How big was the die off of jumpships?

[Korzon77]

Because the thing is, Terra was mentioned as having had "billions" of people flee to other worlds in the years right after the Amaris civil war:

"Almost six billion Terrans chose to abandon their homes in the difficult years after the end of the civil war, seeking out new lives elsewhere in the Hegemony on worlds less ravaged by conflict Accomplished in under five years, this mass migration was one of the largest in human history and yet, because of the cataclysmic events that preceded and followed, it scarcely rates mention in the histories

If we assume they're loaded in Mammoths, the largest dropshiop that can land, and that each dropship can carry 6,000 people, when you account for life support, that means that you would need 10,000 mammoths to carry just sixty million--and 100 times that number of people were moved. Now granted, even if we assume that it took five years and had the best organization (unlikely given the time) that is still an unimaginable feat--Hanse DAvion had to nearly cripple his civil transport infrastructure for the fourth Succession War--and that was a conflict involving, at most, hundreds of thousands.

So what percentage of drop/jumpships were destroyed? 95 percent? 99 percent? more? 

I mean, that really brings home just how utterly devastating to the infrastructure of the Inner Sphere teh wars were.

[Dayton3]

The whole "billion" or even "hundreds of millions" of people leaving Earth for other planets (or the other way around) is a completely unrealistic science fiction trope that is present in virtually every major and minor science fiction franchise.    It isn't even possible with Star Trek level technology.

About the only science fiction franchise where that "might" be possible would be StarGate where you could have thousands upon thousands of people simply line up and march through an open StarGate to another planet at a time.

[Liam's Ghost]

There are early references to private individuals operating "thousands" of personally owned jumpships in the old days.

We also know that the campaigns of the Fourth Succession War put a serious strain on the Federated Suns' economy due to a lack of jumpships for civilian use, despite how relatively small the armies were and how short the war was. Similarly, the Draconis Combine was still recovering from the economic disruption of fighting the war of 3039 when the clans invaded.

Also, shipyards were so depleted that the rate of replacement amounted to something like a dozen new jumpships a year in 3025.

So upwards of 90% might be extremely generous.

[Tai Dai Cultist]

It doesn't follow that the problem necessarily involves the # of jumpships.  The problem posed in the OP is predicated on DropShips no bigger than Mammoths were used in population moving.  You can retrofit a Behemoth for quite a few more people, and use small/shuttlecraft to get people from surface to orbit/aboard the Behemoth(s).

And for that matter, there's no reason to say there wasn't some other kind of craft constructed to be used as single use "terraforming arks" that could have dwarfed the current-day largest DropShips. 

And you don't even have to limit postulation to hypothetical colony-establishment arks. Afterall it's canonical that JumpShips could transport minor celestial bodies via a handful of Jumpships jumping in precise formation.  Since you can transport a billion tons of ice that way, you just might be able to instead transport a billion tons of colony starter packs instead of ice.

[snewsom2997]

You also have to take into account that exodus took place over 500 years from 2300-2800.

I don't think lift capability 2300-2800 is an issue considering in the 3100's you still have Leviathan Jumpships and Drost Dropships still in circulation. They built the things to last, barring combat or misjump. Also with most words having a recharge station, with a slip or two, you have 1000's of slips just in the recharge stations alone, not counting the production facilities. During the SL Era, I'd expect those recharge station slips, to be supplemented, with additional slips, which during the SW wars would've been destroyed or stripped, just like Battlemechs.

As to the period between 2300 and 2800, you have unfettered jumpship and dropship production for 5 Centuries, and between 2450 and 2750 relative peace. I'd imagine, most Terran Hegemony worlds would have Shipyards capable of producing low dozens per year, and systems like Terra and Galax, could produce 100's if not 1000's of jumpships per year in their slips. I'd also Imagine dozens of worlds per House capable of producing a dozen + jumpships per year. You get to a SL peacetime production capability well into the thousands per year just in the Hegemony, and probably and equal number from the houses combined.

