7 ms·
42 feet per gallon
- javanix 16y agoYou 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.
- sosuke 16y agoThe 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
- b_emery 16y agoVery cool. I had to compare it with the Airbus A380-800: 1,300,000 lbs max takeoff weight, using 85472 us gal max fuel capacity, and 6400 mi max range = 395 ft/gal or 513.5e6 ft-lbs/gal
- gxti 16y agoPut 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.
- gregable 16y agoThis 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.
- ghshephard 16y ago"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." http://en.wikipedia.org/wiki/Rolling_resistance http://en.wikipedia.org/wiki/Rolling_resistance
- oiuyftgrghjk 16y agoInteresting 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.
- xxpor 16y agoThe 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-C http://en.wikipedia.org/wiki/W%C3%A4rtsil%C3%A4-Sulzer_RTA96...
- tocomment 16y agoWhy is that? Why don't they use these to generate electri ity?
- oiuyftgrghjk 16y agoBecause external combustion engines (boiler + turbine) are more efficient and cheaper to build at large scale
- tocomment 16y agoSo why not use those in ships?
- 16y ago
- ck2 16y agoArticle doesn't say how far it typically has to travel. Traveling quarter mile, no big deal. Traveling 10 miles, much more expensive.
- drv 16y agoSeems 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 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. :)
- spc476 16y agoThe closest observation point is three miles from the launch pads, so yes, the VAB (Vehicle Assembly Building; it's insanely large) is probably around three miles as well. Why the three mile distance? Back during the Apollo program, engineers determined that if the Saturn V were to explode on the launch pad, the resulting fireball would be around four or file miles in diameter. I think it's a similar radius for the Shuttle as well.
- snth 16y agoSo the fireball would still engulf the buildings? Doesn't that still seem too close?
- kd5bjo 16y ago3 miles away produces a 6-mile diameter safety zone.
- kylemathews 16y agoDiameter not radius. So 4-5 miles diameter = 2-2.5 miles radius.
- photon_off 16y ago
- rue 16y agoSo, 12,8m/3,78541178l or EU standard combined: 29573,53l/100km? I wish at least sciency articles used SI.
- axod 16y agoThe numbers you just put above mean nothing to me. Feet per Gallon is something humans can visualize. I'm sure I'll get downmodded to hell for expressing this opinion here, but I really do prefer imperial measurements.
- jmillikin 16y agoIt's only something you can visualise if you grew up with imperial units; "42 feet per gallon" is not inherently easier than "3.4 meters per liter", nor "125.7 gallons per mile" than "296 liters per km".
- wtallis 16y agoBut all of those are far more accessible than 29573.53L/100km, which most people would just round up to "a hell of a lot". Using conventional units doesn't really help when the magnitude is so high.
- spectre 16y agoThe advantage to the metric system is the ease of converting between units. I can convert from metres per litre to litres per kilometre by dividing the former into 1000. In this case 1000/3.4 = 294 (Approx)
- Nick_C 16y agoMike Rowe of Dirty Jobs got to drive the crawler in one episode. It was a cool episode. You appreciate just how big it is when you see him standing next to the treads.