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Dwarf Fortress => DF Dwarf Mode Discussion => Topic started by: Insert_Gnome_Here on September 20, 2015, 08:15:39 am

Title: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on September 20, 2015, 08:15:39 am
Few travel through the empty desert around Omristuzol village, but those who do see mysterious stone and metal ramps, topped with complex machinery jutting out of the vast flatness of the sands.

I have succeeded in pointing a dwarven shotgun along a parabolic trajectory, in order to rain death upon the likes of goblins, titans & weretortoises.

Code: [Select]
_______R
        \          R:Roller
         \         \:Down Ramp Track
          \        _:Flat Track
           \       W:Wall
...
                 \      W
                  \  W
                   \/
https://mkv25.net/dfma/map-12519-wildoils

The ballista arrows lying about are ammo from the test firing.

Screenshots & tests on live subjects will be posted soon.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: omega_dwarf on September 20, 2015, 10:28:16 am
Awesome title and awesome device!

When I read "howitzer", what came to mind was a friend years ago describing the accuracy with which howitzer teams can hit targets. It seems like there might be room at the top of your device to create three other firing directions, to simulate that. Maybe even at a couple of different heights, to adjust range. Just a thought, though, and probably for the future, after testing.

Have you tried it on any test subjects yet? What is the accuracy/reliability? How much does the ammo spread out on its descent?

Also, it took me a while to figure out where your dwarves lived, lol.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on September 20, 2015, 10:32:51 am
Test Firing with 16 Ballista arrows against random pets:

The only arrow that hit anyone bruised the lung of a captain and sent him flying a tile into a wall.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: omega_dwarf on September 20, 2015, 10:46:20 am
Nice. Sounds like the effectiveness could be increased if the approaches it covered were raised paths between spike pits, or something.

Have you tried filling the cart with oodles and oodles of ingots? Or a similar number of trap components? Ballista arrows take a lot of time to assemble, although they would be pretty cool.

What tips are you using for your arrows?
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on September 20, 2015, 10:57:46 am
Spoiler (click to show/hide)

Spoiler (click to show/hide)

I'm trying with serrated glass discs soon. Currently wooden tips with a few bronze thrown in.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on September 20, 2015, 11:17:42 am
Test 2: Ballista arrows against pets


Mostly bruises and skin damage. One missed and hit a caravan guardsdwarf. Some animals knocked back by force of arrow.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: omega_dwarf on September 20, 2015, 11:22:10 am
The wood tips may be the cause of the bruising. The bronze should be cutting, though, if cutting edges work when falling.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: thegoatgod_pan on September 20, 2015, 02:32:38 pm
Have you tried bricks?  Bolts? Try quantity over quality.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on September 20, 2015, 03:13:39 pm
I'm trying to go for quality over quantity, in order to reduce clean-up.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: omega_dwarf on September 20, 2015, 05:12:00 pm
Quote from: Insert_Gnome_Here on September 20, 2015, 03:13:39 pm
I'm trying to go for quality over quantity, in order to reduce clean-up.

That makes a lot of sense for tests, but you should be prepared to reverse that if you're faced with an actual siege.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on September 26, 2015, 05:09:24 pm
A siege is here. Time for a baptism of the weapon in goblin blood.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: omega_dwarf on September 26, 2015, 05:11:41 pm
I look forward to it :)
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on September 27, 2015, 03:29:26 am
Ok. some refurbishment meant that the howitzer was not operational and I had to solve the problem the old-fashioned way: throwing waves of unskilled dwarves at it until it goes away. A good 40 out of 80 dwarves died.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: omega_dwarf on September 27, 2015, 09:19:02 am
"It was inevitable."
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on September 27, 2015, 09:34:25 am
I'm about to have it up and running with a much higher maximum rate of fire. I'll post the results of the glass disc shot. I also have to finish the screen in front of the depot, as last time I fired, a stray disc took the head of a farmer clean off.

