NIAGARA DISASTER

Evening Post, Volume CXXV, Issue 24, 29 January 1938, Page 10

NIAGARA DISASTER

A 1 FAMOUS BRIDGE.

TINE .VIEWPOINT LOST

fir Y€ARUY ICE JAM *§

The Wrecking of the "International" or "Falls View" bridge across the Niagara" Kiver by a sudden rush of ice has destroyed at once an important communication route, a structure of note in engineering annals (though by no means a large one of its kind) and one of the best places from which the Niagara Falls could be seen. '

.The falls, which are divided into two unequal sections by Goat Island, have a total width of about a mile, but discharge into a gorge of only about one-fourth of that width, and the waterway narrows rapidly downstream. The clear span of the International Bridge arch between the abutments was 840 feet.

The bridge was considered a great engineering feat in its day. It was completed in 1898. The bridge replaced the older Koebling suspension bridge, which was also-a very famous work. It was much the largest railway bridge of its time (the 1850's)," and consisted of a'stiff girder suspended from cables. It proved incapable; of carrying the increasingly heavy railway traffic, and was replaced by the arch bridge which has just fallen. The bridge was a "twohinged parabolic traced-rib arch."

The side spans were of 190 feet and 210 feet. The bridge carried two electric car tracks, two roadways and two footpaths. The main span weighed 1629 tons and the side spans 154 and 166 tons respectively. Professor Claxton Fidler, speaking of the arrangement adopted for putting initial stress on,the top chord, stated years ago that the bridge marked the furthest advance yet made in this type of construction. When such' a rib is erected on centring without initial stress, the subsequent compression of .the arch under its weight inflicts a bending stress and excess of compression in the upper member of the crown. But the bold expedients of the engineer annulled the bending action.

Railway traffic is carried by another bridge lower down the river. Sightseers have still an elevated viewpoint from which, to see the falls, as a cable" carrying a cage was recently constructed across the gorge. The ice which caused the disaster to the bridge 'is a "hardy annual." Blocks of ice from Lake Erie come down'oyer the falls, and owing to the narrowness •of the gorge, become jammed there, forming an "ice bridge." In very severe winters the accumulation ,pf ice.at the lip of the falls results in such a diminution of flow that a large part of the falls becomes frozen, and> the spectacle is astonishing and magnificent. ' The ice bridge is usually broken up by a thaw, helped by the battering of heavy ice coming over the falls, and hitherto this dramatic incident seems to have passed off ' without causing any serious damage. There are hydro-electnc powerstations on each side of the river below the falls, fed with water which is drawn off by intakes above the falls. • It is; a point of interest that Lakes Superior, Huron, Michigan, and Erie, whose overflow passes dyer the Niagara Falls, are .estimated to contain half the fresh water in, the world.