Vector movement

Hello again. This is the second installment on how to build ships using my Intercept design system.  You can get the rules, design system etc here.

Payload

The payload area holds the cargo and hangar bays if any, missile magazines if any, the computer, neutrino and mass sensors and any repair bots. Cargo and Hangar bay volume should be input in dTons (or m3 if the 5 m3 dTon option is used). Cargo and Hangar bay also have fields for entering load in tons so you can calculate actual thrust Gs and frame Gs for loaded and unloaded configuration. I will later change the design sheets so this calculation will be done automatically. Our Suleiman will have 5 dTon (25 m3) cargo hold. Note that the missile magazine entry says “3 missile volleys in launcher”, this is just a reminder that the missile launcher themselves hold three missiles per launcher. Enter a number above 3 to have more reloads for the ships missile launchers if any. The computer then, the clunky old Traveller computers with their quaint model numbers. Just enter the model number you want and see if the TL you picked has it. Above the model limit of a given TL you need 10 parallellcomputers and after that you need 100 parallell computers, beyond that nothing helps. Note that as you go over teh single computer price rises much fastaer. We know from canon that the Suleiman needs a model-2 in order to perform astrogation for J-2.

Next come the neutrino and mass detectors. You may wonder why I haven’t grouped all sensors into one place and the reason is simply that Visual/IR and Radar must work outside of the ships hull but the neutrino and mass sensors see right through the armor and are therefore placed in a separate hitlocation. Our trusty Suleiman has neither neutrino nor mass sensors so we add none. The robots entry let you replace your technicians with robots if you want a highly automated ship. Robot technicians has Computer# -4 skill so before Model-4 they perform worse than regular technicians but take up considerable less space. The Suleiman has no robot technicians so we add none.

Crew

The crew area of the ship holds lifesupport, freezers, various crew stations, the crew living area and the ships floorfield. Lifesupport come in three varieties:

• Basic lifesupport Temperature and air, sufficient for up to 24 hour operation. Sanitation facilities are of the diaper variety.
• Full lifesupport temperature, air, sanitation etc. can keep crew alive indefinitely given enough supplies.
• Closed life support Same features as full lifesupport but it needs no supplies as it recycles water, air, urine, feces etc, think high-tech greenhouse.

Each crew and passenger require lifesupport but robot technicians does not. The Suleiman has four double occupancy staterooms according to the deckplans so we give it 8 Full lifesupport units which need 0.25 tons of supplies per man-week. We assume enough supplies are stored in the cargo bay as buying life support supplies is not part of this design system. Freezers hold crew or passengers in suspended animation. In Traveller there is something called the ‘frozen watch’ which means a duplicate crew complement that gets thawed out when the crew has taken enough casualties. There can only be one frozen watch though, as the frozen watch will also take casualties from crew damage. Activating the frozen watch requires a morale throw if that optional rule is used; activating the frozen watch is a brutal reminder that the high command consider crew expendable. We add two freezers to our Suleiman.

The next couple of entries are the various forms of crew stations. All crewmembers require crew stations except the technicians and robots.

• Limited station Small and cramped station where the crew begin to suffer fatigue after 4 hours. Negates 2 Gs of  thrust. Think jet fighter.
• Limited tank Small and cramped station. Filled with oxygenated fluid to counter acceleration. Fatigue sets in after 4 hours, negates 5 Gs of acceleration.
• Full station Large and roomy cramped station where the crew begin to suffer fatigue after 8 hours. Negates 2 Gs of  thrust. Think wet navy station.
• Bridge station Even larger station with lots of extra displays. Fatigue after 8 hours, 2 Gs negated. Ships with these for each crewmember win initiative ties for Ship tactics and Fleet tactics.

We give our Suleiman 4 Full stations as. Next up is the living area which encompass the staterooms, freshers, mess, corridors and whatever else the crew can move around in. Larger living area let the crew do longer missions without physical or psychological risks, the safe trip endurance is noted for the entry. We give our Suleiman 32 dTon (or 160 m3) living area, enough for 8 crew to live in space for a month before physical and psychological risks appear. Roleplayers have a tendency to cram in too many people in their cramped ships, let them roll for physical and psychological illnesses. Nothing livens things up more than the 120 kg engineer raving about space ghosts and then goes on a murdering rampage with his coolant wrench.

The last entry for the crew location is the floor field. A floor field simulates gravity and counteract acceleration. As noted earlier, the crew stations counteract some of the acceleration Gs and the floorfield does too. Subtract the crew station G protection and the floofield strength before applying acceleration Gs fatigue (these fatigue rules are not yet in the Intercept game rules but they will be, trust me). Any remaining acceleration G is applied as a negative DM on all tasks. Choose whether the floorfield should apply to living room and crew stations only or if you will have it in the cargo and hangar areas as well.

All right, this wraps things up for this time. Next installment will cover the sensors and weapons as well as the ship ratings and how some of the stuff ties in to the Intercept game.

Conserve space; dump in jump!

As there is no tutorial on how to design ships with the Intercept design system I will do just that here. You can get the rules, design system etc here.  

