Valiant vs Avalon

FYI: ERM has to have a runtime of 270s, to equal/outrange Cataphract. 300s would give it a range of 20Mkm. So, highly doubt 300s. Since DW seems to like intervals of 60 in his missiles, I would state the 270s where he used a fraction this time

270s that would be 4m 30 s which would be about right for adding basically half a standard drive to an SDM

Relax wrote:FYI: ERM has to have a runtime of 270s, to equal/outrange Cataphract. 300s would give it a range of 20Mkm. So, highly doubt 300s. Since DW seems to like intervals of 60 in his missiles, I would state the 270s where he used a fraction this time

Yep, that a big part of how I came up my my estimate of 270 seconds (and 16.4 million km).

You're right that 90s / 270s isn't on a nice neat 60 second boundary. But there are other examples of non-60s missiles. Obviously we're directly told that the Mk31 CM & Viper are 75 second missiles. And the pod-based Technodyne missiles at Monica had 75 / 225 second runtimes as well (though you had to do minor number crunching to see that; since the book just gives you acceleration and terminal velocity).

Great speculation.
I want to see what the RMN orders when Manticore has it in-system infrastructure and shipbuilding on line with home produced components. Have to wait for RFC to do that for us.

Jonathan_S wrote:

Relax wrote:FYI: ERM has to have a runtime of 270s, to equal/outrange Cataphract. 300s would give it a range of 20Mkm. So, highly doubt 300s. Since DW seems to like intervals of 60 in his missiles, I would state the 270s where he used a fraction this time

Yep, that a big part of how I came up my my estimate of 270 seconds (and 16.4 million km).

You're right that 90s / 270s isn't on a nice neat 60 second boundary. But there are other examples of non-60s missiles. Obviously we're directly told that the Mk31 CM & Viper are 75 second missiles. And the pod-based Technodyne missiles at Monica had 75 / 225 second runtimes as well (though you had to do minor number crunching to see that; since the book just gives you acceleration and terminal velocity).

If I remember correctly, WOH had a Manty ERM running at 210 seconds. Torch said that Erewhon was running with the ERM technology and advancing it while Manticore had stopped researching it in favor of Multi-drive tech.

I wouldn't take Erewhonese made ERMs and use that for a Manty baseline.

Theemile wrote:

Jonathan_S wrote:Yep, that a big part of how I came up my my estimate of 270 seconds (and 16.4 million km).

You're right that 90s / 270s isn't on a nice neat 60 second boundary. But there are other examples of non-60s missiles. Obviously we're directly told that the Mk31 CM & Viper are 75 second missiles. And the pod-based Technodyne missiles at Monica had 75 / 225 second runtimes as well (though you had to do minor number crunching to see that; since the book just gives you acceleration and terminal velocity).

If I remember correctly, WOH had a Manty ERM running at 210 seconds. Torch said that Erewhon was running with the ERM technology and advancing it while Manticore had stopped researching it in favor of Multi-drive tech.

I wouldn't take Erewhonese made ERMs and use that for a Manty baseline.

Well the Erewhonese ERM is stated to be their version of the Mantie Mk14 ERM; so there's some basis to guess they might have the same performance numbers.

But I've been through WoH in the last couple days and I couldn't find any mention of ERM drive endurance time.[1]

The only 3 ERM data points I found in it were:
* the CA HMS Ephraim Tudor fired on Andie CLs as they reached 15 million km. (No description of closure rate or other geometry)
* Those Andie CLs fired back as they reached 12 million km
* Hellbard and HMS Jessica Epps fought it out at no more than 10 million km.

But if I missed something I'd love if someone could point it out - I'd add it to my notes.

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[1] I'm in the middle of resurveying the books to try and find all the missile data so I can clean up and release my spreadsheet - still have the 3 Torch books, the anthologies, and RFC's posts to search through. And I'm just doing keyword searches; not rereading everything - so some references might well be slipping through the cracks me.

Already found a things that slipped through editing though:
Like a couple spots a "KPS^2" was clearly supposed to be "gravities" or "g". (and one spot where just "KPS" was supposed to be "gravities")

Found that during 4th Yeltson RFC (presumably accidentally) gave Honor's GSN SD's ERMs - the numbers are for 90-ish seconds at full power. Oops.

RMN MDM's got slower during the ceasefire (which I'd noticed and mentioned before). AoV had them at 98,000 g but by WoH they were back down to 92,000 g

And SftS claims the export grade missiles in Monica's BC tubes were utter garbage - max range of 5,900,000 km - less that the CL Fearless had back during OBS. (if you backfit that range and the given terminal velocity you get a half power setting of about 37,577g). I haven't double checked the SoS description of the battle to see if that range works in the story.

Oops, sorry for the massive postscript digression.

They could be using the same type of engine, its the endurance that is the difference. on the missile could be pumping out power and using fuel at a self-destructive levels. While the drone will drip out its fuel and vastly increase its endurance. For a RW example, I once asked the Chief Engineer of the ship I served on how far would the ship go at its max speed versus it most economical speed. he said at top speed we would run out of fuel about 100 nm short of Hawaii and at are most economical would barely make Tokyo.

