Difference of yields between common ship weapons in Trek ENT

[Mr. Oragahn]

There's been two big versus debates thus far where people wondered how torpedoes didn't end being largely favored in ship to ship engagements, notably by the NX-01, when we hear that main phase cannons can range from 80 GJ, 500 GJ to 5 TJ, and with dialable photon torpedoes able to dig a 3 km wide crater in an asteroid, which had people cite yields of several tens of megatons.
There seems to be a wide discrepancy, which puzzles people out of Trek, just like me, like me.

The exact reference for the photon torpedoes is as follows:

[Armoury]

REED: Photonic torpedoes. Their range is over fifty times greater than our conventional torpedoes, and they have a variable yield. They can knock the comm. array off a shuttlepod without scratching the hull or they can put a three kilometre crater into an asteroid.
TUCKER: How long is it going to take to reconfigure the tubes?
REED: We've got three teams working on it. They promise me it'll be done before we leave Spacedock, but I've got to start integrating them into the power grid.
TUCKER: Let's go.

The Expense, season 2.

First, Reed mentions conventional torpedoes. What's this? Did the NX-01 use photon torpedoes, or more of these conventional torpedoes? The shift happened around season 2, that's it?

Secondly - and that's the big part - why does there seem to be such a huge difference of yields?
There's enough evidence in Trek to show that torpedoes are used just as much as phasers, if not less.
We've found evidence, from dialogue posted in the versus debates, that they're largely unfocused weapons, and actually require manual tweaking to release their energy in a cone.

I tried to know if there was a way to make the 3 km wide crater claim fit with sub megaton yields.

The question is how to obtain a reliable figure for that. Either from a calculator, or from real life examples.

Using M. Wong's calculator, with the results under "cratering energy".

There's a problem though, because the mechanism that leaves a crater due to an impact with a massive object has nothing to do with the mechanism of a small torpedoes liberating enough energy, omnidirectionally (even modern Trek torps around TNG aren't focused), to actually dig a crater that is 3 km wide. There's not the massive residual mass of an asteroid to be meshed with the ground.

See, the idea was to use the cratering figures for a 3000 wide asteroid impact, as it "seemed" to suit the case:

"Cratering energy is the energy required to blast out a crater of depth equal to the radius of the asteroid, which should easily result in its catastrophic disruption."

However, with craters due to asteroid impacts, the width is largely superior to the depth.

There's like a good load of sites to ponder this:

http://www.lpl.arizona.edu/SIC/impact_c ... rater.html
http://www.lpl.arizona.edu/SIC/impact_c ... tpage.html 30-50 meters wide asteroid: a mile wide and 570 feet (173.736 m) deep crater. Yield: 20-40 MT.
http://www.lpl.arizona.edu/SIC/impact_c ... ppage.html
http://www.lpl.arizona.edu/SIC/impact_c ... opage.html 30-50 m wide asteroid: 1 km wide, 100 m deep crater. Yield: A hundred times more powerful than the Hiroshima blast.
http://www.lpl.arizona.edu/SIC/impact_c ... tsmap.html

So I tried Wong's calculator. Recent data has shown that his equations disputable when it came to fragmentation energies (omni blast from the center of an asteroid), and that even with melting a vast bulk of an asteroid, this wouldn't even allow the creation of small enough debris, but would let, instead, to the fragmentation of large plates to be hurtled away.

Here, I tried first a 1000 wide asteroid. A 500 m radius. Same for the depth then.

Result: Even the hardest of materials, nickel-iron, only returns a yield of 4.7 megatons.

So according to his program, a ground blast of 4.7 MT would already be enough to dig a 500 meters deep crater into a surface of nickel-iron, while the estimations I link to say that even blasts between 20 and 40 MT weren't even able to leave craters more than 100-174 m deep, in what is nothing more than granite, as far as Africa is concerned, and let's not mention Arizona's rock.

So I decided to input a 200 m wide asteroid. Radius, 100 m, used for the depth, again.

Cratering energies
- Hard Granite: 180.9 tons
- Nickel-Iron: 4.7 kilotons

So we see that the resulting estimations, as far as it goes for cratering figures, are erroneous.

