Washington Street Tunnel
Designer: William Bryson
Harper’s Weekly, May 11, 1867
The Chicago River, a narrow stream runs through the city of the same name. A number of bridges furnish the present means of transit across this river, the width of which is not more than 250 feet. To allow the numerous craft to pass up this stream, which is really the harbor of Chicago, on their way to and from Lake Michigan, the bridges are constructed so as to swing upon a pivot arranged in a pier of masonry built in the centre of the stream. These bridges are continually open, making the crossing of them uncertain that it seems strange that the inhabitants of the Western metropolis should have endured the nuisance so long a time. Tunnels are to be constructed to replace these bridges. The one already commenced at the foot of Washington Street, and which we illustrate on this page (below), it is expected will be completed before another year has passed. Our correspondent thus describes it:
- A coffer-dam of pile is built half across the stream, the other half being left open for the convenience of passing vessels. Beneath this coffer-dam the tunnel is built, when that side of the river will be thrown open and the dam built on the other side. The estimated cost is $408,000.
TUNNEL UNDER THE CHICAGO RIVER,
Sketched By Theodore R. Davis
Harper’s Weekly May 11, 1867
Chicago. A Hand Book for Strangers & Tourists to the City of Chicago, 1869
ONE of the greatest curiosities to strangers visiting the city, is that gigantic undertaking in engineering science, the great pioneer sub-marine tunnel of the western hemisphere. The large number of vessels entering the port of Chicago, requiring the opening of bridges during the season of navigation every few minutes, greatly impeded the long lines of vehicles and pedestrians constantly passing over. The demand for a more eligible means of communication with the several divisions of the city became a necessity. A great public necessity in Chicago can never be long experienced; the people will have a remedy, regardless of cost.
On the 28th of October, 1864, the original ordinance for the construction of a tunnel under the Chicago river was passed by the city council. At this time the real magnitude of the undertaking was scarcely appreciated, and much valuable time was spent in discussing and considering the means and the location. It was at length determined to tax the entire city for the means, and Washington street was fixed on for the location and bids for the work advertised for.
On the 27th of July, 1866 nearly three years after the passage of the original ordinance ground was broken on Washington street for the tunnel, by Messrs. Stewart, Ludlam & Co., to whom the contract had been awarded. They, however, were unfortunate in their mode of procedure, and finally abandoned the work in May, 1867. The contract was then taken by Messrs. J. K. Lake, C. B. Farwell, and A. A. McDonnell, the contract price being $328,500; and they, by a vigorous prosecution of the work, brought it to a successful completion on the first day of the new year 1869, when it was formally opened to the public in an appropriate, though unostentatious manner, the severity of the weather preventing any general public celebration. Subsequently the tunnel was subjected to a practical test of its capacity as a thoroughfare. Five teams were driven through the tunnel loaded heavily as follows: 6,445 lbs., 6,500 lbs., 7,280 lbs., 8,685 lbs., and 9,165 lbs. The weight of the wagons averaged 2,600 lbs. each. The horses were not selected with reference to their drawing capabilities, but were considered as average teams used for that purpose. Those drawing the heaviest load arrived at the top of the grade without showing any symptoms of having been overworked, and all of them went through with apparent ease. Experienced parties gave it as their opinion that loads of 5,000 and 6,000 pounds can be drawn through the tunnel, by ordinary horses, with ease, and with less effort than at many of the bridges. The Board of Public Works were well pleased with the experiment, and entirely satisfied that in this, as in all other respects, the tunnel is a complete success.
