Question

he Thames Tunnel

Marc Brunel was a mechanical engineer who lived in London, England in the 1800s. In 1818, Brunel began considering a new business idea—a tunnel under the Thames River. No tunnel had ever been built successfully under a river. A Thames tunnel had been attempted in 1801 and again in 1807, but the river had broken in and flooded the works both times.
Brunel knew that a tunnel connecting the shipping docks in East London to the warehouses and factories of South London across the river would be good for business. Because the London Bridge was two miles west of the docks, thousands of carts and wagons had to travel hours out of their way each day to reach South London. A bridge could not be built in that area because it would interfere with shipping traffic.
Brunel also knew that tunnel-digging was a big challenge—the work was dangerous due to the tendency of a tunnel's open face to collapse as the digging advanced. One day while Brunel was walking about the dockyards, he had a brilliant idea. He noticed a scrap piece of oak timber that had been the keel of a ship. It was full of wormholes that looked like miniature tunnels. The sides of these cavities were covered with a hard white substance that looked like concrete. Brunel knew that the tunnels had been dug by a creature called the shipworm. He found one in the wood and took out his magnifying glass to inspect it. Its body was soft, but its head was covered by two jagged shells with a pointed beak between them like a drill bit. The shipworm made its tunnel by scraping its jagged shells in the wood. This turned the wood into powder, which the shipworm then ate. As it advanced, it left behind a hard deposit that coated the walls of the tunnel.
Using this as an example, Brunel decided to build a "shield" that would work like the shipworm's shells—it would completely cover the end of the tunnel where workmen were digging. It could be moved forward in small steps without leaving room for the tunnel to collapse. In Brunel's design, the cast-iron shield consisted of twelve separate vertical frames, each frame with three cells. The tunnel was dug by men who stood in these cells. The worker in a cell would remove a thick board and dig out a few inches of earth behind it. Then he would replace the board and support it with a small jack pressed against the frames on either side. The whole frame could then be pushed forward step by step with large jacks that pressed against the tunnel's brickwork walls.

A model of Marc Brunel's shield in the Brunel Museum, London. The iron frames are in the middle with the three cells that workmen stood in. At the right is the wall of earth to dig, supported by boards and small jacks. At the left is the newly completed tunnel brickwork. Large jacks at the top and bottom pushed the work forward a few inches at a time.

Brunel decided to start the tunnel by making an iron ring that was fifty feet in diameter with a sharp edge on the bottom. Workmen built three-foot-thick brick walls on top of the ring, and the weight of it gradually sank through the layers of clay and gravel on the shore of the river. Once the ring and walls were sunk, a vertical shaft was dug down to the ring. Then the work of digging out the soil inside the ring could begin.
Although the project experienced problems with flooding and took eighteen years to complete, Brunel's engineering feat was finally accomplished when the tunnel opened to the public in 1843. Brunel's shield, inspired by the shipworm, proved that it was possible to tunnel underwater in unstable soil. His work eventually led to the building of the London Underground. In fact, the Thames Tunnel is still in use today as part of the London subway train system.
5
Why did Marc Brunel want to build a tunnel connecting East and South London?
A.
People would find it easier to travel to different parts of London on a daily basis for their work.
B.
The tunnel would be cheaper for transportation of goods, which would save an enormous amount of money.
C.
Building a bridge to connect the two parts of London would be more challenging and expensive.
D.
Transport of carts and wagons would become easier through the tunnel, which would improve business.

Answer 1

D. Transport of carts and wagons would become easier through the tunnel, which would improve business.

The passage says thousands of carts and wagons had to travel hours out of their way because the nearest bridge was two miles away, so a tunnel would make moving goods between the docks and factories much easier.