In the desert, you often really don't want to be walking midday, but if the moon is out doing 20 miles in a night isn't too bad, and doing it split over two days is fine. 5 or 6 liters of water plus some food would be plenty, depending on what you have available to carry that ~15 pounds splitting into two days may be more comfortable. Either way, infinitely less risky than building a motorcycle.
4 mph takes talent, especially over distance. Andthat’s on hard surfaces. From what I understand walking on sand is deceptively taxing. I’d say 2-2.5 and not as the bird flies distances. So ten to fifteen hours of walking if your feet let you.
The desert in question isn't all sandy dunes; there's a lot of rocky or compacted surface (see photo), so you can make pretty decent time (but yeah, sustaining 4mph would be pushing it for most people).
I've done 97km in 26 hours before, in the Sahara (I think we started around 8am, and finished around 10ish the next morning), which works out to about 2.3mph, so I'd agree 2-2.5mph is reasonable.
hmm, [0] this says the longest stage was 91km in 2009 (I did it in 2015), so I could be wrong, but I'm going by what my garmin told me.
That was my thought as well. He might not have had something to carry the food and water, but making something to carry it would probably be easier than building a motorcycle.