Service of the Sword:

...Gauntlet's missiles could pull 46,000 g over the same time envelope, which gave her a current powered engagement range of over sixteen-point-three million klicks...

Similarly, in ToF, Rozsak's missiles are going out at 451 KPS^2.

Work backwards from there, and you get 270 seconds.

Duckk wrote:Service of the Sword:

...Gauntlet's missiles could pull 46,000 g over the same time envelope, which gave her a current powered engagement range of over sixteen-point-three million klicks...

Similarly, in ToF, Rozsak's missiles are going out at 451 KPS^2.

Work backwards from there, and you get 270 seconds.

Actually Duckk, having looked at that recently, that passage is less clear than it looks. Yes, 6,000 g for 270 seconds gives a range from rest of 16.4 million km. But from the full quote it's not at all clear that this is supposed to be showing an "at rest" engagement range for Gauntlet.

Service of the Sword wrote:The current range was just over fourteen million kilometers, with a closing velocity of just over sixty thousand kilometers per second. Given that geometry, the effective powered missile range for a Peep missile would have been just over fifteen million klicks at 42,500 g, which would give them a minute and a half of drive time. Gauntlet's missiles could pull 46,000 g over the same time envelope, which gave her a current powered engagement range of over sixteen-point-three million klicks, but that theoretical advantage was rather cold comfort, given that both sides were already in their own range of the other.

(Though it appears David either ran the calc with a ship acceleration factor thrown in, or maybe made a typo, because the math works for closing rate of 50,000 kps, rather than 60,000 kps)


distance = ([initial velocity] * [time]) + (1/2 * [acceleration] * [time])

Peep missile:
15,747,300 km = (50,000 kps * 180 s) + (1/2 * 42,500 g * 180 s)

Gauntlet's missile:
16,302,960 km = (50,000 kps * 180 s) + (1/2 * 46,000 g * 180 s)


Now it could be a coincidence, where the Peep missile was a non-rest range while Gauntlet's was an at-rest one. But when I was trying to parse performance out of it last night I'd assumed both were give as non-rest; but that David was being cute to avoid showing us that the Manties had ERMs...

Note that the quote says that Gauntlet's performance is given "over the same time envelope" (aka over 180 seconds - the same as every missile we've seen t date).
But it doesn't ever actually say that that's the max endurance of Gauntlet's missiles...

Emile's point is still good, though: it's the Erewhon _version_, not the Erewhon copy. IIRC, there's been more than one US weapon system that has shown significantly better performance once the IDF got done with it. It's pretty clear that the Mk14 could have been developed further, and no reason for the Erewhonese not to do so once they were frozen out of BuWeaps. Especially if they had a clear idea what the projected improvements were.

Also, don't forget that there are now Solly hands stirring the tech pot in Erewhon. That doesn't automatically make them better than the locals, but recall that a significant portion of the Manty tech edge has come from collecting tidbits from all over and putting them together. If someone that Barregos has put to work on this happens to have some suitable tidbits in her files, lights can go on and you get a 'you know, we can improve this by...'

Jonathan_S wrote:

Theemile wrote:If I remember correctly, WOH had a Manty ERM running at 210 seconds. Torch said that Erewhon was running with the ERM technology and advancing it while Manticore had stopped researching it in favor of Multi-drive tech.

I wouldn't take Erewhonese made ERMs and use that for a Manty baseline.

Well the Erewhonese ERM is stated to be their version of the Mantie Mk14 ERM; so there's some basis to guess they might have the same performance numbers.

But I've been through WoH in the last couple days and I couldn't find any mention of ERM drive endurance time.[1]

The only 3 ERM data points I found in it were:
* the CA HMS Ephraim Tudor fired on Andie CLs as they reached 15 million km. (No description of closure rate or other geometry)
* Those Andie CLs fired back as they reached 12 million km
* Hellbard and HMS Jessica Epps fought it out at no more than 10 million km.

But if I missed something I'd love if someone could point it out - I'd add it to my notes.

-----------
[1] I'm in the middle of resurveying the books to try and find all the missile data so I can clean up and release my spreadsheet - still have the 3 Torch books, the anthologies, and RFC's posts to search through. And I'm just doing keyword searches; not rereading everything - so some references might well be slipping through the cracks me.

Already found a things that slipped through editing though:
Like a couple spots a "KPS^2" was clearly supposed to be "gravities" or "g". (and one spot where just "KPS" was supposed to be "gravities")

Found that during 4th Yeltson RFC (presumably accidentally) gave Honor's GSN SD's ERMs - the numbers are for 90-ish seconds at full power. Oops.

RMN MDM's got slower during the ceasefire (which I'd noticed and mentioned before). AoV had them at 98,000 g but by WoH they were back down to 92,000 g

And SftS claims the export grade missiles in Monica's BC tubes were utter garbage - max range of 5,900,000 km - less that the CL Fearless had back during OBS. (if you backfit that range and the given terminal velocity you get a half power setting of about 37,577g). I haven't double checked the SoS description of the battle to see if that range works in the story.

Oops, sorry for the massive postscript digression.