kzt wrote:The explanation is that these are much more expensive to buy, require significantly more maintenance (which means more crewmen), and require other upgrades to other ship systems. I tend to find this less than convincing, as a 40% speed increase is roughly the same as having 40% more ships. As the operating costs are portrayed as fairly low, the governing costs would be the bank note on the ship. So unless the hyperdrive upgrade costs something like >50% of the cost of the entire ship (really?) it seems like a money maker.
Economics isn't the strongest point of the Honorverse.
Unless of course you also lose a significant portion of the cargo capacity.
For example as to the impeller upgrade. Trojan Horse ships just turned the aft taper's cargo hold into a pod deployment point installing the rails was trivial for 300 pods. To do the same with the "military" drive requires a whole bunch of redesign as to how the impeller room is laid out. That whole cargo area is non-existent the drive mostly takes up all the room. Yes there are weapons and such but from the old drawings (pre-HoS) they were a much smaller. The weapons in the aft hammerhead (to gain volume) didn't shrink all that much
If the installation cost is 20% more than a "civilian" spec drive component. If you lose 20% of the cargo capacity. If maintenance costs increase 20%. If crew costs increase 200%. If ... well hopefully you get the idea. A few million dollars here, a few million dollars there, pretty soon you are talking real money.
Pretty soon your railroad is losing money to some trucker who can deliver right to the store. <shrug>
Note numbers in the previous paragraph are just drawn out of the air. We really don't have much hard data to go on.
In fairness 40% faster is low. A real number as of 1903 or so would be anywhere up to ~300% faster most merchant ships max ~1089c and warships ~3000c. According to the missing CD figures on Joe's site. JNMTC numbers (from IEH) were enough to get to the eta band or about 1794.5c a ~65% improvement.
Another data point is to get streak capability you need to double the size of the hyper generator (at least for the Alignment) for 2 bands no blooming clue as to the cost.
Hopefully all this makes some kind of sense.
Have fun,
T2M
PS for those interested the JNMTC info paragraph in IEH chapter 7.
The Joint Navy Military Transport Command, composed of midsized ships and normally assigned to the delivery of high-priority, time-critical cargoes (or delivery to potential combat hot spots), was the result. And as part of the same move to speed and streamline the transportation process, the ships designated for JNMTC use had been taken in hand by navy shipyards—Manticoran or Grayson, as available slips permitted—for overhaul. Time was too tight for their civilian grade inertial compensators and impellers to be altered, but they’d received light sidewalls and missile defense systems, upgraded sensors and rudimentary electronic warfare systems, and military hyper generators to permit them to reach as high as the eta bands. Since most merchantmen were designed to cruise no higher than the delta bands, their up-rated generators virtually doubled the sustained apparent velocity JNMTC ships could attain.