200 Ton Fast Courier - An X-boat Refit

[Patron Zero]

Mind be kind as this is a WIP and not all details sorted out, that said presenting a 200 Ton Fast Courier from the X-press Salvage shipyards.

The ship is comprised of a modified standard 100 Ton X-boat hull and the M-drive sections from a 300-400 Ton Gazelle Close Escort (CE) and the addition of an annular wing support section.

Major renovation is the powerplant and J-drive removed & relocated to the M-drive 'nacelles', the now available space refitted for a docking 'slip' for a 20 Ton Ship's Boat.

Fuel tankage has been a concern hence the addition of the annular wing, relocating fuel scoops and fuel processors to the 'leading edge' there

Anticipating 4G and J-2 performance, still number-crunching there but that's the target goal.

I'm seeing the 200 Ton FC as a merchant ship or bonded courier, perhaps a for-hire transport or 'charter' boat for those seeking a low-profile passage outside of standard venues.

Again, a rough design but in my opinion it looks promising.

 

[Whipsnade]

Absolutely love it! Please keep us updated on your progress.

 

[Patron Zero]

Thanks Whipsnade, will do.

The most recent bit I've done is to widen and lengthen the annular wing some, need more surface area for the connecting supports to join to as well as set the M-drive section 'inside' said cylinder.

Which led to the discovery of needing access between the upper hull (X-boat) and lower sections that include the M-drives, J-drive and powerplant as well as the Ship's Boat itself. Such was easily remedied by the addition of two vertical running additions to the hull, one housing a lift and the other a 'standard' 1.5M access shaft with integral hand and footholds.

Another thing that's cropped up has been the relatively small area that can be dedicated as a cargo hold, essentially only one (1) cargo container can fit there but more palleted or free-standing (but secured) freight could. This also brought up the issue of how to load said container or other items, either having a retractable hatch in the deck itself or a wide 'clam-shell' type door in the the hull itself.

Either have good-bad points but such said, the cargo bay could double as an EVA prep area or hanger for an air/raft, also locate a dedicated boarding-docking airlock point there for ease of passengers or access of rescuers should an emergency occur.

Lastly (for now), could the area the Ship's Boat consumes be re-allocated for other uses ? Perhaps 'docking' a 20 Ton module in the 'slip' for purposes of additional fuel or cargo if not 'palleting' cargo containers in the now-available space directly.

As said, a definite WIP.

http://www.TravellerRPG.com/CotI/Gallery/index.php?n=1561

 

[shield]

Just done some number crunching on performance

A J4 drive in the xboat is 5% of the ship = 5tns.
To keep within the JD% in high guard
200tn ship is J1
166tn Ship is J2
125tn ship is J3

The xboat power plant gives PP2 for a 200tn hull

The M5 drives from a gazelle are designe dfor a 300tn ship.
They will easily give M6 on a 200tn hull if you are going by straight tonnage of drive / % of ship displacement. They will be limited in performance by the power plant.

So your 200tn conversion is probably J1, PP2, M2

 

[Selandia]

leaving all number crunching aside, I work with a similar idea for a Pocket Empire early Xboat, a Pony Express type courrier. Instead of beaming data to waiting Xboat (and the planet or bases), you send the launch to dock with the waiting Xboat. The Launch is the precious cargo for it contain the datacore,the Mail vault and may be one courrier (beside the pilot).

Would work great for private courrier.

have fun

Selandia

 

[Patron Zero]

Just done some number crunching on performance .....So your 200tn conversion is probably J1, PP2, M2

Thank you for the specs, the number-crunching bit is were my Kung Fu is somewhat weak.

I'm looking at doing the refit off a retired X-boat hull, not specifically making use of the 'stock' drives or powerplant as such have likely been removed before being mothballed.

I'd say it's a fair assumption the M-drive sections (let's not say nacelles) obtained from a Gazelle CE have also been likewise 'deboned' allowing for non-original components to be refitted under the covenant of the space available agreeing.

That said, the Acinonyx Class ships are essentially hot rods, classic body with a souped-up chassis beneath. A VW Beetle with a Hemi !

 

[Ran Targas]

Very cool concept!

 

[Carlobrand]

You've chosen a challenging pair of ships from which to construct a hybrid.

The classic X-boat's a holdover from an earlier incarnation of Book-2 in which the jump drive didn't need a separate power plant. Thus, the Supplement-7 description of it having no power plant: power for ship's life support and electrical systems was drawn from the jump drive.

