Harvard Bridge: Difference between revisions

Coordinates: 42°21′16″N 71°05′29″W / 42.35457°N 71.09132°W / 42.35457; -71.09132
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"reference" (1) doesn't say that, and (2) is to a WP article. Looking it up on the web just finds reflections of this text. :-/
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In 1898, {{convert|3|ft|adj=on|sp=us}}-wide bicycle lanes were installed next to each curb.<ref name=haer3 /> In 2011 (113 years later), Boston finally connected to these lanes.<ref name=bglanes>{{cite news
In 1898, {{convert|3|ft|adj=on|sp=us}}-wide bicycle lanes were installed next to each curb.<ref name=haer3 /> In 2011 (113 years later), Boston finally connected to these lanes.<ref name=bglanes>{{cite news
| title = Mass. Ave, BU Bridge bike lanes completed
| title = Mass. Ave, BU Bridge bike lanes completed
| author =
| author =
| first = Johanna
| first = Johanna
| last = Kaiser
| last = Kaiser
| url = http://www.boston.com/yourtown/news/back_bay/2012/01/mass_ave_bu_bridge_bike_lanes.html
| url = http://www.boston.com/yourtown/news/back_bay/2012/01/mass_ave_bu_bridge_bike_lanes.html
| format =
| format =
| agency =
| agency =
| newspaper = Boston Globe
| newspaper = Boston Globe
| publisher = New York Times, Co.
| publisher = New York Times, Co.
| location = [[New York, New York]]
| location = [[New York, New York]]
| isbn =
| isbn =
| issn =
| issn =
| oclc =
| oclc =
| pmid =
| pmid =
| pmd =
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| bibcode =
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| doi =
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| id =
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| date = 6 January 2012
| date = 6 January 2012
| page =
| page =
| pages =
| pages =
| at =
| at =
| accessdate = 20 March 2012
| accessdate = 20 March 2012
| language =
| language =
| trans_title =
| trans_title =
| quote = The city installed bike lanes on the northbound and southbound lanes between Huntington Avenue and the Harvard Bridge, connecting them to existing bike lanes, just before the start of the new year.
| quote = The city installed bike lanes on the northbound and southbound lanes between Huntington Avenue and the Harvard Bridge, connecting them to existing bike lanes, just before the start of the new year.
| archiveurl =
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|isbn=978-0762741342
|isbn=978-0-7627-4134-2
|pages=61–63
|pages=61–63
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In 1958, members of the [[Lambda Chi Alpha]] fraternity at [[Massachusetts Institute of Technology|MIT]] measured the bridge's eastern sidewalk by carrying or dragging the shortest pledge that year, [[Oliver Smoot]], end over end.<ref name=haer5 /><ref name=mithistory49>[http://tech.mit.edu/V119/N49/this_week-_49_c.49f.html ''This Month in MIT History'', "The Tech", volume 119, number 49]</ref>
In 1958, members of the [[Lambda Chi Alpha]] fraternity at [[Massachusetts Institute of Technology|MIT]] measured the bridge's eastern sidewalk by carrying or dragging the shortest pledge that year, [[Oliver Smoot]], end over end.<ref name=haer5 /><ref name=mithistory49>[http://tech.mit.edu/V119/N49/this_week-_49_c.49f.html ''This Month in MIT History'', "The Tech", volume 119, number 49]</ref>


