Fuel/Cargo Containers from Deep Space Exploration book

[baithammer]

For warships, this is a really poor idea as you don't want to be the ship that can't respond to mission assignment/request. ( Besides this is what the auxiliary ships are for, also cheaper.)

For freighters, the 5% overhead on displacement is not a good trade off when looking at large scale activities. ( External cargo is often a better setup in this regard.)

For a small scale cargo/explorer, this is where the trade off makes sense.

 

[PsiTraveller]

Freight is the biggest winnner I agree.
I do think it scales and is profitable whenever a ship makes a jump less than its max rated jump. It's self evident. If a Jump 3 transport ship that needs 300 tons of fuel can add in 100 extra tons of cargo and make a Jump 2 then it makes 100 extra tons of cargo profit. This is enough to pay for the upgrade in a few jumps. This is all dependent on there being enough cargo to move.

And crossing rifts in Reft sector is a nice bonus as well.

 

[baithammer]

A jump 3 ship would only be rated as such if that distance and time are essential, otherwise your better off with a jump 1 design.

 

[RogerMc]

As external cargo has been mentioned I have something of an issue with this.

Jump nets are nets and anything you carry in them is not going to be exposed to not just vacuum but radiation, micro-mtteteorites etc.

Thus I can't see anyone just putting 200t of standard trade goods or freight in containers in a net and expecting it to arrive undamaged - so certainly not option for commercial vessels unless they are hauling something like rocks or ice that can't be damaged.

I'd probably rule myself that if you are going to carry normal cargoes you need to have container modules constructed to the standards of a starship hull - which raises the question of whether this additional tonnage counts towards the power point cost for basic ship systems.

And re re-purposing the existing fuel tanks to dual use seems problematic to me - these aren't nano-starships that can reconfigure themselves to make room for whatever odd or regular shaped cargo needs to be accommodated and fuel tanks are designed to make use of any odd corners of the ship as well as to be sealed off from the rest of it - so how do you even get the cargo in?

 

[baithammer]

Jump nets are only for cargo that can handle some knocks, like hull plating and the like from salvage.

There is also an actual external mount which is like a double wrap container. ( Outer shell with mount to hull and the standardized containers within it.)

 

[RogerMc]

Jump nets are only for cargo that can handle some knocks, like hull plating and the like from salvage.

There is also an actual external mount which is like a double wrap container. ( Outer shell with mount to hull and the standardized containers within it.)

CT Supp 9 has the Jump Ship which is indeed pictured with a netfull of rocks and specifies that anything else needs pods:

The jump ship is designed to provide maximum flexibility in interstellar transportation. As built, it is capable of jump-6 and 1-G.
Special field cables attached to the rear of the ship extend the ship's jump field to include this additional cargo. Alterations in displacement will affect the size of the jump itself, but the amount of cargo carried can be varied to fit the needs.

Capabilities: For each 1,000 tons of cargo carried in the mesh cables behind the ship, jump is decreased by one. Thus, if the 5,000-ton ship carries 1,000 tons behind it, it can only perform jump-5. If it carries 5,000 tons behind it, it can only perform jump-1. In all cases, the internal fuel tankage of the ship (3,300 tons) is sufficient to support the jump.

Jump Pods: The jump ship can transport valuable raw ores, planetoid chunks, and other materials directly in its jump mesh. Only durable goods can be carried in this manner because they are exposed directly to the vacuum of space.

To allow the transport of other materials, jump pods have been constructed on a variety of designs. Typically, each displaces 1,000 tons and can function independently of the jump ship. Some basic designs for jump pods include the following:

Cargo Pod: A bulk cargo carrier displacing 1,000 tons and carrying approximately 950 tons of cargo. Several varieties are available, including special liquid tankers, bulk food or grain carriers, and compartmented transport containers. MCr100.

Passenger Pod: A large pressurized hull with 225 staterooms, plus recreational facilities, safety compartmentalization, and fittings for comfort. MCr212.5.

Low Pod: Similar to a passenger pod, the low pod is fitted with 1900 low berths for carrying people or animals long distances. MCr195.

Additional types of pods are possible, and have probably been produced somewhere in the Imperium.

[end quote]

The cargo mount in HG is actually described as 'an external rack or framework' rather than a module that would provide any protection to cargo.

It does however save you needing a jump cargo net.

 

[AnotherDilbert]

External Cargo Mounts and Jump Nets have a similar function, but works differently. Any cargo is obviously not protected by the hull. Neither allows atmospheric landings (I believe), making them only attractive between major highports, unable to serve outposts, so unsuitable to Free Traders...

External Cargo Mounts is simply scaffolding to fasten cargo [containers] to the hull. If it sticks out too much it will not be included in the jump bubble and destroyed (I believe). "Too much" is defined by the Ref...

