Exploding ore tanks

[TanDeeJay]

 

KSP Version 1.4.5

Mods: Kerbal Engineer Redux

 

I have an ore conversion module attached to my Mun fuel station, and every time I try to transfer ore into the tanks they explode.

Here's the ore tanks I'm trying to load from my Rover/lander you can see in the background

 

I seem to be able to transfer ore to 3 or 4 of the tanks, but when I try to transfer the next one, it gets partway through and then explodes.

Any ideas on whats wrong?  is this a build flaw?

 

Regards,

John

 

[Gargamel]

Hmmm.....   KER is your only mod, yes?

Which tanks are you transferring from and to?   

Can you recreate this with a different vessel, or is it this vessel only?  Can you control which tanks explode, is it only the one tank? 

 

I haven't heard of an ore tank exploding before, so hence the questions. We might need the logs for this.  Blow up a tank and post the log.   Perhaps a video too.   

But a gut guess is that the CoM shift from moving the ore around is causing a kraken attack at some overlapping/adjacent tanks. 

[TanDeeJay]

Thats right only KER installed.

I'll need to doc another ore transporter to try and replicate.  I ended up running the ore conversion straight from the docked ore transport ship.  As the "ore rover" you can see in the background suffered minor damage earlier by kraken, when I crash landed on the way back down, I didn't bother reverting to a quick save, as I wanted to rebuild with some minor changes to the rover design... then when I returned to my mining site, I discovered my mining ship had destroyed itself, so I'll need to re-establish my mine site before I can attempt to reproduce the explosion on my station.

The 6 ore tanks in the image are the medium sized ore tanks that hold 300 units of ore each, and are attached radially to a stack of the round batteries directly attached to the convert-o-tron.

I attached the ore tanks using radial attachment mode with the 3-way setting, so that 3 of the ore tanks could have the radiator panels attached, and the other 3 have no attachments.  My alignment of the 2nd set of 3 was by eye to try and fit them neatly between the 3 tanks already attached.  There is a Clamp-o-tron on the end of the stack of batteries.  (This was the 1st module attached to my space station using the Clamp-o-tron.  All previous module attachments are via Clamp-o-tron JR.

The Ore rover uses an advanced grabbing unit instead of a clamp-o-tron (this was so it could connect to the side of the mining ship to collect ore and fuel)

I initially attempted to dock my ore rover directly to the end in the front of the screenshot above and when the ore tank exploded, I thought it might be because the advance grabbing unit somehow impeded the structural integrity of one of the tanks, however, after reverting to a quicksave I next docked the ore rover to the location visible in the above screen shot.

I will endeavor to reproduce the explosion, and see if I can narrow it down to a specific ore tank, and I'll post the log and a video of the explosion.

I tried reproducing on the launch pad, but it seems that I forgot to save the ore conversion module so I had to create a new one which I could not get to explode on the launch pad.

 

 

Edited August 7, 2018 by TanDeeJay
fixed spelling error

[Gargamel]

18 hours ago, TanDeeJay said:

I attached the ore tanks using radial attachment mode with the 3-way setting, so that 3 of the ore tanks could have the radiator panels attached, and the other 3 have no attachments.  My alignment of the 2nd set of 3 was by eye to try and fit them neatly between the 3 tanks already attached.  There is a Clamp-o-tron on the end of the stack of batteries. 

This might be the culprit.  It shouldn't, as I've done similar a bunch of times, but it might be.  While I doubt it will be the cause, it would be the first possible cause I would look to exonerate.    Make a clone of the ship with 6 way with radiators and see if it blows. 

 

[TanDeeJay]

I'll need to get my mining ship back up 1st because the one I had I believe got destroyed by kraken as the drills were mounted low enough that when in operation they lifted the entire ship so that it was bouncing between landed and low in space, making it difficult to leave it while operating.  Had trouble last night launching the new mining ship, as it kept loosing stability once more than 10degrees off vertical. Will try again tonight.

Once I have more ore available, I'll retry filling the tanks again to see if it is a specific tank or a specific quantity of ore.

[mystifeid]

From the launchpad try Alt+F12 -> Cheats -> Set orbit

Were those fuel tanks full? I think the wheels on your ship are autostrutting to the heaviest part and there is nothing you can do about it. Though I'm trying to think whether I've ever seen it make things explode. Landing legs do the same thing and sometimes just docking along a different axis helps. But the grabbing unit means you are not docking cleanly along an axis. Anyway, if you can make it explode again, try it without the wheels. Remember that you can fill ore tanks in the VAB and then cheat into orbit.

[TanDeeJay]

no the LFO fuel tanks were less than half full.  The ones on the rover are about 1/3. The mono propellant module you can see a glimpse of behind the solar panel is full.  I found I need far less mono-propellant than I catered for

Oh yes, your right about the wheels I set everything to autostrut to the grandparent part, but those wheels are locked to autostrut to the heaviest part.  and the main station is going to be heavier than the rover.