Crossing pedestrians are informed by length markers painted at 10-smoot intervals that the bridge is 364.4 [[smoot]]s long, "plus one ear". The qualifier "plus or minus" was originally intended to express measurement uncertainty,<ref>[[Robert Tavernor|Tavernor, Robert]], ''Smoot’s Ear: the Measure of Humanity'' (Yale University Press, 2007; paperback edition 2008), ISBN 9780300124927, Preface</ref> but over the years the words "or minus" have gone missing in many citations, including the markings on the bridge itself.<ref name="stone">{{cite web
Crossing pedestrians are informed by length markers painted at 10-smoot intervals that the bridge is 364.4 [[smoot]]s long, "plus one ear". The qualifier "plus or minus" was originally intended to express measurement uncertainty,<ref>[[Robert Tavernor|Tavernor, Robert]], ''Smoot’s Ear: the Measure of Humanity'' (Yale University Press, 2007; paperback edition 2008), ISBN 978-0-300-12492-7, Preface</ref> but over the years the words "or minus" have gone missing in many citations, including the markings on the bridge itself.<ref name="stone">{{cite web
| url = http://web.mit.edu/newsoffice/2009/smoot-0604.html
| url = http://web.mit.edu/newsoffice/2009/smoot-0604.html
| title = Smoot in Stone
| title = Smoot in Stone
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| last =Brehm
| last =Brehm
| date =1999-09-01
| date =1999-09-01
| month =
| month =
| year =
| year =
| work =MIT News
| work =MIT News
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===Length discrepancy===
===Length discrepancy===
Given that Smoot was {{convert|5|ft|7|in|m|3|sp=us}} tall in 1958, the given measurement in smoots of 364.4 yields a "bridge length" of about {{convert|620|m|ft|-1|sp=us}}. Published sources<ref name=structurae /><ref name=AM17 /> give the length of the bridge as approximately {{convert|660|m|ft|-1|sp=us}}. The difference in length between the sidewalk markings and the published figure represents a {{convert|40|m|ft|-1|adj=on|sp=us}} discrepancy. <!-- A possible cause is that in 1958, there were ramps to [[Storrow Drive]] on both sides of the bridge. There are [[smoot]] marks on both sidewalks, which fail to cover the entire length of the bridge. The fraternity apparently only measured the length of the sidewalk from the point where it is interrupted. It seems possible that the pledges were fooled by the apparent end of the sidewalk at the Storrow Drive ramps. <!-- The bridge (overall) ''should'' be 659.82&nbsp;m<ref name=structurae /><ref name=AM17 /> &divide; 1.7018&nbsp;m/smoot = 387.7 smoots &plusmn; one ear. The smoot marks could be revised to reflect that, perhaps by adding negative smoots southeastward, leaving the traditional markings unchanged to facilitate backwards compatibility with existing uses of the marks by the police and others.{{fact|date=November 2010}} <!-- reads like original research -->
Given that Smoot was {{convert|5|ft|7|in|m|3|sp=us}} tall in 1958, the given measurement in smoots of 364.4 yields a "bridge length" of about {{convert|620|m|ft|-1|sp=us}}. Published sources<ref name=structurae /><ref name=AM17 /> give the length of the bridge as approximately {{convert|660|m|ft|-1|sp=us}}. The difference in length between the sidewalk markings and the published figure represents a {{convert|40|m|ft|-1|adj=on|sp=us}} discrepancy. <!-- A possible cause is that in 1958, there were ramps to [[Storrow Drive]] on both sides of the bridge. There are [[smoot]] marks on both sidewalks, which fail to cover the entire length of the bridge. The fraternity apparently only measured the length of the sidewalk from the point where it is interrupted. It seems possible that the pledges were fooled by the apparent end of the sidewalk at the Storrow Drive ramps. <!-- The bridge (overall) ''should'' be 659.82&nbsp;m<ref name=structurae /><ref name=AM17 /> &divide; 1.7018&nbsp;m/smoot = 387.7 smoots &plusmn; one ear. The smoot marks could be revised to reflect that, perhaps by adding negative smoots southeastward, leaving the traditional markings unchanged to facilitate backwards compatibility with existing uses of the marks by the police and others.{{Citation needed|date=November 2010}} <!-- reads like original research -->


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Revision as of 03:48, 24 March 2012

Harvard Bridge
Harvard Bridge crossing the frozen Charles River from Cambridge to Boston, Massachusetts
Coordinates42°21′16″N 71°05′29″W / 42.35457°N 71.09132°W / 42.35457; -71.09132
CarriesRoute 2A
CrossesCharles River
LocaleBoston, Massachusetts to Cambridge, Massachusetts, USA
Maintained byMassachusetts Department of Transportation (MassDOT)
ID numberB160124EYDOTNBI
Characteristics
Designhaunched girder bridge
MaterialSteel
Total length659.82 meters (2,164.8 ft)[1] (roadway)
364.4 smoots ± one ear (620 m) (sidewalk from Storrow Drive to Cambridge only)
Width21.13 meters (69.3 ft) (total width)[1]
15.8 meters (52 ft) (roadway)[2]
Load limit78.4 metric tons (86.4 short tons)[2]
Clearance below3.7 meters (12 ft)[2]
History
Construction start1887
Construction end1891
Opened1891-09-01,[3] 1990
Closed1983 (temporary closure for repairs)
Statistics
Daily traffic49,000 as of 2005[2]
Lua error in Module:Location_map at line 391: A hemisphere can only be provided with DMS degrees for longitude.
Location
Map