Once the SL left, and took 1,000's of Jumpships with them, in addition to the 500 or so warships. You would have seem a massive drop in Military Lift Capability. The 1st SW War was especially destructive, I'd imagine you have to expect to lose half your fleet until the gentlemen's agreement was finally implemented towards the end of the 2nd War. Pretty soon the houses would burn through their military fleets and start dragooning the civilian ships, hence the number of marginal worlds that drop off the map, since such a large number of civilian  jumpships were required for military operations. Even Comstar was noted as operating the largest Civillian Fleet in the IS post SL, along with having the majority of production capability. Wouldn't have even had to be conflict to destroy jumpships. Think of the amount of debris from Malograta or the Great Lee Turkey Shoot. Giant Balls of Multi Ton debris on Comet like orbits.

Finally Comstar running deathsquads for scientists would've had the biggest toll production. Once you start being unable to make slips, you are left stripping the slips you have for what you can no longer build. Which I expect was mostly software and electronics, not necessarily the Frame for the slip, the manipulators to move stuff around in the slip. Finally you have lost the people able to take a school book on physics and turn that into a KF-Drive/Interplanetary Drive, Even then I suspect it was an Electronics/Software deficit, not a germanium or titanium deficit. If the Jarnfolk can make jumpships, certainly a House can figure it out after Comstar opened Terra, and the Grey Death and Dallas Memory Cores started to spread.

Pre Succession Wars I see no limitation on Production or migration, During the SW's you have massive losses in knowledge, However post Succession Wars you have the Clans, Memory Cores, and compared to Sucession Wars Relative Peace until the FedCom Civil War and Jihad.

If the Sea Foxes really wanted to make money, they would stop selling Mad Cat IV's and Start selling Jumpships.

[cray]

If we assume they're loaded in Mammoths, the largest dropshiop that can land, and that each dropship can carry 6,000 people, when you account for life support, that means that you would need 10,000 mammoths to carry just sixty million--and 100 times that number of people were moved. Now granted, even if we assume that it took five years and had the best organization (unlikely given the time) that is still an unimaginable feat--

I think the proposed time scale is a bit small; 10 to 20 years might be reasonable for the following reasons.

The Hegemony's population probably broadly started realizing it backed the wrong horse c2774 when fighting had been in earnest for a few years. Like the late Succession Wars, the Star League Civil War involved a small number of troops relative to the population, and the losses (1 billion civilians) were also proportionally small on the scale of the Hegemony and, say, 20th Century Wars. Depending on how Amaris and Kerensky mucked with civil transport in the Hegemony, there was an opportunity for anti-Amaris Terrans to start "visiting their mother-in-laws in the colonies" before the end of the Civil War. So that's several years of possible, low-rate emigration.

Second, there was a good 10 years between Terra's liberation (and it got liberated good and hard) and the start of the Succession Wars. In this period, life on Terra started among the worst of the Hegemony planets because of its severe liberation. Further, it would be painfully clear to Terrans - the core, head, and heart of the Hegemony - that the Hegemony's recovery was mostly politely termed a dumpster fire (as discussed in Jihad Hotspots: Terra). That's ten good years to sour the morale of Terrans beyond just "hey, I'm living in rubble." You could expect emigration from Terra in earnest in this period, and the attitudes lead to point 3.

Third, the start of the Succession Wars was not a simple, "Rarg, let's plunder the Hegemony!" The Houses didn't launch invasions of the Hegemony in 2787 in a vacuum, so to speak. There were years of build-up where - among other causes for the Hegemony invasion - the Houses found some Hegemony planets begging to join them. The first shots of the First Succession didn't sweep the Hegemony from side to side at once; it started with conflicts on the House borders and scraps over disputed Hegemony planets. In short, this was not a situation where, in 2787, Terrans suddenly halted their emigration. Rather, it likely took some time before it was clear that the rest of the universe was a worse place than Terra. So, you've got at least part way into 2788 (when Operation Silver Shield kicked off) for Terrans to continue their emigration. After Silver Shield ended, ComStar was eager to show what a fair and enlightened group it was (e.g., offering free tickets home for troops that had opposed ComStar on Terra), so it's possible that emigration continued. As noted in the ComStar SB, it was actually into the 29th Century before ComStar focused on Terran reconstruction specifically to placate Terrans, so they didn't necessarily fall instantly in love with ComStar. Emigration was reasonable until the First Succession War got truly bloody (2790s).

