Welding taking over from Rivets in Skyscraper construction
THE PASSING OF THE RIVET - Those who have lived within earshot of the pneumatic riveters used in the construction of steel-frame buildings will earnestly wish success to the movement to substitute for these the noiseless processes of electric welding. Engineers who are interested in this new method are predicting for it a great future, we are told in the Cleveland Times. Altho the practical application of electric are welding to the building industry is scarcely ten years old, many of the larger structural steel fabricating companies are applying it, we are told by this paper. Notable instances are plentiful where the welding process has replaced riveting building joints. We read:
Today much of the equipment which plays an important part in the make-up of large buildings is made possible by welding, and instances of important structural repairs and building additions are plentiful where welding has been applied.
The ultimate replacement of riveted by welded sections in large buildings is inevitable, because of the tremendous saving which will result from the fact that there is no loss of strength at the joints welded, while the loss of strength on riveted sections runs from 30 to 50 per cent.
Where welding is applied to the supporting members of a structure, this, of course, means that the necessity of having great, heavy steel pieces in the lower stories of a building in order to carry the load higher up, as required on riveted jobs, is eliminated.
The Times quotes I. F. Lincoln, vice-president of the Lincoln Electric Company, of Cleveland, which has been active in this new development, as saying:
Every riveted joint, if it is depended on
to hold the parts together against stress,
must be made from material very much
heavier than would be necessary if a joint
were made by arc welding between the two
pieces of steel, the joint being as strong as
the steel, itself. What the saving from the
use of welding means is staggering in its
When one considers such undertakings as tall buildings, where rivets have been used in the past, and remembers that millions of tons of steel are used for them each year, it is easy to appreciate the savings to be accomplished through the use of arc welding at the joints.
The weight of the parts of a tall building can be reduced at least one-third as an average where the arc welding method is used in place of riveting.
In the case of a tall building the difference between the 100 per cent. joint possible through welding, and the 50, 60 or 70 per cent. joint possible through the various types of riveted construction, is of much greater importance because the effect of the heavier parts which must be used in order to get the strength at the riveted joint becomes cumulative.
It is obvious that the change from the riveted to the arc-welded joint is simply a matter of time. But for the conservatism of many of our present-day engineers the change would have come much more rapidly than it has thus far. While we in this country pride ourselves on our forward look, yet it takes us a long time to change our ideas on many things having to do with engineering.
That the attitude toward the use of welding instead of riveting is changing is well illustrated, the Times reporter tells us, by an instance in Detroit, Michigan. One of the largest firms of architects and engineers there specified that all joining of steel members for an industrial building to be erected for an automobile manufacturer could either be estimated on the basis of using rivets or on the use of arc welding. He goes on:
In the same city a twelve-story addition
has just been erected and joined to the
main building of a department-store structure in the business district. In this case
the engineers specified that the 103 girders
of the old and new structure should be
joined through the use of the arc welder.
On the department-store job, to satisfy the building department, tests were made on the welded sections, and it was shown that they carried nine times the stress which was to be imposed upon them in actual usage. Reports to the Cleveland manufacturers show that the job cost several thousand dollars less than would have been involved had it been necessary to use riveting.
Within buildings themselves the use of the arc welder has long been an important factor, the records of the Cleveland manufacturing firm show. Applications are in successful use on such important parts as passenger elevators, major pipe-lines, stocks, boilers, tanks, and a host of other parts and important pieces of structural equipment.
Massillon bar joists, joined through the use of the welder are used in a great variety of structures. Tests show that in every case they have stood loads far above those for which they are rated, and there has been not a single instance of the failure of the welded portions, it is stated.
In its own plant the Lincoln Electric Company has put the welder to a severe test. Welded steel braces have been successfully erected between the office and the factory buildings to prevent sagging of steel beams and the pulling apart of the two units of the structure.
For a number of years the units of the Lincoln plant had been gradually pulling apart, bringing about a sag in the roof and endangering the entire plant, it is stated.
Sagging had resulted from the fact that the plant is on made ground with a four-foot fill, which, as it settled down at the rear of the property, tended to pull the factory away from the office building.
A great deal of money and time were spent in the past trying to correct this situation. Riveted steel members could not be made to correct the situation, but through the use of steel-ridge construction welding there has been no further sagging.