Firing arcs for Knight Hawks

Blankbeard's picture
Blankbeard
January 28, 2014 - 8:23pm
I've uploaded four diagrams that show possible firing arcs for use with Knight Hawks. They don't require vector movement but they would work well with it. The idea behind adding firing arcs is to add a new layer of tactics through maneuvering. It also allows mass and volume based ship construction systems to mount larger numbers of weapons without being able to focus fire a smaller ship into oblivion.

You can still have 360 degree weapons, they just carry a cost in credits, mass, or volume. Cannons are unchanged.

Here's a rundown of the four diagrams. I'd really like opinions on which, or which combo, you'd prefer. If you prefer the Knight Hawks system, that's fine too.

In all cases, any weapon can fire at a ship in the same hex. Also, white hexes can be fired into by any weapon that can fire on either side of them.

Left and Right Half Arcs

http://www.starfrontiers.us/node/8025

This is the easiest diagram to follow. The center row is shared. One important feature of this diagram is that the white column immediately in front of the ship can be fired at by all weapons.

Fore and Aft Arcs

http://www.starfrontiers.us/node/8026

I call these Battleship arcs because they're similar to WWII capital ships firing patterns. Note the white hexes along the center. Unlike the left and right halves, there is no row where everything can fire. I actually prefer this to the left and right halves for that very reason.

Quadrant Arcs

http://www.starfrontiers.us/node/8027

This is the cleanest diagram, having no overlaps, and my personal preference.

Six Arc Diagram

http://www.starfrontiers.us/node/8028

This has the most overlaps. Its advantage is mostly in its use for armor, or shields in Star Fleet Battles. It's easy to determine which hexside gets hit and only armor and weapons facing that hexside can take damage. This allows ships to attempt to shelter damaged areas by turning away from attackers.

It's possible to combine these. For example, laser batteries might fire using the quadrants while proton and electron batteries were left and right half. Star Fleet Battles uses all of these in different roles. We don't need to get that complex though.

If you would state your preference

One diagram (which one)

Two diagrams for different weapons (which diagrams and what sort of weapons)

None of them (Cannons and 360 weapons only)

Something else (Tell me!)

Note that none of these diagrams affect cannons in any way.
Comments:

TerlObar's picture
TerlObar
January 28, 2014 - 10:16pm
I could see using the one's you call the Battleship arcs if you don't allow the ships to flip around in a single turn as I mentioned in the other thread.  If a weapon is mounted in such a way that the ship obscures part of the field of fire.

However, I don't see the left/right ones applying.  All it would take is a quick rotation and what was on the left is on the right and vice versa.  If the turns have any duration to them it should be possible to fire the left pointing battery, roll over, and fire the right pointing battery at the same target.  I assume that's how KH achieves it 360 degree batteries anyway.

The same applies to the multiple arc diagrams.  I can see fore/aft limits but not side to side.  And not really fore/aft if the ship has time to do a little wiggling in a turn.

If you're doing vectored movement on a small time scale, then they might become more important.  In this case you have to track two different things for both ships: direction of movement and ship attitude (facing).  Unless the ship is simply speeding up, they won't be the same and it is the latter that limits the firing arcs.
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jedion357's picture
jedion357
January 29, 2014 - 5:19am
Looks to me like Blankbeard is possibly influenced by such games as Star Fleet Battles and or Car Wars.

Since Star Trek ship movement is predicated on Warp speed firing arcs kind of go with the territory and for car wars a vehicle's movement is a relationship between friction of the tires and the ground and thus firing arcs are important.

since Terl did the math and stated the case that it would be possible for KHs ships to flip and roll within such a small fraction of 10 minutes it would seem that firing arcs are unneccessary to me. Except of course the FF and MPO restrictions from KHs which suggest spinal mount weapons and that targeting potentially requries some linning up of the vessel straight at the target, and that assumption would seem to be supported by the piloting subskill of increasing the effectiveness of FF weapons.

What does bother me a bit is the low firing rate for weapons during such a long period of time, sure it could be indicative of the fact that there is continuous firing by the weapon during 10 minutes but we make just the one to hit roll and apply the damage the one time for purposes of playability.
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Stormcrow's picture
Stormcrow
January 29, 2014 - 6:20pm
They are, after all, laser batteries...

Blankbeard's picture
Blankbeard
January 31, 2014 - 9:45am
Stormcrow wrote:
They are, after all, laser batteries...


Oh, such Punishment! :)

Yes, I'm influenced by Star Fleet Battles although it is much too complex for my tastes. I've not played Car Wars since the 80's though. What I'd like to do is allow a bit more flexible ship design and a bit more tactical choice without weighing the game down much.

jedion357 wrote:
since Terl did the math and stated the case that it would be possible for KHs ships to flip and roll within such a small fraction of 10 minutes it would seem that firing arcs are unneccessary to me


I didn't call it out in this post but everything that I'm posting assumes the 1 minute turn and 1 gee = 1 ADF assumptions I've been making in all the other posts. I'll make sure to put that up front on future posts.