Therefore, 10 to 20 years of emigration at varying levels is reasonable, IMO.

Using 6,000-person Mammoths completing 12 round trips to another planet per year, a given Mammoth can move 72,000 people per year. In 10 years, it can move 720,000 people. You'd need 8,333 Mammoths to move 6 billion in 10 years. Assuming the average JumpShip involved had 3 collars, you'd 2,778 JumpShips for the full 10 years. That would be about 1/7th to 1/8th of the estimated 3025-era JumpShip fleets. Big, but on the other hand in the 2300s at least one individual owned 1000 JumpShips.

But that's the conventional approach. Using the 1-month round trips suggested above, the Mammoths only need to carry passengers for 2 weeks at a time. The consumable tonnage required by infantry bays is manageable for 2 weeks. For a generous 10 tons of infantry bay and consumables, you can carry 28 Terran refugees; a Mammoth wouldn't be strained to carry 84,000 people. (That's by game rules. DropShips are roomy for their tonnage, but I'm trying to imagine 84,000 people in a 200-meter metal balloon.)

84,000 refugees per Mammoth cuts your DropShip count to 600 (or 2,400 Mules). That's looking a lot more manageable. 800 JumpShips and 2,400 Mules isn't too extreme for the 2780s.

It does, however, indicate how massive losses were in the Succession Wars. The Lyrans couldn't replicate the feat on a smaller scale for the El Diablo incident.

[Korzon77]

Yeah--IO was just thinking of this because I'm doing a littel AU where more people from the Hegemony fled to the Outlands Wastes instead of the surrounding worlds (point of divergence: inglesmond beats off the Dracs, but realizes that ultimately, they will be destroyed unless they get as many people as possible elsewhere), with the assistance of Terra and the soon to be Comstar (Because even though he couldn't reform the Hegemony, I can't see Blake refusing to help former citizens, so long as it doesn't endanger Terra), and I'm trying to get a feel for what the upper and lower level numbers might be.

[cray]

Getting to the Outland Wastes poses a problem of very long transit times. Viable transport numbers are more in the hundreds of millions than billions, which doesn't evacuate much of the Hegemony. On one hand, that does make the Outland Wastes a much more viable entity since they're suddenly receiving a (proportionally) overwhelming, unifying single demographic**, so they're not likely to end up a "Waste." On the other hand, that's not so much a story of the whole Hegemony evacuating there as a small group giving up on the Hegemony.

**In the 2700s, I doubt the future Wastes have a collective population over a billion. Rather, they're a lot of small industrial colonies.

[massey]

If there's a large market for people wanting to leave Earth, you're going to have jumpship owners responding to that demand.  You can make a lot of money transporting people who are desperate to get out of there.  I'd think that anybody looking to make a buck would flock to the Sol system.  Even if you wouldn't normally have that many jumpships available, if the money is right, they will come.

[Tyrchon]

You also need to take into consideration the destruction of the infrastructure that supported Jumpship travel.  I'm not talking just about the yards for building, servicing, and repair, but also all the space stations that provided refueling and recharging.  Losing the refueling and recharging stations means that Jumpship travel now takes longer since we don't really see Lithium-Fusion Battery equipped versions outside the SLDF.  Without the recharge stations especially, things become more difficult and you can see some ship captains deciding to risk hot-loading their jump cores multiple times in succession in order to meet the demands of transit time tables, which ultimately leads to more ships being lost to core meltdowns and mis-jumps.

With that infrastructure intact you could move a number of Jumpships a fair distance pretty quickly in comparison to the Jumpships relying solely on their own charging abilities.  The limitation then becomes one of capacity on Dropships.  Without it, however, things slow down to what we see prior to the Lithium-Fusion Battery refits being (re)introduced.