UPDATE: Fired 3 minecarts at once. Looks like this:
Spoiler (click to show/hide)

A duckling was hit by a ballista arrow and skidded 20 urists away.

Next priority is setting up an aiming system.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Max™ on September 27, 2015, 11:43:33 pm
"Here's a weapon of ridiculous destructive capability I invented, it is capable of wrecking tons of shit in horrific fashion... now I just need to figure out how to aim it."

That's absurdly dwarven of you, I'm so proud to be here to see it.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: omega_dwarf on September 27, 2015, 11:49:37 pm
Quote from: Max™ on September 27, 2015, 11:43:33 pm
"Here's a weapon of ridiculous destructive capability I invented, it is capable of wrecking tons of shit in horrific fashion... now I just need to figure out how to aim it."

That's absurdly dwarven of you, I'm so proud to be here to see it.

I mean...that's sort of how humans do things, too.

But yes, the fact that he is wreaking this carnage with large, sharp objects flung from a minecart in the sky makes the whole thing excessively dwarven :P
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Innocent Dave on September 28, 2015, 08:52:56 am
Aiming is for humans.  A true dwarf just arranges for the targets to be standing in the right place at the right time.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: omega_dwarf on September 28, 2015, 08:57:37 am
Quote from: Innocent Dave on September 28, 2015, 08:52:56 am
Aiming is for humans.  A true dwarf just arranges for the targets to be standing in the right place at the right time.

Yes.

(Because they can't aim.)
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on September 29, 2015, 01:47:00 pm
To be honest, it is currently no less aimable than a standard shotgun, it's just that it is operating in the open rather than down a specific corridor. I should be able to continue with it at the weekend, so look out then.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Urist McVoyager on September 29, 2015, 08:29:47 pm
So make the map a bunch of corridors and floor them with the densest material you can find so all the scudding around hurts worse. That should help you aim. Otherwise it's a lot of logic switch work trying to get the tracks just right.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: crazyabe on September 29, 2015, 08:34:04 pm
That sounds so so Dwarven To use
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: YHVH on September 29, 2015, 09:17:43 pm
Quote from: crazyabe on September 29, 2015, 08:34:04 pm
That sounds so so [size=-webkit-xxx-large]Dwarven[/size] To use
That's the best part about it.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Atarlost on October 01, 2015, 12:32:21 am
I've had a significant number of goblin sieges and all appeared in one of two spots that aren't far apart.  Maybe I should look into this thing. 
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on October 01, 2015, 01:24:05 am
Just point the thing at your entrance.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Urist McVoyager on October 01, 2015, 09:29:15 am
Hook it up TO your entrance. All aiming done for you.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: omega_dwarf on October 01, 2015, 11:11:28 am
That makes it a shotgun again, no longer a howitzer.

Unless you just meant a pressure plate for the trigger, and keep the existing mechanism.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on October 01, 2015, 11:27:44 am
I considered automating it, but the nature of the cart reloading system and the fact it fires all minecarts at once rather than having a magazine means that it is suited to a single firing, which is not too much hassle to perform manually. Firing before the area has been cleared would also risk more collateral damage than I am willing to tolerate.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Urist McVoyager on October 01, 2015, 09:01:46 pm
"That makes it a shotgun again, no longer a howitzer."

Depends on how you make the entrance. If it's not just a tunnel in the mountain, you still could.

And there's probably ways to run it with a single shot instead of the current Metal Storm model you have. Make it multi barreled and have different plates hooked to different barrels, then only set it to shoot one from each barrel. You could also play with bridges as a method for preventing multi-shots.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on October 02, 2015, 10:44:41 am
Multiple shots would not be unfeasible to set up, but failing to put one's my eggs in one obscenely destructive basket is for elves.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Delioth on October 02, 2015, 11:27:39 am
Oh, they're all still in one obscenely destructive basket- the Howitzer.

Just instead of dumping all the magma in one place, you're flinging it across a square mile of forests. Much more effective at burning down a forest- more places for a fire to start.

