Ever wondered how NASA got those tall, thin, towering rockets or the infamous space shuttle up on the launch pad? It’s not quite done like Thunderbirds! There are no sliding floors or vehicles being raised up level with the ground to lift off. NASA always assemble their Saturn V rockets used in the Apollo missions and the Shuttle in the enormous Vehicle Assembly Building (VAB) and then transport them the 9 miles to the launch pad.
Back in the ‘60s they had to find a way of doing this. It had to be very strong to handle the expensive, heavy loads, safely, keeping the rockets, and later the shuttle balanced with no toppling over. Philip Keohring worked for the Marion Power Shovel Company of Marion Ohio and he was greatly involved in adapting his machines to work for NASA. The successful outcome was what is now known as NASA’s ‘Gentle Giants’, their two crawlers-transporters. When they were built they were the largest tracked vehicles ever made. (The crawlers have since been overtaken as the largest traced vehicles by the Bagger 288, a German excavator - a mobile mining vehicle. The Bagger is slightly different as it’s powered from an external source whilst the crawlers are self-powered and carry loads).
The machine had to be very precise. During testing there were many design changes – separate power systems for load levelling, jacking, steering and ventilating. In 1965 during testing the crawler’s support bearings couldn’t handle the loads during turns so modifications were made to the steering hydraulic system.
If you doubt how sturdy they are here are some statistics. They weigh a mere 6 million pounds! They are 131ft wide and 114ft long. They have accumulated just 2, 526 miles, the same as a round trip to New York, but at a very slow speed!
They’re maximum speed is one mile per hour loaded and about 2 miles per hour unloaded. It takes around 5 hours to get the Space Shuttle from the VAB to the launch pad whilst during this journey they burn 150 gallons of diesel oil per mile!
Each gigantic grey crawler has four double-tracked crawlers, each one being 10ft high and 41ft long. Each of the 8 tracks contains 57 shoes per track and each tread shoe weighs one ton. The height of the crawler is adjustable - between twenty and twenty six feet. The top deck is flat and square with two operator control cabs. These are at each end of the chassis and are used to control all the crawler systems.
For those of you interested in engines they are powered by 16 traction motors and driven by two 2, 750hp diesel engines. They use two 750kw generators driven by two 1, 065 diesel engines for jacking, steering, lighting and ventilating. Two 150kw generators are also used for additional mobile launch platform power (at the launch pad). During a journey to the launch pad the Orbiter is kept vertical within plus or ten minutes of arc – this is about the diameter of a basket ball. Arriving at the launch pad the crawlers have to negotiate a five per cent ramp and use levelling systems to ensure this movement continues to besmooth.
In the next two years the two crawlers will be adapted to carry the next generation of rockets in the Constellation Programme taking man to the International Space Station, the moon and maybe even on to Mars. These unglamorous crawlers may not be the star of the space programme but they certainly have been a very important part of it!
Back in the ‘60s they had to find a way of doing this. It had to be very strong to handle the expensive, heavy loads, safely, keeping the rockets, and later the shuttle balanced with no toppling over. Philip Keohring worked for the Marion Power Shovel Company of Marion Ohio and he was greatly involved in adapting his machines to work for NASA. The successful outcome was what is now known as NASA’s ‘Gentle Giants’, their two crawlers-transporters. When they were built they were the largest tracked vehicles ever made. (The crawlers have since been overtaken as the largest traced vehicles by the Bagger 288, a German excavator - a mobile mining vehicle. The Bagger is slightly different as it’s powered from an external source whilst the crawlers are self-powered and carry loads).
The machine had to be very precise. During testing there were many design changes – separate power systems for load levelling, jacking, steering and ventilating. In 1965 during testing the crawler’s support bearings couldn’t handle the loads during turns so modifications were made to the steering hydraulic system.
If you doubt how sturdy they are here are some statistics. They weigh a mere 6 million pounds! They are 131ft wide and 114ft long. They have accumulated just 2, 526 miles, the same as a round trip to New York, but at a very slow speed!
They’re maximum speed is one mile per hour loaded and about 2 miles per hour unloaded. It takes around 5 hours to get the Space Shuttle from the VAB to the launch pad whilst during this journey they burn 150 gallons of diesel oil per mile!
Each gigantic grey crawler has four double-tracked crawlers, each one being 10ft high and 41ft long. Each of the 8 tracks contains 57 shoes per track and each tread shoe weighs one ton. The height of the crawler is adjustable - between twenty and twenty six feet. The top deck is flat and square with two operator control cabs. These are at each end of the chassis and are used to control all the crawler systems.
For those of you interested in engines they are powered by 16 traction motors and driven by two 2, 750hp diesel engines. They use two 750kw generators driven by two 1, 065 diesel engines for jacking, steering, lighting and ventilating. Two 150kw generators are also used for additional mobile launch platform power (at the launch pad). During a journey to the launch pad the Orbiter is kept vertical within plus or ten minutes of arc – this is about the diameter of a basket ball. Arriving at the launch pad the crawlers have to negotiate a five per cent ramp and use levelling systems to ensure this movement continues to besmooth.
In the next two years the two crawlers will be adapted to carry the next generation of rockets in the Constellation Programme taking man to the International Space Station, the moon and maybe even on to Mars. These unglamorous crawlers may not be the star of the space programme but they certainly have been a very important part of it!