CAPE CANAVERAL, Fla. -- Repairing the crawlers that take shuttles to the launch pad is a massive undertaking because the crawlers are so large.
Even the cracked bearings, a word that brings to mind the tiny metal balls we're used to seeing in other machines, are 40-pound steel alloy doughnuts.
It may be a big job, but the people laboring on the hulking Crawler No. 2, sweating in the shadow of the Vehicle Assembly Building at Kennedy Space Center, take big pride in the task.
"This is basically one small team, and you know, for 8 or 10 hours of that little part of the shuttle processing flow, we literally have the whole program on our backs," said Perry Becker of Merritt Island, NASA's lead systems engineer for the crawlers.
In a slow and noisy process, the team used a crane to help install its first 10,000-pound cylinder on Friday, one of two brand new ones ordered for the two crawlers. Each crawler has 16 cylinders with two bearings apiece.
"It was difficult," said Dick Davies of Port St. John, lead mechanic on the transporters for contractor United Space Alliance. "We expected it to be difficult, but it worked very well."
The two new cylinders mark the beginning of a multiyear refurbishment effort during which old cylinders will be sent to the manufacturer for restoration. Removing the first two cylinders led to the discovery of damage to several bearings, which will be replaced. The cylinders had never been removed before from the 37-year-old crawlers, which date from the moonshot days. They'd worked so well, with only a few problems, that no one saw a need.
"The guys that designed the crawler, I've always thought, are truly amazing," Becker said, praising its robust design. "There's a lot of redundancy built into the crawler."
The first cylinder installation took more than two hours. "That's a lot better than we initially planned, so we're feeling pretty good about this," Becker said.
He said repairs should be done in time for a September rollout of shuttle Atlantis, scheduled to launch Oct. 2.
"As we go along, I think we'll speed the process and really get the process down pat," Becker said. "And we intend on going into basically a two-shift, round-the-clock production mode here real soon."
They already worked through the weekend.
At the work site, a bunch of guys were up on the crawler, hovering around the three or four people doing the main work.
The crane that hoisted the cylinder into place was roaring nonstop. It worked almost as hard as the men.
The hardest part was lining up bolts with the four bolt holes in the flat plate on the bottom of the cylinder, Davies said. Each cylinder has a plate and a bearing on both ends.
"There's very little room down there," he said, so they used a small hydraulic tool to get it into place.
"It's kind of enjoyable for me and the guys I'm working with to kind of have a challenge," Davies said. He has nothing but praise for his co-workers.
For this project, they include crawler mechanics, crane operators from the heavy equipment shop, more experts from the weld shop, and engineers, Becker said.
"It gives you a feeling of confidence working with this kind of people," Davies said.
The crawler transporter is a square, flat vehicle 131 feet (40 meters) long and 113 feet (wide that carries a mobile launch platform and a shuttle to the launch pad at the blazing speed of 1 mph. Among its most striking features are dual driving cabs on opposite corners. It actually has two drivers during docking procedures.
It also has two mufflers that look like a typical car muffler -- only each is the size of a passenger car.
On each corner of the crawler are two big tread belts, and in between those are four jacking, equalizing and leveling cylinders arranged vertically around a central point. They automatically keep the shuttle level.
"They're constantly being extended and retracted, even just going out on the crawlerway," Becker said. "The crawler chassis, and everything above it, rests on that hydraulic pool of oil in all these cylinders."
That is why the bearings are so important.
"Some or maybe all of these could have very easily been cracked way back in Apollo," Becker said. "We just simply don't know."
There will be more refurbishment in the future and maybe even a new design for the bearings down the road. A new lubricant is supposed to help prevent damage, too.
Published under license from FLORIDA TODAY. Copyright © 2002 FLORIDA TODAY. No portion of this material may be reproduced in any way without the written consent of FLORIDA TODAY.
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