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Old 04-07-2018, 08:00 PM
Olefin Olefin is offline
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Default Pumpkin' Chunkin' and other non-standard weapons

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Going even further back, just YouTube Pumpkin' Chunkin' and take a look at the power of ancient siege engines. If an air cannon can launch an EIGHT POUND PUMPKIN OVER A KILOMETER, it can launch an 8lb rock too. Look at the Trebuchet's power in use. In fact, one weapon I have considered making is a modern version of a Ballista using truck leaf springs. Imagine 4 leaf springs stacked on what would be, in essence, a crossbow on steroids that fired a 6-foot metal spear. You would use a come-along/winch to cock it and the bowstring would be 10 gauge wire like the stuff used in skyscraper antenna guidewires. I'm willing to bet that it could shoot that 6ft "bolt" completely through a modern passenger car. Primitive does NOT mean ineffective.

Has anyone ever included weapons like this in a campaign?
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Old 04-07-2018, 10:32 PM
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I fondly remember the consternation caused by a radar-insignificant trebuchet lofting a nuclear warhead into the advanced aliens' fortification in "The High Crusade"
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Old 04-08-2018, 06:55 PM
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I fondly remember the consternation caused by a radar-insignificant trebuchet lofting a nuclear warhead into the advanced aliens' fortification in "The High Crusade"
One of my all time favorite books - perfect cross of AD&D with space opera
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Old 04-09-2018, 08:19 PM
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Not for T2K, but I worked on rules for trebuchets for TNE that would still work (though figuring Pen might be a bit problematic). To quote my work at CotI:

"One thing I noticed is that the theoretical performance GREATLY exceeds what any reproductions have done, although the large reproductions have some inefficiencies built into them, with very short counterweight arms and no distance between the arm and the weight, which causes them to suffer reduced performance. The following design sequence includes an efficiency modifier. Numbers from 0.2 to 0.5 should be fairly normal, with 0.75 being close to the upper limit for a good trebuchet builder.

Trebuchets are always considered to perform indirect fire with a Deviation Modifier of 5, a Max Hit Number of 14 and a Max Deviation Reduction of 5. They may only select targets within a range of 90-110% of their listed range.

I. Efficiency
1. Select an Efficiency (Eff) number between 0.2 and 0.75, with higher numbers being more experienced builders who have a better grasp of the science and mathematics behind trebuchets.

II. Ammunition
1. Select the mass of the projectile to be launched (Mp) in kilograms.

2. Cost of ammunition = Mp x 5 in credits

III. Counterweight
1. Select the mass of the counterweight (Mcw). Maximum is 100 times Mp.

2. Cost of counterweight = Mcw x 50 in credits

IV. Dimension of machine
1. Select the height of counterweight drop (Hcw) in meters. This is how far the counterweight falls from its maximum height to its minimum height.
2. Arm length (Al) is equal to 6.7 times Hcw. Of this length, 80% is in the long arm and 20% in the short arm.
3. Machine height (Mh) is equal to 0.67 times Al.
4. Base length (Bl) is 1.35 time Hcw. Base width (Bw) is 0.33 times Bl.
5. Empty weight (Ew) is 2.5 * Mcw + 100 * Hcw^2.
5a. If equipped with "hamster wheels" or windlasses, increase the Mcw multiplier to 3.5.
6. Loaded weight (Lw) is Ew + Mcw.
7. Cost of machine = 40 x Ew in credits.

V. Performance of machine
1. Range = 2 * Eff * Mcw * Hcw / Mp = meters
2. Velocity = (range * gravity [in m/s^2])^0.5 = meters/second
3. Kinetic Energy = 0.5 * Mp * V^2 = joules
4. Damage = (KE^0.5)/15 = D6 of damage

VI. Miscellaneous
1. Crew = Mp/3 + 2 (master artillerist and master loader).
2. Reload = Mp/2 if using windlasses or "hamster wheels." Reload = Mp*2 if using ropes and pulleys.

