Page 29: of Maritime Reporter Magazine (April 1972)

The Use Of Theory In Propeller Design

Subject Of SNAME Chesapeake Section

Shown above at the Chesapeake Section meeting, left to right: John Heffernan, Beth- lehem Steel Corporation; Reuven Leopold, NavSec; Geoffrey Cox, Dr. William Morgan and Dr. W.E. Cummins, of NSRDC, and Jorgen Strom-Tejsen, chairman of the Section.

The theme was "welcome new members" at the February techni- cal session of the Chesapeake Sec- tion of The Society of Naval Archi- tects and Marine Engineers. The response was outstanding. Ap- proximately 130 members were in attendance, and the "old" gave a grand welcome to the "new."

This technical session was held at the Bethesda Naval Hospital

Officer's Club, located on the out- skirts of Washington, D.C. Guest speakers were Dr. William B. Mor- gan and Geoffrey C. Cox of the

Naval Ship Research and Develop- ment Center. Subject matter de^ lineated the current art of contem- porary propeller design, and the presentation was entitled "The Use of Theory in Propeller Design."

The primary message of this de- tailed presentation focused on that fact that moderately loaded pro- peller theory, and the correspond- ing computer programs, have been developed to the extent that theo- retically designed propellers are expected to perform as predicted.

This development, dependent on high-speed digital computers, al- lows .the propeller designer to in- vestigate many more parameters on a rational basis than he could in the past. Even with these de- velopments, many aspects of pro- peller design depend on intuitive judgment.

Design considerations and nec- essary design decisions were dis- cussed, especially with regard to efficiency, strength, vibration and cavitation. Also, the theoretical as- pects of propeller design were re- viewed and the interrelation be- tween lifting-line and lifting-sur- face theory were discussed in some detail. In addition, information relative to highly skewed propellers which have excellent cavitation and vibration characteristics and whose successful development depends to a great extent on theoretical de- sign techniques, were presented.

The moderator of note, as intro- duced by Section chairman Jorgen

Strom-Tejsen, was Reuven Leo- pold of the Naval Ship Engineer- ing Center. His invitation for com- ments to the technical presentation drew a rather unpredictable re- sponse. Scott Dillon of the Mari- time Administration and John Hill of NavSec had what can be gener- ally assessed as positive comments.

However, Dr. K. Schoenherr, for- mer head of" NSRDC, treated all present to an extensive and some- what critical dissertation as to the merits of existing techniques that can 'evolve into most effective pro- peller designs.

The March meeting at the Wash- ington Navy Yard Officer's Club brought to focus "Development and Testing of a Passive Moving

Weight Roll Stabilizer."

Shipbuilders Council

Reelects Edwin Hood

Edwin M. Hood

Edwin M. Hood was reelected as chairman of the board of direc- tors of the Shipbuilders Council of

America, the national industry as- sociation composed of major build- ers and repairers of merchant and naval ships. He was reelected to a fourth term at the Council's 51st

Annual Meeting held in Washing- ton, D.C., and will continue as president, a post he has held since 1961.

Edward P. Ruddy and Mrs. Bev- erly C. Kendall were also reelected for another one-year term as secre- tary and treasurer, respectively.

Mrs. Kendall has additional respon- sibilities as special assistant to the president and is one of the first women to achieve executive status in the U.S. shipyard industry. She was originally elected treasijrer in 1964.

In his annual report to the mem- bership of the Council, Mr. Hood

The Andros Storm, a 143,400- dwt ore/oil carrier, was recently launched at a new 800,000-dwt building dock of the Kure Shipyard of IHI (Ishikawajima - Harima

Heavy Industries Co., Ltd.), Ja- pan. Construction of the ship be- gan in November 1971, and she is the first to be built at the new large dock. The vessel will be delivered to General Sea Transport

Corporation, Greece, this month.

The construction of the 800,000- dwt dock (No. 3 Dock) is still in progress while, shipbuilding is un- der way. Approximately 60 percent of the total construction- work has foresees a steadily accelerating lev- el of shipyard activity stemming from substantial requirements for naval and merchant ships to bal- ance the nation's sea power re- sources.

Jackson Rope Names

D. Philip Skaer II

D. Philip Skaer II

D. Philip Skaer II has been named vice president, marketing, by Jackson Rope Corp., Reading,

Pa., Division of Aspro Inc. An- nouncement of the appointment was made by John C. Sauer, presi- dent of Jackson Rope.

Mr. Skaer was most recently gen- eral sales manager of Broderick and Bascom Rope Company, St.

Louis, Mo. He had been with that company for the past 13 years. He is a graduate of Hamilton College,

Clinton, N.Y., and holds a degree in political science. He has also undertaken graduate studies at

Cornell.

Mr. Skaer is headquartered in

Reading. already been completed. Two 300- ton cranes and one 200-ton crane have been installed along the dock.

At present the dock measures about 1,148 feet in length, and by the spring of 1973 it will foe further extended to approximately 1,673 feet.

Following the launching of the

Andros 'Storm, the keel of the sec- ond vessel to be constructed at the new facility was laid. The sec- ond ship is a 155,000-dwt bulk/ ore/carrier for Kawasaki Risen

Kaisha, Ltd., and Taiyo Kaium

K.K., her joint owners.

First Ship From IHI 800,000-Ton Dock

POWERED BY AVCO LYCOMING: This is one of two Vosper Thornycroft VT-1 series hovercraft ferries which are now making history for the Avco Lycoming Division, Strat- ford, Conn. Having recently completed a trip to Malmo, Sweden, from Southampton,

England, the VT-002 and VT-003 model ferries are the first Lycoming-powered hover- craft to make an international voyage. As of early March, they also became the world's first commercially operated hovercraft to be powered by U.S.-manufactured gas turbine engines. Under a contract with Vosper Thornycroft Ltd., of England, the two fast ferry craft are being chartered and operated over a 35-minute Malmo-to-Copenhagen crossing by Rederai Ab Centrumlinjen, a company in Sweden. The 270-passenger hover- craft will be in competition with hydrofoil and conventional hull ferries.

April 1, 1972 39