Gustave Eiffel engineered the doomed Swiss bridge over the Birs River in 1874-1875. This is indeed the same Eiffel who built the Eiffel Tower in 1889. Later, Mr. Eiffel denied any involvement with the design--he claimed to be involved only in the engineering. He stated the design was by the Switzerland Government engineers.
The 42 meter, single-track bridge was composed of wrought iron lattice girders and consisted of six panels. The bridge was built on a skew--it crossed the river about five meters above water level at an angle of 51 degrees.
In 1875, the bridge was opened. It was damaged in floods in 1881--One of the abutments was destroyed, leaving the bridge resting on just three points rather than the normal four piers. As one corner sank under its own weight, cracks were produced. This twisting seriously injured the floor beams and lateral bracing. The bridge was repaired and was once again declared operational.
In 1890, the floor system was strengthened. Cover-plates were added to the floor beams and stringers, diagonal stiffeners were added to the floor beams and extra connecting angles between the stringers and floor beams were added.
*Sources: Wikipedia and Bridge Failures, by Chester Harris Stevens, 1902.
THE FAILURE OF THE BRIDGE ON JUNE 14, 1891
According to Harmsworth Magazine, Volume 4, the accident occurred immediately following an official inspection of the bridge. The magazine further states,
"A choral festival was to be held at Moenchenstein, and a very heavy train loaded with passengers, many of whom were intending to be present at the festival, produced a collapse of the bridge which spanned the River Beis between that town and Bale. The train consisted of nine passenger carriages, each carrying about seventy people; two luggage vans, and two engines. Two of the carriages fell into the river, killing all their occupants; while others received various injuries. Both engines turned over into the river."
Mr. Chester Stevens, in his Bachelor's Thesis for the University of Wisconsin-Madison, College of Engineering in 1902, relates, "There were on the train about 500 passengers of which number 74 were killed and 200 seriously injured."
"The disaster occurred as the passenger train, that had been travelling at full speed, applied its brakes before and whilst crossing over the bridge, immediately before entering the Münchenstein railway station. Eye witnesses said that the bridge appeared to break in the centre as the front wheels of the locomotive reached the further abutment. The train did not derail at any time during the collapse.
Image: Birs Bridge Collapse 1891.
The front part of the train, the two engines, the two additional passenger carriages, a postal carriage, an express carriage and two further passenger coaches, fell into the river. The first two passenger carriages sank in the floods of the river, as the following wagons pushed them forwards. A further passenger carriage hung diagonal from the abutment facing downwards towards the river. The final five passenger wagons remained standing upon the tracks, virtually undamaged."
The Railroad and Engineering Journal, Volume 65, contains and account by the Cologne Gazette that claims the reason the entire number of passengers was not lost was due to the Westinghouse air-brake:
"The bridge broke in two. The entire first part of the train was precipitated into the river, but six of the coaches remained on the track, held there by the tearing apart of the couplings, which brought the Westinghouse automatic brake into action, and resisted further progress."
Many newspapers of the day carried the horrifying details of the tragedy. Below is a detailed account from the Salt Lake Tribune:
The Salt Lake Tribune, Salt Lake City, Utah, Tuesday Morning, June 16, 1891.
details of One of the Most Fright-
ful of Railway Accidents.
HORRIFYING SCENE AT THE BRIDGE.
Broken Fragments of Carriages,
Wheels, and Crushed and Writh-
ing Forms, in an Inextricable Mass
--Every Family in the Cauton In-
BERNE, June 15.--The total number of people who lost their lives yesterday, by the collapse of the railroad bridge on the Moencheastern (sic) & Basic Railroad, is now placed at 120, with hundreds more or less injured.
Another account of the disaster says fifty-seven bodies have already been recovered, and that forty persons were severely wounded. It is feared many others are dead, whose bodies have not been found. The victims were mostly leading citizens of Basie and its neighborhoods.
Scenes which were heartrending were witnessed in Masie to-day, when the bodies of a large number of the victims were taken there by their sorrowing relatives, for representatives of a majority of the best families in Basie were among the killed and injured. Several families were practically entirely wiped out of existence by the disaster, the full extent of which is not known even at this hour.
Basie is now the scene of bitter desolation and mourning, and nearly every family in the city may be said to have been touched by the calamity, for those families who have not actually lost one of their members have dear friends or acquaintances either among the dead or among those who are mourning the loss of relatives.
