De Pontibus: A Pocket-Book for Bridge Engineers – Chapter XXI


DePontibus – Waddell


1. Study carefully the engineer’s drawings as soon as they are finished, and make out a list of special points and features that will require extra care in the shops to secure good workmanship and proper fitting, then make out a typewritten report of these and submit it without delay to the Engineer.


2. Study carefully, as soon as they are finished and approved, all shop drawings, so as to become thoroughly familiar with the entire construction.


3. Make sure that metal of uniform character and of the strength, elasticity, and ductility specified is furnished by the rolling-mills, following the metal from one process to another from start to finish, and making sure that the test-pieces broken represent correctly the metal they are supposed to represent.


4. Check the chemical analyses of the metal occasionally, so as to see that they are properly made, taking care that the Contractor is informed as to what piece the samples are taken from, so that he can make a check test, if he so desire.


5. See that all the various tests indicate in the specifications are made faithfully, the number of same depending upon the relative uniformity of the metal furnished.


6. Make sure that all the punching is done with such care that the assembled parts will come together so as to make the rivet-holes match so accurately that when the reaming is finished there shall be no irregular holes.


7. Make sure that all pieces are cut to exact length and proper bevel, that all web-stiffening angles bear perfectly at top and bottom against flange angles, and that there are no loose rivets.


8. Wherever rivets with flattened heads or countersunk rivets are called for, make sure that they are properly chipped or otherwise brought to correct dimensions; also see that the ends of all members are limited to the lengths beyond the last rivet or pin hole shown on the drawings. Give particular attention to the ends of all posts and chord-members to see that the “over-all” and the clear dimensions between jaws correspond faithfully to those indicated on the drawings.


9. Take some effective means of ensuring that the entire work shall go together properly and without difficulty during erection, and so that when completed it shall conform in every particular with the Engineer’s design, even if, to accomplish the same, it be necessary in special cases to assemble the entire work at the shops.


10. Watch carefully the punching and handling of the metal in the shops, so as to see that no cracks develop therein, and that the metal withstands properly the manipulation, showing as perfect homogeneity as is found in the best structural steel.


11. Condemn, as soon as it is discovered, any material unfit in the slightest degree for use in the structure, no matter how many times it may have already been inspected and passed.


12. See that all metal-work is properly cleaned by the most approved methods and apparatus before the first coat of paint is applied, and that the latter is allowed to dry thoroughly before the metal-work is loaded on the cars for shipment.


13. See that all shop painting is thoroughly done, and that proper paint, mixed so as to comply with the specifications, is invariably used; and make an occasional chemical analysis of the paint, taking care that the Contractor is notified of the contemplated test after the samples are taken, in order that he may make a check analysis, if he so desire. Take special care to prevent any pieces of metal from being riveted together, unless the contiguous faces be first thoroughly painted.


14. Insist upon the discharge of any employee of the Manufacturing Company who willfully violates or continues to violate the specifications and the instructions given by the Engineer or his inspectors.


15. While endeavoring in every possible way to obtain good work, avoid as much as possible doing anything to annoy or harass the Contractor; but, on the contrary, take special pains to aid him in every legitimate manner to finish his work quickly and inexpensively.


16. Formulate and prepare for each large piece of work the best practicable method of recording progress and reporting thereon, and divide up the total work into groups or sections, so that the notes may be easy for reference. This should be done by the inspecting bureau, and should not be left to the shop inspector.


17. Send into the office of the Engineer regular weekly reports concerning the progress of the work, any special reports that from time to time appear to be required, the tabulated results of all tests of materials, and copies of all shipping bills.


18. Make sure that all shipping weights are correct by seeing the metal weighed, and keep account of the weight of all metal sent out on the work, as the Contractor will be paid by the pound. It will be necessary for the inspecting bureau to check all of these weights against the shop drawings to show how they agree or disagree. A detailed statement of both sets of weights must be sent to the Engineer upon the completion of the contract, or, at his request, upon the completion of any definite portion thereof.


19. The inspecting bureau shall, under no circumstances whatsoever, entrust responsible work of any kind to insufficiently trained assistants. When new inspectors are to be broken in, they must receive their training in such a way as not to jeopardize in the slightest degree the quality of the material or workmanship.


Finally, and in short, do all you can to make the structure in every sense of the word a credit to all concerned in its design.