I have tested a ship with 4 parts. More is not possible!
(http://www.simutrans-forum.de/forum/attachment.php?attachmentid=7847)
This big giant needs a 3 tiles high bridge. This bridge is only 2 tiles high ... Fortunately it is a game. :P
Wow. Good luck with this, you have a head start on other paks. Did you use tilecutter for it? ;D
I haven't used tilecutter. You can see the develpoment (this day ;) ) here: http://www.simutrans-forum.de/forum/thread.php?postid=41184#post41184
First was the middle. Then the back and the latest one is the front. But, I have only 2 directions, at the moment.
This is one nice ship! Perhaps you can make a smaller one (barge?) and then it would fit under the bridge...