[Dayton3]

The battletechwiki at Sarna.net has as their figure that based on the number of inhabited planets in the BT universe and their likely transport needs that there are probably at least 30,000 jumpships active in the Inner Sphere rather than 3,000

And I thought the prohibition on attacking jumpships was part of the truce between the Federated Sun and Capellan Confederation that took effect in 2905 and lasted until 2930.    The jumpship prohibition spreading to the entire Inner Sphere and outlasting the truce.

At least that's what the original Federated Suns sourcebook says.

[cray]

The battletechwiki at Sarna.net has as their figure that based on the number of inhabited planets in the BT universe and their likely transport needs that there are probably at least 30,000 jumpships active in the Inner Sphere rather than 3,000

Yeah, I kind of hinted at the 30,000 number in StratOps just to give a slightly more useful number than the 3,000 suggested in...DropShips & JumpShips?

And I thought the prohibition on attacking jumpships was part of the truce between the Federated Sun and Capellan Confederation that took effect in 2905 and lasted until 2930.    The jumpship prohibition spreading to the entire Inner Sphere and outlasting the truce.

Yep.

[Kit deSummersville]

The Hyper Stellar Transport Vessel or simply JumpShip, also commonly known as the J-ship or simply Jumper, is an advanced man-made spacecraft that once roamed the star lanes of the Inner Sphere in massive herds. They became nearly extinct by a combination of warfare and piracy in the 28th century and the destruction of manufacturing and repair facilities, and have made a recent resurgence largely restricted to nations that took advantage of the Helm Core, such as the Free World's League or Federated Commonwealth. Their historical range roughly comprised a sphere, radiating between Terra and Erewhon in the Lyran's far periphery, rimward to the Periphery states of the Magistracy of Canopus and the Taurian Concordat, and spinward to the far border of the Outworld Alliance (nearly to the Outworld Wastes in some areas) from Raldamax to Valasha and per some sources out to Rim Collection.

[Tyrchon]

Yeah, I kind of hinted at the 30,000 number in StratOps just to give a slightly more useful number than the 3,000 suggested in...DropShips & JumpShips?

Yep.

Ah, good ol' FASA-nomics...being corrected regularly in the pursuit of a better Battletech.  Thanks, Cray!

[Dayton3]

Ah, good ol' FASA-nomics...being corrected regularly in the pursuit of a better Battletech.  Thanks, Cray!

In all fairness,   economics is a very common weakness in almost all science fiction franchises.    No surprise because most people don't understand todays economy anyway.

[Korzon77]

In all fairness,   economics is a very common weakness in almost all science fiction franchises.    No surprise because most people don't understand todays economy anyway.

And also, Btech in the beginning had a very different vibe. A cross between Mad Max and WH40K, as opposed to the modern concept where most "low tech" worlds are actually functioning at the (1980s view) 20th/21st century level.  In that universe, where a single lance was often able to conquer a world, 3000 Jump sips, while still tremendously low, wasn't as bad as it is today.

[skiltao]

Yeah, early FASA stuff makes different assumptions about planets and their needs.

Yeah, I kind of hinted at the 30,000 number in StratOps just to give a slightly more useful number than the 3,000 suggested in...DropShips & JumpShips?

Nah. DS&JS was 2000, it's MH3055 that's 3000.

Weirdly, I think that if enough recharge stations were available, the number of JumpShips, Mammoths and Behemoths described in DS&JS are just about capable of pulling off your ten-year emigration plan. Though even a couple decades may be too fast, considering that drop of six billion is the total difference between Terra's Star League level and its modern (3025) level.

So what percentage of drop/jumpships were destroyed? 95 percent? 99 percent? more?

Per House Steiner: The Lyran Commonwealth (fifth paragraph under "Terms of Exhaustion"), the Lyran "ability to build faster-than-light ships, even the simplest freighter, had been cut by 95 percent" by the end of 2821. That's only one state, and I'm sure the situation deteroriated further, but in general I think it's safe to assume Star League fleets were at least twenty times bigger.

