How To Fix Bad Locomotive Designs

I take requests. Only 3 rules:

#1: If a locomotive suck in 1 County, but was useful in another, the problems was fixed (like Duke of Gloucester), or any problems were caused because of nature like fog, it doesn't count, and will not be on this book.

#2: Please don't spam or hate. Any and all hate and spam will be ignored. If you haven't had your locomotive(s) chosen in a while, then please put them down. Otherwise, wait patiently.

And #3: This is my opinion on how to fix them, and my opinion only. If you have any opinions, then you can say them as long as you respect mine.