Okay, I think I've figured out the profitability issue for large liners:
1. Given the immense purchase price of the ships themselves (on the order of
billions of credits), the only corporations that would truly be able afford to operate large liners would be the shipbuilders themselves.
The shipbuilding corporation would constuct the ships, using manufactuing facilities that they already have available (thanks to their government contracts) at a cost of about 1/2 the actual purchase price of the ship. They would then turn the ship over to a transportation subsidiary, which operates the ship for the corporation.
2. Large corporate liners and freighters would be involved in the "resource trade" aspect of the cargo transport industry, meaning they operate outside the realm of Bulk Cargo and Speculative Trade as detailed in the THB. Since this is, effectively, "subsidized" cargo, the large corporate liners would receive a standard fee per ton (similar to the subsidized mail fee), which I set at 3,000Cr/ton. (Note: I still used an average of the bulk cargo availability values to determine how much cargo space a ship would have.)
3. Passenger liners are supposed to be an experience in their own right: a veritable resort in jump space. To reflect the "resort facilities," I installed an
additional stateroom for each high passenger and an
additional small cabin for each middle passenger, with revenues equal to 5,000Cr/high passenger and 4,000Cr/middle passenger served. These additional staterooms don't require extra life support, since the number of passengers haven't changed. However, The additional services doubles the service crew requirement for the ship.
(I used the 1 per 8 high passengers and 1 per 50 middle passengers formula to determine the number of service crew required for a liner, dividing the service crew between stewards, technicians and cargo handlers for purposes of pay....the additional crew required for the resort facilities are considered to all be stewards for purposes of pay.)
Using these rules, a 6,242-ton Jump-3 merchant liner (133 high pass, 158 mid pass, 209 low pass, 641 tons of cargo) makes a monthly operating profit of just over 5.1MCr/month. While this liner would cost over Cr2.25 billion if purchased, the construction cost is only Cr1.13 billion, making the ship profitable in less than 18.5 years (not counting depreciation, which would be deductible in most situations anyway
).
Using the above example, the liner will make a profit of over Cr1.3 billion over its 40-year life cycle (enough to construct it's replacement outright).
I'm still going to see if I can find a profitable jump-3 airline-style operation within the bulk cargo/passenger rules. Again, stay tuned...
Editor's note: I notice and corrected a typo above. I mistakenly stated 5.1MCr/year when the operating profit was actually 5.1MCr/month. Just a slight difference.