What are those huge things that we see on Youtube and TV channels that transport Giant Rockets and Spaceships?
For starters, They are called Crawler and they are just two in number, to top it all they have been in service for the past 50 years.
Crawlers are unique transport vehicle which can boast of being the largest weight carrying transport vehicle of the world. They were made for NASA, And NASA loves it so much that they have been using it for Half a decade.
Some history on this:
Firstly they are two in the number called Crawler-transporter 1 and Crawler-transporter 2 or (CT 1 and CT 2). NASA’s GSDO (Ground Systems Development and Operations) department is still modifying and maintaining them. The main components of these massive and one of a kind vehicles were built by the Marion Shovel Company in OHIO. They had shipped the components to Kennedy Space Center where they were assembled. This happened in 1964 and the crawlers started their service in 1965 to aid the ambitious Apollo program of NASA, however, the real test for them came in Aug 1967 when they transported the super heavy Saturn range of rockets.
Now coming to the beauty of this mammoth machine. The crawlers are huge, In fact, 40 X 35 meters to be exact and weight a massive 2721000 kgs. The height from ground level can be adjusted from 6.1 to 7.9 meters approx. and this can be done independently from both the sides.
The crawler is a tracked vehicle which means its wheels are enclosed in a track like a tank which gives it more inline stability and integrity. They run on a specific path and have a laden top speed of 1 mile per hour and unladen speed of 2 miles per hour.
How does it Work?
This vehicle is powered by 16 traction motors which are powered by two alternating current diesel generators and two direct current generators. It is piloted by 2 operators on each side and is a complex vehicle to handle with zero room for operational error. It is noticeable that the operators sitting in the cab can only control the forward and backward motion of the vehicle.
Other parameters of vehicles motion are controlled by the JEL system or the Jacking, Equalizing and Leveling system which is controlled independently from crawlers control room and uses highly sophisticated computers to do the same. The JEL systems keep the upper deck pickup points at the same level irrespective of the position of the vehicle that means the level is maintained even when the vehicle is going up or down an incline.
The giant tracks of the crawlers are its main maneuverability tools and their series of motion decides the direction and speed of the vehicle.The tracks are two per corner hence in total 8 tracks are used in real time to move the vehicle properly. Each track has 57 shoes measuring 7.5 x 1.5 feet. These shoes comprise the main weight bearing component of the crawler.The crawlers are also equipped with a laser docking system which allows them to dock with very high precision.
Owing to its huge size and capacities it’s apparent that this is not the vehicle optimized for fuel economy. The crawler has a 19000-liter fuel tank and burns close to 296 liters of diesel per kilometer. Guess heavy work requires heavy stuff after all.