Rate Stock Ladders on the Drag Index

[Hotel26]

Do you put access ladders on your craft as required^[1], or do you omit them due to scalaphobia^[2]?  Here's the poll you've been waiting for.

[1] you know, "by passengers"
[2] "fear of ladders"

Edited March 23, 2021 by Hotel26

[Martian Emigrant]

Hi.

Never worried about ladder-drag.

I use them only for worlds where Kerbals can't fly.

Not an aesthetic consideration, more of a part reduction thing.

 

ME

[Dientus]

They have never bothered me. I actually put a couple of the pegasus mobility enhancers on long term satellites so my engineers have something to hold to during maintenance or upgrades.

 

[Guest]

Probably like most I only use them when I absolutely have to, which isn't very often as there's very few places you actually need them.

[OHara]

The 'Pegasus' ladder with separate rungs that you bolt onto the side of a craft is not very draggy.   The retractable ladders are very draggy because of their big boxes.

KSP's drag model since version 1.0 treats all surface-mounted parts as if they were independently moving through the air.  Maybe the idea was that part-clipping could then be purely aesthetic, with no effect on performance, so we could have challenges and not worry so much about clipping.

The drag of each part is figured automatically from the shape of its visible model (maybe so part-modders don't have to compute a drag model for every part they design).  Pointy shapes get less drag, flat shapes more, and the boxes of those ladders are usually mounted with big flat faces facing the airflow (hidden inside the craft, but that doesn't matter).

Probably Squad should have made a custom drag model for these retractable ladders, counting only the part that is exposed in its normal use. [Edit: shoulda woulda coulda.  Squad lets us edit our configuration files when we don't like the rules they put in the game, or even better to use a Module Manager patch as below]

Spoiler

@PART[telescopicLadder] {
    %DRAG_CUBE{// back of box     face with door  top             bottom          side            side
//	cube = A, 0.13,0.70,0.58, 0.13,0.85,0.17, 0.34,0.96,0.25, 0.34,0.96,0.14, 0.11,0.84,0.19, 0.11,0.84,0.19, 0.149,-0.015,-0.007, 0.57,0.22,0.63
//	cube = B, 0.33,0.79,0.70, 0.33,0.94,0.41, 0.34,0.97,0.54, 0.34,0.96,1.52, 0.20,0.81,0.42, 0.20,0.81,0.44, 0.109,-0.672,-0.007, 0.65,1.56,0.63
	cube = A, 0.13,0.70,0.58, 0.13,0.85,0.17, 0.05,0.70,0.25, 0.05,0.70,0.14, 0.11,0.84,0.19, 0.11,0.84,0.19, 0.149,-0.015,-0.007, 0.57,0.22,0.63
	cube = B, 0.33,0.79,0.70, 0.33,0.94,0.41, 0.10,0.80,0.54, 0.10,0.80,1.52, 0.20,0.81,0.42, 0.20,0.81,0.44, 0.109,-0.672,-0.007, 0.65,1.56,0.63
}}// door is 63cm wide, so if it sticks out 8cm that's about 50cm² area as seen from the top, and rounded so Cd about 0.7
@PART[telescopicLadderBay] {
    %DRAG_CUBE{// back of box     face with door  top             bottom          side            side
//	cube = A, 0.10,0.67,1.03, 0.10,0.84,0.16, 0.50,0.91,0.22, 0.50,0.90,0.22, 0.19,0.86,0.34, 0.19,0.86,0.33, 0.369, 0.091,0.004, 1.00,0.23,0.51
//	cube = B, 0.42,0.80,1.13, 0.42,0.90,0.27, 0.51,0.91,0.65, 0.51,0.90,2.90, 0.30,0.84,0.35, 0.30,0.83,0.35, 0.342,-1.177,0.004, 1.05,3.04,0.51
	cube = A, 0.10,0.67,1.03, 0.10,0.84,0.16, 0.04,0.70,0.22, 0.04,0.70,0.22, 0.19,0.86,0.34, 0.19,0.86,0.33, 0.369, 0.091,0.004, 1.00,0.23,0.51
	cube = B, 0.42,0.80,1.13, 0.42,0.90,0.27, 0.10,0.80,0.65, 0.10,0.80,2.90, 0.30,0.84,0.35, 0.30,0.83,0.35, 0.342,-1.177,0.004, 1.05,3.04,0.51
}}// door is 51cm wide, so if it sticks out 8cm that's about 40cm² area

 

Edited March 29, 2021 by OHara

[Dientus]

@OHara

Thank for the info, I actually wasn't sure how ksp figured drag from inside. Good  patch to.