There may be a way to use the average age of a ship in 3025 (DS&JS puts annual JumpShip turnover around 0.6% to 0.625%) to estimate production in 2750 (or whatever year you want), but since the ratio of production to fleet size won't hold constant, I'm not sure how to proceed.

[Liam's Ghost]

Oddball thought that might throw off estimates, the Belters have their own fleet of jumpships that probably wouldn't count to the inner sphere's totals, but could conceivably support emigration from Terra if the money was right. They use a lot of ships to quickly move around people and materials between their most far flung colonies, and they keep to themselves, so they generally aren't found further beyond the Inner Sphere.

How many ships might they have?

[cray]

Oddball thought that might throw off estimates, the Belters have their own fleet of jumpships that probably wouldn't count to the inner sphere's totals, but could conceivably support emigration from Terra if the money was right. They use a lot of ships to quickly move around people and materials between their most far flung colonies, and they keep to themselves, so they generally aren't found further beyond the Inner Sphere.

How many ships might they have?

My intent was "not many," a handful of ships or a few dozen at the most for making visits between the distant Oort colonies that see visits infrequently. Like, once or twice per year at a jump destination that could service a few Oort habitats willing to send DropShips on weeks-long journeys to a "bus stop." The far flung Kuiper and Oort colonies are not heavily populated like the main Belt, but rather more like independent Periphery colonies or Alaskan homesteads - introverted, and not requiring frequent visits.

[kato]

The whole "billion" or even "hundreds of millions" of people leaving Earth for other planets (or the other way around) is a completely unrealistic science fiction trope that is present in virtually every major and minor science fiction franchise.    It isn't even possible with Star Trek level technology.

Sure it's possible in Battletech. Relatively easy even.

The constraint is to move 6 billion people out of Terra to other planets in the Terran Hegemony. Not somewhere far out, but relatively nearby.

Five years means a weekly transfer of about 23 million people, with about 179 kg for an infantry bay spot plus 50 kg consumables per day of travel. The Terran Hegemony at the time enveloped a range of about 3 jumps out from Terra. That means we need to budget for two weeks (from jump point to jump point), with an overall estimate of 1 ton per person giving us plenty of room. We therefore only need to move 23 million tons out every week; since our jump ships cycle in a maximum 6-week run we need a cargo capacity of 138 million tons to be transported onboard jumpships.

The number of jumpships for the above distances can be further curtailed if we use waypoint stations along the routes for resupply and/or optimize routes for passenger-vs-supply exchange. In an optimized scenario it would be doable with around 100 Leviathans and perhaps around 5,000 dropships of Mammoth size. Which should be well within the "possibilities" of the Terran Hegemony.

[kato]

P.S.: There's also the real quick-and-dirty version if you want to keep jumpship numbers down.

Assume a hub-and-spoke system operating single jumps from Terra. Each spoke operates a single Monolith with nine Mammoths, loads up passengers at Terra and discharges them into the next in another system. We carry the passengers as cargo with five hours of consumables.

To move those 23 million people per week out from Terra requires only 18 (!) Monoliths and 162 Mammoths operating along nine spokes. Extending any single spoke one jump requires another two Monoliths and 18 Mammoths, with passengers transferring over for a Pony Express system.

For up/down mass within systems, chuck those 2.3 million people in each system into Behemoths with infantry bays to transfer them to orbit. The number of Behemoths is dependent on how long the transfer to orbit requires, and ranges between 18 and 36 Behemoths nominally, although for M-Class stars with 2-3 days distance this can be even further reduced to only 3 to 5 Behemoths (this is an atypical scenario, most systems within one jump of Terra are 5-7 days distance requiring 28-34 Behemoths). Once in orbit chuck them back into another nine Mammoths as cargo for transfer down to ground.

In an optimized scenario - single-jump out to M-Class systems - you can therefore transfer those 6 billion people in 5 years using only 18 Monoliths, 324 Mammoths and as little as 27 Behemoths. Plus whatever you need to get them to the jump points at Terra.