Ledge Removal Continues in Vermont Before More Rocks Tumble on Highway

Charlotte’s $427M Light Rail Line Heavy on Contracts

Wed September 27, 2006 - Southeast Edition
Gwenyth Laird Pernie



North Carolina’s first light rail line — a 9.6-mi. (15.5-km) line known as the Lynx Blue Line (LBL) — will soon open in Charlotte, one of the fastest growing metropolitan regions in the United States.

The $427 million light rail line will run from Uptown Charlotte to I-485 near South Boulevard, stopping at 15 stations. It is the first of five rapid transit lines planned along five transportation corridors in the Charlotte region. Also called the South Corridor Light Rail Line, it is being developed by the Charlotte Area Transit System (CATS).

Work on the LBL project includes construction of the entire rail line’s roadbed, installation of 9.6 mi. of dual light rail tracks, construction of four light rail bridges over arterial streets, construction of 15 stations and seven park-and-ride lots.

Progressing concurrently with the LBL are infrastructure and road improvements, which are being coordinated with the City of Charlotte’s South Corridor Infrastructure Program (SCIP) — a collaboration between the City’s Engineering & Property Management, Utilities, CATS and transportation departments. SCIP’s work includes improvements to city streets and intersections, additions to the city’s water and storm drain systems, construction of 14 mi. of sidewalks, 10 mi.of bicycle lanes and 10 mi. of trails.

According to David Leard, CATS senior project manager, the LBL’s uniqueness lies in its integration with the community.

“This integration can be seen in the way multiple city departments participated in the planning and design of the project, in the way CATS brought the public into the decision making process and in the way the project was created as a land use vision for the community,” said Leard. “While the project design’s focus must meet specific tolerances for the operation of the light rail vehicles, it must also take into account its impact on individual homes and businesses along its 10 mi. alignment.”

During the process, he said planners often said they were “building a community, not just a light rail line.”

Further complicating the construction process was that the project was split into 10 different contracts ranging in size from $2 million to $106 million. Each of the contracts had to be integrated in both design and construction with the others, as they all share common elements. For example, the roadbed will be integrated with station construction since the work areas overlap.

In addition, there are more than 100 milestones with the contracts that must be tracked and coordinated among contractors.

Site Preparation

Charlotte-based Crowder Construction was awarded the $2.1-million demolition and site preparation contract, which included clearing and grubbing and removal of 23 buildings and a single track from a former railroad line. This work began in December 2004.

Preparation for the roadbed began in May 2005 and included clearing the bed of debris, utility relocation and modification, drainage work, earthwork, subballast installation, substation site work, power pole foundations, conduit and cable trough work, public art installation and retaining walls.

To prepare for track placement, crews excavated 160,000 cu. yds. (120,000 cu m) of dirt to bring the roadbed down to sub grade. Short walls, called ballast walls, were then constructed. A layer of 5,500 tons (5,000 t) of small aggregate stone serves as the base and 8 to 10 in. (20 to 25 cm) of ballast stone will be placed to serve as the foundation for the tracks and rails. The track will sit at the same level as the top of the ballast walls.

According to Leard, as of August 2006 the majority of the work is focused on light rail bridges, roadbed, track work and station platforms.

Archer Western Leading Project

General contractor for the $106.8-million contract to construct the roadbed for the double-track system, utility relocations, six bridges, retaining walls and roadway construction and modifications is Archer Western Contractors, of Atlanta, GA. Archer Western also holds the $44.1-million contract for construction of the line’s 15 stations and park-and-ride lots.

Archer Western is currently working on four light rail bridges that cross over Arrowood Road, Archdale Drive, Tyvola Road and Woodlawn Road.

Bridges will be constructed of concrete decks with steel and concrete girders. Drilled caissons, some reaching depths of 170 ft. (52 m), were used for most of the bridge abutments, and the majority of the piers sit on H piles.

According to John Couture, senior project manager with Archer Western Contractors, a Raito’s Supertop machine was used to drill the 60-in. (152 cm) diameter shafts that hold the bridge piers. This method uses a rigid framework to hold a steel casing and large rollers (which cause the casing to rotate). At the bottom of the casing are carbide teeth. Working like a giant vertical keyhole saw, the toothed end of the casing can chew through all types of soil, boulders and rock as it rotates. Periodically, a crane operator lowers a hammer grab — essentially a clamshell bucket — into the casing to excavate the material.

“This machine has proven to be a much quicker method of drilling through rocks than conventional methods,” Couture said.

Archer Western and subcontractor Buckner Steel Erection have worked together in the placement of the bridges’ girders.

Frank Ward, CATS manager of construction on the LBL project, explained the process of placing the girders over Archdale Drive, Woodlawn and Tyvola Road, which has been done at night to avoid disrupting busy daytime traffic:

“After the road is closed, the traffic lights and electrical wiring are taken down in order to accommodate two Tadano cranes — a TT-600XL and TT-800XXL — and delivery and placement of the girders. A crane lifts and holds the first girder in place over the road. At approximately 65 ft., this is the longest span over Woodlawn Road. Buckner then uses another crane to place the second girder, which attaches to the first span and the piers. Once the second girder is in place, Buckner bolts the two girders together and lowers the entire piece onto the bearing pad, where it will be anchored to the piers. This construction will be braced to prepare for installation of the second set of girders. In order to clear the site and prepare for morning traffic by 6 a.m., Buckner only has time to erect two steel girders a night.”

Swedish Attachment Places Ties

Ohio-based Delta Railroad Construction was hired to install the track. According to Larry Laurello, vice president of Delta Railroad, Delta purchased a new tie laying machine for this project — the Sleeper Layer SL 800-HD, manufactured by Rosenqvist Rail AB in Sweden. The SL 800 is attached to a Kobelco 235SR excavator and is used for placement of eight adjacent ties simultaneously. The tie layer, which is fully rotatable and tiltable, lifts the ties into position. Placement on the roadbed is then ensured by a precision gauging system that spreads the ties to the desired spacing. A Harsco production tamping machine is then used to surface the track, ensuring proper profile and alignment.

Ridership Expected to Double in 20 Years

According to Leard, the LBL will run north from I-485 at South Boulevard to 7th Street in Center City Charlotte. The system will operate on two tracks (northbound and southbound) generally within the existing railroad right-of-way parallel to South Boulevard. Trains will operate seven days a week from 5:00 a.m. to 1:00 a.m. and the fare will equal the cost of local bus fare. Trains will arrive at stations every 7.5 minutes during rush hour and every 15 minutes during non-peak hours. The South Corridor has an anticipated daily ridership of 9,100 when it opens in the fall of 2007, increasing to 18,300 by 2025

“The light rail line will give commuters a choice over congestion and consequently improve the air quality in the region, thus ensuring successful growth in our rapidly growing community,” Leard said.

According to Couture, as of late August, the LBL roadbed work was 70 percent complete and should be done by June 2007. Construction of the line’s 15 stations and park-and-ride lots began in late summer and should be complete by August 2007.

“The biggest challenge on this project has been maintaining the owner’s budget and schedule through numerous design modifications along with coordinating with Norfolk Southern Railroad and other city and county agencies,” Couture said.

In October, the public will get to voice its opinion on how Charlotte should move forward with the other four rapid transit corridors.

In November, the Metropolitan Transit Commission is scheduled to vote on the 2030 Transit Corridor Plan. CEG