The Gazelle is a difficult design to extrapolate parts from 'cause it occurs in Traders and Gunboats but can't really use the usual Book-2 rules that most of those ships use (no rules for armor, no rules for a Factor-7 power plant). As drawn in Supplement 7, the outboard drive pods appear to house only the maneuver drives; the power plant and jump drives are in the rear third of the main hull. The maneuver drive under Book-5 would be 14% or 42 dTons, leaving 58 dTons to come from some other addition if your hybrid is to come in at 200 dTons.

However, the Gazelle drive pods putout way more drive than a 200 dTon ship can handle. A Gazelle's drive pods put out 5G in the 300 dTon configuration. That gets your hybrid up to 7.5 Gs, which is well beyond what the hybrid can manage or what you want. Still, the drive pod configuration is a cool idea; nothing says we can't put smaller maneuver drives in the pods and then fill the extra space with power plants, jump drives and such.

Let's see what we have.

X-boat:
Bridge: 20dT
Computer, M.4: 4dT, 2ep
Maneuver: none
Jump-4: a 15-dT Book-2 Jump-B
Power plant: none (by canon)
Fuel: 40dT
Weapons: none
Crew: 2 4dT staterooms
Cargo: 1dT plus "massive communicators and message data banks."
Craft: none
Total: 20+4+15+40+8+1=88 plus a suspected 12 dT in data banks

There are alternates to make it fit book-2, or we could invent an Xboat design under book-5, but we don't need those details for this effort. Suffice to say that after pulling the drives out we have a bridge, computer, and a couple of staterooms, same under either Book-2 or Book 5. 32 dT is spoken for, with 68 dT remaining for fuel and other uses.

Now we add the Gazelle drive pods and a mating ring, totalling another 100 dTons to bring the hybrid up to 200 dT. Gazelle drives are too powerful, but the pods can house smaller maneuver drives as well as the jump and power plant.

Let's say we stick to Jump-2, either keep the 15dT Book-2 jump drive or switch to a 6 dT high-efficiency Book-5 jump drive, plus 40 dTons fuel for the jump: 46-55 dTons.

Let's aim for a 4G maneuver drive backed by a Power Plant-4. Under Book-2, that's a Maneuver D, PP-D, 20 dT plus 40 dT fuel; total 60 dT. Under Book-5, that's a 11%/22 dT drive, a 16 dT plant (TL13-14) and 8 dT power plant fuel; total 46 dT fuel.

Book-5 has obvious advantages: for drives and fuel, 92 dTons from Book-5 verses 115 dTons from Book-2. Book 5 leaves 76 dTons for the launch (a ship's boat classically is 30 dT, not 20) and cargo, with all drives and fuel fitting in the drive pods and ring (with 8 dT to spare) - and you can gain another 8 dT if you argue for using a TL15 power plant instead of a salvage job. Book 2 leaves 53 dTons; 15 dT needs to be taken out of the X-boat hull, probably fuel since you're planning on putting a launch where the X-boat's drives used to be.

 

[Patron Zero]

You've chosen a challenging pair of ships from which to construct a hybrid.....

Wow, thanks for all the specifications, Carlobrand, again I bow to those with better skills than I.

Yes, I was looking at installing more efficient-higher performance components for the drives to improve the ship's abilities and potential. The 'classic' X-boat hull and pods from a Gazelle were drawn from what I image to be found in abundance from retired-upgraded fleets scattered about the Imperium.

4G still is a decent bit of speed, I'd prefer a J3 but if the numbers aren't agreeing some things you just end up accepting and be happy the wheels stay on otherwise.

For those following this thread I should have updated sketches uploaded soon, trying to tackle the interior layout and resolve that pesky issue with the limited space of the cargo bay.

My thanks out to mirc for his input and suggestions offboard, he should be credited with the concept of the 'slip' for the ship's boat-launch. All the support and encouragement from all around is genuinely appreciated.

 

[Carlobrand]

I had an odd thought:

Do you recall Annic Nova? What if you merged an X-boat with a pair of 50 ton cutters? The cutters, with their bridges slaved to the X-boat bridge, would serve as the merged ship's maneuver drive. The merge would require very little alteration, therefore be very cheap to perform: find a way to mate the cutters to the x-boat so that the two could maneuver and jump as a single unit. Your mating ring, a simple addition to the existing X-boat, accomplishes that. As with Annic Nova, the cutters could be undocked and docked as needed. About the only significant change might be to pull out and sell off that very nice 30-million credit Model-4 and replace it with a cheaper 9-million credit Model-2.