The Harvard Bridge (also known locally as the MIT Bridge, the Massachusetts Avenue Bridge, and the "Mass. Ave." Bridge) is a steel haunched girder bridge between Back Bay, Boston to Cambridge, Massachusetts, USA, carrying Massachusetts Avenue (Route 2A) over the Charles River. It is the longest bridge over the Charles River at 659.82 meters (2,164.8 ft).[1] It is locally known for being measured in the idiosyncratic unit of length called the smoot.[4][5]

After several legislative attempts fraught with antipathy on the part of Boston, it was finally built between 1887 and 1891 with a swing span by Boston and Cambridge, Massachusetts.[6] The bridge was revised over the years until its superstructure was completely replaced in the late 1980s due to unacceptable vibration and the collapse of a similar bridge. The bridge was named for the Reverend John Harvard.[7]

Conception

In 1874, the Massachusetts Legislature passed two acts, Chapters 175 and 314 to authorize the construction of a bridge between Boston and Cambridge.[8] Nothing further happened until 1882, when a follow-up act (Chapter 155) with more specifics was enacted. The location was expressed as[9]

Acts of 1882, Chapter 155, Section 1: The cities of Boston and Cambridge are authorized to construct a bridge and avenue across Charles river, from a point on Beacon street, in Boston, to a point in Cambridge, west of the westerly line of the Boston and Albany railroad. ... to the limitation that the line thereof shall not be north-east of a line drawn from the junction of Beacon street and West Chester park, in Boston, to the junction of the harbor line with Front Street, extended, in Cambridge, nor south-west of a line drawn from the junction of Beacon street, Brookline avenue and Brighton avenue, in Boston, to the junction of the Boston and Albany railroad with Putnam avenue, extended, in Cambridge.

The bridge was to have a draw with an opening of at least 38 feet (12 m).[9] Boston did not like this act, mainly because it did not provide for an overhead crossing of the Grand Junction Branch of the Boston and Albany Railroad. So nothing happened until the act was amended by Acts of 1885, Chapter 129, which changed the draw to a clear opening of at least 36 feet (11 m) and no more, until the other bridges below the proposed location were required to have a larger opening.[10] Still nothing happened, until the City of Cambridge petitioned the Massachusetts Legislature in 1887 to compel Boston to proceed. This resulted in Acts of 1887, Chapter 282, which was mandatory for both cities. It required that each city pay for half the bridge, and allowed Boston to raise up to US$250,000 (US$8,480,000 with inflation[11]) for this purpose, in excess of its debt limit. This implied an estimated cost of US$500,000 (US$17,000,000 with inflation[11]) for the bridge.

The act authorized a commission to build the bridge. The commission was to consist of the mayors of Boston and Cambridge plus one additional person to be appointed by the mayors. If the mayors failed to appoint a third commissioner, the governor was to do it for them.[12] The mayors of Boston and Cambridge, Hugh O'Brien and William E. Russell, appointed Leander Greeley of Cambridge as the third commissioner.[13] This changed over time.[14]

Year(s) Mayor of Boston Mayor of Cambridge Third Commissioner
1887–1888 Hugh O'Brien William E. Russell Leander Greeley
1889–1890 Thomas N. Hart Henry H. Gilmore
1891 Nathan Matthews, Jr. Alpheus B. Alger Leander Greeley (died 15 February 1891)
George W. Gale

The expectations of having built the bridge were clear.[15]

The effect that the bridge will have upon both cities is obvious. The low land and marshes on the Cambridge side, formerly almost valueless, have been filled in and have become valuable; and Cambridge is now connected with the choicest residential portions of Boston. The residents of the Back Bay, South End, Roxbury, and other southern sections of Boston are now connected directly, by way of West Chester park and the bridge, with Cambridge, Belmont, Arlington, and adjacent towns; and this thoroughfare in Boston, it is believed, will ultimately be the central one of the city.

