27. Railroad tracks (except on section maps-see Plate No. 14-9)....

28. Railroad bumper post.

29. Trestle......

30. Crane....

31. Crane tracks..

32. Capstan..

33. Quay wall.

34. River.

35. Dolphin..

36. Buoy......

37. Salt-water marsh......

38. Fresh-water marsh...

PLATE NO. 14-28.

CHAPTER 16.

CONSTRUCTION OF PUBLIC WORKS UNDER CONTRACT.

16-01. Public works contracts, as contemplated herein, include contracts for the construction, alteration, or repair of public buildings or other structures, for the installation of machinery or other permanent fixtures therein, and for operations affecting the realty. Extensively, they include contracts for those objects defined as "public works," and often for objects defined as "public utilities," in the Navy Regulations. Public works contracts for machinery, mechanical equipment, and the like, differ from mere purchase contracts in that they as a rule embrace not only the delivery of the equipment but also services in connection with its installation or erection.

16-02. Statute requirements and limitations concerning contracts. Statutes quoted in Chapter 27 herein which relate to contracts have been placed in a separate group, paragraphs 27–123 to 27-163, inclusive. Attention is also directed to paragraphs 27-86 to 27-122 of Chapter 27, relating to the application, restriction, and control of expenditures under appropriations. The following referenced statutes impose restrictions upon contract obligations and expenditures, and are of the highest importance in this connection:

27- 88. Specific declaration of appropriation necessary for authority to expend. (Act June 30, 1906, sec. 9, 34 Stat. 764.)

27-89. Appropriations to be applied solely to objects for which made. (R. S. sec. 3678.)

27-96. Appropriations for public works under Yards and Docks available until expended. (Act July 12, 1921, sec. 3, 42 Stat. 139.)

27-97. No obligations or expenditures beyond appropriations. (R. S. sec. 3679, amended.)

27-123. Contracts or purchases prohibited unless authorized by law or under appropriation adequate for fulfillment. (R. S. sec. 3732.) 27-135. No contract to exceed appropriation. (R. S. sec. 3733.)

16-03. Important decisions bearing upon contractual relations will be found in Chapters 28, 29, and 30 herein, made up from the Opinions of the Attorney General, Decisions of the Comptroller,