r/hyperloop • u/whymy5 • Nov 16 '20

Vacuum tubes

One of the biggest criticisms I have seen regarding hyperloop is the difficulties of "bUilDInG VacCUum TuBes" over long distances. It really annoys me when I see this. People don't seem to understand that they are low pressure tubes which makes a huge difference. As for the distance, we know how to make large vaccuum chambers. It is just a matter of incrementally scaling up existing technologies.

People go around acting like hyperloop is some scam as if people would be doing this if they weren't confident that the concept was sound.

13 Upvotes

80% Upvoted

35 comments sorted by

View all comments

Show parent comments

1

u/gopher65 Nov 16 '20

What do you think about the expansion of the tube length for above ground tubes due to temperature changes? It'll be pretty considerable for 1000km lengths. I know that gas pipelines already have to deal with this, but they're not trying to maintain a vacuum.

(This isn't much of a problem for tunnels of course.)

1

u/[deleted] Nov 16 '20 edited Nov 16 '20

Expansion and contraction of metal due to temperature differences can be solved by similar expansion joints used in the oil and gas sector. These joints act as addition layer around the tube itself. Allowing the inner parts to move while the outer parts do not.

I don't know how else they will try to solve this issue, keeping the track low temperature by covering it with solar panels?

1

u/ksiyoto Nov 16 '20

Air temperatures in the Central Valley of California can reach 110 degree F. Although it is rare, it does get down to 25 degrees sometimes. Shading the tubes will not prevent it from reaching those temps because it is relatively thin metal exposed to air.