A unit-price contract is one in which the amount to be paid is fixed in proportion to the amount of work done or materials supplied. This type of contract is the most suitable for sewer construction for a municipality where the contract must be let to the lowest bidder. The contractor is protected in the event of many unforeseen emergencies and the principal is protected against a raise in bids to cover such emergencies and against increase in the cost of the work in order to increase the profits under a “cost-plus” contract.
It is sometimes desirable for the principal to furnish a portion of the materials, the bidders being notified beforehand that this material will be furnished. In this manner the quality of material is assured, contractors with the necessary skill but small capital may be attracted to bid, and uncertainties in the procuring of materials is eliminated.
109. The Agreement.—A contract is an agreement between two or more interested parties to do a certain thing. A contract for the construction of a sewer is an agreement between a municipality or individual desiring sewerage facilities and a company or individual engaged in the construction of sewers. The latter promises to construct a sewer in return for which the former promises to pay a certain amount of money.
The various portions of the agreement which are bound together as the complete contract are: I. The Advertisement, II. Information and Instructions for Bidders, III. Proposal, IV. General Specifications, V. Technical Specifications, VI. Special Specifications, VII. Contract, VIII. Bond, and IX. Contract Drawings. These should be fastened together in pamphlet form and constitute the complete instrument called the contract. No binding contract and specifications can be drawn upon logical deductions alone as legal precedent and tried methods must be followed to insure success. To draw up an original contract requires the combined knowledge of an engineer and a lawyer. The engineer of to-day writes his specifications by copying copiously from specifications used on work which has been completed successfully. In order that selections may be made with judgment and discrimination some examples have been selected from existing published specifications and contracts.
110. The Advertisement.—This should contain: (1) A heading indicating the type of work, (2) A statement as to when, where and how bids will be received and opened, (3) A brief description of the character and amount of work to be done, (4) The method of payment, (5) The conditions under which further information can be obtained, (6) A statement as to the amount of money which must be deposited with the bid, and (7) Any other pertinent facts concerning the work.[[75]] An example of an advertisement follows;
Sewer Construction
Construction Turkey Creek Sewer
Kansas City, Missouri.
Bids for the construction of the Turkey Creek Sewer, two sewage pumping stations to be used in connection therewith, and certain laterals and extensions of existing sewers thereto, for Kansas City, Missouri, will be received up to 2 p.m. August 19, 1919, at the office of the Board of Public Works, City Hall, Kansas City, Missouri.
The main sewer will be about one and one-fifth miles long, and the laterals and extensions about three and one-half miles: the main sewer will be constructed of reinforced concrete, the laterals and extensions will consist of concrete, segment blocks, and clay pipe.