Yet, more on Container ships...

[infojunky]

In my copious amount of free time I have been looking at Container ships...

The most common Container Ship is the Feeder size ships, generally they carry under 1,000 TEUs. But they can service almost any port. In traveller terms a 1,000 TEU capacity ship is in ballpark of 5,000 to 10,000 dTons. And would be streamlined. Please note the 1,000 TEU is that around the max for ships that fall into this class, with around 500 being not an uncommon number. With that Traveller ships sizes from Book2 aren't unreasonable.

Also another thing to consider when looking at real world container ships half or more of their Capacity for TEUs is carried above the Hatches, i.e. external cargo. My only issue with that containers built to Jump conditions will trend towards the price of similarly sized smallcraft hulls.

Now none of the above precludes the truly huge container ships, it just emphasizes that they are on limited Large Volume runs.

 

[Spinward Flow]

Note that a (Solomani) standard TEU as cited by @infojunky measures in at being 2.75 tons of displacement (effectively) per TEU.

TEU Wikipedia LINK
6.1m long x 2.44m wide x 2.59m high
38.55m³ / 14 = 2.75 displacement tons (external size)
33.2m³ / 14 = 2.37 displacement tons (internal capacity)

Thus, for many practical purposes, a 1000 TEU capacity starship would be dedicating 2750 tons towards cargo transport capacity (internally and/or externally), if you want to talk about similar scales for the transport of goods.

The fun thing is, when it comes to containerized transport by starships at these kinds of scales, there's actually something of an "incentive" to bulk up the external loading capacity of a starship IF the containerized cargo modules themselves are built to starship hull standards (MCr0.1 per ton, baseline) (MCr0.06 per ton, Configuration: 4, Close Structure) and adding on external docking capacity (2.75*6=16.5*2000=MCr0.033) in order to link with other TEUs in all 6 directions. The reason being is that doing so means that the starship "proper" can be smaller, reducing the cost of starship hull expenses and you wind up with more of a Maneuver/Jump Tug arrangement that is cheaper for the starship operator to buy and maintain ... you just need to "overpower the drives" to allow yourself sufficient towing capacity when docked with (significant) external loads.



To give an example of the kind of thing I'm talking about here, you would use the same LBB2 standard "letter" drives whether you're looking at building a 1000 ton starship with a 3000 ton external load capacity (combined 4000 tons) or a 4000 ton starship with a 3000 ton internal load capacity. Either way, you're building for a 3000 ton load capacity and you're using the "same drives" to achieve the same performance either way ... so those design factors are basically a wash in the analysis of alternatives.

However ... the 1000 ton starship would be built with a smaller hull (MCr100 base, before configuration/streamlining) while the 4000 ton starship would require a much larger hull (MCr400 base, before configuration/streamlining), which is a differential of MCr300 for the "privilege" of internal vs external cargo capacity just for hull metal alone. At Cr2000 per ton of external towing capacity, 3000 tons of external docked load capacity would cost a mere MCr6.

Net benefit: MCr294 cost advantage to external loading

Additionally, starships over 1000 tons require more crew (LBB2 rules stipulate 10 crew per 1000 tons for craft over 1000 tons).
1000 ton starship = 10 crew
4000 ton starship = 40 crew
That's going to make a tremendous difference in crew salaries and life support overhead costs!

My point being that for "bulk containerized transports" you're looking at a pretty serious economic incentive pointing towards the (overpowered) Tug and (unpowered) Barge model as being the cheaper way to go from an economics standpoint.

Mind you, those 3000 tons of external load capacity would only be able to accommodate up to 2307.69 tons of external loading (because of the 130% tonnage rule for small craft when exceeding 1000 combined tons) within the 3000 tons of external capacity, due to the "inefficiencies of small craft" factor ... but overall the point still stands. The external loading "tug and barge" arrangement would be cheaper to build, maintain and operate than the internal loading "cargo bay cavern" alternative, per RAW.

