Hulls are identified by their mass displacement, expressed in tons. Hulls of different mass displacements come in standard configurations which
divide the tonnage into a (shielded) engineering section and a (pressurized) main compartment. All drives and powerplants must be located in the engineering section, and only drives and power plants may be placed in that section. All other ship components, including fuel, cargo hold, living space, and computer must be located in the main compartment.
The hull types chart indicates the configurations of the six standard hulls, and states the proportion each has devoted to the engineering section and the main compartment, the price of the basic hull (expressed in millions of credits), and the construction time (expressed in months. Hulls in sizes (or engineering/main compartment proportions) not indicated in the chart must be produced on a custom basis.
Outmoded ships may be improved by refitting; obsolete systems are replaced by newer models. All refitting must be done at an A or B starport, and jump-drives may be refitted only at A starports. Refitting involves the complete removal of an old system and the installation of a new one; for instance, if a power plant is refitted, the entire power plant is removed and a new one put in its place. Refitting takes up shipyard capacity equal to the refitting ship's tonnage.
Changes in power plant, maneuver drive, or jump drive are major changes. They cost 1.5 times the amount the new system would cost in a new ship; the time required to install major changes is one fourth the time required to build a new ship (from the construction time table). Changes in any other ship component are minor changes. They cost 1.1 times the cost of the system in a new ship and take one tenth the time required for new ship construction.
Refitting is subject to the same time modifiers and weekly costs as in the ship-building rule. If several ships of a class are being refitted the same way, all ships after the first receive the time benefit. Work may proceed concurrently: if several ship systems are being replaced, the refit takes only the time required for the longest one.
The degree to which a ship may be changed is limited. Power plant, M-drive, J-drive, and spinal mount weapons may not be increased in tonnage. There may be no additional launch facilities built (although they may be removed). Armor and configuration may not be changed. The number and size of weapons bays may not be changed.
It is important to note, from the maximum drive potential table, that some drive and power plant types will not function in certain types of hulls (those situations indicated by a dash); the drives and power plants table also indicates that some drives will not fit into some hulls. It is also possible to fit a set of drives and power plant into a hull and then to have insufficient tonnage remaining for fuel, basic controls or life support. The completeness is intended to cover situations where custom hulls are produced. A jump capability of greater than 6 (or an acceleration of greater than 6 Gs) cannot be achieved with the 24 drive types listed in the table.
The installed power plant must be of a letter type at least equal to the drive letter of the installed maneuver drive (the power plant letter may be higher than the maneuver drive letter).
1. This being from the original Book/Two.
2. Would indicate that once you have constructed a hull, the engineering section is separate and can't be increased in size.
3. Though the engines themselves, could be, if the combined tonnage remains within the limitations of the engineering section.
4. So, in theory, if the design rules still require an engineering section, once allocated, you can adjust the size of all engines, if they stay within the designed limits.
5. However, it's quite possible that hulls nowadays have all sorts of engineering sections.
6. For example, distributed power production.