Engineering

The Act of 1887 declared the bridge to be a wooden pile structure with stone pavement for the first 200 feet (61 m) because the Charles River Embankment extension was expected to take that space, but that was changed such that the whole distance would be of iron spans on stone piers. The general plans were approved on 14 July 1887.[16] The engineers were William Jackson (Boston City Engineer), John E. Cheney (assistant Boston City Engineer), Samuel E. Tinkham (assistant engineer), and Nathan S. Brock (assistant engineer at bridge).[17]

The subsurface conditions at the bridge location are extreme. Much of Boston is underlain with clay, but the situation at the bridge is exacerbated by a fault which roughly follows the path of the Charles River itself. From a depth of approximately 200 to 300 feet (60 to 90 m) below existing ground, is a very dense till composed of gravel and boulders with a silt-clay matrix. Above that to approximately 30 feet (9 m) below the surface is Boston blue clay (BBC). Over this are thin layers of sand, gravel, and fill. The BBC is overconsolidated up to a depth of approximately 70 feet (20 m).[18]

The substructure originally consisted of two masonry abutments and twenty-three masonry piers, as well as one pile foundation with a fender pier for the draw span. The superstructure was originally twenty-three cantilevered fixed spans and suspended spans, of plate girders with one swing span.[19] The Boston abutment rests on vertical piles, while the Cambridge end is directly on gravel.[18]

Postcard of Harvard Bridge looking toward Boston in 1910

Originally, the bridge was built across the Charles River connecting West Chester Park, in Boston, with Front Street, in Cambridge. This is now called Massachusetts Avenue on both sides of the river. As originally built, the total length between centers of bearings on abutments was 2,164 feet 9 inches (659.82 m) with a draw 48 feet 4 inches (14.73 m) wide between centers. The width of the bridge was 69 feet 4 inches (21.13 m) except near and on the draw.[20]

The bridge as built was composed of fixed and suspended spans roughly 75 feet (23 m) long and piers 90 feet (27 m) apart, center to center.[21] The span lengths alternated between 75 and 105 feet (23 and 32 m). The longer spans were cantilevered, while the shorter spans were suspended between the cantilevers.[18]

The original roadway contained two lanes for horse-drawn vehicles and two street car tracks, for a total width of 51.0 feet (15.5 m). There were also two 9-foot-2-inch (2.79 m) sidewalks.[6] The original roadway and sidewalk stringers were of wood, with an approximately 1.25-inch (32 mm) thick covering of asphalt on the sidewalk.[6]

The exception was at the swing span, which was 48 feet (15 m) wide. This span was approximately 149 feet (45 m) long, and sat on a wooden pier. It was a double-cantilevered, electrically-driven structure also carrying a bridge caretaker's house.[6]

The bridge opened on 1 September 1891.[3] The original cost of construction to 1 March 1892 was US$510,642.86.[22] This is equivalent to US$17,320,000 with inflation.[11]

Naming

Postcard of Harvard Bridge and MIT between 1916 and 1924

The bridge was named for the Reverend John Harvard, for whom Harvard University is also named, rather than after the university itself. Other names suggested included Blaxton, Chester, Shawmut, and Longfellow.[7] The structure now called the Longfellow Bridge opened 15 years later. John Harvard was an early donor to what later became the university; not, as is often assumed, its founder.[23]

Possibly due to its proximity to the bridge, there have been a number of tales reported at MIT as to how the bridge came to be named "Harvard", all apocryphal. The Harvard Bridge was first constructed in 1891. MIT did not move to its current location adjacent to the bridge until 1916.[24]

Maintenance and events

Harry Houdini jumps from the bridge

In 1898, 3-foot (0.91 m)-wide bicycle lanes were installed next to each curb.[6] In 2011 (113 years later), Boston finally connected to these lanes.[25]

According to a marker near the southeast end of the bridge, Harry Houdini performed one of his "well known escapes" from this bridge on 1 May 1908. Other sources have it as 30 April 1908.[26]

The bridge was declared unsafe in 1909, requiring all of the iron and steel to be replaced. The draw was elevated slightly and the trolley rails were replaced as well.[27]

When the Metropolitan District Commission (MDC) took control of the bridge in 1924, they rebuilt much of the bridge superstructure. They replaced the wooden stringers with steel "I" beams, topped wooden deck elements with concrete and brick, and replaced the street car rails.[6] Structural steel hangers replaced wrought iron. The swing span was converted into two 75-foot (23 m) fixed spans the same width as the rest of the bridge. The wooden pier was heavily modified with concrete and stone to make it resemble the other piers, increasing the number of stone piers from 23 to 24.[18][28]

Heavy traffic at the Mass Ave and Memorial Drive intersection on the Cambridge end of the bridge led to the construction of an underpass in 1931. The underpass eliminated the at-grade intersection.[4]

