Problem converting lines to a 3D model/surfaces

[gareth.newton.2021]

I am having trouble converting lines, that I have structured to resemble a simplistic 3D barge model, to a 3D object/surfaces.

Any help or advice would be appreciated, as I am fairly new to Autocad.

[neaton]

To convert linework to a 2D planar object it must be closed polylines. Your drawing is made up of lines, not polylines.

Here is a link on how to convert 2D lines to 3D object https://knowledge.autodesk.com/support/autocad/learn-explore/caas/sfdcarticles/sfdcarticles/How-to-c...

Nancy