Thanks for the hint about the set orbit.   That will enable me to get up a wheel-less rover full of ore... I'd better get stuck into it... lots to test, and I also need to finish off the Saving Jebediah story...

[JoE Smash]

In the event you can't get this odd bug sorted, you could try another mod out too and see if the tank in question still explodes when using said mod....

TAC Fuel Balancer:

If it works for you it also removes the need to manually dock to each individual tank to move ore/fuels.

You can move stuff to any tank connected to your ship/base/whatever.....

 

 

[mystifeid]

5 hours ago, JoE Smash said:

If it works for you it also removes the need to manually dock to each individual tank to move ore/fuels.

You can move stuff to any tank connected to your ship/base/whatever.....

Unless "Resource Transfer Obeys Crossfeed Rules" is checked in the difficulty options of your game you can move ore between any tanks on your vessel anyway. By default this option is checked in moderate and hard difficulty but not in normal difficulty (which most people play).

And even in stock you can move a resource from one tank to multiple other tanks in a balanced fashion (or vice versa) by the simple expedient of continuing to hold the Alt key while you right click the tanks and then selecting "out" or "in" on the tank you are transferring to or from. The stock way might be clunkier than the mod but...

One thing the above mentioned mod does that may occasionally be useful is to add the ability to dump fuel.

[TanDeeJay]

Finally got another ore rover full of ore docked and captured this video of the exploding tank

https://www.dropbox.com/s/azrybhzavxc5i4s/Kerbal Space Program 11_08_2018 9_48_15 PM.mp4?dl=0

I've experimented a bit, and found it is not a specific tank, it occurs as the 5th tank full of ore is transferred.

In the video, I'm transferring from a single tank on the ore rover, to the last 2 tanks on the station.  However, I have done the transfer single tank to single tank as well with the same catastrophic result.

Here is the KSP.log file from immediately after this incident.

https://www.dropbox.com/s/bp4zcdktteuzk70/KSP.log?dl=0

I have a save point prior to beginning the ore transfer so I can re-do the transfer if you want me to enable additional logging.

Found the output log file:https://www.dropbox.com/s/1yja27ei16h78ai/output_log.zip?dl=0

 

Regards,

John

 

NOTE:  the LFO tanks on the station are full this time from previous ore conversions done without transferring to the station based tanks so wouldn't those rover wheels autostrut to the Rock-o-max LFO tanks?

Edited August 11, 2018 by TanDeeJay
added note, and link to output_log.txt

[mystifeid]

As you have probably noticed, the logs seem to show the fireworks starting with a docking port colliding with a small tank. But not, as far as I can see, why.

2 hours ago, TanDeeJay said:

NOTE:  the LFO tanks on the station are full this time from previous ore conversions done without transferring to the station based tanks so wouldn't those rover wheels autostrut to the Rock-o-max LFO tanks?

Should do. So is this a clipping issue? Hard to say. It would certainly help to have the craft files.

[TanDeeJay]

Since everything is docked, that would just be a single file?

I'll have a look once I'm back on the home computer later today.

[JoE Smash]

2 hours ago, TanDeeJay said:

Since everything is docked, that would just be a single file?

I'll have a look once I'm back on the home computer later today.

That video is pretty crazy. So it looks like the ore is going into two empty tanks simultaneously, but one of the already full ones blows up. Is that what occured?

Does it happen if you only fill one of the empty tanks at a time, and is there a way to close off the full tanks so the fuel isn't trying to go into all the full tanks too?

I've never used the stock tank filling tool. I have no idea how it works.

It's pretty crazy that a vibration seems to develop from filling a tank with fuel though...

It looks like there must be some sort of strut or clipping problem though for such a crazy vibration to happen like that.

This game does sooooo much weird crap all the time. It's astounding really....

Edited August 12, 2018 by JoE Smash

[mystifeid]

2 hours ago, TanDeeJay said:

Since everything is docked, that would just be a single file?

It would be easiest (for me anyway) to have the individual craft files. You can find them in [game directory]\saves\Dad\Ships\VAB\

[TanDeeJay]

3 hours ago, JoE Smash said:

Does it happen if you only fill one of the empty tanks at a time, and is there a way to close off the full tanks so the fuel isn't trying to go into all the full tanks too?

...

Yes, I did testing only filling 1 tank at a time which was how I determined it was not a specific tank but rather while the 5th tankfull was being transferred. In the video, I opened the popup for all the station mounted tanks to show the 4 full tanks, and then when I did the transfer, it transfered to both empty tanks at the samr time. I think the wobble leading to the explosion started after a certain quantity of ore had been transferred.

According to the log, the explosion occurred when a docking port collided with a tank. I think it was the wobble that caused the collision. So question is what caused the wobble?

Will look for the ship files to upload shortly...

Edited August 12, 2018 by TanDeeJay

[TanDeeJay]

Hmmm... I don't actually have the module that contains the station attached ore tanks saved in the VAB directory.  I think I created it and forgot to save it, so only version available is the one attached to the station.