839 TEU @ 2.75 tons each = 2307.25 tons external load on 3000 tons external capacity (max limit)
1090 TEU @ 2.75 tons each = 2997.5 tons internal load in 3000 tons internal capacity (max limit)

So the internal loading ship would cost more (build, maintenance, overhead) ... but also carry more, per jump (about 690 tons more in this example) ... so depending on the route and markets being serviced, that may or may not be an additional expense worth paying for.

However, in order to know for sure, you'd need to build out the rest of the ship details and specifications so as to be able to run an economic analysis to determine if the marginal cost of an increase in cargo capacity in the range of ~690 tons per jump can "solve the revenue problem" by that old merchant's maxim ... we make it up in volume.

 

[giant.robot]

The J-drive tug can also disconnect from the "barge" which can be hauled in-system by a dedicated M-drive tug. IIRC an M-drive tug could pull multiple "barges" around.

 

[infojunky]

Note that a (Solomani) standard TEU as cited by @infojunky measures in at being 2.75 tons of displacement (effectively) per TEU.

Yes, but the standard container is 3.85 dTons in Traveller. As per the writeup for the March Harrier.

I of course rounded to 4 dTons. Note do my best to keep things in Traveller Terms.

To give an example of the kind of thing I'm talking about here, you would use the same LBB2 standard "letter" drives whether you're looking at building a 1000 ton starship with a 3000 ton external load capacity (combined 4000 tons) or a 4000 ton starship with a 3000 ton internal load capacity. Either way, you're building for a 3000 ton load capacity and you're using the "same drives" to achieve the same performance either way ... so those design factors are basically a wash in the analysis of alternatives.

But you miss the that Drives are usually the biggest cost in a ship. What you "save" on hull you lose on increased drives for a desired level of preformance.

Additionally, starships over 1000 tons require more crew (LBB2 rules stipulate 10 crew per 1000 tons for craft over 1000 tons).
1000 ton starship = 10 crew
4000 ton starship = 40 crew
That's going to make a tremendous difference in crew salaries and life support overhead costs!

While I didn't cost out crew salary requirements, they still are inconsequential when compared to issues...

But what I was pointing out is that the 2000 to 5000 dton ships have a solid place within the overall discussion.

 

[Spinward Flow]

But what I was pointing out is that the 2000 to 5000 dton ships have a solid place within the overall discussion.

THAT has never really been a point of contention. The larger "feeder line" cargo transports just work different routes and markets from the ones that the tramp traders dealing in the "spot market" do (which is what is detailed in LBB2).

The bulk transport carriers have to work pre-planned routes that they are "bound" to. They can't go wandering off on adventures on a whim. As such, the larger 2-5k starships are hardly ACS ... Adventure Class Starships ... simply because they're too big/too valuable to divert away from their scheduled runs along predictable routes. They simply operate "by different rules" than the small time penny ante tramp free traders do.

 

[TamsinP]

Actually, with the exception of the smallest container ships, the majority of containers are carried in holds below deck. There are two main reasons for this

1) Stability of the vessel - stacking above deck increases the side profile that can be acted on by cross-winds (as happened with the Ever Given); it also raises the centre of mass, making the ship more susceptible to effects of rolling.

2) Security of the load - you can only securely lash a few tiers of containers above deck; the ones above that are relying solely on the twist locks at each corner joining them to the container underneath. You can add more on-deck containers by moving the accommodation block (and navigation bridge) forward allowing the stacks behind to go to maximum height (the stacks ahead of the bridge have to drop in height to allow clear viewing lines to the bow). For the very largest container ships, the 24,000 TEU mob, with maximised above-deck stowage capacity the ratio is about 52% below deck to 48% above deck assuming a theoretical 11 tonne TEU - the average actual weight/TEU is higher, so the true ratio skews to a higher percentage below deck.