((I assume an obscenely destructive basket must actually mean a steel bucket menacing with spikes of pitchblende filled with magma.))
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on October 02, 2015, 12:24:24 pm
Spoiler (click to show/hide)

Poor sods. Won't even know what happened to 'em.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on October 02, 2015, 12:50:41 pm
Spoiler (click to show/hide)

There are quite a few of them.

Spoiler (click to show/hide)

EDIT: I'll post a gif of the shot as soon as I can find decent CMV to GIF software.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Bumber on October 02, 2015, 11:54:56 pm
Quote from: Insert_Gnome_Here on October 02, 2015, 12:50:41 pm
EDIT: I'll post a gif of the shot as soon as I can find decent CMV to GIF software.
Play the CMV while recording it with gifcam (http://blog.bahraniapps.com/gifcam/).
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on October 03, 2015, 01:37:28 pm
I can't get gifcam to work. I'll try to put the video up some other way. If necessary, I can set up an ftp server and host it myself.

In other news, The goblins slayed Windoils to a dwarf. The last survivor was the mayor, who was knocked off a staircase and fell to his death. A new fort has been founded, to turn the howitzer from a proof-of-concept into a viable weapon.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Atarlost on October 04, 2015, 01:40:18 pm
Quote from: Insert_Gnome_Here on October 03, 2015, 01:37:28 pm
In other news, The goblins slayed Windoils to a dwarf. The last survivor was the mayor, who was knocked off a staircase and fell to his death. A new fort has been founded, to turn the howitzer from a proof-of-concept into a viable weapon.

Maybe you shouldn't have put all your eggs in one extremely destructive basket. 
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on October 04, 2015, 04:40:13 pm
I expect to be busy for the next few weeks, with little time to make the new outpost, Grippedcopper, megaproject-ready. I will still have time to answer questions etc. on this thread and may work out how to post a video of the firing. If this thread has died by then, I will start a new one focusing on shotgun/howitzer aimability, otherwise I will continue posting here.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Delioth on October 04, 2015, 10:03:54 pm
Notable: you may be able to aim it a little by giving the track a couple of turning tracks (I think someone did !!science!! that the carts track partial sideways velocities as well, so if you put tracks >> - + < it might give a bit of sideways velocity, where - is like a NW track and + is a SW track, with bridges to cover each of them to allow for turning or non-turning. Worth trying. If you've not posted yet, I'll work it into my current cannon to see. That might actually be today or tomorrow.)
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on October 05, 2015, 01:12:36 pm
My plan is actually to collide minecarts at the last minute, although that could theoretically work, as could sideways rollers near the end of the track.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: omega_dwarf on October 05, 2015, 10:37:56 pm
Quote from: Insert_Gnome_Here on October 05, 2015, 01:12:36 pm
My plan is actually to collide minecarts at the last minute, although that could theoretically work, as could sideways rollers near the end of the track.

Yeah, this was just mentioned in the thread that I started. You can potentially use differently-weighted minecarts colliding in midair to control the angle of deflection. In theory.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: SOLDIER First on October 07, 2015, 08:52:07 am
Maybe it would be possible to mine a tunnel a certain distance away from your entrance, with walls funneling traffic from the tunnel to the entrance, and position the entrance-ward end of the tunnel where the projectiles usually land to "aim" it at enemies - or, really, you aim THEM at IT.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on October 11, 2015, 02:06:54 pm
Tests on deflecting minecarts using collisions prove hopeful. I need to tweak relative masses & speeds to ensure the right amount of deflection, then I can incorporate it into the new howitzer.

