WORLD'S SLOWEST DRIVER
BEGINS TRIP TO THE MOONKENNEDY SPACE CENTER -- Ed Walsh is probably the world's slowest driver, yet he's the lead-off man on the trip to the moon.
Ed is not an astronaut, but an employee of Bendix Launch Support Division, which has the job of transporting the moon rocket and its mobile launcher -- an unwieldy 12.6 million pounds rising 451 feet above the ground -- from the Vehicle Assembly Building (VAB) at this sprawling space complex to the launch pad, three and a half miles away.
The rocket and launcher are mounted atop a transporter or "crawler,'' one of the biggest, slowest, strongest, strangest and noisiest land vehicles ever devised by men. It weighs another 3.5 million pounds, adding up to a kingsized balancing and juggling act calling for, in the words of Fred Renaud, one of the control engineers, "some pretty hairy maneuvers."
The trip normally takes 6 to 8 hours, because the "crawler" lives up to its name traveling at a cautious maximum of .75 miles per hour.
"You can't imagine the difference between .7 and .9 miles an hour with this much weight," says Frank Reaves, one of the hydraulic engineers. At .7 the ride is very smooth, at .8 the vibrations may be noticeable, but tolerable, and at .9 it's pretty sure to be difficult, to say the least."
Two transporters, which took three years to make, are maintained and operated by Bendix.
Each has two cabs containing the usual controls found in an automobile - an accelerator, foot and parking brakes, speedometer, air conditioner, radio (for two-way communications), adjustable seat and windshield wiper.
Some Warm-Up!
While the accelerator on the family car controls a single engine rated at around 250 horsepower, the crawler's counterpart controls 16 motors with a capacity of more than 6,000 horsepower, equal to more than 32 automobiles!
Preparing a transporter for duty goes far beyond the simple turn of an ignition key. The supervisory engineer first advises the control room, the actual operating "heart" of the vehicle, that all is ready.
It takes approximately 90 minutes for the crew of 14 Bendix engineers and technicians to start and warn-up the six diesel engines, energize several dozen electrical circuits, start up three hydraulic systems, one pneumatic system, a fuel system and two lubricating systems, and make a series of checks called for by a 39- page startup procedure manual.
Each of the eight tank-like tracks on the transporter is made up of 57 plates called "shoes," and an individual shoe weighs literally a ton. The largest of the six mufflers on the vehicle weighs 3,000 pounds, and is about nine feet long. Handling such a monster machine requires a cool head, extreme patience, and much teamwork, especially the loading and unloading at either end of the trip.
"The first time out is an awesome experience," says Ed. "You think about that terrific weight up there and what would happen if you had some catastrophic malfunction. You know, on paper, it will do the job, but you wonder if it really works. You don't quite know what to listen and look for."
Don't Lean On The Brake
Inside the VAB, the transporter must be steered with the aid of gauges, guidelines, and a personal judgment by Bendix personnel stationed at strategic checkpoints, to within two inches of a set of pedestals ranging across the 150-foot width of the mobile launcher to allow the load to be firmly bolted down.
"When a man stands next to the 'crawler,' it looks big," says Bill Clemens, supervisor of the transporter team, "but when you see it under the mobile launcher, it looks incapable of lifting such a big 'cad."
But it does, and then begins the slow, painstaking methodical trip to the pad.
"This part of the move is not particularly hard," says Ed, who, by now is perched in his cab, steering the massive vehicles
"The main concern is just staying on the road, and if you have to stop quickly, don't lean on the brake. The small jolts and jerks down here are sledgehammers on top."
"One of the hazards is you tend to overcontrol the machine because it takes things so long to happen. You come up to a curve, put in a steering signal, and about 25 minutes later you come out of the curve. The tendency is to put all the steering in at once."
Up The Hill
At the pad, the transporter now with its crew of as many as 30 men, most of them on radios to monitor the trip, must negotiate a 1200- foot-long incline, at about a 5 per cent grade, before depositing its precious cargo on another set of pedestals.
Ed and one of his counterparts, possibly Ken Kelley, in the cab on the other end of the transporter, steer the front and rear ends into position, while the foreman on the pedestals give verbal directions to move right or left.
"The effort to negotiate the grade is not noticeable on the way up because of so much excess power," says Ed, "but coming down you don't dare allow yourself to go too fast. She wants to free-wheel and coast, and if you overspeed too far the diesel engines will shut off -- which spells trouble! You must keep the speed under control."
In Supervisor Clemen's view, connecting the Mobile Service Structure (MSS) to the Saturn V at the pad is the trickiest and most delicate maneuver of all.
Tight Squeeze
The MSS, which towers 402 feet above the ground, provides five access platforms for final checking out and testing the Apollo spacecraft and the rocket booster stages. It is hauled to and from its parking site on the crawler.
"You have only a few inches of clearance when you're mating the structure to the pad," said Bernie Smith, who has now relieved Frank as the JEL operator. "There are clamshell doors that hinge and close around the bird, and if you run into them there will be no shot. It's as simple as that."
Seven of the 21 men who maintain and operate the crawler are qualified drivers. Their formal title is "operating engineer" and each is a graduate engineer. They perform a dual role as an expert in hydraulics, diesel engines, electronics, electrical power systems or structural maintenance.
To Clemens, supervising the operation of the "crawler" is exciting, even though the incredibly slow vehicle is a tremendous contrast to the speeds which he was accustomed to traveling while in the Air Force.
Now he's a landlubber, and revels in the accomplishment of traveling 3-1/2 miles in 6-8 hours.
Copyright 1997-2005 by John
Duncan |