With regard to the proportion of container ships that are "feeders", looking at the Equasis Word Fleet Statistics for 2020 (2021 is available and is fine for cargo ships, but weird for some of the others - passenger ships in particular; 2022 isn't available yet) we get the following:

Small (100-499 GT) - 20 ships; 8.000 GT; Ave 400 GT (= 112 dTon)
Medium (500-24,999 GT) - 2,258 ships; 26,276,000 GT; Ave 11,637 GT (= 3,001 dTon)
Large (25,000-59,999 GT) - 1605 ships; 60,063,000 GT; Ave 37,422 GT (= 9,183 dTon)
Very Large (60,000+ GT) - 1507 ships; 169,924,000 GT; Ave 112,757 GT (= 26,841 dTon)

* I've used 1 dTon = 13.5 m3

Unfortunately, the Equasis stats don't include the TEU capacity data for container ships. However, looking at data I've collected from various second-hand ship sale sites, listings for Maersk's ships, etc. the feeder container ships will fall into the "small" and lower end of the "medium" categories. The largest second-hand ship I found was 601 TEU and 7004 GT (= 1803 dTon). I've done a rough extrapolation from the (limited) data set I have and get the following formula:

TEU = (0.08*GT)+66

Plugging in your 1000 TEU capacity, we get a GT of 11,675 which converts to 2961 dTon; 2000 TEU would come out as 24,175 GT (= 6006 dTon); 3000 TEU comes out as 36,675 GT (= 9005 dTon).

One issue is that GT would only include containers stores in the holds and not those carried on deck. That being said, in space where centre of mass and rolling aren't issues there is no limit (other than drive capacity) to how many containers can be carried externally.

When it comes to designing container ships for Traveller, I would tend towards making them fully internal stowage. Who wants to pay MCr 0.5 for a starship-hull grade 5 dTon container to transport goods that may only be worth Cr 50k? Yes, it can be re-used, but what if you don't see it again? No, people will go for cheap containers worth much less than the goods that will be shipped in them.

If you do go for all external containers, IMHO, the ship carrying them should be designed as if it is the total tonnage including the external cargo. That would include bridge, crew, drives, fuel, etc (I'm sure that Spinward Flow will disagree with me on the first two of that list ). That being said, I am in full agreement with him on his last post regarding feeders, liners and tramps and how they operate.

 

[TamsinP]

Just as an extra note, having gone back to my spreadsheets and done some more calculations, the formula I gave for approximating TEU to GT is from a very small data set and probably only really works for smaller capacity ships.

I've also done it for the Maersk fleet (just the ships I could find data for) ranging from 3600 to 20568 TEU and got the following formula:
TEU = (0.09*GT) + 455

I then looked at the 108 largest container ships (20119 to 24346 TEU) and got:

TEU = (0.13*GT) - 6429

 

[Condottiere]

Spaceships: Containerization

1. The crane is strong enough to lift fully loaded containers of up to 65 tons and can couple with most pallets and crates.

2. There probably are smaller containers, four and eight tonnes, and larger ones, whatever they are.

3. But this is specifically mentioned in High Guard.

4. The crane is strong enough to lift fully loaded 32 and 65 ton containers and can couple to most types of pallets or creates.

5. Though, the thirty twoer seems to have been dropped.

6. There's no indication as to whether we can decrease or increase loading capacity on the crane.

7. Also, I would think that coordinating infrastructure and transportation modes, such as modular cutters, maglev railways, and so on, have this/these standards.

8. If they are sixty five tonnes, you might want to design smallcraft to transport them.

9. Even with the modular cutter, assuming you use a cradle, the container would be below thirty tonnes.

 

[Spinward Flow]

If you do go for all external containers, IMHO, the ship carrying them should be designed as if it is the total tonnage including the external cargo. That would include bridge, crew, drives, fuel, etc (I'm sure that Spinward Flow will disagree with me on the first two of that list ).

You're correct. I disagree as you've surmised, but perhaps not for the reasons that would be immediately obvious.
Bridge: No.
Crew: No.
Drives: Yes.
Fuel: Yes (mostly, although there are some edge cases that can get tricksy).

The reason why I disagree on bridge and crew is because a "tug" craft is built to its designed displacement tonnage for these things, not the tonnage of whatever might (occasionally) get bolted onto it from time to time. This is where it is helpful to think in terms of L-Hyd Drop Tanks (once again).

