BLADES REPLACE SCREWS

Evening Star, Issue 22687, 29 June 1937, Page 16

BLADES REPLACE SCREWS

HEW SHIPPING INVENTION HOPES OF FUTURE SUCCESS A new system of ship propulsion by blades instead of screws has been invented by a German. Trials have proved so successful that two British steamship companies, both with long" experience of paddles and screws, have placed orders for passenger-carrying vessels to be fitted with the new system. In maritime circles it is thought that the invention may prove as revolutionary as was the introduction of screws. This new system, known as the Voith-Schneider, after its inventor, is entirely novel. It consists of a circular group of vertical curved blades projecting from beneath the cut-away counter stern of the vessel. These are geared to the shaft of the main engine, which can be of any type, but is usually a Diesel, and not only does the whole group of blades revolve in cither direction, but each blade is separately movable ou its own axis. OPERATION FROM BRIDGE. Thus, with a simple set of three combined controls operated, by one anan on the bridge, the ship can be made to go fast or slow, ahead, astern, or even sideways—like a crab—and can also be steered in any direction, no rudder being required. There are six blades in the propeller group, and with twin groups a vessel of up to about 200 ft length can make a complete turn in less than a minute and in little more than its own length. The chief advantages are greater propulsive efficiency with less power than either screw or paddle, ease of manoeuvring, more manoeuvring capabilities, namely, sideways movement—and reduction of time lag between the giving of a bridge _ order and its execution, due to the direct control. j The companies which are pioneering this invention in Great Britain are the Southampton, Isle of Wight, and South of England Steam Packet Company and the Southern Railway. The Isle of Wight Company has placed with John I. Thomycroft and Co., Southampton, an order for a passenger vessel 195 ft long by 30ft beam, fitted with two 600 h.p. Diesel .engines, each driving a six-bladed Voith-Schneider propeller. This ship will have a speed of 15 knots, and will be employed in the regularservice between Southampton and Cowes. POPULARITY ON CONTINENT. The Southern Railway has ordered a slightly smaller vessel from William Denny Bros., Dumbarton. It will measure 148 ft by 36ft, and will have two 200 h.p. Diesel engines, each driving a six-bladed propeller. It will be used as a passenger and motor car ferry between Lymington and Yarmouth, Isle of Wight. Voith-Schneider propulsion is ideal for navigation in crowded and narrow Waterways, and for this reason it has already attained considerable popularity on the Continent in the past year. Germany has several tugs and small passenger vessels fitted with the invention on Lake Constance and the Rhine; France has a few passenger launches ou the Loire at Nantes; and early this summer six Voith-Schneider motor “ gondolas ” will he in service on the canals of Venice,