Hi constantin,
Are you trying to place a container on a ship in the mission editor? If so, there are two basic things that you must do:
First you need to adjust the height of the container because all objects are initially placed at sea level. You must also keep the gismo properly reattached to the container after each adjustment.
Second, you must use an action in the initializing logic to attach the container to the ship. If you do not do that, the ship will sail and leave the container behind.
All of these chores are explained in the Mission Editor Notes that you can download from:
http://80.95.161.114/shipsim/forum/index.php/topic,19793.0.html (http://80.95.161.114/shipsim/forum/index.php/topic,19793.0.html)
If you have any specific questions, you can send me a PM or, preferably, an email to the address in my profile. Email would allow us to exchange program files with examples.
A better place to ask question about missions or the Editor is the Missions board. There you will find many bold blue topics that you might find helpful.
Regards,
Marty