A grove of 250-foot tower cranes, tallest of all construction cranes, soon will fill a gap in Galveston’s skyline reserved for the new 13-floor Jennie Sealy Hospital, which is scheduled to open in 2016.
Two of the big cranes already are at the hospital site, hoisting material and equipment in an industrial-grade aerial ballet. Two more are due in October and December.
“The arrival and installation of the tower cranes is exciting because everyone in Galveston can see them and know that UTMB is making progress,” said Jake Wolf, senior project manager.
The tower cranes will help place Jennie Sealy’s vertical columns, which are expected to start going up by January. The hospital will have two distinctive towers, 310 patient rooms and an adjoining seven-floor support building, the Clinical Services Wing.
“The crane is the lifeblood of the project,” said Joe Burrus, project superintendent for Hensel Phelps Construction Co., the hospital general contractor. “Everything revolves around it.”
Coordinating the movements of tower cranes is a lot like controlling air traffic. “It’s a dance,” said Barry Enderle, superintendent with Vaughn Construction, contractor for the Clinical Services Wing. “And a good dancer knows when to lead and when to follow.”
In Galveston, the two contractors, Vaughn and Hensel Phelps, have abutting work areas. They operate their own tower cranes, but work together every minute on their maneuvers. Each crane operator has two spotters on the ground, a flag or signal person who guides the operator, and a crane coordinator who communicates movements with other cranes on shared radio frequencies. Cranes at the site also have an electronic collision-avoidance system.
Crane maneuvering can be tricky in congested work areas. A tower crane hoists cargo from a boom, or jib, that extends horizontally more than 200 feet. The jib can rotate 360 degrees and enter the perimeter of another crane’s jib. Collisions can be avoided by timing a movement or changing the elevation of the jib’s cargo, much like air-traffic controllers do.
“Safety is our No. 1 priority on the jobsite,” Wolf said. “We want to ensure that all the construction workers, hospital staff, visitors and patients go home safely to their families.”
A crane operator’s workday lasts 10-12 hours, usually starting before dawn with the day’s toughest physical challenge – climbing an enclosed ladder up to the cab at the top of the crane.
“I may take 20 or 30 minutes to get to the cab some mornings, but usually I’m up there in about 15 minutes,” said Keith Crawford, 57, crane operator for Hensel Phelps. He starts work at 4:30 a.m. His crane is 260 feet high.
Crane operators and their coordinators are usually among the most experienced construction personnel at a site. Crawford has been a crane operator for 27 years; his ground coordinator, Elroy McKnight, also a certified crane operator, has 33 years of experience. Operators undergo a rigorous process of regular physical exams and job-skill testing to get certified.
Tower cranes are built to withstand high winds. One tower crane at Galveston, for example, is designed to withstand 95-mph winds; another is designed for up to 138-mph winds. A Category 1 hurricane has sustained winds of 74-95 mph. Crews will lower a tower crane if the probability of a hurricane arises.
Crawford and McKnight said they have ridden out thunderstorms. “I’ve been in 80-mph winds and you don’t know whether to stay in the cab or try to climb down,” said McKnight, 63. “You are almost always better off staying in the cab because there are greater dangers climbing down like getting hit by lightning or being blown off the ladder.”
Do operators get a break? “Only when the crane is not in use,” said Burrus, the Hensel Phelps superintendent. “The operator takes his lunch with him so that he does not have to climb down until the end of the day. He has facilities to use the bathroom and amenities for when he is not working. He has video access in the cab so he can watch Doppler radar for any adverse weather developments.”