Radio proximity fuzes for fin-stabilized missiles

Front matter

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Foreword

T he primary program of Division 4, NDRC, was development of proximity fuzes for bombs, rockets, and trench mortar projectiles. The National Bureau of Standards [NBS] provided facilities and personnel for the Division’s Central Laboratory and the Division (or its predecessor, Section E of Division A) served as the principal liaison between NDRC and NBS. In large measure the developments presented in this Division 4 STR must be credited to the National Bureau of Standards. Credit also is due the Ordnance Department of the Army for excellent cooperation. The maintenance of effective liaison was due largely to Colonel H. S. Morton, whose enthusiasm for the program coupled with intelligent criticism and suggestions based on sound technical knowledge contributed much of value.

The present volume summarizes the Division’s development of radio proximity fuzes. The technical direction of this development was throughout in the able hands of Harry Diamond, leader of the little radio fuze group organized at the Bureau of Standards in December 1940, and finally Chief of the Bureau’s Ordnance Development Division. Throughout the program, he received invaluable technical assistance from W. S. Hinman, Jr., Chief Engineer of the aforementioned NBS division. The excellent presentation found here is due to the editor of these three volumes, A. V. Astin, Assistant Chief of the Ordnance Development Division, NBS.

Other Division 4 contractors made valuable contributions to particular projects on which they were engaged. Deserving of special mention are the University of Florida for work on trench mortar fuzes, the Globe-Union Company of Milwaukee for work on safety and arming devices and ceramic circuits, and the University of Iowa for improved recovery devices and a smooth working proof organization. The development of generator power supplies was largely carried out by the Westinghouse Company in Baltimore and by the Zenith Radio Corporation.

Reliability of radio fuzes depends at least as much on good production methods and techniques as upon good design. In the solution of production problems outstanding contributions were made by the Zell Corporation, Baltimore, and Bowen and Company, Bethesda, Maryland, who operated pilot lines; and by the Arnold Engineering Company, the Emerson Radio and Phonograph Corporation, the General Electric Company, the Globe-Union Company, the Philco Corporation, the Raytheon Manufacturing Company, the Sylvania Electric Products, Inc., the Westinghouse Electric and Manufacturing Company, the Rudolph Wurlitzer Company, and the Zenith Radio Corporation, who produced fuzes or fuze components.

Alexander Ellett Chief, Division 4 vii

Preface

T he Summary Technical Report of Division 4 has been prepared in three volumes : Volume 1, describing the work on radio proximity fuzes, the major work of the division; Volume 2, discussing bomb, rocket, and torpedo tossing, a new fire control method for airborne missiles; and Volume 3, a report on various miscellaneous projects. An overall summary of the Division 4 program appears as Chapter 1 in Volume 3.

The present volume treats the technical problems relating to the design, production, and use of radio proximity fuzes for fin-stabilized (nonrotating) missiles, including bombs, rockets, and trench mortar shells. For a treatment of work on fuzes for spin-stabilized projectiles, the reader is referred to the reports of Section T of OSRD. For work on other types of proximity fuzes for fin-stabilized missiles, the reader is referred to Volume 3 of the Division 4 STR. The latter reference includes a general survey of various types of proximity fuzes and a detailed summary of the work done by Division 4 on photoelectric fuzes.

A primary consideration in the preparation of this volume has been to arrange the material so that it will be useful for reference purposes. To fulfill this objective, the various chapters are reasonably self-contained, and each chapter may be read separately without too much loss in meaning. This mode of presentation has, of course, resulted in some duplication of material, but it is believed that the advantages justify the extra space required. Numerous cross references between the chapters are included to facilitate expansion or clarification of various items.

For the reader who is interested primarily in the essential operating characteristics of the radio proximity fuzes placed in production, Chapter 5, “Catalogue of Fuze Types,” is the only part of this volume which need be read. The catalogue chapter also includes a description of the important features of design for each of the various fuzes.

The introduction to the volume (Chapter 1) explains the objectives of the development program, how radio fuzes operate, and includes a brief summary of the accomplishments in the development and production program.

Chapter 2 discusses in detail the basic theory of operation and shows how the required operating characteristics of a fuze may be converted into an engineering design problem. The material of Chapter 2 is fundamental to any fuze design involving interaction of radio waves with the target. Because of the great potential use of this theory in future development work, the treatment of Chapter 2 is much more thorough than would appear necessary merely as a summary of completed work.

The methods by which the electrical design problems were solved are discussed in Chapter 3. Section 3.4 of Chapter 3 deals with the design of generator power supplies, one of the outstanding features of the later fuzes developed by Division 4. Although this section is included in the electrical design chapter, it contains considerable material relating to the mechanical design of generators. A clear-cut separation of the mechanical and electrical design requirements for the generator was not practicable. Chapters 2 and 3 are quite technical in nature and will probably be of interest only to scientists and engineers. These chapters may be omitted by the nontechnical reader.

Chapter 4 analyzes the problems of mechanical design and layout and includes a treatment of the arming and safety features of the fuzes.

Chapter 6 describes the production methods and summarizes accomplishment in the production program. Since the problems of reducing a laboratory design of a proximity fuze to a model which could be built in mass production were fundamental to the entire program, the story of this chapter is of basic importance. It should be of interest to both the technical and the nontechnical reader.

Chapters 7 and 8 describe the methods of testing proximity fuzes in order that their quality might be evaluated and their performance under operational conditions predicted. The former chapter is concerned with laboratory test methods and quality control. A description of testing apparatus is included. The

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PREFACE latter chapter deals with field test methods and proving ground procedures in which operational conditions were simulated.

Chapter 9 gives a somewhat more detailed analysis of the operating characteristics of the fuzes than is given in Chapter 5 in that the results of all important tests which were carried out on the fuzes are summarized. The chapter includes evaluations of performance for each of the fuze types under a variety of operating conditions. The operational experience is also presented in this chapter.

An analysis of problems pertaining to countermeasures and counter-countermeasures has not been included in this volume.

The successful development of radio proximity fuzes, or VT fuzes as they are commonly called, involved the cooperative efforts of many organizations and individuals. A listing of all of the individuals who contributed to the success of the program would be an extremely difficult, perhaps even impossible, task. However, the organizations which participated in the development program are listed at the end of the volume.

This volume was prepared by the staff of the Ordnance Development Division of the National Bureau of Standards, which served as the central laboratories for Division 4. Reports of the various contractors to Division 4 have been used freely, and these are listed as references in the bibliography.

The editor wishes to take this opportunity to record thanks and appreciation for the efforts of the many individuals who cooperated in the preparation of the volume. In particular, some of these are: Dr. Robert D. Huntoon, who assisted in the overall planning of the volume and who was also the senior author of Chapter 2; Dr. Alexander Ellett and Mr. Harry Diamond, Chief, Division 4 and Chief, Ordnance Development Division, respectively, who offered valuable suggestions and advice on numerous items ; other authors who are listed in the table of contents as well as in footnotes to the various sections which they prepared ; Mr. Theodore C. Hellmers, who prepared the photographs used in this volume (unless credit is otherwise indicated) ; Mr. E. W. Hunt and his staff for their diligent and painstaking efforts in the preparation of other art work; Miss Lee Smolen and Mrs. Henrietta Leiner for preparation of bibliographical material; and Miss Helen Olmstead, Mrs. Betty Hallman, and Miss Jane Grant for their untiring efforts in the preparation, assembly, and correction of manuscripts.

A. V. Astin E ditor

Contents

CHAPTER PAGE

OSRD Appointees 463

Contract Numbers 464