If you're using a 10 minute turn, even the slowest ship can rotate three times around any axis and you should allow all weapons including cannons to fire in any direction at all.

jedion357 wrote:

What does bother me a bit is the low firing rate for weapons during such a long period of time, sure it could be indicative of the fact that there is continuous firing by the weapon during 10 minutes but we make just the one to hit roll and apply the damage the one time for purposes of playability.


Another advantage of a 1 minute turn. Less of this.

TerlObar wrote:
However, I don't see the left/right ones applying.  All it would take is a quick rotation and what was on the left is on the right and vice versa.


In a true 2d system, I don't think you should be modelling rolls about the x or y axis. I also have concerns that relatively realistic maneuvering jets probably don't carry enough propellent for extremely extensive maneuvers. I guess you could simply start a roll and go through combat that way but you're going to complicate your manuevering and possibly aiming. Some sort of barrel roll might make a good maneuver for someone with space ship piloting skill.

I decided to look up the shuttle as the only example of a sizable space craft we have. NASA also puts up a reference manual that has a lot of description in it. Combine that with what's on wikipedia and and this post from Mark Kirkman (Flight Director for the Shuttle program for like, 40 years)  Scroll to the bottom of the page for the relevant post.

He's saying that the Shuttle normally performed manuevers at rates of rotation of 1-12 degrees per second, or half that for Yaw. That means it can rotate 180 in a minimum of 15 seconds. Note that's using nearly the full potential of all 38 of the main RCS engines, about 143 kN. Doing so requires about 8 m/s of delta-V, about 4 seconds of engine firing. The shuttle has about 300 seconds of fuel at this level (The aft RCS has an additional 500 seconds for its 24 engines)

Using very crude methods, I estimate the total volume of the orbiter to be about 1500 cubic meters. I'm just modeling it as a rectangular box  6*7*32 meters with 2 triangular wings about 14*9*1 meters. That is close to hull size 3 and a suprisingly low density (about 80 kg per cubic meter fully loaded).

Ignoring the half yaw rate, I think space shuttle RCS rate is a very reasonable rate for a small ship like an assault scout. Using a 1 minute turn, each degree per second translates into 1 MR or 60 degree hex face change. For a ship this small, facing doesn't matter as it can change facing 12 times per minute or 120 times per Knight Hawk turn.

A HS 5 frigate is 12 times the volume of the shuttle. If mass scales with volume it would need 12 times the thrust in its reaction control system. But it's also 3 times as long, increasing the moment arm and thrust by a factor of 3 as well. So that frigate needs 33 times the RCS to keep the same shuttle like performance. A hullsize 9 ship would need 90 meganewtons of thrust for the same performance.  That's about the thrust of the main engines of a hull size 5 ship. The first stage of a Saturn V has about 34 meganewtons of thrust, just as a comparison.

If you assume that a ship larger than an assault scout has enough thrust in its RCS to turn a number of hex faces per minute equal to its MR, the numbers are a bit smaller. The frigate needs only 3 times the thrust of the shuttle and the hullsize 9 ship needs about 20 meganewtons. That's still quite a bit even if you assume improved Frontier technology.

So while I think that crews and the ships themselves could stand the forces of rotating fast, I doubt if large ships have enough thrust in whatever manuevering jets they carry to actually rotate them fast enough to bring every weapon to bear on a single target.

But really, I think it's best from a game play standpoint to have some sort of firing arcs if you're going to use vector movement. Otherwise, why bother tracking facing at all?


Abub's picture
Abub
February 3, 2014 - 6:15pm
I am using a basic version of these arcs in my Big Ship Adventure game but mainly just to make the party coordinate actions... Captain ordering rolling manuevers to the pilot so that the gunners can get thier shot off so I'm only using basically your Left and Right half arcs.  I could maybe see using the diagrams with four or more arcs if the ship I'm having them man was bigger than a Frigate but with the smallest capital ship one battery on each side is all I need (rocket on one side, laser on the other)
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Blankbeard's picture
Blankbeard
February 4, 2014 - 12:04pm
I've been thinking. Maneuvers like the roll, tumble, and quick turns could be implemented as sub-skills of the pilot skill.

There's a basic problem here and I think you're hitting on it. A battleship is nearly two thousand times the volume of an assault scout. If an assault scout can carry a laser battery, a battleship should be able to carry hundreds or thousands of them. Similarly, a battleship has less than 10 times the hull points of an assault scout.

I guess there are multiple ways to deal with this. The way I've been leaning towards involves essentially having large, medium, and small ship classes with similarly sized weapons. Mounting a smaller weapon is possible but in a limited way that I have not worked out details on yet. I don't want small ships to have zero survivability but I do think if you send a squadron of fighters against a cruiser, you should expect to not get them all back.