The bridge was often known as the "Xylophone Bridge" because of the sound its wooden decking made when traffic traveled over it. This decking was replaced in 1949 with 3-inch (76 mm) concrete-filled "I-beam lok" grating topped with a 2.25-inch (57 mm) thick bituminous wearing surface. At this time, all bearings were replaced, and the trolley car tracks were removed, as were granite blocks. The trolley car poles were reused for street lights. Ramps between the bridge and the under-construction Storrow Drive were added.[4]

The 1924 sidewalk slabs were replaced by precast, prestressed slabs in 1962.[4] The fifteen expansion dams were replaced or repaired in 1969.[29]

Engineering study, 1971-1972

An engineering study was performed by the Metropolitan District Commission (later merged into the Department of Conservation and Recreation) in 1971-1972 due to complaints by bridge users of excessive vibration.[4][30] The bridge was found to be understrength for its load. Before the final study was complete, the recommendation was to place a load limit of 8 short tons (7.3 t) per axle and a total of 15 short tons (14 t) per vehicle, or to restrict trucks to the interior lanes, where the bridge was stronger. A 25-short-ton (23 t) limit was imposed.[31]

Suggestions made included strengthening the existing structure by adding either struts or plates to make the existing four beams along the length of the bridge into a stiffening truss, or to replace the superstructure with a new one, made of either steel or concrete, which would be up to current standards.[30] The recommendation was to replace the superstructure with one weighing approximately the same in order to reuse the piers, which were in good condition.[31]

The reasoning was that the cost of a new structure could be predicted much more easily than the cost of repairing and reinforcing the existing bridge. The resulting new bridge would be of known materials and quality, such as ductile structural steel rather than brittle wrought iron, and rated at AASHO HS-20. Repairing the existing structure would leave old wrought iron of uncertain quality and condition standing, and would not bring the design up to (then) current standards.[31] Detailed engineering calculations were included.[32] The price was estimated at 2.5 million to 3 million U.S. dollars[31] (US$18,000,000 to US$22,000,000 with inflation[11]).

The action taken based on this study was to establish load restrictions on the bridge, 15 short tons (14 t) in the outer lanes, 25 short tons (23 t) on the inner lanes. This was expanded in 1979 to a flat limit of 15 short tons (14 t) on the whole bridge.[33]

Superstructure replacement, 1980s

After the failure of the Mianus River Bridge at Greenwich, Connecticut in 1983, the Harvard Bridge was shut down and inspected because it contained similar elements, specifically the suspended spans.[34][35] Traffic was restricted to the inner two lanes due to the discovery of two failed hangers on span 14. A few days later, all trucks and buses were banned from the bridge.[33]

In 1986, a report was published containing the plan to replace the superstructure on the existing supports. Alternatives considered were very similar to the 1972 report, and were similarly decided.[36] Structural modifications included an upgrade from four longitudinal girders to six of the same shape, elimination of ramp "B", and replacement of a stairway with a handicapped pedestrian ramp on the Boston end of the bridge.[37]

The historic value of the bridge was considered significant, so the plan was to make the replacement superstructure appear similar, with similar railing and lighting. In order to document the pre-existing structure, a Historic American Engineering Record (HAER) would be prepared.[38]

Ramp "B", from southbound (Boston bound) bridge lanes to eastbound Storrow Drive, caused traffic to merge onto Storrow Drive from the left (high speed) lanes using a short acceleration lane, causing safety issues. The MDC requested elimination of this ramp. Compared to overall bridge traffic of 30,000 vehicles per day, traffic on ramp B was found to be low, approximately 1,500 vehicles per day with a peak of 120 vehicles per hour.[39]

Pier 12 was exhibiting inappropriate movement and was scheduled for reinforcement.[40]

The work would be done in two phases. Phase 1 would reinforce the downstream side of the bridge to allow MBTA bus traffic, and was expected to take 5 months. Most of this effort would be spent on the underside of the bridge and would not affect existing traffic. Phase 2 would replace the entire superstructure and was expected to take three construction seasons to implement. Cost was estimated to be US$20M[40] (US$56,000,000 with inflation[11]). Phase 1 finished in 1987, and Phase 2 in 1990.[41]

