Re designing for Murray & Darling conditions: A lot of the boilers and engines were derived from UK traction engine and steamroller practice.  Gearing was common: direct gears, chain drive and rope drive.  Nearly all were woodburning; I can't recall any traditional (or modern) coalburner.  I am aware of only a couple of oilburners, and they are modern.  When railways were rebuilding from saturated to superheated, many railway boilers were cascaded to the river.  Some river boilers (notably PS Industry) were purpose built, but were modelled on railway designs.  A few river vessels were twin compound.
Windage was a severe issue, even on a relatively sheltered river.  When I was being given lessons on a large preserved one, my mentor said that handling a Murray River paddlesteamer is like handling a Frisbee with a brick on it.  Even my 9 m riverboat has that characteristic: 2 m airheight above 10 cm draft.  I was on a rare three-deck vessel rounding up in wind; it got half way, and then was just blowing downstream.  The trick is get more than half way, then the current does the rest.  It isn't just paddleboats which have windage trouble.  I was on a full-size ocean voyaging cruise ship trying to get off a dock when the wind was keeping on the dock.  That wharf had a black rubber strake.  The ship got off by rubbing the whole way, and had a black streak along its hull.
The Murray is its own magic world: it is impossible to be just a boater; one has to absorb history, culture, technology, environment and economics.  I always invite our overseas readers to plan a trip, and experience all this.  One grand chance comes soon: PS Marion is voyaging from Mannum to the Victorian border, then back to Berri for survey slipping.
Roderick

More at Mannum on Sun.23.9.01.  (Roderick Smith)
PV Black Shag.  This one had come through from Echuca on a brief rise.
MV Kingfisher, SWPV Goolwa.  This one was about a 3/4 version of the original PS Captain Sturt.  It had joined the fleet at about Renmark.  Today it is a static b&b at Goolwa.
PV Canally, PV Kulkyne, PV Impulse, QWPV Tamara Rae.
MV Progress, PS William Randell, PS Oscar W.  Progress had been a former Murray Bridge milk boat.

Roderick