Here's the save point just prior to doing the ore transfer.  The Mun fuel station starts at line 18867 (sorry i made a typo when I named the space station, so it is currently called "Mub Orbital Fuel Station")

https://www.dropbox.com/s/r2978iuxwj7vc8z/PRE TRANSFER.loadmeta?dl=0

https://www.dropbox.com/s/s9bdpaayqwqnf44/PRE TRANSFER.sfs?dl=0

[mystifeid]

24 minutes ago, TanDeeJay said:

I think I created it and forgot to save it, so only version available is the one attached to the station.

Rats. I was just about to go to bed too. I'll see how I go but I'm pretty tired right now. Luckily there are others who will probably have a look at this. One thing that is obvious now is that the ring of six ore tanks are clipping each other. If only for aesthetic reasons I generally try to avoid clipping things. For a situation like this I might try and spread them outward a little by attaching them with decouplers (with decoupling disabled).

[mystifeid]

Yeah, pretty sure It's the ring of six clipping ore tanks. When I duplicate that configuration in a much simpler vessel - like shown below - and cheat it into orbit, the same thing happens. Halfway through transferring the fifth tank I get an explosion. With certain things you can convince yourself that clipping them is not unrealistic but fuel/ore tanks sharing the same volume is not one of them and I'm not unhappy the game rejects it.

When I attach the ring of six tanks with tt-38k decouplers , a gap opens up between the tanks and I can then transfer ore into all six tanks with no explosions.

Edited August 12, 2018 by mystifeid

[Gargamel]

4 hours ago, mystifeid said:

Yeah, pretty sure It's the ring of six clipping ore tanks. When I duplicate that configuration in a much simpler vessel - like shown below - and cheat it into orbit, the same thing happens. Halfway through transferring the fifth tank I get an explosion. With certain things you can convince yourself that clipping them is not unrealistic but fuel/ore tanks sharing the same volume is not one of them and I'm not unhappy the game rejects it.

Huh... that is odd.   Wonder if it happens with other symmetries of ore tanks.  I wold imagine it might, as Tan said he used 2 - 3x's for the symmetry on his craft. 

[TanDeeJay]

Thanks @mystifeid you seem to have nailed this one. I think I can now accept this as a design flaw in my module, not a bug in KSP. Also, Your test proves it is not the locked autostrut on the rover wheels but the overlapping ore tanks. I think I'd be happy to replace my fuel conversion module with an upgraded design, and I can stick with my ore transport rover.  The aim was to load up the station based tanks and start the conversion, and immediately return the ore rover with now empty ore tanks to the mine to fetch the next load of ore. 

[mystifeid]

4 hours ago, Gargamel said:

Wonder if it happens with other symmetries of ore tanks.  I wold imagine it might, as Tan said he used 2 - 3x's for the symmetry on his craft.

I was curious about that too so I just used 6x symmetry.

44 minutes ago, TanDeeJay said:

Thanks @mystifeid you seem to have nailed this one. I think I can now accept this as a design flaw in my module, not a bug in KSP. Also, Your test proves it is not the locked autostrut on the rover wheels but the overlapping ore tanks. I think I'd be happy to replace my fuel conversion module with an upgraded design, and I can stick with my ore transport rover.  The aim was to load up the station based tanks and start the conversion, and immediately return the ore rover with now empty ore tanks to the mine to fetch the next load of ore. 

Have fun!

[TanDeeJay]

I've been thinking about this, and wondered if this was something that the engineers report could report on in the VAB? Along with "missing ladder", "missing parachute", etc... Add a "overlapping tanks" with a red exclamation mark

[Gargamel]

On 8/13/2018 at 4:34 PM, TanDeeJay said:

I've been thinking about this, and wondered if this was something that the engineers report could report on in the VAB? Along with "missing ladder", "missing parachute", etc... Add a "overlapping tanks" with a red exclamation mark

Well, clipped tanks are't supposed to explode, so the report shouldn't have to look for it. 

If this can be reproduced in a stock game, a bug report should be filed.  If not, then maybe we can hunt down the offending mod. 

[mystifeid]

1 hour ago, Gargamel said:

If this can be reproduced in a stock game, a bug report should be filed.

My test was stock but since I'm not a clipping fan it won't be me filing a bug report - though you should feel free.

The top six ore tanks in my screenshot above are joined directly to a stack of z-1k batteries with 6x symmetry and are empty. The bottom six ore tanks are full. Cheat the craft into orbit  Even on the launchpad you should be able to start transferring ore and see some fireworks halfway through transferring to the fifth tank.

And If you send the craft to the launchpad with the top six ore tanks already full, then you will have to do nothing. It will just explode.

Bad things also happen if the ore tanks are replaced by clipping fuel tanks.

Edited August 15, 2018 by mystifeid

[TanDeeJay]

Ive only got KER, so easy enough for me to get a stock install and to replicate the way @mystifeid did. I'll look into raising a bug report.