Posts Tagged ‘dulles’

A Complicated Dig: Dulles Airport MetroRail Extension (Wash Post)

Monday, October 19th, 2009

tysonstunnel_101909

[Editor's note: Explanatory graphic from this weekend's Washington Post illustrates how "Building a Metrorail Tunnel at Tysons Corner Takes Brute Force Applied With a Deft Touch" in five panels. Click image above for larger version.]

18 Feet Done, Many More to Go

Republished from The Washington Post.
By Lisa Rein. Graphic by Todd Lindeman and Brenna Maloney.
Sunday, October 18, 2009

Cars crawl down Route 123 in the afternoon rush. Forty feet below them, giant machines and men wearing yellow hard hats begin their advance under Tysons Corner to bring Northern Virginia commuters their holy grail: a new subway.

At $85 million, the half-mile tunnel is the costliest and most complex engineering feat of the 23-mile Metro extension to Dulles International Airport. It will be built while 3,500 cars and trucks cross its path each hour, while the Courtyard Marriott serves breakfast and guests swim in its pool, while hands are shaken over aerospace deals at BAE Systems. It will carry on under two miles of tangled utility lines that convey to Tysons everything from electricity to some of the nation’s most secret intelligence. As of Friday, after three months of digging and prep work, workers had hollowed out the half-mile tunnel’s first 18 feet.

One wrong move and the foundation of an office garage could settle, a top-secret communique through the U.S. Army’s microwave tower right above the tunnel’s path by Clyde’s restaurant could be lost.

“You’ve got gas lines, water lines, drainage lines, electrical duct banks, black wires and a lot more in a busy urban area, which makes for a very challenging tunneling environment,” says Dominic Cerulli, the engineer for Bechtel in charge of building the tunnel. He guides visitors on the first tour of the project on a recent weekday. “I’ve been on jobs where you’re tunneling out in the middle of a parking lot. Here you’ve got to keep businesses up and running.”

When it opens in 2013, the first leg of the rail line will extend 11.5 miles from East Falls Church through Tysons to Wiehle Avenue in Reston. The tunnel, scheduled for completion in late 2011, will connect two of the four Metro stations in Tysons. Cerulli likes to say his project is the toughest part of the line. “But don’t say I said that, because the guideway is also complicated,” he jokes, referring to the elevated section, still 18 months off, that will carry the trains 55 feet above the Capital Beltway.

Continue reading at The Washington Post . . .

See SRTM Satelite at Smithsonian’s Udvar-Hazy Center!!! (Kelso)

Friday, February 27th, 2009

I went out to the Smithsonian’s Udvar-Hazy Air and Space museum annex at Dulles International Airport in Chantilly, Virginia last weekend and was pleasantly surprised to see one of the SRTM payloads hanging off the ceiling. The Shuttle Radar Telemetry Mapping program helped produce a significantly more accurate and detailed world-wide digital elevation model (DEM, DTM) in the early part of this decade and was a great leap forward for shaded relief generation. If you make the trip, you’ll find the SRTM between 22 and 23 on the map below in the “space shuttle” hanger. The map does a good job of indicating what altitude different aircraft can be found in the hanger.

Here’s a photo:

Cannister/Mast, Shuttle Radar Topography Mission Payload
(republished from the Smithsonian)
In 2000, the Shuttle Endeavor carried the Shuttle Radar Topography Mission (SRTM) payload into orbit. Shuttle astronauts used the payload, manufactured by the AEC-Able Engineering Co., to map in high detail and three dimensions more than 70 percent of the Earth’s surface–the most complete and accurate rendering of the planet’s land masses ever attempted. The Museum possesses two components–the mast canister (this artifact) and the outboard support structure with its antennas–crucial to that mission.

To acquire this data, the SRTM used a novel hardware system that featured a main antenna located in the Shuttle payload bay, a folding mast (in the mast canister) that extended 60 meters from the Shuttle, and then another antenna system that was positioned at the end of the mast (the outboard structure). It was this dual antenna system–the largest rigid structure then flown in space–that produced, through interferometry (a technique for combining the information obtained from the two, separate antennas), a three-dimensional mapping of the Earth.

The mission was a joint undertaking of NASA’s Jet Propulsion Laboratory and the Department of Defense’s National Imagery and Mapping Agency. The military will use the highest resolution data from SRTM for terrain navigation for planes and cruise missiles. A lower resolution data set will be made available to civilian scientists and other users.

NASA transferred these artifacts to the Museum in 2003.

Transferred from NASA
Manufacturer: AEC-Able Engineering Co.
Country of Origin: United States of America
Dimensions:
Overall: 292.1 length x 136cm diameter, 984.3kg weight (9ft 7in. x 4ft 5 9/16in., 2170lb.)
Materials:
Aluminum, steel, titanium, plastic, copper
Inventory Number: A20040261000

General layout of the museum:

Transit on Thursday

Thursday, May 1st, 2008

nytimes dc taxi picThe New York Time’s Ariel Sabar has an article on today’s switch-over to time-distance meters for Washington DC cabs: Adopting Meters, Washington Ends Taxi Zone System. The first few graphs:

Over the objections of cabdrivers, the District of Columbia is set on Thursday to scrap its seven-decade-old method of calculating taxi fares. Conventional time-and-distance meters will replace a system based on geographic zones.

The District was the only major American city to base fares on how many zones a cab crossed. Many riders, particularly out-of-town visitors, found the system of 23 zones confusing. Critics said it was too easy for unscrupulous drivers to overcharge.

‘The riding public asked for a more transparent fare system, and the mayor responded,’ Leon J. Swain Jr., chairman of the Taxicab Commission, said in a phone interview. Continue reading . . . 

Back up in New York the Times also covers a revision to the subway map made by Massimo Vignelli for the May edition of Men’s Vogue.

ny metro map comparions

Returning to DC, the WMATA subway and bus authority considered expanding our own system after the Feds breathed new steam into the planned Silver Line from Falls Church to Dulles International Airport and beyond to Loudoun County, the fastest growing country in the US recent years.

dc metro 2030 view