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The Scouts' Version of the A2

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Starting here with an outline, or rather, a concept. I might not go any farther with it, and perhaps don't need to.

The specs of the A2 Far Trader ('81 compliant; that is, pretty much the J2/2G version in Adventure 3) look a lot like what I figure the default IISS requirements ought to be for a semi-expendable 200Td ship. Out-of-universe, it's sized to fit the largest practical player character party -- while you could fit 8 PCs into a Type S, they aren't going to be happy living in it for weeks or months at a time. In-universe, the Scouts will have a need for a ship that can support light but extended survey missions, or transport personnel, or carry replacement drive units to stranded XBoats (and if necessary, lash that XBoat to the hull and drag it to a repair base one parsec at a time).

So, an ordinary A2 would work. But that's too easy!

Key features include the least expensive streamlined hull (stretched sphere from LBB5), and the use of drives already used in other IISS vessels for easier logistics. Those drives include a standard modular drive package for an XBoat (Jump B and Power Plant B -- but unlike in the XBoat, there will be maintenance access from within the ship) and two Size A Maneuver Drives from the Type S Scout/Courier (which somehow take up 3Td instead of 2 because in game terms they're a Maneuver Drive B -- don't think about it too hard, ok?) It may have additional fuel to enable a third parsec of range (1J2+1J1) to parallel the capabilities of the Type S (if the Type S stretches the TCS/JTAS #14 power-down rule to allow weekly increments). I haven't decided on that yet; it's really an out-of-universe excuse to reduce the ship's cargo capacity to make it more amenable to Detached Duty Scout campaigns than Merchant ones.

I've already done up the Type S as a prolate spheroid tailsitter, and this is going to be similar. It'll also serve as a set of plans for an ordinary A2 if you want one in that configuration (just skip the setting fluff about it having two Size A Maneuver Drives instead of a Size B one, and delete the extra 20Td of fuel if my final design includes it), and the hull shape/size could also be used for a Type A Free Trader with some minor drive-bay tweaking and reshuffling of the interior spaces.

This is a work not quite yet in progress. :)
 
Ok, I've got the explanation for "Two Size A Maneuver Drives taking up 3Td because the rules say they're a Size B drive". The XBoat drives don't include the energy output systems that would be used to power a maneuver drive, since XBoats don't have maneuver drives. The extra 1Td is therefore an adapter to get the energy from the power plant to the maneuver drives.

Yeah, it's just setting fluff.

Note that this assumes XBoats are an LBB2'81 version that has a power plant B and 10-12Td power plant fuel*, and only a very small message data bank.

-------------------
* House rule: 10Td of power plant fuel should be enough for the week spent in Jump (1/4 of the 40-ton, 4 week requirement). If an allowance needs to be made to deal with the possibility that the jump can take 10% longer than normal (it's 168 hrs +/- 10%), then that's 11Td fuel. If it needs full power plant fuel burn to power the XBoat while it waits for the XBoat Tender to arrive -- which seems like overkill to me, but whatever -- then make it the whole 12Td. In any case, there's still the other 40Td of Jump fuel for a total of 50-52Td capacity. Pilot gets a half-stateroom, and in the worst case the message data banks can come out of bridge tonnage.
 
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Overthinking- the A2 as us would need that cargo space for carrying multiple vehicles and a base camp with lab. Or small craft for more astrographic missions.

Or give it a J3 capability. And/or offline B power plant/drive for redundancy, no fuel use unless brought online.

Came up with an interesting idea at least to me. The Corsair was originally a scout support/LR dangerous frontier ship.

The 100 tons of ship it can carry bay is in the shape of a classic Type S wedge- it can recover whole/disabled ships. That’s why the extra wide bay doors.

Has enough guns to be self sufficient without being a top end gunship.
 
Size A Maneuver Drives from the Type S Scout/Courier (which somehow take up 3Td instead of 2 because in game terms they're a Maneuver Drive B
I bump up the A maneuver drive to 3 tons to get rid of that little hiccup leftover from the '77 edition...
 
I bump up the A maneuver drive to 3 tons to get rid of that little hiccup leftover from the '77 edition...
Not a bad idea. It's not a hiccup, though -- they meant to do that. It's just that the table "really" begins at 200Td, and the 100Td row is mostly just there to show what happens when you stuff a proportionately huge drive into the smallest hull it works with. (You get the Type S, the XBoat, a so-so 2G non-starship, a less-practical 4G non-starship, and a pointless 6G non-starship -- that's what.)
 
The 100 tons of ship it can carry bay is in the shape of a classic Type S wedge- it can recover whole/disabled ships. That’s why the extra wide bay doors.
Problem is that big craft (100+ tons) require 110% of their tonnage to be carried internally. (LBB5.80, p32)
So you need a 110 ton hangar pay to stow a 100 ton scout/courier in.
 
