WesWorld

Quoted

Ocean Liners: These are a special class of merchant ships, which obviously carry mainly people, not cargo. In wartime they may serve as troop transports or as fast armed merchant cruisers. For liners, miscellaneous weight may include some cargo capacity, but mainly represents the weight of the passenger accommodations - cabins, dining saloons, promenade decks, and so forth.

To sim a liner, provide miscellaneous weight for passenger accommodation as follows (in addition to any miscellaneous weight used for cargo, perhaps 10-20 pct of the total). Required miscellaneous weight can be estimated as follows:

Liners laid down up till 1900: 4 tons per cabin-class passenger, 1.5 tons per steerage passenger (i.e., immigrants to America).

After 1900: multiply the above figure by 1 plus (date - 1900) / 25. Thus, for example, a liner laid down in 1910 will require 1.4 times the miscellaneous weight needed for one laid down in 1900 or earlier; a liner laid down in 1925 will require twice as much.

For liners used as troopships, assume they can carry one soldier per 2 tons of miscellaneous weight.

When simming a liner, allow plenty of freeboard - at least half the beam, or even 60 percent. When you compute gross registered tonnage, add 10-20 percent - this allows for the extensive superstructures of liners. Displacement + (freeboard x loading submergence) / 2.5 is a handy formula to use, and adds 14 percent to the standard cargo ship figure.

The gross registered tonnage of a liner should be at least equal to her displacement, typically about 20 percent more (the Normandie had a registered tonnage close to twice her displacement).

The baseline gross registered tonnage of a liner built in 1900 or earlier should be 15 tons per cabin passenger and 5 tons per steerage passenger. Multiply this by the same formula as above for ships built later than 1900.

Note: In practice, when you sim a liner you may have to use the formulas in the other direction - your ship will have a given miscellaneous weight, and you'll have to determine how many passengers she can carry.

Suppose you lay down a liner in 1910, and she has 8000 tons of miscellaneous weight. You allow 1000 tons for cargo, leaving 7000 tons for passengers. Divide by 1.4, the multiplier for 1910 to get 5000. If 4000 tons of that is alloted to cabin passengers, she can carry a thousand cabin passengers, the remaining 1000 tons of date-adjusted passenger weight capacity allows her to carry 667 steerage passengers. This liner should have a gross registered tonnage of at least 25,669 tons.

(Yes, I know this formula is cumbersome, but it's easier than hitting an iceberg and having to watch Leonard DeCaprio and listen to Celine Dion!)