rated 2000 horsepower at full power, with a typical rotational speed of 13 RPM. This cylinder arrangement is known as "cross-compound," and, I believe, was only used on the Delta Queen and Delta King, both built in California in 1927.

When the Delta Queen used to operate out of Cincinnati, she moored at a "wharf boat," a sort of floating warehouse containing offices, parking and storage, with automobile ramps onto the levee.

The Delta Queen is currently in use as a floating hotel in Chattanooga, but hopefully, if various political and business challenges can be overcome, she will cruise again.

The noble steamboat Delta Queen (built 1926, since retired, but there are two newer sister "Queens") carried my mom and me up and down the Mississippi and adjoining rivers on a number of memorable trips in the 1980s. Yes, riverboats always nose upstream when mooring, turning around if required; the "mighty Mississippi's" current rolls along at a steady walking pace. The charm of a riverboat is the ability to nose to to the bank most anyplace there's a good tree to tie to, dropping the gangplank and letting the passengers off to explore a plantation or small town. Larger towns had paved embankments as shown here. Since the water level changes by many feet over the season, docks are not generally practical. In fact each boat sets out a specially painted stone near the water's edge to gauge changes in the water level, even during a relatively short stop.

The Delta Queen's engine room was open to visitors. Steam pressure at 150 lbs was admitted to a first cylinder of about 12-inch bore and ten-foot stroke, the exhaust from this high pressure cylinder crossed over to the other cylinder of 26 inch bore, creating a dual compound engine coupled to both sides of a single stern wheel. The mechanism for adjusting steam inlet duration used a sliding cam riding on the giant pitman arm (crank) whose position was adjusted by an ingenious movable lever system that I think is called a Watts linkage. All of this produced visible mechanical motions with satisfyingly direct clanks and hisses whose effects would be obvious to any mechanically inclined lad of the 19th century.

Meanwhile, passengers rode at ease in varnished lounges or open verandas, watching the riverbanks slide by.

Stern wheel boats were sort of hard to handle in reverse, plus by coming up against the current, they could make a much easier landing than by trying to hold against the current in reverse.

The Hercules Carrel has the largest "scape pipes" I've seen. Apparently the boat also has some leaky poppet valves that are allowing steam to go to waste.

The guy sitting on the Pitman arm looks like his dog just died, or is playing with his iPhone.

Why would they all be moored facing the same direction? Random chance would dictate that at least a few would be preparing to go up river and a few down river, and they could load and unload from either side. Once secured, the river current wouldn't make a huge difference, would it?

The Subdivided Pratt truss in the background is the Old Louisville & Nashville Railroad bridge. Now its been rebuilt into a pedestrian bridge and repainted in a shade of purple. Hence the new more recognizable name of "The Purple People Bridge."

Here is a nice aerial view from today looking at the same landing/levee area as in the picture above (it's the second bridge from the right):

Some nice info on this bridge as well here.

I've never seen that many paddlewheel boats in one shot. I see a lot of men drifting toward the nickel beer sign at the left end of the bridge.

Note the painted sign on one of the buildings: "Ives Family Soap - Wrappers Redeemed." Soap wrappers aren't the sort of thing one thinks of as redeemable.

"Pitman arms."

The two long tapering objects in the left foreground appear to paddlewheel cranks (or whatever you call them) -- the same size and shape of the ones that are connected to the paddlewheels on the riverboats.

Looking east from here, you would see the edge of Paul Brown Stadium, possibly the National Underground Railroad Freedom Center at the end of the Roebling Bridge,a construction site (Banks Project)& Great American Ball Park would be right before the bend in the river.