Not a bad idea. It's not a hiccup, though -- they meant to do that. It's just that the table "really" begins at 200Td, and the 100Td row is mostly just there to show what happens when you stuff a proportionately huge drive into the smallest hull it works with. (You get the Type S, the XBoat, a so-so 2G non-starship, a less-practical 4G non-starship, and a pointless 6G non-starship -- that's what.)
Actually it's the fall out of the Manuver and Power slice in the '77 edition being 5 tons smaller than the jump drive.
 
Interesting way to view it.

I figured it was to give m-drives a unique formula -- the other two drives have a positive constant-value component, so m-drives get a negative one just to be different.

That, and it's a block with a hole in it that gets bolted onto the power plant exhaust...
 
Reminds me that I really ought to get back to my Play-by-Post, if only to do more interior scenes in that Patrol Cruiser.
Wi4JoMA.gif
 
Well.

I've figured out how to scale up the Sulieman Type S to 200Td nominal (multiply its dimensions by the cube root of 2 -- thanks, square-cube law!) for my Type ST (J4/2G) design, at least a rude attempt at it anyhow. It's not actually 200Td -- the original was about 85Td so the upscaling brings it to about 170-ish. But the principle is sound, and can be tweaked to hit a arbitrary volume.

The next thing is to try to reconcile my technobabble (it uses XBoat drives, in part) with the pie-slice Type S layout. The drive bay will look weird, at least.

Here's the 200Td scaled-up scoutship, just for the basic hull shape (it's pretty much just splicing in an extra few deck squares of length --the back end is where all the volume is on this shape):
Cropped ST jpg.jpg

The next step is to reverse-engineer the canon XBoat (the IMTU house-ruled LBB2'81 version) enough to figure out the dimensions of its drive bay. It's necessarily a conic section of some sort, but I need to figure out what angle the cone needs to have so I can work out what shape the drives are.
 
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Ok, here's the one from S7: Traders and Gunboats

Screenshot 2023-08-08 at 08-50-48 Classic Traveller - S07 - Traders and Gunboats.pdf.png
I can probably use that cone as-is, perhaps grabbing a bit more space on the big end of it for the power plant that this one doesn't have because it's a '77 design. Stuff in the maneuver drive (or drives, since my technobabble says it's a pair of Size A maneuver drives with an adapter that brings them up to the 3Td of a Size B maneuver drive).

So, it's a 9m diameter cylinder or so, once you add the access passages around the edges. Well, not quite, but that's where I'll start.

But I really ought to do the math to figure out how much volume it's actually drawn as having.

From a bmp file taken from a screenshot of the book (so the measurements won't actually match the original dimensions in the book, but they're internally consistent):
[THIS IS A WORK IN PROGRESS]

.22" = 1.5m. (from the scale square above the map key)

Top section is 1.24" diameter, 0.62" radius
Bottom section is 0.28" diameter, 0.14" radius.
Height is 1.5"

V = 1/3 × πh(R^2 + Rr + r^2)
where R is the radius of the large end slice, and r is that of the small end slice.

I was going to approximate by taking the average of the areas of the top and bottom slices, then multiplying that by the height. Might even resolve to the same equation, but there it is. I'll get to the math in a subsequent post since I'm headed out on errands and the edit window will expire.
 
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Ok, scaling math:
.22" = 1.5m. (from the scale square above the map key)
0.147"=1m.
Top section is 1.24" diameter, 0.62" radius
Bottom section is 0.28" diameter, 0.14" radius.
Height is 1.5"
R is 4.2m
r is 0.95m
h is 10.2m

⇒ V = 1/3 × πh(R^2 + Rr + r^2)
V=1/3 x pi x 10.2 x (4.2^2 + 4.2 x 0.95 + 0.95^2)
V=10.68 x (17.64 + 3.99 + 9.025)
V=10.68x30.655
V= 327.4
V is in m^3, so it's 24.24Td nominal. Wait, what? Even if it's from '81 (and it's not, it should be '77 with all the extra room on the plans), the drive bay only needs to be 22Td (Jump-B @15Td, Power-B @7Td). I'll take it though, mostly.
 
Still, it would fit better in a tailsitter prolate spheroid (US football) than a pie-slice wedge.

I did say this is a work in progress...
 
Interesting way to view it.

I figured it was to give m-drives a unique formula -- the other two drives have a positive constant-value component, so m-drives get a negative one just to be different.

That, and it's a block with a hole in it that gets bolted onto the power plant exhaust...
If you look at the simplified mathematics set that CT uses. And consider that when CT was written scientific calculators weren't all that common. With that laying out the the numbers as presented the train of thought pretty much falls out in a mathematical sense.

Counting by 5s is pretty much a reflexive action from grade school on, so why use anything more complex?
 
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