42 feet per gallon
nasa.gov
42 feet per gallon
1–10 of 38 posts
Re: 42 feet per gallon
#2You know, 42 feet per gallon sounds pretty terrible, but I'd say moving 5.5 million pounds of equipment 42 feet with one gallon of gas is pretty damn impressive.
Re: 42 feet per gallon
#3You know, 42 feet per gallon sounds pretty terrible, but I'd say moving 5.5 million pounds of equipment 42 feet with one gallon of gas is pretty damn impressive.
The weight of the crawler is 5.5 million pounds, it carries 12 million pounds on top for the trip. I'm not sure if the FPG calculation includes the cargo
Re: 42 feet per gallon
#4You know, 42 feet per gallon sounds pretty terrible, but I'd say moving 5.5 million pounds of equipment 42 feet with one gallon of gas is pretty damn impressive.
Put differently, a 30mpg, 4500lb car gets 713e6 feet-pounds/gallon (30m/g * 5280f/m * 4500lb). A loaded crawler gets 756e6 feet-pounds/gallon (42fpg * 18e6 lb). Not so different after all! And the car looks much less attractive if you look at just the payload.
Re: 42 feet per gallon
#5You know, 42 feet per gallon sounds pretty terrible, but I'd say moving 5.5 million pounds of equipment 42 feet with one gallon of gas is pretty damn impressive.
Put differently, a 30mpg, 4500lb car gets 713e6 feet-pounds/gallon (30m/g * 5280f/m * 4500lb). A loaded crawler gets 756e6 feet-pounds/gallon (42fpg * 18e6 lb). Not so different after all! And the car looks much less attractive if you look at just the payload.
This is a meaningless calculation. It's not as though the amount of energy required to move something a specific distance is weight related. The amount of force required to accelerate it to a specific velocity is, but once at that velocity, energy required is a function of friction. Of course larger objects have more air friction on average, but really what you want is some measure of the surface area of the object.
Bah, not that it matters in the least.
Re: 42 feet per gallon
#6Earlier quoted context omitted.
Put differently, a 30mpg, 4500lb car gets 713e6 feet-pounds/gallon (30m/g * 5280f/m * 4500lb). A loaded crawler gets 756e6 feet-pounds/gallon (42fpg * 18e6 lb). Not so different after all! And the car looks much less attractive if you look at just the payload.
This is a meaningless calculation. It's not as though the amount of energy required to move something a specific distance is weight related. The amount of force required to accelerate it to a specific velocity is, but once at that velocity, energy required is a function of friction. Of course larger objects have more air friction on average, but really what you want is some measure of the surface area of the object.…
"It's not as though the amount of energy required to move something a specific distance is weight related. "
" really what you want is some measure of the surface area of the object."
Re: 42 feet per gallon
#7Earlier quoted context omitted.
Put differently, a 30mpg, 4500lb car gets 713e6 feet-pounds/gallon (30m/g * 5280f/m * 4500lb). A loaded crawler gets 756e6 feet-pounds/gallon (42fpg * 18e6 lb). Not so different after all! And the car looks much less attractive if you look at just the payload.
This is a meaningless calculation. It's not as though the amount of energy required to move something a specific distance is weight related. The amount of force required to accelerate it to a specific velocity is, but once at that velocity, energy required is a function of friction. Of course larger objects have more air friction on average, but really what you want is some measure of the surface area of the object.…
Interesting comparison.
A container ship does about 24knots = 40feet/second
It uses around 350tons of fuel/day = 4.5 l/s = 1.2USgall/s
So it does a very similar consumption - around 35feet/gallon
While carrying 150,000tons of cargo = 320million pounds.
Re: 42 feet per gallon
#8Article doesn't say how far it typically has to travel.
Traveling quarter mile, no big deal. Traveling 10 miles, much more expensive.
Re: 42 feet per gallon
#9Earlier quoted context omitted.
This is a meaningless calculation. It's not as though the amount of energy required to move something a specific distance is weight related. The amount of force required to accelerate it to a specific velocity is, but once at that velocity, energy required is a function of friction. Of course larger objects have more air friction on average, but really what you want is some measure of the surface area of the object.…
Interesting comparison. A container ship does about 24knots = 40feet/second It uses around 350tons of fuel/day = 4.5 l/s = 1.2USgall/s So it does a very similar consumption - around 35feet/gallon While carrying 150,000tons of cargo = 320million pounds.
The low speed (90 rpm) diesels in those ships are by far and away the most thermally efficient internal combustion engines on the planet. The biggest ones approach 50% efficient.
http://en.wikipedia.org/wiki/W%C3%A4rtsil%C3%A4-Sulzer_RTA96...
Re: 42 feet per gallon
#10Article doesn't say how far it typically has to travel. Traveling quarter mile, no big deal. Traveling 10 miles, much more expensive.
Seems to be about 3 miles from most of the launch pads to the VAB, so about 377 gallons for a one-way trip (http://www-pao.ksc.nasa.gov/nasafact/count3teaf.htm)
The crawler can travel about 1 MPH loaded; the tour guide at KSC (at least when I was there several years ago) made a big deal about the blazing 2 MPH it can do when unloaded. :)