If I have a 2k ton starship, 2% of the hull needs to be dedicated to a Bridge, which in this instance means 40 tons of Bridge space allocation.
If I have a 3k ton starship, 2% of the hull needs to be dedicated to a Bridge, which in this instance means 60 tons of Bridge space allocation.

Now, if I have a 2k ton starship with 1k ton L-Hyd Drop Tanks attached and those tanks are retained through jump ... so the total displacement involved when jumping is 2+1=3k tons ... does such a starship require 40 tons of Bridge space, or 60 tons ... in this example?

My answer is that regardless of the size of the L-Hyd Drop Tanks, when retaining the drop tanks through jump, the "size of the bridge required" to meet the 2% threshold does not change. You don't need to allocate a bigger bridge in the design at the naval architect stage in order to accommodate the addition of the drop tanks. Basically the drop tanks are "towed displacement" that are sometimes present, but not always under all circumstances.

Same thing applies to crew.
Just because I add 1k tons of L-Hyd Drop Tanks onto a starship does not ipso facto mean that I need to add +10 crew members to the crew in order to operate the starship.

Drive performance and fuel consumption is DEFINITELY affected ... but bridge and crew requirements are not.

Extrapolate that same thought process proof over to other kinds of external loads and things start to fall into place. External loads MAY have additional crew requirements for them (medics and stewards for passengers, pilots and gunners for fighters, etc.), but those are specific details relevant to the "contents" of those external loads. If all you're carrying externally is a fuel drop tank ... or a collection of cargo box modules ... those don't require additional crew (per se).

Now ... if there's a boarding action and you want to resist being boarded ... having more crew/troops available to repel such an intrusion can have a lot of value as far as security measures matter (go figure, eh? ), but it isn't going to be something necessarily mandated by regulations (you need an extra 10 crew to babysit these 1000 tons of cargo modules or you'll be prevented from departing!).

 

[TamsinP]

Actually, those were the reasons I suspected you'd disagree with me. RAW, it could be taken either way.

I do like your idea of the un-powered barges transferred between the jump-tug and in-system tugs. That would be a good way of aggregating container loads on planet for shipment to orbit where they can be picked up by the jump-tug.

 

[whartung]

Given these dimension for 1 TEU:

• External length: 20 feet (6.1 meters)
• External width: 8 feet (2.44 meters)
• External height: 8.6 feet (2.59 meters)

We get 38.5 m^3 per TEU.

At. 14 m^3 per dTon, 1000 TEU = 2750 dTons.

A Book 2 4000 ton J2/M2 ship, crew of 9 with 6 staterooms, has 2839 dTons of storage space, 1032 TEU.

Ship costs 938MCr.

 

[kilemall]

Actually, with the exception of the smallest container ships, the majority of containers are carried in holds below deck. There are two main reasons for this

1) Stability of the vessel - stacking above deck increases the side profile that can be acted on by cross-winds (as happened with the Ever Given); it also raises the centre of mass, making the ship more susceptible to effects of rolling.

2) Security of the load - you can only securely lash a few tiers of containers above deck; the ones above that are relying solely on the twist locks at each corner joining them to the container underneath. You can add more on-deck containers by moving the accommodation block (and navigation bridge) forward allowing the stacks behind to go to maximum height (the stacks ahead of the bridge have to drop in height to allow clear viewing lines to the bow). For the very largest container ships, the 24,000 TEU mob, with maximised above-deck stowage capacity the ratio is about 52% below deck to 48% above deck assuming a theoretical 11 tonne TEU - the average actual weight/TEU is higher, so the true ratio skews to a higher percentage below deck.

