... redistribution on the surrounding wads, which can cause a wave of wad failures resulting in a sudden collapse of a large swathe of ceiling with little or no warning signs. In the present day, it means that a large portion of UK listed buildings have weak or vulnerable ceilings, calling for innovative monitoring...

... is given of the history of use and failures of rocker bearings from nineteenth-century railroad bridges to US highway bridges with tall and slender rocker bearings that date from the late 1950s. Figure 4 Bridge in south-eastern US: (a) extremely tilted rocker bearing; (b) tilted rocker bearing...