Photo 3.1.38. February 20, 1918. A view of another drift, where forms are built for the sewer. The entire space between the sewer form and the tunnel wall is filled with concrete. The final exterior cross-section is a rectangle with the interior horseshoe-shaped cross-section for the sewer. The structure supported the roadway and a railroad bridge center pier. (MWRD photo 6397)

Photo 3.1.39. September 25, 1917, looking west in 120th Place from Prairie Avenue to Indiana Avenue. The sewer runs north under Indiana, turns east under 120th, and then turns north under Prairie. This one-block zigzag was needed to accommodate the two railroad crossings, one at 117th Street and the other at 121st Street. (MWRD photo 6208)

Photo 3.1.40. November 2, 1917, looking north in Prairie Avenue from 120th Place. The monolithic concrete sewer has internal dimensions of 14-feet high and 17.5-feet wide. With side walls, the overall width of the structure is 24.5-feet and that is why the entire street right-of-way is required for construction, including narrow-gauge tracks running on the sidewalk. (MWRD photo 6245)

Photo 3.1.41. November 2, 1917, looking down from 120th Place, and illustrating both the depth and size of the sewer. The section 6 sewer is deep because it is at the downstream end of the sewers draining to the Calumet Sewage Pumping Station at 125th Street and Indiana Avenue. Horizontal struts temporarily support the trench wall. (MWRD photo 6246)

Photo 3.1.42. November 2, 1917, looking north in Prairie Avenue from 120th Place. A concrete mixer is ready to discharge a batch of concrete down the chute into the sewer forms for the elbow at this intersection and also, going north, into the straight reusable sewer forms. (MWRD photo 6249)

Photo 3.1.43. July 27, 1917, looking north. The Illinois Central Railroad required the open-cut method for the section 6 sewer to pass under their Blue Island commuter branch on Indiana Avenue south of 120th Place. Excavation has already begun. Bracing is required to support the timber pile bents upon which the steel girder span is mounted. (MWRD photo 6065)

Photo 3.1.44. July 27, 1917. In addition to installing bracing on the timber bents, hand digging is necessary beneath the span because the dragline operator cannot cast the bucket without hitting the span. Hand digging will not be needed as the excavation deepens and larger equipment can be used. (MWRD photo 6066)

Photo 3.1.45. August 17, 1917, looking north from the Illinois Central Railroad viaduct on toward 120th Place. The dragline is excavating the sewer trench ahead of sewer construction in the foreground. (MWRD photo 6142)

Photo 3.1.46. July 27, 1917, looking north. The shovel is turning from Indiana into 120th Place, following the route of the sewer. Byrne Brothers is using a self-propelled steam shovel for excavation of pavement materials and shallow soils in Indiana Avenue. The shovel is mounted on wide steel wheels with lugs for traction. (MWRD photo 6068)

Photo 3.1.47. July 27, 1917. Byrne Brothers is loading spoil to dump cars for transit to the spoil area near 123rd Street and Indiana Avenue. Excess excavation spoil from section 6 sewer construction was required to be deposited in a designated location. (MWRD photo 6069)

Photo 3.1.48. A year passed and the sewer trench under the railroad viaduct had not been backfilled, and, by May 1, 1918, the excavation had filled with water. The area south of the rail line was unimproved land, and with labor shortages due to World War I, backfilling this trench was low priority. The tracks in the foreground were used for hauling excavation spoil. Before electrification, commuter trains were moved by steam locomotives. (MWRD photo 6461)

Photo 3.1.49. The flooded excavation became an attraction for neighborhood youngsters. None were found swimming when this photo was taken, May 1, 1918, but that doesn’t mean swimming didn’t occur at other times. Fortunately, no one drowned. However, a boy was hit by a train while he was playing too close to the tracks. The District was not liable for the boy’s injuries. (MWRD photo 6463)

Photo 3.1.50. December 12, 1916, looking north. Farm buildings in the background are near present day Vermont Street. Winter may soon stop work. Constriction of section 7 began near the Blue Island Lock and continued to the Calumet Sewage Pumping Station, two miles east. Before work on the lock, construction began on the sewer northwest of the outfall to the channel. (MWRD photo 5726)

Photo 3.1.51. April 20, 1917. Forschner, the section 7 contractor, has nearly completed the sewer near the outfall. Looking southwest, while lock and channel construction is underway in the background, the connecting structure is complete and the sewer is being completed in the foreground. The rectangular cross-section shape was used to support the access road to the lock. (MWRD photo 5868)

Photo 3.1.52. April 20, 1917. The North Drainage Ditch passed just north of the Blue Island Lock construction area and crossed the route of the section 7 sewer. The ditch could not be disturbed until after lock construction was completed. Forschner left a 200-foot long gap in the sewer and completed it in 1919. (MWRD photo 5869)

Photo 3.1.53. June 4, 1917. After a length of 600-feet, the sewer no longer supported the access road and transitioned to the more traditional horseshoe-shaped cross-section. The sewer ran north under Throop Street, then turned east under Riverdale Road, presently known as Vermont Street. (MWRD photo 5962)

Photo 3.1.54. June 4, 1917. Construction proceeds to the north, through an easement that will become Throop Street, before the turn east under Riverdale Road. The sewer invert has already been constructed in the foreground, while a mixer at right supplies concrete to sewer arch forms. (MWRD photo 5963)

Photo 3.1.55. April 20, 1917, looking east over 127th Street. The sewer trench in 127th Street—for the sewer to cross under the Pittsburgh, Cincinnati, Chicago and St. Louis Railroad, presently CSX—is supported with timber sheeting and bracing. Sewer construction had not progressed to this point. The railroad required a cross-section with extra reinforcement. (MWRD photo 5866)