With regard to the proportion of container ships that are "feeders", looking at the Equasis Word Fleet Statistics for 2020 (2021 is available and is fine for cargo ships, but weird for some of the others - passenger ships in particular; 2022 isn't available yet) we get the following:

Small (100-499 GT) - 20 ships; 8.000 GT; Ave 400 GT (= 112 dTon)
Medium (500-24,999 GT) - 2,258 ships; 26,276,000 GT; Ave 11,637 GT (= 3,001 dTon)
Large (25,000-59,999 GT) - 1605 ships; 60,063,000 GT; Ave 37,422 GT (= 9,183 dTon)
Very Large (60,000+ GT) - 1507 ships; 169,924,000 GT; Ave 112,757 GT (= 26,841 dTon)

* I've used 1 dTon = 13.5 m3

Unfortunately, the Equasis stats don't include the TEU capacity data for container ships. However, looking at data I've collected from various second-hand ship sale sites, listings for Maersk's ships, etc. the feeder container ships will fall into the "small" and lower end of the "medium" categories. The largest second-hand ship I found was 601 TEU and 7004 GT (= 1803 dTon). I've done a rough extrapolation from the (limited) data set I have and get the following formula:

TEU = (0.08*GT)+66

Plugging in your 1000 TEU capacity, we get a GT of 11,675 which converts to 2961 dTon; 2000 TEU would come out as 24,175 GT (= 6006 dTon); 3000 TEU comes out as 36,675 GT (= 9005 dTon).

One issue is that GT would only include containers stores in the holds and not those carried on deck. That being said, in space where centre of mass and rolling aren't issues there is no limit (other than drive capacity) to how many containers can be carried externally.

When it comes to designing container ships for Traveller, I would tend towards making them fully internal stowage. Who wants to pay MCr 0.5 for a starship-hull grade 5 dTon container to transport goods that may only be worth Cr 50k? Yes, it can be re-used, but what if you don't see it again? No, people will go for cheap containers worth much less than the goods that will be shipped in them.

If you do go for all external containers, IMHO, the ship carrying them should be designed as if it is the total tonnage including the external cargo. That would include bridge, crew, drives, fuel, etc (I'm sure that Spinward Flow will disagree with me on the first two of that list ). That being said, I am in full agreement with him on his last post regarding feeders, liners and tramps and how they operate.

If anyone is interested in this, I can point you to a post where I did a whole subgame in which merchant captains could have a sideline of providing the containers as an additional capital/cargo risk reward play. I had the internal and external containers with 5-ton and 10-ton sizing. The internal ones cost 10% of starship hull cost.

There are also reasons to run more of a starship hull if the cargo is pressurized, temperature sensitive, requires an atmosphere inside the container, liquid, radioactive or otherwise hazardous, etc. I cover that too including a hazmat code system.

Else this is like other cargo costs, the normal shipping overhead of issues like warehousing, getting through customs, fees, tariffs, etc are not the responsibility of the merchant vessel.

Speculative lots may come with a container buy/rental fee. You could waive it away as part of the purchase price or put it in as something to manage or time limits on container rental.

 

[Spinward Flow]

A Book 2 4000 ton J2/M2 ship, crew of 9 with 6 staterooms

Errors (plural!) detected.

LBB2.81, p16 or TTB, p61:

For starships of greater than 1000 tons hull mass displacement, the crew should also include a commanding officer (or captain), his executive officer, and at least three administrative personnel. Extremely large starships should have at least 10 crew members for each 1000 tons of mass displacement.

Last I checked, 4000 tons is "greater than 1000 tons hull mass displacement" by my reckoning (your mileage may vary, of course).
Therefore, under the "10 crew members per 1000 tons displacement" rule cited above, your 4000 ton J2/M2 starship requires a crew of 40 ... not a mere 9 (I see what you did there ).

Additionally ... LBB2.81, p14 or TTB, p57:

A commercial ship must have one stateroom for each member of the crew.

So if you have 9 crew on a commercial ship, you have to provide them with 9 staterooms ... not 6.
And if your ship really ought to have 40 crew, not 9 ... you should provide them with 40 staterooms ... not 6.

These points will be on the Merchant Academy test at the end of semester regarding LBB2 logistics and overhead expense reports. Anyone who gets these answers wrong on the exam will be reassigned to purging life support waste system components during all routine berthing procedure checks as your official punishment, to be followed by relentless ridicule and mockery from your fellow students and crewmates who didn't make the same mistakes you did. If you don't want to be known as a "methane breather" for the rest of your life, don't screw this up.