Example:
Let's build a light trebuchet on a low-G (0.7 g) world.
1. Efficiency is 0.5 - pretty good, but not great.
2. Mp is 10 kilograms, a light trebuchet projectile. Ammo costs 50 credits per round.
3. Mcw is 600 kilograms, 60% of the maximum. The counterweight costs 3000 credits.
4. Hcw is 5 meters, meaning the weight drops 5 meters from its maximum height to its minimum height. Arm length is 33.5 meters, machine height is 22.445 meters, base length is 6.75 meters, and base width is 2.2275 meters.
5. The trebuchet is equipped with a windlass, so empty mass is 4600 kilograms, and loaded mass with counterweight is 5200 kilograms.
6. Range is (2*0.5*600*5)/10, or 300 meters.
7. Velocity is (300*0.7)^0.5, or 45 m/s
8. KE is 0.5*10*45*45, or 10,125 joules
9. Damage is (10125^.5)/15, or 7D6 (rounded up from 6.7)
10. Total cost is (600*50)+(4600*40) = 214,000 credits plus 50 cr per shot.
11. Required crew is 5, and Reload is 5.
Without the windlass, Ew would be 4000 kilograms, cost would be 190,000 credits, and Reload would be 20.

Ew, cost, crew, and reload are all speculative, but crew and reload are loosely based on recorded performances. The sample trebuchet is very small, and examples of trebuchets firing projectiles of up to 136 kilograms are recorded (Edward I's Warwolf)."

There's also a thread over there on torsion siege engines, but since atpollard did the majority of the work on them, I don't feel comfortable with copying and pasting his work elsewhere.
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Old 04-10-2018, 07:08 PM
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I'll follow The Dark's lead here but I can tell you that I watched a YouTube video of an air cannon firing PUMPKINS that actually knocked down a silo slated for demolition. It destroyed a minivan pretty quickly too.
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Old 04-18-2018, 07:18 PM
.45cultist .45cultist is offline
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There was a video of Brits launching small cars!
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Old 04-18-2018, 07:37 PM
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After some thought, I'd go ahead and just use the equivalent of Small Arms Pen 2 for trebuchets. The projectile's not incredibly fast, but it's heavy and dropping from the sky in a parabolic arc like a mortar shell.

I'm also tempted to allow shorter ranges (though that can be done by lightening the counterweight), since I've seen notes about adjusting the length of the sling that holds the projectile to change the arc and thus the range.
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Old 04-19-2018, 09:14 PM
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I saw on YouTube a video of a compressed-air cannon that in rapid succession (well, I'm sure there was editing for time) pumpkins, cantaloupes, bags of oranges and apples, a watermelon, and even an open can of paint! It was a versatile buggar!
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Old 04-20-2018, 12:01 AM
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Quote:
Originally Posted by pmulcahy11b View Post
I saw on YouTube a video of a compressed-air cannon that in rapid succession (well, I'm sure there was editing for time) pumpkins, cantaloupes, bags of oranges and apples, a watermelon, and even an open can of paint! It was a versatile buggar!
Sounds kind of like the British Holman Projector from WW2.
https://www.navyhistory.org.au/the-holman-projector/
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Old 04-21-2018, 01:34 PM
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here is one that can throw a live cow

https://www.youtube.com/watch?v=ey0wvGiAH9g
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Old 04-21-2018, 04:51 PM
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Quote:
Originally Posted by WallShadow View Post
Sounds kind of like the British Holman Projector from WW2.
https://www.navyhistory.org.au/the-holman-projector/
No, this was much bigger. Guaranteed to paint your wall at 2000m...
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Old 05-16-2018, 05:34 PM
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I have been doing some research into the Ballista for Twilight. I found this guy who is ACTUALLY posting data about his weapon systems.

www.wattsunique.com


If you Google him, he has data on his site.
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Old 05-17-2018, 12:00 PM
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Quote:
Originally Posted by The Dark View Post
After some thought, I'd go ahead and just use the equivalent of Small Arms Pen 2 for trebuchets. The projectile's not incredibly fast, but it's heavy and dropping from the sky in a parabolic arc like a mortar shell.

