Space trains does sound pretty awesome, sorry for the derailment (get it ) from the original post.

Maybe I'm wrong, but I remember Steve removed the possibility to create "space trains" long ago.
Now it should not be possible to create a caravan using just one tug and many engineless freighters linked one to the other with tractor beams.

Hmm never thought of using Tug for hauling cargo, nice .  Still doesn't work though because Tug speed is only affected by the tonnage of what it is hauling, regardless of what the hauling thing is hauling,

The idea was that you could vary the total tonnage by attaching only as many "cargo unit" ships as you need.

can a Tug tractor multiple ships at the same time? I thought it was 1-to-1 but never tried multiple tbh.

If not you might be able to attach a tractor beam to each "cargo unit" ship.

I know it's a big workaround and not exactly smooth, but for someone that likes to RP something like this it might work

the only thing I would like for Cargo ships is a bit of a complex mass system to affect speed depending on how much cargo it has so an empty cargo ship will travel faster then a fully laden one, would be quite a bit of work to add in though so I am not too bothered about even putting it as a suggestion in the suggestions thread.

It might be possible to use a space train

Tug + X amount of engine-less bulk freighter holds tied together. The more you add the slower it'll go.

You can't blow up the cargo of cargo ships to make them explode, you can with colliers though.

I suppose that's the beauty of SM mode though, you can RP it how you want so you can have Cargo ships holding whatever, the only thing I would like for Cargo ships is a bit of a complex mass system to affect speed depending on how much cargo it has so an empty cargo ship will travel faster then a fully laden one, would be quite a bit of work to add in though so I am not too bothered about even putting it as a suggestion in the suggestions thread.

I assumed you meant civilian freighters, my fault. If you do all that then I don't see why you have a problem building a collier or two more if it becomes obvious you need a few more.  I'd like to have some dedicated military cargo ships myself, for moving things like pre-fabricated PDC parts around.  I may need something like that for my salvage ship as well.

I can't comment on the maintenance supply question except that it is likely due to the definition of a ship as a supply ship more than anything else.   There is no logical reason one can't have maintenance supplies in cargo spaces.  The only thing is that only those at hand can be used for repairs.  The maintenance bay is basically, in my view, like that ship the had in Once a Hero...or the next book which was basically a huge maintenance repair facilty and had this huge warehouse for spare parts. 

As far as colliers go I'd rather see a specialized magazine for that.  One that holds more missiles per tonne but is not usable for firing them and instead has a missile exchange function.  So it speeds up missile exchanges between ships.

Moving missiles around should not be made easier, and it is currently pretty trivial, because the difficulty in keeping the beast fed is supposed to be a balance point. 

It would come down to Safety Equipment ... A normal Merchant Ship will not have the required storage containment facilities for Nuclear Missiles while a collier would have.

I rather doubt it is a function of "ability" to move them.  For example in War in the Pacific I transport military supplies including crated air craft in every sort of cargo vessel imaginable.  But they move (usually) in convoy.  Now consider that you are talking about moving nuclear warhead armed missiles about on a completely defenceless ship, or an attack craft with the capacity to launch those birds I think most modern militaries would say "not on my watch."

I don't know how NATO moves its ammo around, but I do know that the Canadians pulling out of Afghanistan was done in different stages with the final stages being more or less infrastructure equipment.  I don't know how they got their leopards, artillery and related ammo back to Canada but I'd have thought on one of the US Auxiliary ships.

I don't see where the problem is in having a few colliers and escort carriers for this sort of task.  Logisitics like this is bread and butter for a military.  Going back to War in the Pacific you would be astounded at the number of different ship designations that exist to cover every task conceivable.