Washington Street Tunnel, East Entrance
Photographer: John Carbutt:
The tunnel is divided into two portions. That for vehicles dips from Franklin street on the east end, and Clinton street on the west end, forming an open passage way twenty-two feet wide in the middle of Washington street, for a distance of one block on each side of the river. For 332 feet from the entrance the tunnel comprises a single large chamber. It is 10 feet 6 inches at the entrance, and about 150 feet from the river center it increases to 23½ feet. From the invert to the top of the arch the height is 20 feet 6 inches. The invert itself is 20 inches thick, being the segment of a circle 47.66 inches in diameter. At the base the abutments are 8 feet broad, until they reach the height of 5 feet 2 inches, when they continue 6 feet thick for 7 feet more. The arch is 32 feet thick at the sides, and 24 at top ; is 9 feet above the springing lines, and has 3 centres, The spandrel backs are formed of rubble masonry. The chamber at 150 feet distance from the river centre is 18 feet high, the inverts 16 inches thick, the abutments 7 feet 2 inches at base for a height of 3 feet 4 inches, then 6 feet thick for another foot, and 5 feet thick at top. The height above the springing arch is 7¾ feet here. This section extends 364 feet on the west side, and has a corresponding section on the east side, which extends 269 feet. At 110 feet from the river centre, on either side, separate double wagonways begin. Each are 11 feet wide and 15 high. A thick wall divides them, and supports and strengthens the work directly beneath the river bed. The two ends of the passage correspond. Parallel with the carriage-way the foot-passage extends 11 feet high at the centre, and 6 at the sides of the arch. A flooring of white pine is laid on joists, making a good even surface. The lights are 40 feet apart here and 50 in the carriage-way. Entrances are pierced through the walls to the roadways and the other footway.
Neat passenger houses, of Tuscan style, each 22 feet long by 19 feet 4 inches wide, stand on either side of the river over the passenger entrance. Eighteen steps are in each house. Ventilation shafts are sunk 110 feet from the entrance, and by these and other arrangements the air of the tunnel will be kept fresh.
Washington Street Tunnel, West Entrance (Franklin Street)
Photographer: John Carbutt:
Washington Street Tunnel, East Entrance
Sanborn Fire Insurance Map
The following is a table of the dimensions and grades of the tunnel:
- From centre of Franklin to center of Clinton street, 1,603 feet.
Between arches, 930 feet.
Between entrances to passage way, 810 feet.
Grade of descent westward from Franklin street, 1 in 16, for distance of 306 feet.
Grade of descent eastward from Clinton street, 1 in 18, for distance of 625 feet.
Depth of river channel, at tunnel, 16 feet.
Between walls, at Franklin and Clinton streets, 23½ feet; at arches, 19% feet.
Height of river section, 18.83 feet; of approaches, 20½ feet.
Total length of Nicholson pavement, laid on Joliet gravel, 1,608 feet.
The visitor will better understand the magnitude of the enterprise by the following statistics:
From July, 1868, to December 31st, 1869, 600,000 hours of mechanics and laborer’s work have been expended in its construction; 45,000 cubic yards of clay excavated; 5,000 cubic yards of cement laid; 6,000 of brick, and 10,000 of stone masonry; 10,000 of broken stone and sand, and 20,000 barrels of Falls City cement. In addition to the manual labor, a large amount of horse and steam labor was used, and several stone quarries were engaged in getting out the stone for the abutments and arches, not to mention the manufacture of the brick, which of itself gave employment to a large number of workmen.
A few items of comparison with the celebrated Thames Tunnel in London, England, will be found interesting to the visitor. The Thames Tunnel was built for the purpose of effecting a ready communication for wagons and pedestrians between the Middlesex and Surrey sides of the river, at a point below London bridge, where it is inconvenient to erect a bridge on account of the width of the river and the heavy East Indiamen and other vessels passing up to the docks. The approaches have never been graded. Over each of these shafts a small house is erected, and the descent is by a winding staircase. Devised by Sir Isambart Brunei, it was commenced in tlie year 1825, but was not opened] until 1843, and has never yet been finished, and probably never will be. It consists of two arched avenues, 1,200 feet long, lighted by gas, and cost 500,000 sterling, or $2,500,000 in gold. Its income has never paid its incidental expenses. In every foot are 6,000 bricks, and its external dimensions are 37 feet 6 inches in width, and 22 feet in height. During its construction the river broke through five times, great loss of life resulting from the irruption of the water.
