The American Pyramid
You don't grow up in Hawkes Bay without learning to appreciate Art Deco architecture and the Hoover Dam was unexpectedly beautiful with Art Deco features everywhere. We were on a tour that took us over the dam and then down into the generator hall so if you're not interested in all things power stations, building and engineering maybe just scroll to the pictures!
The dam itself took two years to build with 4.3 million cubic yards of concrete delivered in buckets every 70 seconds. The logistics of doing this with comparatively minimal technology and the challenging geology is just incredible. In summer of 1931 the canyon temperatures reached 60 degrees C. Before the dam was built however, 4 tunnels were bored into the sides of the canyon - two on either side. These diverted the river so that the dam could be built. Each tunnel is 4,000 feet long, 56 feet in diameter and lined with three feet of concrete and were bored using pneumatic drills and dynamite: for every 14 feet of tunnel, one ton of dynamite was used and 1.5million cubic yards of spoil was removed from the tunnels. Two of the tunnels were then repurposed for power generation and two as spillway tunnels. The spillway tunnels have only ever been used twice: once in 1941 when the reservoir was finally filled and they were tested and again in 1983 when the dam was spilled for 63 days after record breaking snow and rain up in the Rockies which feed the Colorado River. The hard water has left behind calcium which creates a distinctive line to the high water mark.
The numbers are just staggering as is the speed at which it was completed - 2 years to build the spillway, 2 years to build the dam and 1 year to build the external infrastructure. Compare this to the Pat Tillman Memorial bridge above the dam was started in 2003 and took 7 years to build.
The power station part of the dam is considered a bonus - the dam was specifically built to control downstream flooding so they popped a power station on like icing on a cake. The water runs down vertical intake towers into part of one of the original tunnels with tunnels for each generator branching of from this tunnel. The water level in the reservoir is at nearly record lows so only 3 generators are running at the moment. Each generator weighs 500 American tons and the rotor has 40 one ton magnets. The entire generating hall is paved with marble tiles with various mosaics on the floors. The attention to detail and commitment to producing something beautiful and function was so impressive. I certainly don't recall the power stations of New Zealand being lined in marble!!
After finishing the power station tour and perusing the tourist trap (aka gift shop), we drove us out of the canyon to the bridge where Ant got marched up 124 stairs and hustled across the walking part of the bridge. It's also a 6 lane traffic bridge with plenty of trucks so combine vertigo and bridge shaking and it's quite the experience!
Antoine’s Content Corner
Best story of the day: Jason our tour guide once had the NZ 7s team on the tour who noticed Jason not hopping off at a stop where there were desert bighorn sheep. One of the boys asked Jason if he wasn't jumping out because he was scared one of the sheep might call him D-a-a-a-a-a-d.