Jump Nets extend the jump field to include the cargo [containers,ore] (I believe), but does not firmly attach the cargo, making manoeuvring difficult. It is like carrying cans in a string bag.

I tend to use both at the same time, to both attach the cargo securely and extend the jump field.

 

[M J Dougherty]

These are essentially cargo holds with plumbing, and obviously need to be constructed in a way that allows cargo to be handled.

It's not really feasible to retrofit a bunch of odd-shaped fuel tanks to make them into extra cargo space.

The option is mainly useful for ships that may have to cross the occasional gap. For a vessel that is likely to remain within its normal jump capability, the extra expense and space lost is probably not worth it.

In a commercial sense, if you're going to put a jump-3 drive in a ship then it's only worth the expense if you use the 3-parsec capability on a fairly regular basis, in which case dedicated fuel tankage might well still be the best option. The intent with these tank/holds was to permit ships operating in a sparse region or intending to cross between mains from time to time to be able to do it and retain most of their cargo capability when making shorter trips. For a vessel operating within a main, the lost 5% cargo space is a lot of missed revenue during the lifetime of the ship.

So, I'd expect these units to be used aboard smaller vessels operating on a free trader/frontier basis, or by freighters intended for long runs with gaps to cross. Most commercial shipping will retain the standard model of dedicated cargo and fuel space because it is more cost-effective under normal circumstances.

 

[AnotherDilbert]

Warships don't _need_ the cargo space and the price of 1-2% of the hull (5% of 20 - 40% of the hull for fuel) in a tightly packed ship is high, but the added flexibility might make it worth it. We would have to make the ship slightly larger to fit the same firepower making them perhaps 3-6% more expensive. Investing GCr ~3 in a battleships would allow it to do the work of a GCr ~15 civilian-grade transport.

The Imperium only goes to war every century or so, and most often on one front at a time. Consequently most warships will be decommissioned without ever firing a shot.

Capital ships have very little to do in peacetime, unlike smaller ships. Having cargo space would allow them to handle part of the Navy's logistical need, and e.g. transport troops securely to any colonial police action, while still being fully battle-worthy.

Civilian grade freighters would of course be cheaper, but we have already paid for and are operating the warships, so transporting stuff on warships would allow the Navy to buy and operate fewer freighters, actually saving money. This of course assumes that we can mobilise enough civilian shipping in wartime.

A BatRon could easily carry a division or two with equipment and fighters for local space patrol into a warzone much safer than civilian grade transports that would need an escort anyway. This would obviate some need for assault carriers that, unlike freighters, are not cheap.

 

[baithammer]

Warships that aren't required but still viable are simply put into mothballs, using them as adhoc transports is simply too expensive.

Certain warships are already designed to perform policing actions but aren't particularly good at larger scale operations and trying to add extra specializations to a design simply makes them less efficient at each task then a specialist design.

Civilian ships during wartime can be pressed into service and the navy maintains its own transports to keep the fleets operational to begin with.

As to the safety of operating transport fleets, if a forward fleet needs to be reprovisioned and hasn't established control in their area of operation, then the fleet falls back to a controlled territory.

 

[Reynard]

Dromedary ships could make use of the F/C arrangement since they deal in carrying both fuel and resupply cargo.

 

[phavoc]

Warships don't _need_ the cargo space and the price of 1-2% of the hull (5% of 20 - 40% of the hull for fuel) in a tightly packed ship is high, but the added flexibility might make it worth it. We would have to make the ship slightly larger to fit the same firepower making them perhaps 3-6% more expensive. Investing GCr ~3 in a battleships would allow it to do the work of a GCr ~15 civilian-grade transport.

The Imperium only goes to war every century or so, and most often on one front at a time. Consequently most warships will be decommissioned without ever firing a shot.

Capital ships have very little to do in peacetime, unlike smaller ships. Having cargo space would allow them to handle part of the Navy's logistical need, and e.g. transport troops securely to any colonial police action, while still being fully battle-worthy.

Civilian grade freighters would of course be cheaper, but we have already paid for and are operating the warships, so transporting stuff on warships would allow the Navy to buy and operate fewer freighters, actually saving money. This of course assumes that we can mobilise enough civilian shipping in wartime.

A BatRon could easily carry a division or two with equipment and fighters for local space patrol into a warzone much safer than civilian grade transports that would need an escort anyway. This would obviate some need for assault carriers that, unlike freighters, are not cheap.

I cannot ever see a battleship ney cargo carrier. It is one of those things that sounds great on paper but would not see the light of day. Warships should always make horrible merchants because they are designed and built from the core out to wage war (and survive) war. Merchants are built as cheap as possible to maximize profits. The two types are at opposite ends of the scale.

