Locomotives

I also hear that whoop sound on lot of G.E. locomotives especially Amtrak, it’s pretty cool!

Go Amtrak and CSX!

Thanks Grandma and Granddad for your support and inspiration!

Sounds like a compressor starting up to me.

Yup…

Brilliant subject line by the way…

if I remeber correctly what you are hearing is the air compressor kicking in. The whoop is sometimes followed by I guess you could call it a pounding, not really sure what to call it.