Two Halves of an Arch
Two Halves of an Arch
For most of the 1920s, Sydney residents who wanted to cross the harbour between the city and the North Shore had to take a ferry or make a long journey around by road. A bridge had been proposed many times, but the distance was formidable, and the harbour had to remain open to tall ships.
The design finally chosen was a single steel arch. Its builders could not rest the arch on supports in the water while they worked, so they built it outward from both shores at once. Each half leaned out over the harbour like a reaching arm, held back by enormous steel cables anchored in tunnels cut into the rock behind it.
For two years the halves crept towards each other. Every new piece of steel had to be lifted by cranes that travelled along the top of the arch itself, and every piece made the cables bear a little more weight. Engineers checked the measurements constantly, because a small error at the base of each half would grow into a large one at the top.
By August 1930 the two tips were close, but they were not simply pushed together. The engineers slackened the cables a little at a time, lowering the halves gently towards each other. Heat made matters more delicate still: the steel expanded in the warmth of the day and shrank in the cool of the night, so the gap itself kept changing. When the halves were finally joined, the arch could stand on its own, and the cables that had held it for so long were no longer needed.
The deck that carries the road was then hung from the arch, and the bridge opened in 1932. Today it is so familiar that it is easy to forget that, for a time, it was two halves of a promise, each waiting for the other.
Worked explanation 1
In the first paragraph, 'the distance was formidable'. In this sentence, formidable means
- AA.
widely admired and praised.
- BB.
so great it was hard to overcome.
- CC.
impossible to measure exactly.
- DD.
slowly getting smaller each year.
Answer: B
Answer: B
Read the sentence around the word. A bridge had been proposed 'many times' but not built, so the distance must have been a serious obstacle. That matches 'so great it was hard to overcome'. Nothing suggests the distance could not be measured, so C does not fit.