Vandy Tenders? Benefits?

Can someone tell me why some railroads used vandy tenders? Was there a benefit to them? Was it a look thing?

I can’t state categorically that this is why, however this makes sense to me. I’m unsure why tenders were ever square, as a round drum-like tank is a stronger container for liquids. Vandy tenders were a tank, in one of its’ simplest forms. A round tank could be made from lighter material for a given strength and need much less reinforcement, therefore offering an as strong, yet lighter vessel. If anything, the square tank might have been considered to be the better looking as it carried the square shape of the cab back to the end of the locomotive. I like both and wish I could use vandys! However the N.P. did not use them.

If I’m wrong about all this, at least it was an educated guess.

I hadn’t thought about the square tender carrying the lines of the cab back…that makes sense to me. I really like the look of the vandy’s. After seeing the new pictures of the BLI UP mountains I really wish i had ordered one…