Joint venture partners Hensel Phelps Construction Co., Doracon Contracting and Banks Contracting Company, Inc. are at work on the Hilton Baltimore Convention Center Hotel, which will connect to the Baltimore Convention Center and is adjacent to Oriole Park at Camden Yards, home of the Baltimore Orioles. When completed, the new hotel — the city's largest and its first major design-build project — will feature 757 rooms, 550 parking spaces, two large ballrooms, meeting rooms, a restaurant, bar, and fitness center.
The entire project has been divided into three sites — west side, east side and the pedestrian bridge over Howard Street that connects to the convention center. Each site features different foundations and construction techniques.
With project plans 35-percent completed, Doracon began the deep-hole excavation in February 2006 and removed 100,000 cubic yards of soil. Shoring and lagging work followed.
The slab-on-grade foundation for the west side superstructure site, which is concrete, sits on 194 caissons reaching depths of 40 feet to 50 feet and then pier caps. The perimeter walls are shotcrete.
Bill Thumm, project manager with Hensel Phelps, says that on this phase of the project "we had a small consortium of small businesses do the slab-on-grade, underground drainage and pier caps. We took our big concrete package and broke it down into sub-packages to develop more diversity on the job site."
CECO Concrete Construction has been on-site since November and is doing all of the structural concrete work on the west side. CECO has reached the 10th floor of the 20-story superstructure, and they have been using a modified table system — the perimeter is tabled and the interior is handset — and a concrete pump to pour one floor a week.
"Two floors have forms at one time," explains Thumm. "Once you hit 75-percent design strength, you can pull them out and fly them to the next level. You want to pour your deck and pour your columns in the same day, and a regular deck is three pours. You do three pours to finish one floor a week."
The east side of the project is a structural steel package that sits on a different foundation system. After stripping the site down 3 feet to 4 feet, it was brought back up with engineered fill. Hayward Baker Inc. then engineered and installed the aggregate piles for the site. Thumm explains that a lense of existing fill sits between the structural fill and the native soils. The aggregate piles span between the two.
Work on the structural steel began in March 2007 and has been going well. Thumm explains that they have had to plan around the steel, but design-build delivery offers more flexibility when placing mill orders. Hensel Phelps worked closely with Baltimore Steel and ACM Erectors to "lock up the mill orders, procure the steel early and start detailing to get it to the job site at the right time," says Thumm.
The third site on the project is the pedestrian bridge over Howard Street. Building the foundation for the abutment on the east side of the bridge proved to be particularly challenging because of a CSX Rail tunnel running alongside the location of the proposed foundation. Built in the 1880s and still in active use, Thumm explains that they "had to thread between the convention center, the CSX tunnel and whatever utilities were there.
"Initially (the design) started out as 5-foot-diameter caissons, but we changed it to micropiles. We went through seven micropile designs in the course of a month to hit the deadline to have the steel delivered before the ballpark opened. We (installed) 12 micropiles to accommodate the abutment on the east side of the bridge."
Hensel Phelps' first big milestone was to get the bridge steel erected before the Oriole's opening day on April 9 in order to avoid the lane closures that would interfere with fans making their way to Camden Yards. Using four cranes, United Crane accomplished the task in one Saturday night.
Canam Steel fabricated the bridge trusses at their facility in Point of Rocks, Maryland. The trusses were shipped to the job site and assembled on the ground. A 300-ton Link-Belt HC-278H crane picked up and flew the first truss and did a mid-air transfer to another 90-ton Liebherr and a 120-ton Grove GMK5120B, which set and held the truss in place. The 300-ton Link-Belt then picked up the second truss, setting it and holding it in place. Finally, a 40-ton Grove TMS500E hydraulic crane stitched in the cross members.
Because the pedestrian bridge crosses over Baltimore's light rail line as well as Howard Street, work hours are restricted to five-hour windows on Friday and Saturday nights when the light rail trains are not running. So, construction continues on the bridge, which will feature a curtain wall on each side, metal panels underneath and a standard roof.
Work will soon begin on the exterior skin and the studs. The exterior on the lower podium is Cushwa brick that will match the brick at Camden Yards. Above that a metal panel system comprised of metal studs, sheathing, an air barrier, and a 2-inch insulated Centria wall panel will form the exterior of half the remaining superstructure, while the other half is a corrugated rain screen panel.
At this point in the project, the utilities are nearly 75-percent done. The concrete superstructure is scheduled to top out on September 28, the structural steel in mid-July on the lower podium and the high steel by mid-October. Once construction is finished, however, Alisha Schmitz, project manager with Hensel Phelps, is responsible for the interior upfit of the hotel — right down to the silverware.
"Normally developers handle their own furniture and their own operating supplies — glassware, stemware, computer systems, knick knacks, etc.," says Thumm. "We're working with the Parker Company, which is a purchasing agent for the hotel industry."
According to Bill Thumm, this is a growing trend in construction contracts — contractors being responsible for Fixtures, Furniture and Equipment (FFE) and Operating Supplies and Equipment (OSE) so that these items can be incorporated into one contract.
With a scheduled completion date of August 9, 2008, the Hilton Baltimore Convention Center Hotel is on schedule and going well. "We've gotten past the design stage and we're fully permitted," says Thumm. "We're projecting to meet or beat our goals. It's a great collaborative team, which is what you want with design-build."