Capital ships have the same actions in peactime as they do in wartime - except in peacetime the warfare is simulated. They will still need to train like they are going to war, and that means firing missiles and energy weapons, making jumps and full-speed maneuvers. Instead of enemy warships being their targets they will shoot at drones and rocks. That has always been the practice of well-run navies throughout history. Even when simulators are used units still have to shoot and scoot on a regular basis to train their crews and keep confidence in knowing they can fight if it comes to it.

Also, all that armor a warship, especially a battleship, would mount requires internal support structures. Hits on the outside of the hull would crumple the armor if it had no engineering behind it to dissipate the energy. Just look at the internal structure of armored warships built in the days of gunfire and you will see real-world examples of such.

Plus, what merchant leagues are going to sit back and allow military ships to steal their profits? The taxpaying merchants of the Imperium would scream bloody murder for letting the military take their profits away during peacetime. A 'combat' freighter would really just need speed and escorts - assuming it's very close to the front. Otherwise a large 50,000 ton freighter can easily out-gun smaller raiders in the few thousand ton range. And, with the new rules, they could install reaction drives and simply outrun their pursuers until they reached jump range. It's a silly ruleset, but hey, might as well use it.

These are essentially cargo holds with plumbing, and obviously need to be constructed in a way that allows cargo to be handled.

It's not really feasible to retrofit a bunch of odd-shaped fuel tanks to make them into extra cargo space.

The option is mainly useful for ships that may have to cross the occasional gap. For a vessel that is likely to remain within its normal jump capability, the extra expense and space lost is probably not worth it.

In a commercial sense, if you're going to put a jump-3 drive in a ship then it's only worth the expense if you use the 3-parsec capability on a fairly regular basis, in which case dedicated fuel tankage might well still be the best option. The intent with these tank/holds was to permit ships operating in a sparse region or intending to cross between mains from time to time to be able to do it and retain most of their cargo capability when making shorter trips. For a vessel operating within a main, the lost 5% cargo space is a lot of missed revenue during the lifetime of the ship.

So, I'd expect these units to be used aboard smaller vessels operating on a free trader/frontier basis, or by freighters intended for long runs with gaps to cross. Most commercial shipping will retain the standard model of dedicated cargo and fuel space because it is more cost-effective under normal circumstances.

The problem is that's not how the rule systems tend to get used. A hydrogen tank can be just about any form, but typically it's close to being a cylinder because that helps with the pressure and it drains better. A container version would need insulation, drains in the floor, and some way to pressurize/cool the system so the hydrogen remains in liquid format. And there'd need to be some valves to depressurize things before you popped open the doors.

If it's not a feasible design for most ships then it should be labeled as such, and there needs to be something in the rules that would outline the limited usage. Otherwise it gets used in min/max designs that players tend to make as opposed to the balance designs the core books tend to showcase.

 

[baithammer]

The problem is not understanding the 0.05 t per t of displacement penalty, which a small scale isn't much of an issue; But when you get to the point where cargo containers become a thing that 0.5t per t becomes a much bigger deal.

 

[PsiTraveller]

My thoughts on a few things.

Jump Nets: Items may not have to be a jumble of rocks. If your net is large enough the net might go around an entire ship to transport an SDB from one system to another.
Another option might be to have several cargo containers locked together into a rigid mass with connectors on the cargo containers corners for example, or even something like external cargo mounts the containers are fastened to. The entire item may be stationary and the Jump net attached at the Jump point so no towing of the mass through space is required. The containers the cargo is housed in could be built of something sturdy enough to handle the conditions in space. A container strong enough to handle the conditions of shipping is a basic need for freight.

External cargo mounts require the same sturdy container as Jump Nets if you want to ship something in one piece.

Gurps Far Trader has some good descriptions of various types of containers on pages 56-58

The Cargo crane description in HG on page 39 describes a cargo crane as being able to lift fully loaded 32 and 65 ton containers. So there are containers of at least two different sizes mentioned in HG.

Maybe the military is not the best option for the F/C containers, although I think AnotherDilbert's math is right in that converting a ship to carry cargo in peacetime could reduce the logistical needs of the military. I never thought of the Navy as trying to go into the freight business, that would be like an aircraft carrier covering the deck in cargo containers and delivering stuff to wal-mart. I always looked at the idea as a military ship moving all the equipment a modern military needs. Food, ammo, vehicles, uniforms and everything else a unit requires.
Then again I look at a lot of the designs from CT on and think that there has not been a lot of use of the rules for things like external cargo mounts, Drop Tanks, collapsible bladders and all the other tech that has been shown in various supplements, but not put into practice.