The merged unit functions as a 200 dT ship with jump-2 and 2G acceleration, 60 tons cargo capacity via two interchangeable cutter modules (and 6 additional tons of excess space: 2.5 on each cutter, 1 on the X-boat per canon). Crew is 2, living in the X-boat's pair of staterooms. Use of the cutter modules gives it flexibility: it can be configured for cargo or passenger transport or mixed service, using either cargo or stateroom modules; the cutter passenger module would contain 7 4dT passenger rooms plus a 2 dT cabin for a steward. The mating ring serves primarily as a passageway between the airlocks of the three ships, a ring just below the widest portion of the X-boat, with a tube running up to the X-boat's airlock.

It wouldn't be able to maneuver with one cutter off on an errand, but it is intended as a cheap salvage job, perhaps a cargo transport thrown together to serve some small out-of-the-way mining colony that can't afford a proper subsidized liner for their transport needs, so a few quirks are to be expected.

Price is tricky. A free trader costs MCr37 new. If the hybrid comes in anywhere close to that, it makes more sense to buy a free trader - but an X-boat costs MCr 70 new and isn't likely to cost less than half of that as a functioning retiree. Same for the pair of MCr28 cutters (grossly overpriced, IMO, but it is the price dictated by the game). Selling off the old computer saves a few million, but it is an old computer so you can't get full price for that. Perhaps there's some special program where the Imperium constructs these from retired x-boats and navy cutters, then sells the hybrid at a low price to small colonies in order to foster colonization and economic growth.

 

[Patron Zero]

Clever idea Carlobrand, that's the sort of resourcefulness I think is often overlooked in general with ship designs in Traveller, a few exceptions about but not many.

I think one only has to look at how circumstance and situation has brought about often unconventional solutions to such needs, specifically to site how real world inventiveness is applied to keeping vehicles operating in countries with a less-than available parts-service facility being down the street as we most enjoy.

Mind not to sound like a Nationalist but I refer to such as Yankee Ingenuity.

 

[Selandia]

The same way that there are jump shuttles for SDB and other non jump ship there can be "maneuver tug" for Jump only ships.

I use commercial versions of the military Tender/Rider combination in liner service (Merchant Prince). The expensive Jump Tug with expensive J drive is not used to run to the planet. It jump in, Maneuver Tugs pick the inbound cargo pods and fit the outbound (nice choregraphy there), the Jump Tug get refueled and as soon as J Drive get cleared for jump, here it goes back.

Tandem of jump/non jump ships have aplenty of fun options

have fun

Selandia

 

[Patron Zero]

Update- The ships slowly evolves towards completion.

Relocation of cargo deck to provide larger volume of freight to be carried, also allows for said space to be refit for additional passenger accommodations if vessel is operated as subsidized transport or charter service.

In cargo configuration deck can also be used for EVA and hanger for air/raft(s) or container mover ('Jeep'). Potential location for deployable docking arm for ship-to-ship or hard-dock crew transfers.

Also redesign of ship's boat to better fit docking area available. Potential for payload of two (2) standard cargo containers in place of passengers.

Overall revisions offer flexibility to operate as dedicated transport-charter vessel or mixed passenger-freight hauler.

 

[Patron Zero]

Let me blow the virtual dust off this thread and my apologies for letting the ship in development be so neglected.

Update: A new idea I've been tinkering with concerning the Acinonyx Class Fast Courier and it's docking 'slip' for a Ship's Boat might be making use of that feature for other purposes.

Since the Ship's Boat has an established displacement-tonnage I wondered why could not an equal-equivalent 'hull' be allowed to be carried by the vessel in lieu of said small craft.

This then lead to the concept of a specially designed and manufactured transport pod that could be utilized to uprate the amount of cargo by the Fast Courier without need for further modification or expense.

Mind the transport pod would offer the potential for 'bonded' shipments to be managed without question of integrity or 'damage' potentially incurred by standard cargo containers. Aside from moving freight in said pods there also exists the option of such being modules acting as 'Airstream' trailers for discrete and extremely low-profile travelers.