Photo 3.1.56. July 27, 1917. Construction of the section 7 sewer was proceeding eastward along Riverdale Road. The sewer invert in the foreground is completed and the mixer at right is supplying concrete to the sewer arch forms. Locomotive-drawn dump cars are backfilling the sewer trench in the background. (MWRD photo 6063)

Photo 3.1.57. June 16, 1921. Construction has already begun on section 8, the wet weather discharge conduit for the Calumet Sewage Pumping Station, outside the southwest corner of the station, with an elbow connected to the discharge gate chamber. The conduit runs directly south to the Little Calumet River. (MWRD photo 8235)

Photo 3.1.58. June 16, 1921. Construction of a cofferdam has already begun for the outfall structure on the river’s north bank. This bend in the river would later be called Acme Bend and be widened to accommodate commercial navigation. A large steel plant will be built on the wooded floodplain in the right background. (MWRD photo 8233)

Photo 3.1.59. August 9, 1921. In just two months, the conduit and outfall are nearly complete. Backfilling of the conduit trench remains and will be completed after the struts and concrete mixer are removed. The outfall headwall rises above the conduit in the background. (MWRD photo 8361)

Photo 3.1.60. August 9, 1921. Proud of their work, the Byrne Brothers’s crew poses in the conduit and on the outfall headwall. The District usually has its name displayed on prominent structures, but the District’s name was not shown on the contract plans. Apparently, Byrne Brothers took the initiative to display their own name. (MWRD photo 8359)

Photo 3.1.61. May 8, 1919. Section 11 was the first true intercepting sewer and was built mostly by open cut to serve areas east of the Calumet River, Chicago’s East Side. The sewer begins at Baltimore Avenue and Ninety-Sixth Street, connecting to section 1. It ran southeast, cutting across the south end of the John Mohr & Sons site, shown here looking east. Three segments of section 11 were built by the tunnel method. (MWRD photo 7038)

Photo 3.1.62. January 29, 1923. The first tunnel was under a railroad embankment east of Baltimore Avenue and about 120 feet long. The shield method was used for tunneling because the soil was soft clay overlain by water-bearing sand. The structural steel shield is driven as excavation proceeds. Following the shield, tunnel support is installed and the exterior sewer form is built. The annular space between tunnel support and form is packed with bags of sand or sawdust. (MWRD photo 9621)

Photo 3.1.63. May 8, 1919. From Mohr’s site, the sewer ran east crossing under the Calumet River and under eight railroad tracks. The route is marked by the two Xs on the photograph. At left is a Chicago Southeast Side landmark, four dual-track railroad lift bridges used by several railroad companies. (MWRD photo 7042)

Photo 3.1.64. September 6, 1922. Set back from the west river bank, a pile driver is driving casing for a reinforced concrete shaft to contain syphon tubes, gate stems, and pump shafts. The bottom of the shaft is in hardpan clay a few feet above bedrock. (MWRD photo 9474)

Photo 3.1.65. October 22, 1922. A freighter heads north on the Calumet River, while construction of the shaft is underway. Looking southeast, the shaft’s oval shape is distinctive. Future shafts constructed by the District are circular. A concrete bucket is about to be lifted and moved to the mixer at left. (MWRD photo 9573)

Photo 3.1.66. October 22, 1922. The freighter is passing under the open lift bridge at left while across the Calumet River new elevators are being constructed. The syphon tunnel, 13 feet wide and 11.75 feet high, is about 40 feet below the river bank, just north of the elevators. (MWRD photo 9574)

Photo 3.1.67. October 3, 1922, looking down into the completed shaft from its northwest side. Reinforcement bars protrude where anchors will be attached for vertical piping. On the opposite side at the bottom is an opening for the tunnel that will cross under the river. This is the first inverted syphon built by the District. (MWRD photo 9570)

Photo 3.1.68. October 22, 1922. The tunnel opening at the bottom of the shaft is large to accommodate three barrels of the inverted syphon. The bulkhead, installed when the shaft was constructed, will be removed when tunneling begins. (MWRD photo 9571.1)

Photo 3.1.69. January 29, 1923. After the bulkhead is removed, tunneling begins. Forty feet below the river, the hard pan and hard blue clay requires strenuous digging. Within the void created, the bottom half of the concrete syphon is built and topped with the form for the syphon arch. The protruding reinforcing rods along the wall will be straightened and support the floor of the upper syphon barrel. (MWRD photo 9626)

Photo 3.1.70. January 29, 1923. Mining the clay is hard work in dirty and unsafe conditions. Light is provided only at the tunnel heading, and ventilation is provided through a pipe from the shaft. Until 1931, wood was used for tunnel supports and forms. A tragic tunnel fire in that year reformed tunnel construction methods and materials. (MWRD photo 9627)

Photo 3.1.71. March 20, 1923. The three-barrel syphon has two smaller barrels below one larger upper barrel. This view, immediately downstream of the control chamber, shows construction of the syphon with the two lower and smaller barrels already encased in concrete. Concrete has been poured to form the invert of the upper barrel. (MWRD photo 9647)

Photo 3.1.72. March 20, 1923. Near the lower end of the syphon, the larger barrel for wet weather flow is already completed. The electrical cables mounted on the wall are for construction purposes only. (MWRD photo 9648)

Photo 3.1.73. June 13, 1923. This first syphon was more elaborate than most. Looking north, masons are building the walls of the syphon downstream shaft head house. The three gate operators can be used to close gates on each of the three barrels in the syphon below. Similar gates were included on the upstream end. (MWRD photo 9798)