Halo: In Amber Clad (Mass and Size)

[Steven Snyder]

So I am arguing with a guy on the HBO forums about the size of In Amber Clad and I want to put my thoughts out here for peer review.

In Amber Clad is a USNC Missile Frigate (Fast Frigate by the FFG designation). The claim that was made is that she was 460 meters long, which I disagree with.

What is known:
The USNC destroy Iroquois mass was stated at 8,000 tons.
The Iroquois was said to be almost as massive as two frigates.
A destroyer is essentially a frigate with an extra meter of Titanium-A armor.
A modern destroyer, the Arleigh Burke class, masses at 8,100 tons and is 142 meters long.
A modern frigate, the Oliver Hazard Perry class, masses at 4,100 tons and is 133 meters long.

So:
It is possible that the author used the mass figures of modern destroyers and frigates, they do seem consistent.
It is reasonable to assume the USNC frigates mass at about 4,000 tons.
The In Amber Clad should have a similar mass as the other USNC Frigates.

For me it all comes down to density, which when combined with mass can give you a rough estimate on the size of a vessel. If we assume that USNC ships are about as dense as modern warships that would indicate that USNC ships should have similar physical dimensions to equivalent mass modern warships.

So a 133 meter long, 13 meter tall and wide frigate with a mass of 4000 tons should have a density roughly on par with a modern warship. But if you took the same basic shape (10x1x1) and elongated it to 460 meters then it would have a density of 4.11 kg/m3...less dense than Xenon gas per unit.


Am I way off base here, could the In Amber Clad actually be 460 meters long given the a mass of 4,000 tons?

Thanks in advance.

[Black Admiral]

The In Amber Clad, assuming that she's the same class of frigate as the Gettysburg, is ~500 meters long (First Strike, page 279).

If someone can get me a length for the Pelican though, I can scale off an image in The Art of Halo.

[Beowulf]

mass and size frequently get fucked up in SciFi. As an example, Honorverse formerly had lighter than air space ships.

[Laird]

D77-TC Pelican is 30.6 meters according to the Halo Lib.

[Steven Snyder]

mass and size frequently get fucked up in SciFi. As an example, Honorverse formerly had lighter than air space ships.

I would accept that...except....

Flip back the author's credits on TFoR and First Strike. Eric Nylund is glad to tell you about his degrees in chemistry and physics. I hear he is even going for a PhD in physics.

If it were KJA I would write it off, but Nylund is suppose to know his science.

[Black Admiral]

D77-TC Pelican is 30.6 meters according to the Halo Lib.

Okay, that's good enough.

Now, on the page the IAC's 13cm long, and the Pelican is 1cm long. 13 times 30.6 equals 397.8 meters long.

So, now we've got three potential lengths.

[Hawkwings]

also remember IACs shape. It's definitely not similar to a wet navy frigate we have right now.

[Steven Snyder]

D77-TC Pelican is 30.6 meters according to the Halo Lib.

Okay, that's good enough.

Now, on the page the IAC's 13cm long, and the Pelican is 1cm long. 13 times 30.6 equals 397.8 meters long.

So, now we've got three potential lengths.

Did you catch how tall or wide it is?

[Black Admiral]

Did you catch how tall or wide it is?

No width, but the IAC's about 137 meters high.

[HemlockGrey]

That's a lot of unsupported assumptions you're making.

[JointStrikeFighter]

To add more confusion to the mix, in the opening cutscene In Amber Clad frigates are flying past. From the longswords next to them [64m long IIRC] we get a figure of 800ish metres.

Anyay, the 460m figure comes from thye model of the IAC in the level cairo station where you can walk on it.

[Steven Snyder]

That's a lot of unsupported assumptions you're making.

Care to elaborate?