FOREWORD (a) These specifications@ for pumping@ cable tool@ and rotary drilling rigs and derricks were prepared - by the A. P. I. Committee on the Standardization of Standard Rigs and Derricks and are recommended for the use of the oil industry in all districts of the United States. (b) This Committee@ which is composed of representatives from all districts@ first collected and tabulated various dimensions of derricks and standard rigs used throughout the industry. A process of consolidating similar dimensions resulted in the elimination of a great many different height and base sizes. (c) Derrick and Standard Rig manufacturers have been represented at all meetings of this Committee@ so that the industry as a whole@ including manufacturers as well as users@ has aided in this standardization work. (d) Effective Date: Authority to use the A. P. f..- I. monogram on standard rigs and derricks will be ^' granted to manufacturers 90 days after the final publication of the first edition of these specifications@ upon their making application therefor in the form presented in the Appendix. (e) Revisions: These specifications will be in effect for one year following date of publication@ after @@ which they can be revised by regular Committee action@ except that@ in order to care for changes which may prove necessary on account of obvious errors or inconsistencies@ upon approval by the Engineering Sub-Committee@ the matter may be referred at once by letter to the membership of the ^ ' various Committees that have been active in drawing the specifications@ and a letter ballot taken on the proposed change@ which may then be made effective at once.
API STD 4-1931 history
1944API STD 4-1944 SPECIFICATION FOR STANDARD RIGS AND DERRICKS AND ACCESSORY EQUIPMENT (Twelfth Edition; Incorporates Supplement 1: June 1946)
1942API STD 4-1942 SPECIFICATION FOR STANDARD RIGS@ DERRICKS@ AND ACCESSORY EQUIPMENT (ELEVENTH EDITION)
1940API STD 4-1940 SPECIFICATION FOR STANDARD RIGS AND DERRICKS (Tenth Edition)
1936API STD 4-1936 SPECIFICATIONS FOR STANDARD RIGS AND DERRICKS (Eighth Edition; Supp No. 1: September@ 1937)
1935API STD 4-1935 SPECIFICATIONS FOR STANDARD RIGS AND DERRICKS (Seventh Edition)
1934API STD 4-1934 SPECIFICATIONS FOR STANDARD RIGS AND DERRICKS (Sixth Edition; SUPP 1: September 1934)
1931API STD 4-1931 SPECIFICATIONS FOR STANDARD RIGS AND DERRICKS (FIFTH EDITION)
1930API STD 4-1930 SPECIFICATIONS FOR STANDARD RIGS AND DERRICKS (Fourth Edition; SUPP 1: February@ 1931)
1927API STD 4-1927 Standard Rigs and Derricks (First Edition)