“Most starships are constructed using one of the six basic standard hulls… Custom hulls of up to 5000 tons mass displacement may be ordered.” – Traveller, Book 2
The 1977 version of Traveller shows us a universe with starships that are relatively generic, small and uncommon by the standards of later editions. In an earlier post (How Many Ships?) I calculated that a typical subsector would have only a few hundred starships operating in it, exclusively of small, standard types; let’s talk about why that is.
Ships are built on standard designs because it’s cheaper; you don’t have to pay the naval architect 1% of the ship’s cost, and the shipyard offers a 10% discount. That in turn means the annual maintenance costs are lower, as the overhaul is effectively at a 10% discount as well, to my mind reflecting generic parts produced in a more competitive marketplace, and engineers who are familiar with the ship type, and therefore need less training and work faster.
Merchant ships are small because as the size of a ship increases, the ratio of the revenue per ton to the cost per ton falls – the amount of profit they make, even when full, drops rapidly as ships get bigger. This is partly because the cost per ton to build and operate a ship increases with size, and partly because the amounts of cargo and passengers available are the same whatever size ship you have. The sweet spot for a standard commercial ship is 200 to 400 tons; ships smaller than that can’t carry all the available cargo and passengers, so they leave money on the table, but bigger ones find it harder to make a profit.
Now it’s entirely plausible that these rules only apply to small vessels which PCs might own and operate, and that big ships owned by big corporations use different rules; but the point of this exercise is to see what the game world looks like if the rules are an accurate reflection of it – and unless the PCs actually are a big corporation, they don’t get to play by the big corporation rules anyway.
Military ships? A single successful missile attack has roughly an 80% chance of disabling the power plant on anything except a Type C; a single missile rack is a credible threat to anything short of a cruiser, so whoever is operating the patrol and pirate ships doesn’t need anything better.
As an aside, in over 40 years of play I have only seen two starships custom-built by PCs; one was a 1000 ton jump-capable casino, and the other was a 400 ton jump-6 vessel built as a courier for hire. So, I didn’t get too excited about Mongoose dropping the starship construction rules from the core book.
Small ships have small crews. This means it’s entirely credible that all of them go to check out the alien ruin together; it reduces the number of NPCs the referee has to generate and run; it means the free trader crew has at least some chance of fighting off the cruiser’s boarding party; and above all, it means every member of the crew matters in every adventure.
That’s what we want, isn’t it?