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Tay Bridge disaster

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4.4 Photographs showing the detail: partly collapsed piers

There were only two piers that showed tiers still standing, piers 1 and 3, next to the south pier still standing (pier 28). They are important because the debris lying on the platforms is much reduced, giving clear views of the platform surface and the state of damage of the upstanding tiers.

Two views are shown of pier 3, a view from pier 2 (Figure 27), and a close-up of the lowest tier looking west (Figure 28). That the two views are of the same pier is easily confirmed by the common feature of the hanging cross tie rod, with one of the quadrant (quarter-round) fixing castings still attached to its free end. It can just be seen in Figure 28, to the right, behind the right-hand diagonal tie bar in the foreground of the photograph. It formerly reinforced the first and second tiers, and is suspended at one end from a junction between the two tiers (Figure 27).

Figure 27 Remains of pier 3 with one tier left standing, viewed from pier 4, looking south
Figure 28 Remains of pier 3, looking west. The broken east-facing lugs are indicated by the arrows

What does the pair of pictures show, and what can they tell us about the way the failure may have occurred on pier 3? Figure 27 shows an apparently intact lowest tier, with one exception. That exception is the failed diagonal tie bars that were bolted to the column bases (right-of-centre). The corresponding members (bolted left-of-centre) are both intact. Indeed, the outer tie bars – on the corner faces – are also intact in both directions, while at least two of the tie bars on the opposite face are also intact. All the horizontal struts visible in the two figures are intact. The two failed tie bars hang down, and have fallen to the floor of the pier where their fractured ends rest.