[Hotel26]

Just culled this from a KerbalX entry...  And I quote:

Quote

The ladders (formerly just one) were moved inside the cargo bay to mitigate the insane amount of drag they cause. Hopefully some day their drag cubes can be fixed and we can use them in the most logical way again.

Hmm.

Does that sounds like a +1 for "Unrealistically draggy"??

Jest sayin'...

[OHara]

25 minutes ago, Hotel26 said:

Does that sounds like a +1 for "Unrealistically draggy"??

You would run the risk of double-counting, though.  In any case we should make sure @swjr-swis has access to the proposed repaired drag cubes two posts above, since he did ask for them.

You know I have some sympathy that the drag system from KSP 1.0.5 probably seemed like a very good idea at the time.  Run an automatic mini FAR-like analysis over each part the first time KSP sees that part, cache the result in PartDatabase.cfg, and combine parts using simple rules.  Sound very mod-friendly.  I will fault them for the poor documentation, though, because unintended consequences, like ladders acting as if their containers were exposed, are hidden in mysterious tables of numbers.

Many parts have worse problems.  The new decals (a.k.a. flags) somehow trick the analysis into thinking they have only one side, so they get body-lift from one side only, allowing creative exploits.  The part creator knew to turn off drag and leave out any lift module, but the automatic analysis gives them drag-free lift anyway.  Zeroing the areas in the 'drag-cube' would be a trivial fix, if those numbers were less mysterious.

We have seen our suggested custom drag cubes be adopted into stock in the past, so I'll post theses fixes,
once I find or make the reports on the bug-tracker.

[Hotel26]

7 minutes ago, OHara said:

We have seen our suggested custom drag cubes be adopted into stock in the past, so I'll post theses fixes,

Very constructive!  Nice work.

[swjr-swis]

3 hours ago, OHara said:

 In any case we should make sure @swjr-swis has access to the proposed repaired drag cubes two posts above, since he did ask for them.

I somehow missed thanking you for those when you first posted them. Belatedly: thank you (and @Hotel26 too, for this reminder).

I have been aware, and archived them for later use, together with a whole list of other fixes the stock game still needs and the community has come up with over time. When the announcement comes we've seen the last update to the game, i'll evaluate which of those are still required, and they'll get permanently added to my installs.

For now, I'm still stubbornly playing the stock game though, even down to these things.  Hence I still mutter about such matters. I guess I still hope they may fix things in the stock game.

[swjr-swis]

On 3/23/2021 at 3:00 PM, Hotel26 said:

Do you put access ladders on your craft as required^[1], or do you omit them due to scalaphobia^[2]? 

To answer the original question:

On planes I do omit them most of the time. Drag is a prime consideration in most planes, and the excessive ladder drag is simply incompatible. When I do feel a ladder is absolutely required, I actually add them mirrored, to counter the otherwise unbalanced forces causing constant 'phantom' roll or yaw. So even when deemed required, it's a very mindful decision due to the double-drag punishment.

On rockets, even though the drag tends to be even worse (they end up facing their biggest surface into the airstream), they tend to be required to make hatches accessible on higher gravity worlds, so I add them anyway. Due to the vertical take off, drag quickly tapers down to where it is of little influence on the gravity turn anyway. Here too though, I am always keenly aware of where I place them, as there is a certain amount of unbalanced forces added to the rocket (more even than its excessive weight, this is one of the reasons I hardly ever use the Mk1-2 command pod - there's no good way to place a continuation ladder without unbalanced force effects).

On landers, surface base, or other constructs, since they tend to be shielded during ascent, hatch accessibility is the only real consideration, so ladders are added if required with no second thought.

 

On 3/23/2021 at 3:57 PM, Dientus said:

I actually put a couple of the pegasus mobility enhancers on long term satellites so my engineers have something to hold to during maintenance or upgrades.

I do this too, for that same reason, although it's often the much less draggy Pegasus I rungs. Also do this on some station modules, for additional or more accessible 'grab-on' area to aim for when returning from EVA.

I saw someone else post recently about how structural trusses really should allow grabbing onto and climbing like ladders, which I very much agree with. It would be a better alternative in many situations that now force the addition of ladders parts.

[ZinkBot]

1 hour ago, swjr-swis said:

I saw someone else post recently about how structural trusses really should allow grabbing onto and climbing like ladders, which I very much agree with. It would be a better alternative in many situations that now force the addition of ladders parts.

I agree as well. It makes a lot of sense.