  • Before-and-after images
  • This image shows the bridge from the upstream Cambridge side in 1985. If you click on the image, you can see construction barrels restricting traffic from the outside lanes, and how the bridge was showing wear.
    This image shows the bridge from the upstream Cambridge side in 1985. If you click on the image, you can see construction barrels restricting traffic from the outside lanes, and how the bridge was showing wear.
  • This is roughly the same view, in 2009. This superstructure is in much better shape, only 20 years after completion, than the 1985 image of the superstructure roughly 40 years after its most recent major work.
    This is roughly the same view, in 2009. This superstructure is in much better shape, only 20 years after completion, than the 1985 image of the superstructure roughly 40 years after its most recent major work.
  • Underside of the bridge in 1985. Image shows how the bridge was originally built and modified later, but before the superstructure was replaced.
    Underside of the bridge in 1985. Image shows how the bridge was originally built and modified later, but before the superstructure was replaced.
  • Underside of the bridge in 2009. Image shows how the replacement superstructure was built, with 6 longitudinal girders and a different bracing, et cetera.
    Underside of the bridge in 2009. Image shows how the replacement superstructure was built, with 6 longitudinal girders and a different bracing, et cetera.

Bridge length measurement

Main article: Smoot
Smoot mark 210, east side of the bridge

The Harvard Bridge is measured, locally, in smoots.

In 1958, members of the Lambda Chi Alpha fraternity at MIT measured the bridge's eastern sidewalk by carrying or dragging the shortest pledge that year, Oliver Smoot, end over end.[4][5]

Crossing pedestrians are informed by length markers painted at 10-smoot intervals that the bridge is 364.4 smoots long, "plus one ear". The qualifier "plus or minus" was originally intended to express measurement uncertainty,[42] but over the years the words "or minus" have gone missing in many citations, including the markings on the bridge itself.[43] The marks are repainted twice each year by members of the fraternity.[4][44]

During the reconstruction in the 1980s, the smoot markings were repainted on the new deck, and the sidewalks were divided into smoot-length slabs rather than the standard six feet.[45] The Cambridge police use the smoot marks as a coordinate system when reporting accidents on the bridge.[46]

Length discrepancy

Given that Smoot was 5 feet 7 inches (1.702 m) tall in 1958, the given measurement in smoots of 364.4 yields a "bridge length" of about 620 meters (2,030 ft). Published sources[1][20] give the length of the bridge as approximately 660 meters (2,170 ft). The difference in length between the sidewalk markings and the published figure represents a 40-meter (130 ft) discrepancy.

Panoramic view from Harvard Bridge in the winter, looking east, with the Cambridge shore on the left and the Boston shore on the right. The Longfellow Bridge is in the middle, downstream.
The Harvard Bridge is decorated with both serious and comical statements of art.

See also

Notes

a.^ See the following sections, especially Maintenance and events and following.