I'm also tempted to allow shorter ranges (though that can be done by lightening the counterweight), since I've seen notes about adjusting the length of the sling that holds the projectile to change the arc and thus the range.
You can adjust range by adjusting the height at which you release the sling.

I have seen (pictures of trebuchets) with marks on the supports for the sling arm - lowest = max range, other marks for less range. You adjust the length of the rope used to pull the sling arm down until it matches the angle for the desired range.

These are, of course, crude increments, as trebs are fairly inaccurate weapons compared to cannon from 1600 on - the tossed load is inconsistent in shape and weight, and each trebuchet will be a bit different even if produced in a consistent pattern - material used, age, current weather, and measurements used.

But for T2K or TNE, you can handle that by raising the difficulty of a shot based on the target size.

"Hit the east wall of town or something behind it" may not be difficult once the range is determined may not be too difficult.

"Hit the VW bug parked outside the town gate" may take a long while...

Uncle Ted
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Old 05-17-2018, 05:11 PM
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Quote:
Originally Posted by unkated View Post
You can adjust range by adjusting the height at which you release the sling.

I have seen (pictures of trebuchets) with marks on the supports for the sling arm - lowest = max range, other marks for less range. You adjust the length of the rope used to pull the sling arm down until it matches the angle for the desired range.

These are, of course, crude increments, as trebs are fairly inaccurate weapons compared to cannon from 1600 on - the tossed load is inconsistent in shape and weight, and each trebuchet will be a bit different even if produced in a consistent pattern - material used, age, current weather, and measurements used.

But for T2K or TNE, you can handle that by raising the difficulty of a shot based on the target size.

"Hit the east wall of town or something behind it" may not be difficult once the range is determined may not be too difficult.

"Hit the VW bug parked outside the town gate" may take a long while...

Uncle Ted
Yes, although sling adjustments are (necessarily) limited by the lengths of sling that you have. The 90-110% was intended to cover sling adjustments and the like, though I'll admit it was a wild guess because there's not much information on how much they could vary range without changing ballast weights.

swaghauler - Watts' work on his in-swinger was a big influence on some of the suggestions I made to adjusting torsion engines on the Citizens of the Imperium board. Once he has an engine that can reliably perform to his objectives, I'd love to see it tested for things like penetration at range to see what it would do.
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Old 05-17-2018, 10:16 PM
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Quote:
Originally Posted by The Dark View Post
swaghauler - Watts' work on his in-swinger was a big influence on some of the suggestions I made to adjusting torsion engines on the Citizens of the Imperium board. Once he has an engine that can reliably perform to his objectives, I'd love to see it tested for things like penetration at range to see what it would do.
Hmmm...Torsion-powered ballistae using high-tech materiel components being used to micro-manage the positioning of a belter mining site....?
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Old 05-18-2018, 04:23 PM
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Quote:
Originally Posted by unkated View Post
You can adjust range by adjusting the height at which you release the sling.

I have seen (pictures of trebuchets) with marks on the supports for the sling arm - lowest = max range, other marks for less range. You adjust the length of the rope used to pull the sling arm down until it matches the angle for the desired range.

These are, of course, crude increments, as trebs are fairly inaccurate weapons compared to cannon from 1600 on - the tossed load is inconsistent in shape and weight, and each trebuchet will be a bit different even if produced in a consistent pattern - material used, age, current weather, and measurements used.

But for T2K or TNE, you can handle that by raising the difficulty of a shot based on the target size.

"Hit the east wall of town or something behind it" may not be difficult once the range is determined may not be too difficult.

"Hit the VW bug parked outside the town gate" may take a long while...

Uncle Ted
More fun would be "throw that disease ridden dead cow inside their defenses" (nice Monty Python aspect to that)
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