A way to make sense of this is to suggest that his calculator assumes a rather spherical crater, maybe slightly flattened, but not by much.

But let's do a final test. Frankly, I thought that was an OK way to reach sub megaton yields. We see that in the examples mentionned above, that a crater's final depth is generally a tenth of its width.
So for a 3 km wide crater, we'd get a depth of 300 meters.
Though Wong's program, it gives us those values:

Cratering energies
- Hard Granite: 4.9 kilotons
- Nickel-Iron: 127.5 kilotons

As far as hard-granite is concerned, the yield doesn't come far ahead of the cannons stuck on a maximum of 500 GJ x 10 (overload) each. With two fore phase cannons, we're in a total yield in the 2.39 KT per salvo, per second (I'm unsure as to how long the beam weapons can't be kept firing at maximum power).

The Enterprise is said, early in the show, to have 14 beam weapon spots, a few of them being major cannons like the ones mentionned above.

So, the situations are:

- The pages I've linked to are severely wrong when it comes to yield estimations (or relies on a definition of "crater depth" due to an asteroid impact that is different than the one which corresponds to the crater depth described on Wong's page), but we need to reinterpret the meaning of certain elements and assume that the crater left on the surface of the fictional asteroid mentionned by Reed will share the same kind of shape as a post-asteroid-impact crater. Thus, we obtain ranges from low kiloton to medium kiloton level warheads, which establishes a level of consistency that is satisfying.

- Wong's calculator is largely flawed (or relies on a definition of "crater depth" that is different than the one which corresponds to the depth of a crater left by an asteroid impact), and ENT Trek torps are easily in a range around 40~60 MT, if not more. But then we're still left with that illogical gap of warheads being many thousand times more powerful than beam weapons, and yet rarely used despite the NX-01 facing head to head, numerous times, much more powerful enemies.

Episodes like the Aenar really disputes the vast differences of yields.

Any thoughts?

PS: that's my first Trek centric thread ever; go easy with me guys. :P

[AFT]

First, Reed mentions conventional torpedoes. What's this? Did the NX-01 use photon torpedoes, or more of these conventional torpedoes? The shift happened around season 2, that's it?

You didn’t watch that much of Enterprise, did you? The NX-01 was equipped at launch with something called spatial torpedoes, essentially missiles with fusion warheads, this are the conventional torpedoes that Reed meant. And they shift to photonic torpedoes during the last episode of the second season, The Expanse, the episode you’re quoting.

Secondly - and that's the big part - why does there seem to be such a huge difference of yields?

There seems to not be that great of a difference in yield between phase cannons and spatial torpedoes, the original weapons complement of the NX-01, however for the mission into the Expanse better firepower was needed, so during that episode the NX-01 was upgraded with the mentioned photonic torpedoes, clearly better weapons than the previous spatial torpedoes.

There's enough evidence in Trek to show that torpedoes are used just as much as phasers, if not less.

First, that’s future Trek where you can say that the difference in yield is not that big, however their use greatly depends on the situation, when you need finesse and precision phasers are the way to go, when superior firepower is needed they use photon torpedoes. In large engagements they use both. And since Starfleet doesn’t has the habit of blasting opposing starships out of hand it makes sense that they used phasers a lot.

But then we're still left with that illogical gap of warheads being many thousand times more powerful than beam weapons, and yet rarely used despite the NX-01 facing head to head, numerous times, much more powerful enemies.

The first two seasons can’t be helped, they simply didn’t have those far more powerful weapons, however after they got the photonic torpedoes their pattern was very clear, in any battle they first used the phase cannons, if that wasn’t enough then photonic torpedoes were used. And not rarely, they fired quite a bit of photonic torpedoes during the last two seasons, hell, even during that very same episode they went trigger happy with photonic torpedoes on the Klingon Birds of Prey that were chasing them into the Expanse, destroying one of them.

