We’ve told you about the ambitious Crossrail underground system being built in London, the one that's 26 miles long and expected to ferry more than 200 million passengers through the belly of the city every year. And we told you about the 1,000-ton Earth-moving drills that had to be extracted from the tunnels piece by piece because they were too large to remove intact.
Now that the tubes are fully carved, it’s time to outfit the railways with all the infrastructure needed to make them fit for trains. That means ventilation shafts, power lines, signaling devices, communications systems, and, of course, tracks. All that finishing work requires a new fleet of custom machines.
For the tracks, the Crossrail workers will start by sending a 1,500-foot long train to pour concrete for 80 percent of the new track slab. The remaining 20 percent will use a variety of designs to mitigate noise and vibration. Then four rolling gantries will carry in and lay down more than 70,000 ties and 35 miles of rail.
Next comes the drilling rig, with two on-board drills that will bore some 250,000 holes into the tunnel’s lining. The first machine on the rig will make openings to accommodate cabling, walkways, and fire mains. The second makes holes for the overhead electricity line that will power the trains. It's all to make the eventual passenger experience comfortable. The train doors will be wide enough to let three people pass through at once, and riders will be greeted by air conditioning, free Wi-Fi, and access to 4G networks.
The $28-billion Crossrail system is expected to open in 2017, which is probably a few decades before New York City or San Francisco have their subterranean transit projects completed.
