The Ronan Point Material Failure
Material failures occur throughout many engineering designs along with human and design error, poor maintenance, and extreme conditions. But these failures become disasters when the preexisting problem lies with material failure. And a combination of the above along with a preexisting material failure leads to a catastrophe.
In 1968 Ronan Point a tenant of the 22-story tower block lit a match that caused and explosion, which subsequently took down the whole load-bearing wall on the south-east side . The explosion although minor was caused by the material failure of the nut and hose that hooked up the gas line. During the investigation for the cause of the collapse of the building engineers found that the nut and hose had failed during installation due to over-tightening which led to the leak. Normally, a minor explosion similar to the one that occurred in this case wouldn’t cause a whole section of a building to collapse. This was caused by the unique construction design of the tower building, Larsen-Neilsen system. This system used prefabricated concrete walls to install panels with linking joints making the loadbearing wall being supported by the one below it. With the collapse of the one wall due to the explosion, the wall above collapsed into the other floors leading to the collapse of the entire south east wall. This domino effect is defined as progessive collapse which leads to costly damages as the damage ensues all the way to the foundation level.
The Ronan Point collapse in 1968 was originally caused by two seperate incidents of material failure. However, the design flaw in the lack of load paths greated the catastropic event that resulted in 260 deaths. Ironically, years later tests reveal that the design flaw in the Larsen-Neilsen system would reduce the building life from 60 years to 15 years. The original design plan had not accounted for the wind variable. The climate conditions along with the height would have caused the same failure in 15 years as the explosion had from the gas leak.
As a result of the Ronan Point disaster the British Building Regulations of 1970 and also the British standard structural design codes for concrete were set in place to was set into place to minimize this type of progressive collapse to not happen again for buildings above 5 stories. And also any building above 5 stories were required to be able to withstand a certain amount of explosive force. Even though all these safety regulations were put into place the public had turned against the idea of a "tower block building" due to failures that happened before. As of 1986 tower blocks were abolished for low level houses.