1839 - First Ocean-Going Screw Propeller Steamship, Archimedes

Henry Wimshurt, 34, designed and also built Archimedes, a 240-ton three-masted schooner launched last year, which has been fitted this year with a machinery supplied by Mssrs Rennie, consisting in a flue boiler feeding twin vertical 30-hp engines acting on the same crankshaft, itself extended by a shaft driving a whole 360° screw in a single thread. This propeller is retractable so as to reduce its drag when the ship intends to sail. It is noticeable that the engines run at 25rpm and, for the purpose of keeping its size down, the propeller runs six times faster thanks to a gear.

¤ Two years ago, two engineers - Francis Pettit Smith, 29 then, and Johan Ericsson, 34 then - separately patented screw propellers. The first gentleman has been involved in the financing of Archimedes and in running the company. The second has demonstrated a screw steamboat to the new Surveyor of the Navy, William Symonds, and to his staff - a demonstration which was successful in its essence but very discouraging for the inventor as Symonds did not waive his prejudices against setting a screw propeller before the steer, despite any evidence. Ericsson, who is a Swede, has left Great Britain to make his name in the United States.

¤ Symonds, 55 then, is very much involved in improving sailing qualities of the ships of the line, which has been the very reason of his appointment. He is neither a master shipwright nor an engineer, but an enlightened amateur in designing sail ship, so to speak. He follows the tracks outlined by a Mr Beaufoy thirty-years earlier after experiments that demonstrated superiority of triangular hull shape. Thus Symonds' great business is certainly not of hosting a screw propeller on his streamlined hulls.

Archimedes has trialed between Gravesend and Portsmouth at a remarkable speed of 10 knots. Yet there is much vibration and the machinery has proven to be a bit flimsy, as breakdowns have occurred and required extensive repair.

Supposed to demonstrate for some expected commercial purpose in the Netherlands, she has broken her crankshaft on the way and has been refitted. She is now fitted with a new propeller having two 180° screw threads in opposition, which has healed her vibration troubles.

The ship has been trialed at Dover against the best paddle-wheel packet steamers of the same size under the supervision of the Admiralty. She has proved to equal the best one, which assures the future of the screw in the warships.

It is obvious that the screw propeller is friendly with broadside armament, contrary to the paddle wheel. As it does not waste propelling power, we may predict that it will supersede its predecessor.

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IN RETROSPECT FROM TODAY

NOTE A - on Johan Ericsson's career in the USA

Johan becomes John and, thanks to an ephemeral friendship with Captain Robert Stockton, he is awarded the building of a screw-propeller sloop, Princeton, launched in 1843. She makes a success at her appearance. But Stockton becomes a rival as for the design of heavy 12-inch guns as well as for the fatherhood of the screw sloop. Fortunately, Ericsson meets Cornelius DeLamater with whom he will cooperate for many years. We will find him again for a major breakthrough, with the ironclad Monitor, which will be the matter of a chronicle, of course.

NOTE B - on Archimedes

In 1840, she circumnavigates Great-Britain with much success at an average speed of eight knots without any other failure, then sails to different countries to demonstrate her quality with some commercial expectations which are not met.

Then Smith agrees to loan her to Isambard Kingdom Brunel who explores the possibility of the screw propeller in view of the future steamship Great-Britain, launched in 1843. Archimedes plays an important role as being the prototype of the screw ships under Brunel's keen eye. Brunel will push the concept of screw propeller very far from Smith's views, by multiplying the number of blades especially (he chooses six blades finally), which generates a clash between the two talented characters.

No commercial expectation is met and the company finally collapses.