[Mike DiCenso]

It should be noted also that the Klingons (as per "Sleeping Dogs [ENT1]) and possibly other older spacefaring powers in the 2150's already have photon torpedoes. Certainly the Vulcan High Command possessed photonic torpedo technology as they are stated as using them to bombard the Syrannite's stronghold.

Two of the Klingon photon torpedoes are powerful enough, even what appears to be a default setting to be able to kick a Raptor-class ship several hundred meters upward inside the dense atmosphere of a gas giant.

The effects of a Klingon ENT-era photon torpedo on the gas giant's atmosphere:


http://ent.trekcore.com/gallery/display ... 18&pos=433


The Raptor is initially stated as being 100 kilometers deep in the gas giant's atmosphere. A single torpedo set to dedonate at 3 km down from the Raptor does not have enough energy to push the Klingon ship up againt the gravity and atmospheric drag. A second torpedo dedonated at an unspecified closer range knocks the ship upward 200 meters.
-Mike

[SailorSaturn13]

They initially had lasers and spatial torps. Then tghey got phase cannons and used them A LOT. THEN they got photonic torpedoes. However:
1. They first try to disable, not blast, enemies.
2. New torpedoes are precious resourse, unlike in TNG
3. Not having shields means their own ship can be heavily damaged by torpedoes.
4. brute force not always succeeds. In "cost of living", phasers fracture asteroid core which torpedoes could not, depite less strength.

[l33telboi]

The Raptor is initially stated as being 100 kilometers deep in the gas giant's atmosphere. A single torpedo set to dedonate at 3 km down from the Raptor does not have enough energy to push the Klingon ship up againt the gravity and atmospheric drag. A second torpedo dedonated at an unspecified closer range knocks the ship upward 200 meters.
-Mike

You could get the kinetic energy of the blast by simply measuring the acceleration the torp imparted to the ship. If there's no known distance between torp and ship, then assume it was almost on top of the ship itself. In either case, you're going to get energy figure quite large i'm guessing.

[Mike DiCenso]

Unfortunately, unlike the starship Voyager, we don't have any statement concerning the mass of the Raptor-class vessels. So any number you assign to it is pure guesswork, really.
-Mike

[Mike DiCenso]

SailorSaturn13 wrote:
4. brute force not always succeeds. In "cost of living", phasers fracture asteroid core which torpedoes could not, depite less strength.

Actually, they used some kind of technobabble beam fired from the E-D's deflector dish to destroy the asteroid's core, not the phasers.
-Mike

[Jedi Master Spock]

The Raptor is initially stated as being 100 kilometers deep in the gas giant's atmosphere. A single torpedo set to dedonate at 3 km down from the Raptor does not have enough energy to push the Klingon ship up againt the gravity and atmospheric drag. A second torpedo dedonated at an unspecified closer range knocks the ship upward 200 meters.
-Mike

You could get the kinetic energy of the blast by simply measuring the acceleration the torp imparted to the ship. If there's no known distance between torp and ship, then assume it was almost on top of the ship itself. In either case, you're going to get energy figure quite large i'm guessing.

If the ship only goes up 200 meters and then stops, then you can get it from elevation. However, the figure is not that large. Gravitational potential: U=mgh.

If g is locally 50 m/s/s - high even for someone in the outer atmosphere of a gas giant - then you have a 10 kJ/kg change. The Raptor is estimated on EAS to only be 145m long; it's probably not much off from 100,000 tons (1e8 kg). Assume an additional identical energy loss due to friction, and the Raptor only taking 10% of the blast, and only 10% of the blast's energy being translated into kinetic energy, and we'd have squeezed our way up to 2e14 joules - i.e., 50 kilotons. You're not going to get high figures using this technique unless the numbers are rather different.

[Mike DiCenso]

Unfortunately, as I pointed out before, we have very actual little canon information to go by for the Raptor class ships. The 145 meter length number seems to come from the behind-the-scenes information posted on forums like Sci-Fi Flare. The mass figure you give is as good as anything we've got, and we know next to nothing about how far down the Raptor sank into the gas giant's atmosphere, or any of the gas giant's actual characteristics. Is it bigger or smaller than Jupiter? We don't know. So you can make any assumptions you like.
-Mike