Smithfield Street Bridge in Pittsburgh, Pa

Jake Neal and Jay K

Information OFFICIAL NAME:

Smithfield Street Bridge

OTHER DESIGNATION:

LOCATION:Pittsburgh

USGS 7.5" Topo Quad - UTM Coordinates:Pittsburgh

West - Zone 17; 0584 4476

LENGTH OF MAIN SPAN:2 main spans, 360 ft each (344 ft clear)

TOTAL LENGTH (including longest elevated ramp):1,184 ft

HEIGHT OF DECK:42.5 ftEmsworth Dam normal pool level 710 ft

YEAR ERECTED / ENGINEER:1881-83; Gustav Lindenthal, engineerupstream side added 1889; widened to

match downstream span 1911

Smithfield bridge Table of Quantities (Suspension Bridge) Length of bridge between abutments . . . 1500 feet Number of spans . . . 8 Average width of spans from centre to centre . . . 188 feet Diameter of cables . . . 4-1/2 inches Number of wires in each . . . 750 Weight of superstructure of one span, as far as supported by cables . . . 70 tons Tension of cables resulting from it . . . 122 tons Weight of four six horse teams, loaded with 104 bushels of coal each . . . 28

tons Tension resulting from it when at rest . . . 48 tons Weight of 100 head of cattle at 800 lbs . . . 40 tons Tension resulting from it when at rest . . . 70 tons Aggregate weight of one span as far as supported by the cables, plus 100 cattle

at rest . . . 110 tons Tension resulting from it . . . 192 tons Ultimate strength of two cables . . . 860 tons Section of anchor chains . . . 26 inches Section of pendulums . . . 63 inches

Connection BETWEEN:

-- Fort Pitt Blvd on right descending bank of Monongahela River-- Carson St on left descending bank of Monongahela River

CROSSES:Monongahela River

Cost

Cost: 16.3 million

Carries 4 lanes of roadway2 pedestrian walkways

In 1845 half of Pittsburgh burns

to the ground including the Smithfield Street

Bridge.

FIRE

Thursday, January 24th, 2008An ICY FallThursday, January 24th, 2008

Great amusement and humor today. And like most humor: it came at somebody else's expense.

One of my colleagues reported that there was an icy spot on the Smithfield Street Bridge and that people were falling who crossed it.

Our office overlooks the bridge and a few of us took a gander. Sure enough: within moments we saw a beautifully executed pratfall. As if we were watching a circus performance, we ohhed and ahhed as about one out of every ten people who crossed the spot fell. (I'm guessing we saw an average of one fall every three minutes during the morning rush hour.)

Stress Sheet

The Smithfield Street Bridge and basic facts

TRUSS LENGTH: 34 Inches, 246 scale ft. (32 % reduction)

TRUSS HEIGHT: 6.5 Inches, 47 scale ft. (7% reduction)WIDTHS: 2 girder spans, 9.5 Inches (0% reduction)2 truss spans, 9.96 inches (0% reduction)1 pony truss, 9.5 inches (0% reduction)

PARTS COUNT: Estimated 8,000 - 9,000

WOOD TIES: 1,100 (rail side)

MAN HOURS: Estimated 2,000 minimum

RAW MATERIALS USED: C-V bridge girders, Plastruct Structural Shapes and Cement, Evergreen strips and sheet stock, 36 ft. code 100 rail.

PAINT: Aluminum and gray primer, Brass suspenders (120), plastic lower truss eye bars (456), H&R plastic masonry pier covers 

A holiday card featuring Pittsburgh's historic Smithfield Street Bridge. The inside greeting is "Wishing you peace and joy this holiday season

THE END