Code: [Select]
>===#
    ^
> , ^ roller in direction indicated
= , # track

The 4 way track has a pressure plate linked up to a gear attached to the up roller, & the right roller is connected to a lever.  Both rollers have minecarts left on them.
When triggered, the minecart on the left rolls over the pressure plate, launching the lower minecart into it and deflecting its course upwards.
(layout is flat; 'up' & 'down' refer to diagram)
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Iliithid on October 11, 2015, 06:33:50 pm
I think this entire concept is the greatest thing I've ever witnessed in my dwarven life.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Amperzand on October 15, 2015, 04:46:38 am
This seems like an amazingly good idea.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Gwolfski on November 19, 2015, 01:06:28 pm
Quote from: Amperzand on October 15, 2015, 04:46:38 am
This seems like an amazingly good idea.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: puke on November 19, 2015, 05:55:07 pm
Quote from: thegoatgod_pan on September 20, 2015, 02:32:38 pm
Have you tried bricks?  Bolts? Try quantity over quality.

I hate to ring this tired old bell, but have you considered Magma?  no cleanup, easy reloading (assuming you dip through a reservoir on your cart circuit). 


Quote from: Insert_Gnome_Here on October 02, 2015, 10:44:41 am
Multiple shots would not be unfeasible to set up, but failing to put one's my eggs in one obscenely destructive basket is for elves.

can put the carts on an impulse ramp circuit for continuous fire, if loading from a liquid source.  Otherwise, I guess it would require loaders.  If loading from stockpiles, You could have a multiple-shot system with several pre-loaded carts queued up -- or even multiple loads set to dump into your one 'firing' cart

Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Iliithid on November 21, 2015, 06:51:29 pm
Quote from: puke on November 19, 2015, 05:55:07 pm
Quote from: Insert_Gnome_Here on October 02, 2015, 10:44:41 am
Multiple shots would not be unfeasible to set up, but failing to put one's my eggs in one obscenely destructive basket is for elves.
can put the carts on an impulse ramp circuit for continuous fire, if loading from a liquid source.
Literally.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Larix on November 22, 2015, 08:26:17 am
I expanded the concept of the minecart shotgun into a perimeter defence system:
http://www.bay12forums.com/smf/index.php?topic=15096.msg6618589#msg6618589

Several passages at the border of the surface area used by the fort are rigged with pressure plates, and triggering a plate releases a shot of ~150 trap components, going very fast. The system keeps three carts (each serves nine or ten of the 28 "gun barrels") in circulation and will path them towards the barrel that is to release the shot. Carts return to the loading station automatically, ammo must be collected and brought back to fort by haulers.

So far, it has killed one wombat and two yaks (wandering wild animals) and one tame cougar (friendly fire). Unfortunately, the hostile civs haven't sent troops for years. Reloading one cart takes several weeks.

Even if you don't bother looking up the linked post, the test shot may be worth watching:
http://mkv25.net/dfma/movie-2744-perimeterguntestshot

If something is in the way of the shot, it gets very thoroughly splattered. The strength of the shotgun is that it has no minimum range  - it can blow apart something standing right next to the barrel - and an effective range at ramp-max speed of ~70 tiles, in a narrow cone. The main weakness i see with my design is the slow reaction: shot triggering depends on the raising of a bridge and carts are on a large cycle, requiring up to 160 steps of waiting until the cart cycles around again. In the 150-300 steps reaction time of the gun, wandering animals will often be outside of the shot cone again. A faster design with compact acceleration coil and door-triggered shot release should allow reaction times of about 50 steps.

Ballistic shots, especially at significant shot speeds, have minimum ranges of 50-150 tiles. If your minimum range (free-flight distance covered before getting back down to the floor) is 100+ tiles and your target zone is anywhere near the main fort, you'll have to set up the gun somewhere on the fringes of the embark. Have fun maintaining and reloading such a gun. I think that's a serious practical issue with a ballistic gun. Travel times (ammo can spend 70+ steps in flight) will also play a role.
Title: Re: Tarmid-Udar: Dwarven Howitzer
Post by: Insert_Gnome_Here on November 22, 2015, 10:18:47 am
I once considered building a network of small shotguns, but having a large underground track servicing many barrels is something I never considered. As it is, once I have mended Windows and got back to playing DF, I plan to use minecarts in a rather different perimeter defence network.