It seems Fate decreed that the construction of a successful tunnel should be deferred for the young city of the Western World!
Scientific American Supplement, September 19, 1891
THE WASHINGTON STREET TUNNEL.
THE Chicago River and its branches constitute the harbor of Chicago, where all the business of the port by Lake craft is transacted. The arrivals and departures of vessels have reached the enormous aggregate of over 22,000 annually in a season of navigation of about seven months, making Chicago the first port in the United States as far as the number of arrivals and departures is concerned. Along this river are great lumber and coal yards, grain elevators, meat packing establishments, and generally all the means and appliances and paraphernalia of the great commerce by lake centering at Chicago, as well as facilities for transfer from rail to water transportation. The main river and its south branch cut off the business center of the city from the populous north and west sides, and it requires the most careful management by the city officials to accommodate the streams of pedestrians and vehicles and the passing vessels. The opening of a bridge blocks up the streets for long distances, and at certain hours of the day vessels are detained by closed bridges.
This great inconvenience, in spite of quick turning bridges, is daily becoming
more burdensome and annoying to both land and marine interests, and means are eagerly sought to reduce this annoyance, even at a great expenditure of money. Besides the swing bridges, there are two traffic tunnels under the river, and a third one for street car service in progress of construction. The Washington street tunnel illustrated was built in 1869, at a cost of 512,700 dollars, and is 1,525¼ feet long. The bed of the river and the top of the masonry of the river portion are the same, but unfortunately it was built at that time to allow of but 14 feet depth at low water in the river; this depth has always been insufficient, and the tunnel, on this account, was a serious obstruction in the river.
A few years ago the West Chicago Street Railway Company got permission from the City Council to operate its cars through the tunnel, on condition that the level under the river should be lowered so as to have at least 17 feet of water over it at the lowest stage, or 19 feet at mean water, and also that they build a masonry center and end piers over the tunnels to accommodate a swing bridge, the city supplying the super structure. Mr. S. G. Artingstall, engineer, of Chicago, was intrusted with the work, and it was completed in the spring of 1890. For the river section one-half of the stream was closed by a cofferdam, the timber crib which was to Serve as the foundation for the masonry center pier serving as the head of the cofferdam; when this was pumped dry of water the arch of the old tunnels was taken up and a cover for the tunnels built with steel girders 20 inches deep and 2½ feet centers, with brick arches between the girders in four rings of brick, covered with a layer of asphalt and then with 12 inches in thickness of cement concrete. This girder construction was adopted because it required the least amount of lowering of the roadway of the tunnel, while at the same time the necessary depth of water was obtained in the river. For the portion under, the crib for the center pier, and also under the dock walls or end piers, a three-centered arch, built with five rings of bricks, was adopted. The part under the center pier was built by by the usual methods of tunneling under the cofferdam. This part has no only to serve the purpose of a roof over the tunnels, but also is now supporting the masonry center pier and swing bridge. he approaches and all parts of the tunnel at the time were put in thorough repair, the grade of roadway under the river lowered to correspond with the lowering of the roof and the grade of show the old tunnel before work was commenced, and the shaded lines the structure as it now exists.
The West Division Street Railroad Company are now building under the Chicago River, about ¼ mile south of Washington street, a tunnel for the exclusive use of their street cable cars. This work is being done under the direction of Mr. Artingstall, who is now chief engineer of the sanitary district of Chicago, and it is expected will be finished in the fall of 1892. The dimensions of the tunnel are very large, as the company are sparing no expense to make it light, airy, and pleasant for their passengers. The tunnel is 30 feet clear width inside by 16 feet high, and besides passing under the river, goes under two seven-story buildings and one five-story building, and also under all the railroad tracks entering the Union Depot. A large portion of this tunnel is built, and the part under the tracks is in process of construction; the tracks have been undermined and supported without interfering with the passage of a single train. The cost of this tunnel will be about $2,250,000.–Engineering.