References

  1. ^ a b c d Harvard Bridge at Structurae
  2. ^ a b c d e f Nationalbridges.com
  3. ^ a b Alger and Matthews, p. 15
  4. ^ a b c d e f g HAER, p. 5
  5. ^ a b This Month in MIT History, "The Tech", volume 119, number 49
  6. ^ a b c d e f HAER, p. 3
  7. ^ a b Alger and Matthews, p. 14
  8. ^ Alger and Matthews, p. 5
  9. ^ a b Alger and Matthews, pp. 5-6
  10. ^ Alger and Matthews, p. 9
  11. ^ a b c d e 1634–1699: McCusker, J. J. (1997). How Much Is That in Real Money? A Historical Price Index for Use as a Deflator of Money Values in the Economy of the United States: Addenda et Corrigenda (PDF). American Antiquarian Society. 1700–1799: McCusker, J. J. (1992). How Much Is That in Real Money? A Historical Price Index for Use as a Deflator of Money Values in the Economy of the United States (PDF). American Antiquarian Society. 1800–present: Federal Reserve Bank of Minneapolis. "Consumer Price Index (estimate) 1800–". Retrieved 29 February 2024.
  12. ^ Alger and Matthews, pp. 10-12
  13. ^ Alger and Matthews, p. 13
  14. ^ Alger and Matthews, p. 31
  15. ^ Alger and Matthews, p. 30
  16. ^ Alger and Matthews, pp.13-14
  17. ^ Alger and Matthews, p.32
  18. ^ a b c d HAER, p.4
  19. ^ Alger and Matthews, pp. 18-26
  20. ^ a b Alger and Matthews, p. 17
  21. ^ Alger and Matthews, p. 18
  22. ^ Alger and Matthews, p. 29
  23. ^ Landmarks at Harvard
  24. ^ A Walk Across the Harvard Bridge
  25. ^ Kaiser, Johanna (6 January 2012). "Mass. Ave, BU Bridge bike lanes completed". Boston Globe. New York, New York: New York Times, Co. Retrieved 20 March 2012. The city installed bike lanes on the northbound and southbound lanes between Huntington Avenue and the Harvard Bridge, connecting them to existing bike lanes, just before the start of the new year. {{cite news}}: Cite has empty unknown parameters: |pmd=, |trans_title=, and |deadurl= (help)
  26. ^ Clinger, Julia (1 June 2007). It Happened in Boston. It Happened In (1st ed.). TwoDot. pp. 61–63. ISBN 978-0-7627-4134-2.
  27. ^ "Famous Harvard Bridge Unsafe" (pdf). The New York Times. 16 July 1909. Retrieved 20 March 2012. The famous Harvard Bridge connecting Cambridge and Boston was declared to be unsafe in a report made to-day by a commission of Boston and Cambridge engineers, and announcement was made that work would be started on Monday next to strengthen the structure. The commission finds that all of the iron and steel beams of the bridge, which is nearly three-quarters of a mile long, will have to be replaced by new ones, at the same timethe draw will be elevated slightly, and new surfacing will be put on. The Boston elevated railway company, which operates its cars across the bridge, is ordered to install new rails and new supports.
  28. ^ "Commonwealth Begins Work on Harvard Bridge" (pdf). The Tech. Cambridge, Massachusetts: Massachusetts Institute of Technology. 3 October 1924. p. 5, col. 4. Retrieved 27 April 2009.
  29. ^ HAER, p.6
  30. ^ a b Leet, phase 2
  31. ^ a b c d Leet, phase 3
  32. ^ Leet, phase 3, appendices
  33. ^ a b HAER, p.8
  34. ^ Keane, Tom (10 September 2006). "It's the Engineering, Stupid". Boston Globe Magazine. Boston Globe. Retrieved 11 September 2006.
  35. ^ "AROUND THE NATION; Boston's Harvard Bridge Closed to Heavy Trucks". The New York Times. United Press International. 6 July 1983. Retrieved 13 April 2009.
  36. ^ Replacement, p.7
  37. ^ Replacement, p.4
  38. ^ Replacement, p.11. Note the use of the HAER document throughout this article.
  39. ^ Replacement, page 4-6
  40. ^ a b Replacement, page 5
  41. ^ Ronald Rosenberg, Globe Staff (12 September 1990). "MASS. AVE. BRIDGE TO REOPEN FOUR LANES AFTER SEVEN YEARS". Boston, Massachusetts: Boston Globe. p. 35 (METRO section). {{cite news}}: |access-date= requires |url= (help); Cite has empty unknown parameters: |pmd= and |curly= (help)
  42. ^ Tavernor, Robert, Smoot’s Ear: the Measure of Humanity (Yale University Press, 2007; paperback edition 2008), ISBN 978-0-300-12492-7, Preface
  43. ^ "Smoot in Stone". MIT News. Cambridge, Massachusetts: Massachusetts Institute of Technology. 4 June 2009. Retrieved 20 July 2010. Specifically noting the bridge's length of 364.4 Smoots (+/- 1 ear), the plaque, a gift of the MIT Class of 1962, honors the prank's 50th anniversary. {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
  44. ^ MIT Tech Review article
  45. ^ Fahrenthold, David A. (8 December 2005). "The Measure of This Man Is in the Smoot". Washington DC: The Washington Post. Retrieved 20 April 2009. And then there was a little help from the government: When the bridge was renovated about 15 years ago, officials agreed to let the markings stay, even going so far as to score the sidewalk at 5-foot-7 Smoot intervals instead of the usual six-foot ones.
  46. ^ Brehm, Denise (1 September 1999). "Keyser describes his top five hacks - MIT News Office". MIT News. Cambridge, Massachusetts: Massachusetts Institute of Technology. Retrieved 4 March 2012. When the bridge was rebuilt in the 1980s, the Cambridge police requested that the smoots remain because they use them to indicate precise locations in accident reports. {{cite web}}: Cite has empty unknown parameters: |doibroken= and |month= (help)

Bibliography

External links

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