Holds as tanks. I always thought the F/C containers would be units brought onto the ship and plumbed into a piping system leading to the Power Plant, not actually the hold itself. If it is the hold itself I think the hold then becomes a series of side chambers with a door and a central corridor you can move down. It would have to be this way to allow you to divide the amount of fuel and cargo you get into different areas.

 

[Condottiere]

1. You don't need a jump net unless some of the volume is poking outside the jump bubble.

2. Fuel tanks have zero volume overhead, so there's no volume or cost penalty; making them multipurpose is free money.

3. I've often joked about the Terran Express; the Imperium probably doesn't feel the need to have this convertibility, the Confederation probably does, as the option of a fast massing of ground forces would be a very attractive capability.

4. As regards to health and safety, I couldn't say.

 

[baithammer]

converting a ship to carry cargo in peacetime could reduce the logistical needs of the military.

It doesn't as the ship by design is far more expensive to run than a large commercial vessel, further would have far less cargo to displacement. What you do with vessel that are still usable but too expensive to operate is to put it in orbit of a cold storage facility so that it cab be put back into service when needed.

 

[PsiTraveller]

You need a Jump net if you want to Jump something bigger than your cargo hold. This assumes you have the extra Jump capacity in terms of engine percentage.

2. Fuel tanks have zero volume overhead, so there's no volume or cost penalty; making them multipurpose is free money.

Hmmm, I would argue there is an ongoing cost to a fuel tank, 10 percent of the volume of the tank, times the distance travelled. That's the cost in fuel it takes to move that volume of ship. This cost is there if the tank is empty because it was just emptied to move the ship into Jump space, or if it was empty beforehand and fuel from a second tank was used to move the ship into Jump space. So this could cost between 100 and 500 Credits per ton for fuel. Plus whatever other costs for skimming and processing the fuel if you skimmed it yourself.

So if the tank space is empty it still has a cost to move it. That's why Drop Tank economics works nicely in several threads. Your cost of ship is lower because you are not paying for the volume of hull to hold the fuel tank, 50 000 Credits per ton, plus interest on your mortgage.

The ability to turn empty space into cargo space and make money from it is a big bonus. How big a bonus depends on how often a ship is jumping at a lower rate than design, and if there is cargo to fill the F/C container.

 

[PsiTraveller]

I have not run the numbers for a military ship so cannot comment about how much money it would cost. I agree it may not be the best for a military ship. I keep looking at the opportunity cost for moving material at lower Jump numbers. That is where your cargo ability happens. Maybe this is not something a military would do and the focus will be on exploration and smaller traders.

Trade routes would need to be examined to see where a j3 ship might end up with a J2 crossing and then be able to grab the extra cargo to earn extra income.

In Reft Sector for example a J3 ship would be able to use the J2 and J1 Main of Old Islands to take more cargo for the shorter trips. This offers a lot of opportunity for increased profit.

In a Sindal campaign a J3 ship could use a J1 or J2 route to take along extra cargo along the Hierate route, or the Florian route.

The 5 percent loss in capacity up front should be able to be overcome with income on the shorter legs of the journey.

 

[Condottiere]

You may need a net, but not one that's charged; speaking of which, since the jump drive is switched off, it would need a week long residual charge. You probably get a misjump if it failed before coming out of the rabbit hole.


Empiric Provost: FI-6334. Laid down 991. First flight 993. Declared surplus, weaponry removed, renamed Marie Luise and sold to Tukera Lines 1008.
Forward Starbow: FI-6394. Laid down 1000. First flight 1003. Declared surplus, weaponry removed, renamed Rimward Pride and sold to Tukera Lines 1021.
Sparkling Distress: FI-6379. Laid down 997. First flight 1000. Declared surplus in 1023. Intended to be disarmed, but transferred in irregular fashion while still armed to Oberlindes Lines and renamed Emissary (see Emissary Class Cruiser). Operated in Vargr Extents, based at Pandrin (Gvurrdon 0610). Attempted mutiny in 1105.

Probably retrofitted.

 

[baithammer]

The 5 percent loss in capacity up front should be able to be overcome with income on the shorter legs of the journey.

However, the drive itself needs to be taken in consideration.

Using a J3 ship to haul J2 ( 2.5% loss of displacement) or J1 ( 5% loss of displacement) isn't efficient usage.

As to drop tanks, the trade off for a long endurance ship isn't served very well by dumping a tank to jump. ( Smaller vessels have less of issue with this.)

You need a Jump net if you want to Jump something bigger than your cargo hold. This assumes you have the extra Jump capacity in terms of engine percentage.

External Cargo mount is the other solution if you don't require atmospheric capability.