Is there one big enough to carry it? You can do it as a static scenery piece if you add some invisible track set to the height of the flat car or truck, then add the loco, then slide the flat under it.
To make a loco haulable you'll have to severly edit it to make it into a product. If you want it to include the bogies you'll have to also edit them to make them meshes to be added to the loco mesh.
To make a loco haulable you'll have to severly edit it to make it into a product. If you want it to include the bogies you'll have to also edit them to make them meshes to be added to the loco mesh.
Basically to put it on a wagon it needs to be a product. So step one find a product and clone it. Rename the clone. Then replace the mesh and texture files in the cloned product. Experiment with the loco mesh first. You may have problems with the attachment points on the wagon. I'd add the new product tq the queue on the wagon. The position tag may help.