Electric Trolley Weekly, November 26, 1910
The rebuilding of the three tunnels under the Chicago river and the preparation for their utilization by the cars of the Chicago Railways Company is coincident with the remarkable rehabilitation of surface traction facilities in Chicago under the direction of the Board of Supervising Engineers Chicago Traction as well as with the plans for an unobstructed river channel which, in response to popular demand, the federal government has insisted upon as an aid to Chicago commerce. The three tunnels, each of which accommodates two tracks, are as follows:
- 1. The Van Buren street tunnel under the south branch of the Chicago river, located between Clinton and Franklin streets, just north of Van Buren street. This tunnel has a total length of 1,517 ft. between Franklin street, in the business center, and Clinton street, on the West Side, and is divided into an east approach of 112 ft., a tunnel length of 1,095 ft. and a west approach of 316 ft.
2 The Washington street tunnel extending along along the center line of Washington street, under the south branch of the Chicago river at \\ashington street, has a total length, with approaches, of 1,520 ft. between Franklin street, in the business district, and Clinton street, on the West Side.
3. The La Salle street tunnel, extending along the center line of La Salle street under the main Chicago river between Randolph street, in the business district, and Michigan street, on the North Side, has a total length of 1,887 ft., of which 1,170 ft. of the old tunnel was brick arch, about 180 ft. of iron girders, with brick arches between, and the remaining 537 ft. about equally divided between the approaches.
Progress of the Work
As stated in ELECTRIC TRACTION WEEKLY, issue of October 22, 1910, the Van Buren street tunnel, which had been in course of construction since July, 1906 was on October 16 officially opened to traffic for small cars, and steps are being taken to remove certain steel columns supporting the elevated railway structure which now prevent the operation of the large through-route cars through this tunnel. As reported in our issue of November 19, 1910, the Washington street tunnel is nearly completed and the installation of car tracks is proceeding while the tunnel builders, George W. Jackson, Inc., are finishing the work at the east approach. The La Salle street tunnel work is well advanced. The War Department has issued a permit naming December 2 as the date upon which the river current may be shut off at Lockport and shipping may be denied passage and the work of pouring concrete about the twin steel tubes which have been constructed in a shipyard may be commenced and the tunnels to La Salle street then sunk into place. As it requires several days to float the tubes to La Salle street, they have been started on their journey.
History of The Tunnels
The Van Buren street tunnel was built between the years of 1890 and 1894 by the West Chicago Street Railroad Company to accommodate the cable line passed which was then being built on Blue Island avenue. The tunnel was a three-centered brick arch of 30-ft. span at the springing line and 20 ft. in height from the invert to the crown of the arch. The west 500 ft. of the tunnel is directly under the Pennsylvania Railroad Company’s yard, while the east 300 ft. support four seven-story brick buildings. The Washington and La Salle street tunnels, very similar in general form of construction, were built with the proceeds of city bonds, the former in 1867 and the latter between 1869 and 1871. In the late 80’s when the street railway companies were contemplating a change from horse cars to cable lines, the Washington and La Salle street tunnels were turned over to them for car operation on condition that the roof of the Washington street tunnel be lowered so as to provide a depth of water over it of 17 ft. instead of 14 ft. This work was done by the company in 1889. In September, 1901, the Secretary of War, in obedience to an act of Congress of April 27, 1904, notified the Chicago Union Traction Company to lower the roof of the Van Buren street tunnel to provide a depth of water over it of at least 22 ft. and also similarly notified the city of Chicago with regard to the Washington street and La Salle street tunnels.
The maximum depth over the tunnels in 1901 was but 18 ft. while the depth at mean water level was as low as 16 ft. The increase in the draft and tonnage of lake vessels made the tunnels a barrier to shipping and this was particularly noticeable when the river level was lowered by reversal of the current due to the opening of the Sanitary and Ship Canal.