 

[TamsinP]

LBB2(81) "Extremely large starships should have at least 10 crew members for each 1000 tons of mass misplacement."

Note - no definition of what constitutes an an extremely large starship.

LBB5(80) - "If the ship is 1,000 tons or under, then the rules stated in Book 2 should be followed. For ships over 1,000 tons, the rules given below govern."

 

[Spinward Flow]

no definition of what constitutes an an extremely large starship.

Seriously?

LBB5(80) - "If the ship is 1,000 tons or under, then the rules stated in Book 2 should be followed. For ships over 1,000 tons, the rules given below govern."

If you're building a LBB5.80 design that is over 1000 tons, then fine. No objection.

It's when you do things like THIS that you start running into problems:

A Book 2 4000 ton J2/M2 ship

Doesn't sound like a LBB5.80 ship (and therefore, crew requirement rules) to me.
Sounds like a LBB2.81 ship (and therefore, LBB2.81 crew requirement rules) to my way of thinking.

Also, since when has a "Book 2 4000 ton J2/M2 ship" NOT been considered "an extremely large starship" by LBB2 standards, where the largest hull size is 5000 tons maximum? Please provide documentary details in your answer.

That's akin to saying "anything below 800k tons is not classified as extremely large by LBB5.80 standards" ... which, apologies in advance, can't possibly pass the ROFLcopter test.

 

[whartung]

Errors (plural!) detected.

Cool!

This looks better.



I added an extra admin for each 1000 tons above 1000, and shoved the rest into "Misc. Crew".

(Oh, the updated design, w/40 staterooms comes in at 2703 free tons for cargo. Close enough to 1000 TEU for Government contracts. 4072 nets the complete 2750.)

 

[TamsinP]

@Spinward Flow

OK, a few things to unpack here...

If we are sticking to purely Book 2 designs, then "extremely large" starships will probably be 4000+ dTons; that's 10-40 times the size of the typical adventurers' ship. Looking at what was also in publication by then, Supplement 8 Library Data A to M shows us the 100,000 dTon Sylea class battleship and the 300,000 dTon World class Battle tender with Battle Riders.

Other considerations also come into play if it's pure Book 2:
1) No L-Hyd drop tanks
2) No external cargo mounting

If we go with LBB5, the goalposts obviously shift and L-Hyd drop tanks come into the rules and we can assume by extension the possibility of external cargo pods/barges which could be added at the same cost as L-Hyd drop tanks (which are clearly safe for in-system and jump transit, despite costing less per dTon than ship hulls). For ships with Dispersed Structure hulls, looking at the "Vehicle Launch Facilities" section the pods/barges can be attached with no additional fittings or cost.


By the way, I've come around to your way of thinking with regard to the crew and bridge requirements for the jump tug container ships.

 

[Spinward Flow]

I added an extra admin for each 1000 tons above 1000, and shoved the rest into "Misc. Crew".

For reference, the way that I personally think about this question (so Your Mileage May Vary) is that the dividing line is 1000- tons are the "small" ships where the individual crew positions are enumerated (as usual) ... but then the 1001+ tons are the "large" ships where the 10 crew per 1000 tons rule takes precedence as a minimum. So if, for example, an 1100 ton starship had 10 turrets on it, it would require 10 Gunners (@ 1 per turret if they're all mixed loadout turrets) along with pilot, navigator, engineers, medic, etc. as normal. However, you then have to pile on the additional command crew (captain, XO, computer officer and 3 bridge support personnel) because the ship is over 1000 tons. Obviously, this would mean a crew in excess of 11 (for 1100 tons in this example), so you calculate the crew "both ways" (by positions required as normal and by tonnage) and simply use whichever number is larger. So in this example demonstration case I'm building here, the crew complement ought to be 24 for an 1100 ton ship armed with 10 mixed turrets ... not a mere 11 crew.

However, if the ship were scaled up to be 4000 tons and thus require (by regulations) a crew of 40, things change a bit ... which is where the personal interpretation comes into play.

My thinking is that with (fuzzy logic definition) "large crews" you're not looking at defining individual people to individual posts like you do with smaller (1000- ton) ships. Instead, the larger crew complement requirement is there to provide shift rotations.

