Jack Craib's Rowboat Motor Information Site

Ducassou

  

While a book or two from the early 20th century called it a "Ducasson", the patent clearly names the inventor as Ducassou.

CLICK HERE to see the patent in PDF.

The following excellent description is by the Paris Correspondent of the Scientific American, February 1912.

An interesting exhibit at the reccnt Paris show was the motor and propeller shown in our illustration. This is specially designed for small launches, and presents some original features. The chief aim has been to build the device as one unit, so that it can be readily and quickly mounted on any boat without making any material alterations.

Our illustration shows the gasoline motor, and the elongated casing which contains the transmission gear. This vertical casing extends down below the water lovel, and carries the screw propeller at its lower extremity. The parts can be quickly assembled, and the whole installed in the boat in short order. Any of the common types of motor can be used—gasolene, steam or electric.

For use with an internal combustion motor, as in the arrangement here illustrated, a new carbureter is provided, which can be used with gasolene, alcohol or oil. The motor has direct drive on the horizontal shaft running aft. At the rear end this shaft engages a gear through which it actuates the vertical shaft running down to the screw.

This latter, in addition to the regular rotary motion, has also freedom to move about produce a steering effect. For this purpose tho screw is mounted in a separate casing rotatably attached to the bottom of the long vertical casing. The propeller casing is held in place by a long vertical rod extending up to the top, where it is geared to an inclined rod running to a hand wheel near the motor.

By working the wheel the screw propeller can be turned at any angle to the axis of the boat, without interfering in any way with the regular running of the motor. To reverse the motion of the boat the propeller is simply turned through 180 degrees, without touching the motor. If the handwheel is completely let go the screw sets up a continuous rotation about its vertical axis, so that the motor can be allowed to run while the boat is stationary.

Starting and altering the speed present no difiiculty whatever. The “propulseur amovible," as M. Ducassou's invention is called, is made in various sizes from 4 to 40 horse-power and more. It has been adopted for small craft in the navy of several nations, among others of Russia, which has installed the device in the jolly boats of the gunboat "Krabry" and the battleship “Cesarewitch.” Boats equipped with the Ducassou unit are also in use in the French, Brazilian, and Japanese navy.

YIKES! It is BIG!!

1905
2nd Section: Ocean navigation: Communications, Volumes 1-36

Another reversing gear by means of the screw has been applied on a large scale to explosive engines built by the Société des Propulseurs Amovibles, systhme Ducasson (Neuilly-sur-Seine). These are small removable engines which are placed at the stern of boats used in river navigation, and are arranged in the following manner:

The driving shaft transmits the movement to a vertical shaft which transmits it by means of conical gearing to the horizontal propeller shaft, as shown on the accompanying figure.

The case E which encloses the propeller shaft can turn around the vertical axis gg, so that the screw not only propels but also steers.
As the propeller shaft can make a complete revolution in its own horizontal plane, a turn of 180° will make the vessel go astern and a turn of 90°, that is when the propeller shaft is perpendicular to the axis of the vessel, will cause the latter to turn upon itself. The direction of the vessel can be altered or reversed without reversing the engines.

This is a very neat and simple device which, naturally, can only be applied to low powers and to navigation in tranquil waters. For this reason it is very suitable for tugs or cargo boats in river navigation. The aforesaid firm also builds removable engines of this type up to 50 H. P. These engines, placed astern, leave the vessel perfectly free for loading and manoeuvering. The engines can be easily and rapidly set up or removed.
The engines are fairly light ; they weigh, everything included, about 25 kilos per horse-power. In instance a 12 H. P. engine weighs 260 kilos and consumes 4.60 litres of spirit per hour.

A Compact Launch Motor

The Propeller is Rotatably Mounted and Serves Also as Rudder

By the Paris Correspondent of the Scientific American

AN interesting exhibit at the reccnt Paris show was the motor and propeller shown in our illustration. This is specially designed for small launches, and presents some original features. The chief aim has been to build the device as one unit, so that it can be readily and quickly mounted on any boat without making any material alterations.

Our illustration shows the gasoline motor, and the elongated casing which contains the transmission gear. This vertical casing extends down below the water lovel, and carries the screw propeller at its lower extremity. The parts can be quickly assembled, and the whole installed in the boat in short order. Any of the common types oi‘ motor can be used—gasolene, steam or electric. For use with an internal combustion motor, as in the arrangement here illustrated, a new carbureter is provided, which can be used with gasolene, alcohol or oil. The motor has direct drive on the horizontal shaft running aft. At the rear end this shaft engages a gear through which it actuates the vertical shaft running down to the screw. This latter, in addition to the regular rotary motion, has also freedom to move about produce a steering efiect. For this purpose tho screw is mounted in a separate casing rotatably attached to the bottom of the long vertical casing. The propeller casing is held in place by a long vertical rod extending up to the top, where it is geared to an inclined rod running to a hand wheel near the motor. By working the wheel the screw propeller can be turned at any angle to the axis of the boat, without interfering in any way with the regular running of the motor. To reverse the motion of the boat the propeller is simply turned through 180 degrees, without touching the motor. If the handwheel is completely let go the screw sets up a continuous rotation about its vertical axis, so that the motor can be allowed to run while the boat is stationary. Starting and altering the speed present no difiiculty whatever. The “propulseur amovible," as M. Ducassou's invention is called, is made in various sizes from 4 to 40 horse-power and more. It has been adopted for small craft in the navy of several nations, among others of Russia, which has installed the device in the jolly boats of the gnnboat "Krabry" and the battleship “Cesarewitch.” Boats equipped with the Ducassou unit are also in use in the French, Brazilian, and Japanese navy.

Launch Fitted With Motor-propeller Unit Exhibited at the Recent Paris Show.

produce a steering efiect. For this purpose tho screw is mounted in a separate casing rotatably attached to the bottom of the long vertical casing. The propeller casing is held in place by a long vertical rod extending up to the top, where it is geared to an inclined rod running to a hand wheel near the motor. By working the wheel the screw propeller can be turned at any angle to the axis of the boat, without interfering in any way with the regular running of the motor. To reverse the motion of the boat the propeller is simply turned through 180 degrees, without touching the motor. If the handwheel is completely let go the screw sets up a continuous rotation about its vertical axis, so that the motor can be allowed to run while the boat is stationary. Starting and altering the speed present no difiiculty whatever. The “propulseur amovible," as M. Ducassou's invention is called, is made in various sizes from 4 to 40 horse-power and more. It has been adopted for small craft in the navy of several nations, among others of Russia, which has installed the device in the jolly boats of the gnnboat "Krabry" and the- battleship “Cesarewitch.” Boats equipped with the Ducassou unit are also in use in the French, Brazilian, and Japanese navy.