Among those who were wounded were so many seriously injured that almost each hour records another death or another case in which the physicians have geven up all hope of saving the patient's life.
Everything the local and municipal authorities can do to help the wounded, recover the dead or assist those in distress is being done. Clergymen and physicians, a large force of troops and firemen and scores of vehicles to be used as ambulances have been dispatched to the scene of the wreck. The troops and firemen are busily engaged removing the wreckage, recovering the bodies of the dead and transporting the wounded to their homes or to the hospitals. Physicians and ministers of the gospel are doing noble work in administering to the wounded and comforting the bereaved.
The neighborhood of the collapsed bridge now resembles in many features, after the episodes of a battle, the closing acts in some warlike struggle. Stlil (sic) more so was this the case last night, when the river banks were illuminated by huge fires, troops and firemen working unceasingly, dragging the river for the dead, nursing the wounded and keeping guard around the spots where it was not thought advisable to admit the crowds of people, who had flocked to the scene from every village in the canton.
Image: Railway accident, Munchenstein, Switzerland, 14th July 1891. Artist: Unknown.
The work of the soldiers in dragging the river was greatly impeded by the fact that the stream was considerably swollen by the melting snow. Thus the waters carried away many bodies and several days dragging will be required before the soldiers' work will be complete. That somebody is to blame for the accident nobody doubts, but the people are so taken up with their present duty that the question of blame has been postponed for the present from official consideration.
Shortly after the first horror of the crashing of the engines and cars through the bridge and into the swiftly running stream had died away, the survivors saw a scene which rivaled in horror the most heartrending features of the Johnstown disaster. Beneath what remained of the bridge was a hideous mass of broken car wood, car wheels, engines, etc., intermixed with the still quivering heads bespattered with blood and brains, protruding arms and legs, bloody garments of all descriptions, hats and bonnets, umbrellas and parasols, hands and feet of the dead and faintly struggling men, women and children, a few now and then uttering horrible cries.
After the first moment of partial paralysis which followed the revelation of this horror, the survivors did their utmost to rescue those whose lives were in danger. The work of pulling those who remained in the two suspended cars from the perilous position in which they were placed was one of great danger and difficulty, and resulted in a number of instances of heroic conduct. In the meanwhile passengers were dispatched on all sides for medical relief. It was most urgently needed by the hundreds of wounded people, whose distressing cries for help and prayers to God, asking Him to relieve them of their sufferings, were most heartrending.
When the relatives of the dead and wounded began to arrive and identified some of the victims, there was another most awful series of incidents. The wildest grief was expressed on all sides, weeping and mourning filled the air, and several people were with difficulty restrained from casting themselves headlong into the stream.
As night drew near enormous crowds of country people and citizens of Basie gathered around the fatal spot, taxing the power of the military to its utmost in the efforts of these people to get a nearer and closer view of the horrors piled beneath the bridge. To such an extent did this prevail that crowds of people imitated the soldiers, firemen and railroad men, and bivouacked for the night in the vicinity of the remains of the broken bridge.
THE CAUSE OF THE FAILURE
In Bridge Failures, Mr. Stevens claims the failure was undoubtedly due to over loading the structure. He calculates the stress in the end post to be 49,000 psi and he contends the entire design was very poor and includes a sketch of the badly designed compression members.
Image: Compression Member of Moenchenstein Railroad Bridge.
Source: Bridge Failures, by Chester Harris Stevens, 1902.
"The subsequent inquiry focused on the state of the bridge, the quality of the ironwork and the design. A new institute "Empa" (Building materials test institute) started work in 1880. In its first years of activity, "Empa" was involved in wide-ranging quality testing of building and structural materials for the Swiss National Exhibition of 1883. Intensive research work by the co-founder and first director, Prof. Ludwig von Tetmajer, gave rise to the first publications on the testing and standardisation of building materials and metals.
Tetmajer was also commissioned to investigate the cause of the collapse of the Münchenstein railway bridge. Tetmajer's investigation of the collapse (which was at that time the largest railway disaster to have occurred in Europe) revealed that Euler's formula for buckling, which had hitherto been used to calculate design loads in such structures, needed to be corrected for slender bars (Wikipedia)."