You don't need just 1 Pilot (minimum), you need 2 or 3 of them to set up a watch rotation.
Same with the Navigator, who is responsible for monitoring the long range sensors (in addition to course plotting duties).
The "extra" personnel can be distributed around in such a way as to increase the numbers of personnel in the Engineering department so that the drive rooms can be fully staffed at all times using a shift rotation.
... and so on and so forth.

Basically, larger ships (over 1000 tons) are "spacious enough" to permit multiple crews in order to have a rotation of personnel standing watch in various departments. The "10 crew per 1000 tons" is just a slide rule way of thinking that gets you there in a free form kind of way that doesn't require too much thought process or getting bogged down in specifics.

If you look at LBB A1 The Kinunir, p31-36 for the crew roster of 80, it becomes rapidly apparent that 79 crew for a 1200 ton (in LBB A1) starship is kind of excessive. That's 10 officers, 14 petty officers, 21 ratings (45 crew) plus 4 marine officers, 10 marine NCOs and 20 marine enlisted (34 marines). Obviously, with that large of a crew (35 petty officers and ratings), not including officers, for a 3x 8 hour watch rotation of all crew stations for a 1200 ton ship ... so 11-12 crew per watch with the officers layered on top so as to exceed the "12 crew per 8 hour watch minimum" requirement to meet the 12 crew for 1200 tons threshold stipulated by LBB2 for ships over 1000 tons.

Also, having a larger than minimum necessary crew like that means that the ship could take crew hit casualties in combat and remain operational, because the Kinunir class was a "warship" when it was created at that time in CT ... before LBB5.80 (and S9) came along and upended the gaming table on starship scaling.

 

[Spinward Flow]

A corollary to this notion of having "enough" crew to enable rotations comes into play with (of all things) the Scout/Courier and Seeker designs, particularly in the context of long endurance missions such as prospecting (CT Beltstrike) and/or other exploration/survey operations that require continuous manning. I would even argue that starships such as the Express Tenders ought to have multiple crews aboard, rather than just the single minimum crew necessary, in order to provide 24/7/50 continuous manning of posts and stations on a watch rotation of either 3 or 4 watch rotations daily.

For smaller ships such as Scout/Couriers, if the ship is armed you really want a crew of 2 (Pilot, Gunner) ... but then if you've got 2 crews aboard you can run 12 hour shifts and be able to sustain a continuous manning posture for both stations (bridge and turret) at all times. Seen in that light, the seemingly "extravagant" design paramter of having 4 staterooms starts to make a bit more sense, since it allows the onboarding of 2 crews who can rotate standing watches during extended operations.



So if you want to look for more ... nuance ... in the crew and accommodations rules, there are reasons and rationales "lurking" between the lines of what you'll see and read in print.

 

[TamsinP]

Looking at shift patterns on commercial vessels, the navigation watch usually operate on two 4-hour shifts per day 12-4, 4-8 and 8-12 (AM and then PM). The officers usually start 10-15 minutes early for handover (and to get a coffee) and then between shift do their other assigned duties. For the engineering department, it depends on the ship - most modern ships have unattended machinery systems and everyone is on a day-shift, with the engineering officers rotating for 24-hour on-call.

Engine ratings and any deck ratings who aren't part of the navigation watch are usually on day shifts.

In port, the shift pattern changes for deck officers to two 6-hour shifts (12 to 6, 6 to 12, AM and PM) for the junior officers and the chief officer (or master on smaller vessels) switching to day shifts.

When entering or exiting port, everyone is on duty.

That would work fine for the big ships in Traveller, but for small ships (up to 1000 dTons), you'd probably be looking at the two 6-hour shift pattern. In the example of the armed Type S, the gunner probably doesn't need to be on duty at all times and the role could easily be assigned to the off-duty pilot. So, two pilots who double-up as engineer or astrogator and triple up as gunner if needed during their off-time. On larger small ships with dedicated gunners, the question becomes what the heck are they doing the rest of the time (particularly during jump)?