Main Street Bridge: Sinks Two Inches
- from Wheeling Daily Intelligencer, March 10, 1892, p. 5.
Main Street Bridge
IT SANK TWO INCHES.
The Arch of the Main Street Bridge Freed of its Support.
THE YIELDING NOT UNEXPECTED.
The Sand being let out of the Boxes very Gradually, but the Arch now Supporting its own Weight, and no Further Sinking is Expected — Brick Work Begun.
The crucial test was made at the Main street stone bridge yesterday, when the stone arch was let down so that it received no support from the wooden centre or false work which held it in place while it was built. The arch became self-supporting. At that moment more anxiety was naturally felt than at any stage of the work. The bridge sank. It was expected that it would, for all stone arches of any size do sink. The question was, how much of a depression would there be?
The sand-boxes which supported the false work were first tapped on Monday. At that time a pint of sand was taken from each. The openings in the sides of the boxes were uncovered, and the sand ran out nicely into the pint measure held to receive it. When the measure was full the holes were covered again and the flow of sand stopped. On Tuesday another pint of sand was taken out, and yesterday the third pint, which left the arch without any prop from below.
The engineers, Superintendent Bradley and the people most interested in the success of the structure were all on hand, carefully watching the result. The bridge had sunk, up to last night, two inches. This was a little more than it was thought it might go, but not too much for safety. Several inches is allowed for sinking, and the engineering was so carefully done that there was scarcely any reason to be uneasy as to the result. The greatest sinking on record of any stone arch to date was in an English bridge, which went down two and one-half inches. Proportionately to length of span and rise, the sinking of this bridge is about within the average.
The taking out of the sand will go on gently for a day or two, and then the centres will all be taken out, as they will have served their purpose and not be longer needed.
The crowds of spectators who have daily watched the progress of the work on the bridge have expressed some curiosity to know if the open spaces between the spandrel walls at each end of were to be filled in with concrete. This curiosity was yesterday set at rest, when the work of arching these openings over laterally with fire brick was begun. Then a new source of curiosity arose: "How do they get the little wooden centres or false arches out from under the brick arches?" This was asked half a score of times yesterday. An Intelligencer reporter shared the curiosity, and asked the same question. He was told that the wooden arches could be removed by being shoved over toward the open end. Of course the last section of wood support put in will have to stay. In fact probably all of them will be allowed to stay, for removing them would not add anything to the bridge nor letting them stay do any harm.
A good deal of work remains to be done before the bridge is complete in all its details.
- from the Wheeling Daily Intelligencer, March 11, 1892, p. 5
Main Street Bridge
THE BRIDGE ALL RIGHT.
A Careful Measurement Shows that is has not sunk any Farther.
THE CREDITABLE ENGINEERING.
With Careful Supervision and Competent Management by the Contractors, Achieved a Degree of Success bound to make the big Wheeling Bridge Famous.
It was reported yesterday that the stone bridge was still sinking. The engineers themselves thought this might very probably be true, as two inches, the yielding noticed the day before, was a very low proportion to the span. A careful observation yesterday afternoon, however, showed that the bridge was rigid at the point it had reached at the time of the last observation the day before. It has only sunk tow inches since the removal of the centers from beneath the stone was begun, and as it stood twenty-four hours without any further sinking, it is evident that is has reached its resting place.
There was never a more successful job of bridge engineering and building accomplished. The plans were so intelligently and carefully drawn that every stone fit in its place just as if it had been cut to fit the place by actual measurement. Engineering alone, however, could not have accomplished the work. Messrs. Hoge and White, the engineers in charge, did their part as well as it could have been done. This is shown by the fact that the sinking of the arch breaks the record. But without the competent work of Capt. K. G. Hallock, the managing member of the firm which had the contract, and the most faithful inspection of Mr. Bradley, who was charged with the duty of seeing that every piece of material that went into the bridge was what it ought to be, the engineers could have done little. All connected with the work operated together so harmoniously that the best results were to be expected, and they were obtained.
Two inches of sinking in an arch of 159 feet span will be regarded by the engineering world as a marvelous achievement. The closest record before made was on the Grosvenor bridge in England, where on the first attempt the bridge fell in when the false work was removed from beneath it. The arch was rebuilt, with more care, and on the second attempt the bridge was so nicely adjusted that it sank but two and a half inches. That was until the Wheeling arch was complete the high water mark of bridge engineering. It is something for a community to have a bridge which excels the finest former feat of engineering. Already the interest felt in it is intense and widespread. Requests for blueprints of the plans and for information as to details have been received from a number of prominent people.
It is thought that the bridge can be complete in every detail, including the laying of the water pipes and the arrangements for underground electric wires, inside of a month. The work of arching over the open spaces between the spandrel walls is being pushed along as fast as possible in spite of the weather. The cutting of the stone for the curb and the parapets is all that will require any special time, and it is understood that this is making good progress. At any rate the driveway can be paved and ready for use inside of a month. The sidewalks need not be pushed. It is not known whether the contractors would allow the bridge to be thrown open to vehicles before it is entirely completed and turned over to the city or not, but in all probability they would offer no objections.