1854: Variable-Pitch Boat Propeller (VPP) Patent

A variable-pitch propeller or controllable-pitch propeller (CPP) is a type of propeller with blades that can be rotated around their long axis to change the blade pitch. A VPP can be efficient for the full range of rotational speeds and load conditions, since its pitch will be varied to absorb the maximum power that the engine is capable of producing. When fully loaded, a vessel obviously needs more propulsion power than when empty. By varying the propeller blades to the optimal pitch, higher efficiency can be obtained, thus saving fuel. A vessel with a VPP can accelerate faster from a standstill, and can decelerate much more effectively, making stopping quicker and safer. A CPP can also improve vessel maneuverability by directing a stronger flow of water onto the rudder.

The variable-pitch propeller has significant advantages over the fixed-pitch variety, which include:
  • selecting the most effective blade angle for any given speed.
  • when motorsailing, the ability to coarsen the blade angle to attain the optimum drive from wind and engines.
  • the ability to move astern (in reverse) much more efficiently. (Fixed props perform very poorly in astern).
  • the ability to "feather" the blades to give the least resistance when not in use (e.g. when sailing).
  • Variable-pitch propeller - Wikipedia
  • Propeller - Wikipedia

A similar VPP screw appears to have been used to propel our famous SS Great Eastern a.k.a. Leviathan in 1850s.

Great_Eastern_Leviathan_18_1.jpg

Source

As far as I understand, the Variable Pitch Screw Propeller was not yet invented in 1858.

I was unable to find any official marine VPP inventor information on the internet. Additionally, there appears to be no single individual the invention of the Boat VPP is attributed to. The only info I was able to find pertains to the aircraft VPP.

The first proposal for a variable-pitch propeller was made in 1871 by a Frenchman named J. Croce-Spinelli. Croce-Spinelli proposed a design for a propeller whose pitch was changed by hydraulic pressure (forcing oil through a tube). Croce-Spinelli claimed that this would be most useful during takeoff, when an airplane needed the most power (Croce-Spinelli was one of two men who died in 1875 when they went too high in a balloon). Another Frenchman, Alphonse Pénaud, also proposed using a variable-pitch propeller in his patent on airplane design in 1876.
  • The first practical controllable-pitch propeller for aircraft was introduced in 1932. French firm Ratier pioneered variable-pitch propellers of various designs from 1928 onwards, relying on a special ball bearing helicoidal ramp at the root of the blades for easy operation.
  • An American engineer, F.W. Caldwell, conducted research on hydraulically controlled propellers in the late 1920s. He did some of his work on his own, but ultimately went to work for the Hamilton-Standard division of United Aircraft. He built a test propeller in 1929-1930 and tested it on an airplane.


You can imagine my surprise when I came across this little article in the 1855 issue of Mechanic's Magazine.
  • Could 16 October, 1854 be the date when Mr. W. Wain patented the VPP?
vpp1.jpg

vpp2.jpg


KD: I did mean patented, and not invented, for the pub does not say that he invented it. To be honest even if it did, I would still think that it was invented by somebody else, and at a different time.
  • Yet, it looks like Mr. W. Wain was denied some well "deserved" recognition.
Additionally: After scrolling through these pubs, I have no idea why 60 years later horses were still the main mode of transportation. Funny how everyone, and their brother were filing patents day in and day out. R&D was probably happening in their heads only.
  • It only appears that whoever was not fighting in some war, would be laying bricks (rebuilding) after one of the urban fires. Apparently they were simultaneously inventing stuff.
 
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