Getting a. Bridge Built

Transcription

1 Getting a Bridge Built The progress of the Black River bridge construction was recorded by two I men, the clerk and the bookkeeper of the project. Their photographs of the work have left a wonderful record of how a major engineering project was completed with only steam and manpower. We do not know the complete names of these men, but they presented albums of the photos to railroad executives, including Jack Myers, an inspector for the B & O, whose album has been preserved by his family and was given to the Lodi Historical Society. The batch plant mixed concrete to be poured into the cavity of the large stone piers that were built to support the bridge. Materials were brought by railroad car. There seems to be a steam pressure tank in the right background that might be sending steam in a line from a boiler in the building. The river bottom was found to be soft shale; therefore piles had to be driven to solid rock using this steam-powered pile driver. The men are standing on the superstructure over a cofferdam that kept the river from flooding the area. The excavation for the cofferdam was dug by hand. Each shovel of soil would be placed in the large bucket on the right and a steam-powered boom-jack would lift the load from the excavation. Piles and all timber used in the project were cut locally. FOURTH QUARTER 2013 The Sentinel 9

2 Keeping the inside of the cofferdam clear of water was a constant job done by steam-powered pumps. This photo shows a pier being built adjacent to the bank of the river. This photo, probably taken from the bridge structure, shows all the major components of the job. The pile driver sits on a cofferdam; a boom-jack moves piles into place. In the background great stacks of stone are visible near the batch plant. On the right a narrow-gauge track is visible. These small tracks were placed and moved as needed to move stone and wood. All these tools were driven by stationary steam engines, some small and movable, and some in a central location with lines to the job. One pier has been completed behind the pile driver. Taken from the top and west end of the site, this photo offers another look at the basic components of the job. Hundreds of wood piles await the pile driver, which is centered over the cofferdam. The nearby countryside provided more than 3,00 piles for the bridge and trestle structure. The steam-powered boom-jack, predecessor of the modern crane, provided the great lifting power required. The machine consisted of two large wooden beams seated in a rotating base. The upright bea was connected by cable to the second beam, or boom, from which a lifting cable could be extended. By changing the angl of the boom to the upright beam with cable, the direction of the boom and lift cable could be moved. 10 The Sentinel FOURTH QUARTER

3 Berea sandstone, transported by rail from a quarry near Plymouth, Ohio, was the ultimate building material. It was both economical and convenient. Crude stone was cut and refined by English and Italian stone cutters. Each stone had to be individually cut to specific dimensions to form the arch. The top and bottom of the stone might vary by only one-quarter of an inch. Concrete was used only in the piers of the bridge. Every other stone was held in place by its own mass and gravity. By the summer of 1906 the principal piers were complete. The rounded ends of the piers are upstream and will divert the flow and occasional floodcarried debris around the bridge. The piles driven into the middle of the river will support the cribbing that is to be built to support the arch under construction. 5[_:s The central arch is complete with the river running freely underneath. The cofferdam protecting the piers and cribbing has been removed. FOURTH QUARTER 2013 The Sentinel 11

4 Each arch is a perfect half-circle The wood cribbing had to be stable and rugged enough to support the weight of the stone until the entire arch was finishe When the cribbing was removec each pier supported an estimate 22 tons of weight. The capstone is placed, but the work has only begun. Light showing through the cribbing shows that much more stone must be placed. Each stone in an arch had to be tapered onequarter of an inch even though the stone might be 5 feet long. Work continues on all three arches. At this time the walls between each arch are being constructed, to be filled in with aggregate material. Two platforms about 50 feet above the river support the boom-jacks needed to finish the structure. 12 The Sentinel FOURTH QUARTER

5 I The first row of stone is complete and the walls are gradually being added. The trestle for the final track is visible on the left. When the bridge is completed the trestle will be an embankment completely covered with soil and gravel. A great deal of fill material was required to bring the adjacent track up to the level of the completed bridge. An extensive wooden trestle was constructed and fill material excavated nearby was brought using a donkey engine and sidedumping cars. The fill area is about a mile long on either side of the bridge. i Even though the cars of fill material were usually pushed out onto the trestle and the engine was kept on the embankment, accidents did happen. The area near the east end of the project is muck soil and considered a swamp. Locals have a story that one engine and its cars fell from the track into the nearby swamp and disappeared. I On top of the arches, now almost complete, aggregate is added to fill the trough created by the walls. The fill material is lifted in barrels by boom-jack and then distributed by manpower. The unbonded stone and aggregate act as a cushion for the weight and vibration of trains. Weep holes allow water drainage and no freezing z=-3v3& mm. fee.*-..,*, *,«; FOURTH QUARTER 2013 The Sentinel 13