So it seems you CAN use fuel lines for refueling ships...kind of...

[Yellowburn10]

Not sure if this particular point has been discussed or not, but if it has, mods feel free to merge this into the appropriate post.

 

So, it's pretty clear by now that you can't use EVA construction to merge 2 craft together, so you can't simply just get two vehicles close by and hook a fuel line to both of them. But, if you were to merge them before hand, either with a docking port or a klaw, you could then place parts on both vessels unabated. Yeah, sounds obvious, I'm aware, but the implications are pretty neat. Take this for an example: Here I have this recently flown SSTO in low Kerbin orbit;

It only has enough fuel to reach LKO, but I can take it to the Mun or Minmus orbit with a topoff. However, it doesn't have any docking ports, so refueling by docking is out of the question. And my current ruleset makes fuel transfer a lot more strict, so I can't just slap a fuel tank with a klaw to the ship and fuel it up that way either. For my solution, I sent up a proof-of-concept refueling ship, with mini klaw attached, and attached it to my SSTO.

But wait, I just said a klaw wouldn’t work, so why am I using it? Well, I said that just a klaw wouldn’t work. This is where fuel lines come in. Once I hook up the ships, I have an engineer come out and hook up some fuel lines, and whala! My ship can now be refueled!

(One note: for some reason, the fuel transfer only worked if I had a fuel line going both too and from the tanker. Having just one run from the tanker to the ship didn't seem to want to work.)

 

So yeah, done like this, fuel lines actually can be used for refueling ships. I'm sure I'm not the first person to think of this, so I'd like to know your thoughts about it, and what you've come up with to deal with problems like this yourselves.

Edited January 3, 2021 by Yellowburn10
Better sentence structuring and explanations.

[Bej Kerman]

9 minutes ago, Yellowburn10 said:

And my current ruleset makes fuel transfer a lot more strict, so I can't just slap a fuel tank with a klaw to the ship and fuel it up that way either. For my solution, I sent up a proof-of-concept refueling ship, with mini klaw attached, and attached it to my SSTO.

Not to be pedantic, but...

[Yellowburn10]

1 hour ago, Bej Kerman said:

Not to be pedantic, but...

I know, I know, I realized it as soon as I hit post. I just thought the following sentence would show how this would be different. I went ahead and revised it.

Edited January 3, 2021 by Yellowburn10

[James M]

If it makes you feel better, I thought what you did was cool. And made sense. Which does matter!

[Yellowburn10]

21 hours ago, James M said:

If it makes you feel better, I thought what you did was cool. And made sense. Which does matter!

I appreciate the comment, but it seems like everyone else knows that this works as well, so I guess I was just pointing out the obvious. But it still is very useful to know this is possible now.

[royying]

If you don't mind using mod, I think KAS is a better choice, it have hose reel and hose connector part, enough realistic for me 

[Yellowburn10]

10 hours ago, royying said:

If you don't mind using mod, I think KAS is a better choice, it have hose reel and hose connector part, enough realistic for me 

Oh I'm well aware of KAS, my point was to show how you can use a stock method to refuel ships with fuel lines. I agree that using KAS fuel hoses is a less complicated method, and it would be nice to have something like that in the stock game, but if you play without mods or on Enhanced Edition this method is a close second.

Edited January 23, 2021 by Yellowburn10

[theJesuit]

Nice to know that EVA Transfer mod is kinda stockish. 

[Kernel Kraken]

Can't you just build the fuelling ship with a long boom holding a small tank and a docking port, with a fuel line going from the tank to the main ship? 

[Xavven]

Great idea! Thanks for sharing this.

 I put mini docking ports on things I think will need refueling, but even though a mini docking port is light, its weight is actually significant on smallish satellites. It's sometimes enough to unbalance a craft to the point that I have to counterbalance it with either a second mini docking port or something else of similar weight on the opposite side.

I'll definitely use this trick.

Edited January 26, 2021 by Xavven

[Yellowburn10]

8 hours ago, Kernel Kraken said:

Can't you just build the fuelling ship with a long boom holding a small tank and a docking port, with a fuel line going from the tank to the main ship? 

Well, yes you could, but it would kinda miss the point of what I was trying to demonstrate here. Like I mentioned, this specific SSTO didn't have a docking port, so something like that wouldn't be too useful.