The work of lowering the Van Buren street tunnel and removing the roofs of the Washington and La Salle street tunnels was begun by the receivers of the Chicago Union Traction Company in 1906. The Van Buren street tunnel was acquired by the Chicago Railways Company in 1907. On February 11, 1907. the city council passed an ordinance providing for the completion by the Chicago Railways Company of the the work of lowering the river section of the Van Buren street tunnel and the reconstruction of the Washington street and La Salle street tunnels.
The work on the Van Buren Street tunnel, as begun by the Chicago Union Traction Company, consisted of the building of a new steel girder and concrete roof in the river section, the building of bulk heads at each end of the new roof, the cleaning out of old tracks, cables, yokes, etc., lowering the invert and underpinning the old foundation for practically the entire length of the tunnel, rebuilding the pump chamber and well and removing the old roof in the river section. The completion of this work and the equipment of the tunnel for modern operation has been noted.
The work of removing the Washington street tunnel which, in order to comply with the act of Congress was begun under the direction of the receivers of the Chicago Union Traction Company, consisted of the building of a new steel girder and concrete roof over the river section, tearing out the south wall of the roadway, building new foundations in the old foot passage of the tunnel, building water tight bulkheads and finally removing the river section of the old tunnel roof and the center pier of the Washington street bridge, which rested upon the tunnel. This work was completed about October, 1907.
The New Washington Tunnel
About a year later plans were prepared for the construction of a new tunnel and the western approach, designated as section No. 1, was completed by George W. Jackson, Inc., in 1909. In January, 1910, the same company began work on section No. 2, which embraced the east approach and the river section. This work, which is now practically completed, has constituted not only an important but a novel engineering feat, a plan new in tunnel construction having been devised by George W. Jackson, Inc., and used for the first time in this work. When the old tunnel in the river section was torn out, a flat roof, consisting of steel girders supporting a concrete slab, was put in, mainly with intent of complying with the government’s requirements that the old arch be removed as an obstruction to navigation. It was at this time not determined in exactly what manner the flat roof built just above the old invert tunnel would be utilized in building the new tunnel. However, Mr. Jackson and his engineers decided that this roof, as built under the bed of the river, would serve satisfactorily for the roof of the new tunnel and that he would proceed to build concrete side walls under it to support it. An ac companying cross section shows how this was accomplished. Tunnel headings were started and the clay removed in the space represented by the base of the wall to be built. Forms were built, steel reinforcement rods placed and the concrete put in. When the walls had been completed at the base, excavation above this wall and up to the old foundation walls was carried forward. The work was done in sections and lagging at the sides of the walls left in place and all necessary provisions made for the proper support of the old wall until the new wall was ready to support its load. After the new walls had been built, the old invert and the core below were taken out, exposing the new concrete walls. About 200 ft. of this work was done under the main bed of the river.
There still remained 996 ft. of Section 2 to be built, including the east approach, and much the same process was pursued in building the concrete arch. Numerous headings were established, in the manner shown in one of the illustrations, and the clay and rock, removed by means thereof, corresponded to the mold which it was desired the new concrete wall and arch should occupy. The walls of the excavated arch were lined, as rapidly as headings were advanced, with the timbers constituting the forms for the concrete arch; reinforcement was laid and the concrete put in, as the excavation progressed. Later, the core of clay was taken out, exposing the forms, the removal of the latter revealing the finished arch, which has a width of 28 ft. The two tracks of the tunnel are separated up to within 100 ft. of the portals with a curtain wall which, except under the river section proper, was built at the same time as the remainder of the arch and in the manner above described, so that the removal of the core was in two bores as shown in one of the illustrations. The concrete invert for the new tunnel was then put in place. The Chicago Railways Company will proceed with the installation of car tracks as soon as material can be carried into the tunnel and while the tunnel builders are finishing the work at the east approach.
