Good morning Friends...last night i as watching a rare programme in History channel. it was about some extra ordinary crafts, basically used at port side. because of the nature of the programme i started my own research in the subject of TUGs. actually i have started work for a TUG, with some samples, along with my imagination.as i tried to explore things, i got even more exciting things from old Popular Mechanics, elder than me,and in that article writer says the word TUG means a VIOLENT PULL...yes i saw it in video. my doubt is this...ho engineers produce great amount of violent thrust within minimum RPM..? if i can explore it, it may much helpfull to me, while making my TUG, all with limited stuffs with ,me... will some one advice me..?