For one train to complete the journey:
But now we have 2 trains, going at the same speed, so they will meet at 50 miles. So for the trains to meet each other will take 100 mins.
Now for the bird.
The bird has 100 minutes to go as far as he can before his imminent and brutal death... (Oh the calamity)
EDIT: This looks like such a small distance. Something doesn't seem right.
EDIT2: Messed up with the time, let me correct it.
EDIT3: There we go, 100 miles