The Board of Supervising Engineers has carried out its intention to build the Washington street tunnel in harmonious accord with the future subway system. Accordingly the track in the present west approach is laid on a temporary grade of 9 per cent, and is, for present use, supported on temporary trestle work consisting of bents on 10-ft. centers with stringers between them to support the ties. The east approach is on a temporary 10 per cent grade. The rail now laid on the west approach is a low T-rail. A double flooring over the ties completes the approach. As will be noted from the profile drawing, the permanent track grade from the subway system into the tunnel is intended to be 2.9 per cent on the west approach and 3 per cent on the east approach. The permanent grade in the tunnel itself is 5.3 per cent. The track work in the tunnel proper will have no unusual features, the subgrade and ballast resting on the heavy concrete invert, which has a minimum thickness of 2 ft. 10 ins. The Board of Supervising Engineers expect the opening of this tunnel to have an immediate effect in relieving the traffic congestion, towards the accomplishment\ of which the efforts of the board have been directed during the past two years. With the Washington street bridge closed to traffic since the commencement of work on the tunnel and with the frequent interruptions to traffic due to the necessity of opening the other bridges over the south branch to permit the passage of vessels, the operating ingenuity of the company and the patience of the public have been severely taxed.
La Salle Street Tunnel
The designs for reconstruction of the La Salle Street tunnel made in 1906 contemplated a new roof in the river section. But in November, 1906, water broke through the invert as the result of a leak and flooded the tunnel. After ineffectual attempts were made to repair the damage it was decided to abandon the old tunnel and to remove it by dredging a deep trench along the outside of the walls, then drilling the walls and roof and blasting. All work of removing the roof and side walls to provide the necessary depth of water required by the government, was completed by April, 1907. Various methods of reconstructing the tunnel were proposed. Owing to the fact that the United States government objected to the obstruction to navigation which would result from the construction of the river section by the open cut method, a double bore steel shell, to be erected in dry dock, floated in place, lined with concrete and sunk to position upon foundations previously prepared, was later designed and finally adopted.
Chicago Examiner, January 30, 1911
Defying superstition, the Chicago Railways Company formally opened its new Washington street tunnel yesterday with car No. 313 on run No. 13, and not a mishap resulted.
Every seat in the car was filled, many being occupied by officials of the company, who rejoiced with the other passengers that there will be no more delays on the line because of traffic on the river keeping the bridges open.
According to Conductor William Lemke the trip was made in one minute and twenty seconds, and though this route takes the cars two blocks out of the old Madison street route the time gained in going from Franklin to Canal street more than overcomes the time lost on the old route by reason of vehicles and open bridges.
Simultaneous with the opening of the Washington street tunnel the La Salle street tunnel tube was towed from the Northwestern docks, foot of Kinzie street, to the north side of the river, between Clark and Wells streets.
A crew of 500 men will be set to work on March 1 and J. A. Green of the Ann of McCovern & Green, who have the contract, said last night that the tunnel will probably be opened for traffic not later than September 1.
Washington St. Tunnel, East Entrance
P. B. Greene, Photographer
John Carbutt, Photographer
Chicago Tribune August 28, 1938
BY HAL FOUST.
George Barton, engineer for the Chicago Motor club, yesterday completed an analysis of a proposal to convert street car tunnels under the Chicago river into automobile passageways. He concluded that money for such an improvement could be spent with more benefit to traffic by elevated highway construction.
There are three of these tunnels—in Washington, and in La Salle street, and near Van Buren street. The Van Buren tube lacks direct approaches from the east and from the west. Heavy motor trafic crosses the bridges over the other two tunnels. With no street car in sight and with a jam of automobiles ahead, drivers have looked covetously at the mouths of these subways as a possible avenue for easy entrance or exit to or from the loop.
Studies Washington Tunnel.
The worst automobile congestion is in Washington street, where the bridge is old and narrow. So Barton selected the tunnel there for detailed study. He found that 1,046 automobiles an hour creep across this antiquated structure during the morning rush at an average of eight miles an hour between Clinton street and Wacker drive.
The motor club engineer calculated that the tunnel, notwithstanding grades so steep as to require second gear driving, could handle 635 automobiles per hour per lane at a rate of twelve miles an hour. The subway has two separated passageways, each wide enough for one lane of motor cars. If both lanes were to be moved in one direction during the rush periods, the capacity would be 1,270 cars per hour, 21 per cent more trafic than is now able to crawl across the bridge.
