Search Challenge (7/15/15): What kinds of buildings are these?

I have to admit that I'm fascinated... 

... by old industrial buildings.  Maybe it's a side-effect of having grown up in Los Angeles, where there were many older buildings from the industries that abounded in south-central LA.  I saw all of these buildings growing up, and now as they begin to fall out of favor or use, I can't help but see them with a bit of nostalgia.  

But despite having grown up with these buildings, I'm not sure I know all that much about them.  Can you help me identify what these typical industrial building types are, and why they have these peculiar shapes? 

I have three different shapes of buildings, and the Challenge for this week is the same for each type: 


1.  What is this kind of building called?  Why does it have this distinctive shape?  


Building Type A:  Here's the building that started it all for me.  I was driving near the docks in Seattle, saw this building, and shot the picture when I paused in traffic.  (It's at 47.5529417,-122.3365972 if that helps.)  

I'm still looking for a better picture, but you see this kind of building everywhere in industrial zones.  They all have the large double curved shapes growing up from the roof.  What ARE those things?  Why do they have such a distinctive and odd shape?  (If I find a better picture, I'll update the post.)  

(You can click on any picture to see it full-size.)  

Building Type B:  You used to see this distinctive shape everywhere.  There are still a bunch of these buildings out there, often repurposed from their original use.  What are these things called? 

For what it's worth, the second building is about 2 km from my house and was reshaped a bit from its original design to become a garage.  (This photo is from a few years ago--it's still exactly the same, only the cars have been updated.)  



Building Type C:  Here's another common industrial building design pattern.  Why would they make the roof like that?  

The bottom picture is the original HP building from many years ago.  This view can't be seen any more, but for years, the building poured light into the night sky of Palo Alto.  I lived about 1 km from this building for a while, and got to know it well.  As with the others, this is a common pattern you see in many places.  Just curious:  Why such an odd roof? 


As always, please let us know HOW you found the answer.  Your path to success is of real interest to all of the readers.  (So don't just tell us "it's this!" -- tell us how you came up with your successful search queries, and what resources you used along the way.)  

Search on!