Ship Design
Hi,
This is a really interesting thread. One of the things I always liked about Traveller was the ability to design stuff, especially ships. Unfortunately by the time MegaTraveller came out I had started moving on to other things and never really got into that setting or how those rules worked.
In real life though, I am a Naval Architect and I can see how there are probably a lot of parallels with trying to design something in MegaTreveller and trying to design a modern ocean-going ship. A big factor in modern ship design is that it tends to be iterative, because sometimes you need to try and guess at some stuff early on in order to calculate other things, and then once you're done, go back and see if you early estimates were good enough or not.
An example of this might be total ship size. Early on you might need to make an estimate of total ship size in order to estimate hull and outfitting weights, and the like. Once you estimate those weights, and all the other weigth groups you can go back and see if your 1st estimate of displacement was adequate to balance all the ship's weights, or if you should re-iterate using your new estimated total displacement.
Another example might be total ship resistance and powering. If you can make an early estimate of power, you can calculate the size and weight of the powerplant you will need, which impacts how big and heavy the ship will be. Once you estimate all of the weights you can then go back and see if the power plant size you originally estimated is big enough to provide enough thrust to overcome the ship's resistance to allow the ship to go the speed you want.
In general to help a designer to make these early stage estimates its not uncommon for Naval Architect's to put together design charts and graphs to show approximations that can be used as an initial first guess for some systems or size estimates. Here's a link to a site I am currently putting together for modern ocean going ship designs that kind of illustrates some of this.
MNVDET
In specific, here are some graphs from that site showing a relationship to total ship displacement vs Groups 400 & 700 (which in modern ship terms kind of represents the controls and armament of the ship), vessel length vs total displacement, and a kind of non-dimensionalized estimate of installed power vs a non-dimensionalized form of vessel speed.
Along these lines, for a system like MegaTraveller and Fire, Fusion, & Steel, etc, does anyone know whether anyone has tried to come up with say a graph of powerplant size vs ship size or something similar that designers could use to make early stage estimates to help ease the design process?
Another thing from modern ocean-going ship design that might be relevant to MegaTraveller like ship designs is how electrical power is handled. In kind of a broad way, when trying to figure out how big the electrical system needs to be on a ship on modern ships you typically use something called a load factor, which accounts for the fact that a given component will probably not be in use 100% of the time in all conditions. And sometimes you will have different load factors for combat conditions as opposed to non-combat conditions.
For instance in MegaTraveller, in normal operations you'd probably use your maneuver drive alot in both non-combat conditions as well as combat conditions, so the load factor for it will probably be close to 1. However, your weaponry will probably have a very low non-combat load factor (near 0), but a very high combat load factor (near 1). Other stuff like general life support (and lighting), etc can probably be powered down a bit in combat to make power available for weapons and sensors, etc. As such, when determining total power plant size requirements you wouldn't necessarily use the total power rating of all the stuff that uses power in the ship, but instead would add up the "weighted" ratings and then make sure the plant(s) could provide this amount of power. Additionally, you'd probably also want to do a calc for power requirements in Jump space to make sure you can meet those as well.
Finally, on modern ocean-going ships you'll typically have more than one power plant/generator providing this power, and you'd probably try and size them so that you could maybe provide all the power for use in Jump space using just one plant, while all the power required for normal operations may require two plants on line, and combat operations may require 3 or more (or something like that).
Such an approach may ultimately end up more complex than how people are currently dealing with power plants in MegaTraveller, but its a possible alternate approach.
Anyway, sorry if I've gotten off tangent here, but just thought I'd share some thoughts based on my experiences.
Regards
PF