This diagram shows alternate proposals for converting the Washington street car tunnel into a passageway under the Chicago river for automobile trafic. The estimates of costs and of benefits were prepared by the Chicago Motor club. The club s engineering studies favored the longer of these alternate plans, but rated both far below elevated highways in benefits per dollar of expenditure.
Bridge Opens for Ships.
Barton calculated non-rush hour trafic makes as good time over the bridge as it could make using the subway where grades of 9 and 10 per cent would slow the speed. However, the tunnel trafic would not be stopped by bridge openings. In May, the Washington street bridge was opened for ships and boats 175 times for an average of 3.1 minutes.
Summarizing these factors, it was deduced that 17,000 automobiles a day would use this tunnel if street cars were rerouted. Each auto would save an average of twenty seconds. The total saving, using a somewhat standard evaluation of 2.75 cents for vehicle minute, would amount to $48,600 worth of motorists’ time per year.
Washington Street Tunnel
Robinson Fire Maps
Would Return 5 Per Cent Interest.
This $48,600 saving a year, Barton figured, would return 5 per cent in- terest on an investment of $970,000. This is less than the $1,200,000 that he estimated would be required to pay the street car company for its equity In the tunnel and to illuminate, ventilate and pave the tube for automobile use.
It would be a better investment, according to this engineer, to spend $1,500,000 more, or a total of $2,700,000, and extend the tunnel east beyond La Salle street and west beyond Des Plaines street easing the grades to a maximum of 4 per cent. This would step up the driving pace through the subway from twelve miles an hour to twenty-five mines an hour.
Motorists Could Save Three Minutes.
Traffic on the surface and bridge of Washington street between Des Plaines and La Salle averages nine miles an hour In rush periods and fourteen miles an hour in nonrush periods. In the morning and evening rushes, motorists could save three minutes by using the tunnel. The average saving per trip throughout the day would be two minutes. Through east and west trafic would underpass the busy intersections at Jefferson, Clinton, Canal, Wacker, Franklin and Wells street.
The motor club estimated that, at 2.75 cents per vehicle minute, the time that would be saved by the elongated tunnel would amount to $228,175 a year, justifying a capital investment of $4,560,000, or $1,860,000 less than the actual cost of the improvement.
“From these figures,” said Barton, “it would seem that the state highway department or the city should develop the tunnel for automobiles. However, the proposition does not appear so favorably when it is compared with elevated highway construction, where a maximum of safety and convenience is obtained for each dollar invested.
Tunnel Might Prove Dangerous.
“For $1,200,000, the estimated price of the short tunnel, a four lane elevated highway could be built from Clinton street to Union park. For $2,700,000, the price of 3,600 feet of two lane tunnel, the state might build 5.45 miles of four lane elevated highway under Dr. Miller McClintock’s estimates of the cost of a light weight structure for passenger automobiles only.”
“Furthermore, an elevated highway is the safest trafic facility while the tunnel, if the 9 and 10 per cent grades were to remain, might prove prohibitively dangerous. In addition to these steep inclines on which automobiles would have to stop and start, there’s another hazard due to the fact that the tunnel’s two lanes are separated by a retaining wall. In event of a wreck or a fire or even a stalled car it would be difficult to evacuate the tube.”
Streetcar emerging from the east end of the Washington Tunnel at Franklin Street.
Chicago Tribune, January 27, 1956
Newly installed fence blocking entrance to old street car tunnel beneath river at Washington and Clinton streets.
George De Ment, acting public works commissioner, reported yesterday that a new fence, barring the entrance of the old street tunnel at Washington and Clinton was erected primarily to keep derelicts from nearby Madison st. from entering the tunnel and possibly drowning in the water that partially fills it. It also deters motorists unfamiliar with the old entrance from driving into it.
By 2013 both approaches had been covered.