Heavy fuel tanker -- design challenge/commission

[Hotel26]

Hail! all talented KSP aero designers!!

The following challenge is actually more like a Commission to Design...  But, if you like designing airplanes for KSP, you will have fun with this.

I'll spruce this front page up with some screenshots and a short video, as well as add some reference material, but I'd like to post the Specifications now so that you can get started thinking about it.

I have actually made an attempt and built a Silly Prototype that works as a Proof of Concept but the transporter aircraft itself is pretty shameful.  I freely admit that I am a carp desinger...  [had to get that past the censors somehow!  you'll know what I mean when/if I post a screenshot of that first transporter...]

OK.  Here is a link to the Gryphon II fuel rover, which is the payload for this mission...

This is a shot of Gryphon I (prior version) refueling two other craft, illustrating the "universal" docking method:

Mission Objectives:

Transport is effectively a mobile fuel base that can fly to land in a remote field and then provide fuel (both LF and OX) to client craft.  It should be able to conduct many refueling operations before having to return to KSC for more fuel.  It should also carry a mobile surface unit (Gryphon II) to the destination and deploy it to directly refuel the client craft, returning to the transporter to 'milk' more fuel as required.

Specifications:

• range of 1,500 km
• should transport at minimum 1x Mk3 LF fuselage (5,000 LF) plus 1x Mk3 LF/OX short fuselage (1,125 LF & 1,375 OX) -- or equivalent
• use a Mk3 cargo ramp for transportation and deployment of Gryphon II.  (This machine, weighing 5t, will be provided (shortly) via KerbalX.)
• KSP version 1.6.0 or earlier
• cruising speed in excess of 750 m/s
• demonstrable capability to absorb slow and rough landings
• extra kudos for demonstrable capability for aerial discharge and safe landing of the Gryphon II payload (I have been unable to pull this off, myself)

Further Instructions

• loading procedure for Gryphon II should be as follows:

1. raise landing gear to sit Transporter on its belly
2. lower the cargo ramp to just touch the ground
3. drive Gryphon II onto the cargo ramp and set the park brake
4. begin raising the cargo ramp and switch to Gryphon II to release its brake
5. the Gryphon II should dock with a claw set in the wall to which the cargo ramp is attached
6. lower the gear in preparation for departure
7. Transporter and Gryphon II should now be a single craft and nothing or very little of Gryphon II should protrude outside the cargo ramp

• submissions should include a link to KerbalX or some other electronic conveyance for craft files, as well as plenty of screenshots, to be posted in this thread
• Commissioner (c'est moi) reserves the right to publish any submission, with or without further modifications, on his KerbalX/Hotel26 site with a name of his own choice, but fully represented and attributed as the original work of the author (c'est vous)
• if you have to use KSP later than 1.6.0, don't let that stop you, but the earlier the version, the wider your audience!
• no mods.  none.  sorry.
• loading Gryphon II is a time-consuming procedure, so you might be well advised to "bolt" it into your cargo ramp so you can deploy and flight test pronto.
• don't forget to perform feasibility first and last after all the flight testing
• my silly prototype uses 4x Panthers.  Let's not rule out Whiplash et al or anything that would inhibit creative solutions, though
• please have fun with this: remember it's not a competition, but a commission and a chance to learn and benefit from each other
• Good luck!

 

Here's a shot of Gryphon II to whet your imagination...

 

 

Edited February 5, 2019 by Hotel26

[Hotel26]

And here's the video of the loading procedure:

 

[lobe]

Is that 1500 km range one way or round trip (750 out/750 in)? 

[FleshJeb]

This will probably work--It's a Laythe cargo seaplane/SSTO/refueler for another project. I haven't looked at it in a couple of months, but I recall that it could SSTO 35T to Kerbin orbit from a water launch. It's ridiculously overspecced for this job. Feel free to rip parts out of the main cargo bay-They're for loading wide rovers/other cargo.

https://www.dropbox.com/s/wjnyi8mm5zj50yg/Aerocon Wingship Short.craft?dl=0 v 1.5.1.

Check the Action Groups: IIRC it has 3 types of engines + mode switches, and some hydrodynamic flaps.

MJ and KER are modded into the cockpits, but it loads fine in pure stock.

Frankly, I'd abandon the Gryphon II idea, and just ram the claw on the nose into whatever.

If you load a significant tonnage of cargo (such as more fuel), center the mass on the main cargo bay.

FYI, it started out as a simplified version of this: https://books.google.co.uk/books?id=EZJzG4ZVq3AC&pg=PA38&dq=aerocon&as_brr=3&ei=pJ2nSvGBI56yNPOroaoK&hl=en#v=onepage&q=aerocon&f=false

[Hotel26]

2 hours ago, lobe said:

Is that 1500 km range one way or round trip (750 out/750 in)?

That's a really good (and difficult) question!

With the amount of fuel such a transporter it carries, range shouldn't be a problem.  But, yes, I think it should be able to come back.  So, the 1,500km was chosen  as, "should be able to get [nearly] to the other side of Kerbin", and come back.  Which would make the desired range more like 3,000km.

The difficulty is: how much of the payload fuel should it "pirate".  And that becomes subjective.  It refers to this idea:

13 hours ago, Hotel26 said:

It should be able to conduct many refueling operations before having to return to KSC for more fuel.

So, it's 1,500 km out and then back AND have enough excess fuel at the destination site to be able to conduct "many refueling operations".  I can't put a number on that, but no matter.  I'm hoping other people might find this fuel base idea useful and can select submissions that look good and useful to them.  Certainly, useful to their authors!  The feasibility is HIGH, I'd say, from my prototype.  And of course, as Wernher would say, "the MOAH the BETTAH!"...

 

36 minutes ago, FleshJeb said:

Frankly, I'd abandon the Gryphon II idea, and just ram the claw on the nose into whatever.

Thanks for this and I'll look at it with interest!

The part I did a really bad job on was putting wings on the transporter to carry that load and I simply slapped three different kinds of (fuel-bearing) lift parts on it almost at random.  It looks really BDA!  (bad)

About Gryphon, the challenge I've experienced in the field is having a system that is flexible enough to dock with ANYTHING to transfer fuel.  Anything means from rovers to small thru midsize to the largest of craft.  Gryphon has a lateral dock mounted as low as possible for rovers and the noses of very small craft that can be swung sideways into it,  and a vertical claw (also mounted as low off the ground as possible) so that bigger craft can drive over it and then retract the nosegear to "sit on" that vertical claw.  I think this is the most flexible scheme I've experimented with so far (see Chrysalis for my penultimate concept).

The one difficulty with Gryphon is that you have to line up your entry direction to dock with it such that you approach uphill if possible.  Otherwise a craft can find itself trapped on top of Gryphon and unable to get off!!  This was the case with Gryphon I, anyway, since that attempt was not mobile.  Gryphon II is mobile mainly to assist with undocking but also to return to the mother ship for more fuel (instead of the mother ship having to taxi).  Anyway, take a look at the OP schreenshot of the Mink seaplane docked on the vertical claw and the Invader rover docked on the horizontal claw.  Also this, exhibiting the nosegear retraction method:

[Hotel26]

(For others), this is @FleshJeb's Aerocon Wingship Short:

and it has plenty of wing area which ought to assist it with out-landings (i.e. away from KSC).  It looks significantly more attractive than my poor attempt at a transporter!!

Thanks, FleshJeb!