Open Data.xls first       

The design system consist of two files; Data.xls that contains the design tables and Ship.xls that will hold your design. You must open the Data.xls first so that Ship.xls can read from it, then you open Ship.xls and save it with whatever name you want, typically the ship class name of your design (Suleiman.xls or Scout.xls in our case). The renamed Ship.xls files should reside in the same folder as Data.xls to simplify things.       

Suleiman type S scoutship

Known facts about the Suleiman       

Before starting a design you should have a rough idea on what the ship must be capable, how much it can cost and how large it should be. Our example is the Suleiman class type S scout ship, known from the Traveller roleplaying game, so we already know a few things about the ship. It is a 100 dTon ship with J-2 and 2G of acceleration. The TL varies depending on ruleset, we choose TL 13. the ship has four double occupancy staterooms so we should give it lifesupport for 8 people. The ship is armed with a single turret holding a laser, a missile launcher and a sandcaster, we’ll change that to a top mounted turret holding a laser with a missile launcher and a small belly mounted turret with a sandcaster. We set the cargo space to 5 dTons. The Suleiman should cost around 40 MCr.       

Design basics       

IMTU the dTon is 5 m3 instead of the usual 13.5, 14 or even 15 m3 (the sources differ on this one). In the top left corner of the design sheet there is a dark yellow cell holding the value 15. Change it to whatever value your Traveller system uses for the dTon, the value chosen won’t affect anything except the ships mass. If you enter something other than 5 the design system assumes you will input hull size, cargo space, crew area etc in dTons and power in EPs (High guard Energy Points), if you enter 5 exactly the design system expects m3 values for volumes and MWs (Mega Watt) for power. My 5 m3 designs assume 25 MW equals one EP, the value of the EP has no effect on your designs otherwise. Note that all cells depend on the value of the dTon are dark yellow in color. Cells that can be edited are yellow in color, just leave the input cells empty if you don’t want that particular component. The Components column summarize the values for each component.       

The hull      

We set the hull size to 100 dTon as we know that the Suleiman is a 100 dTon ship from Traveller canon (if you use the 5 m3 variant you must enter 500 m3 instead). We set the hull TL to 13 and we add 3 to the armor. IMTU the Suleiman has extra armor to make it a rugged and tough ship built to withstand lower tech attacks. If we ignore the extra armor we shave off 1.5 MCr. Material type (basic, advanced or extreme) are abstract terms for how advanced the hull materials used. Material type affects volume and mass of the hull, hull price goes up sharply if more advanced materials are used. We give the Suleiman Advanced materials and a frame that can withstand 2G of acceleration. The G rating in parenthesis is the G rating modified by ships density, the value before the slash is loaded and after the slash is unloaded performance.

There are four degrees of streamlining in Intercept    

• Open frame Suicidal to use for aerobraking or skimming. 150 km/h safe speed in 1 atm. Lots of surface area, good for mounting weapons and sensors but bad for armor.
• Normal Dangerous to use for aerobraking or skimming. 500 km/h safe speed in 1 atm.
• Streamlined  OK for aerobraking or skimming. 1000 km/h safe speed in 1 atm. Less surface area.
• Airframe Good for aerobraking or skimming. 3000 km/h safe speed in 1 atm. Little surface area.

Surface area limits how much weapons and sensors you can add but you can increase surface area by adding wings to your ship (as a percentage of hull volume). Wings have no further effects in space combat. We give the Suleiman Streamlined airframe as a compromise between airspeed and surface area.     

The Suleiman is supposed to land on planet so we give it skids as Traveller canon illustrations doesn’t show it with wheels. As the Suleiman should be able to skim fuel from gas giants we also give it fuel scoops. Fuel scoops allow gas giant skimming given a hull with good enough streamlining and it will also turn the fission or fusion thrusters into airbreathers that use the surrounding air as remass  drastically reducing fuel use and radioactive exhaust when moving in an atmosphere.     

There is no stealth in space     

That is what they say at Atomic rocket and I agree in general, any realistic thruster will have a signature that is easily detectable at huge ranges (if our Suleiman would have 2G Fission drive, it would be trackable by a similar ship to 0.7 AU). Intercept however, allows us to use reactionless drives with no visual or IR signature and so stealth does play a part here. Also note that while the signature and sensor rules in Interecpt are based on real world data I have on purpose reduced the sensor capabilities to suit my Traveller campaign. In Interecpt there are separate stealth systems against Visual, IR, radar, Neutrino and Mass sensors. Each stealth system come in three qualities (none, basic and advanced). Aside from price, each stealth system use up surface area so you cannot really make a super stealthy ship with a full load of weapons. Tradeoffs, it is all about tradeoffs. As our Suleiman deals with lower tech cultures we give it basic visual stealth (make the hull really black) to make it harder to detect with visual sensors. This reduces its Vis(hull) signature by 2.     

Propulsion     

A ship needs a propulsion system unless it is a space station you are designing. Propulsion come in three forms:     

• Fission / fusion thrusters that need remass to operate and need to track thrust expenditure. The drive capabilities are based on the more extreme technologies from the Atomic rocket site.
• Reactionless thrusters that use electricity to create reactionless thrust (and break the laws of physics).
• Jump drives use jump fuel to enter hyperspace and travel a number of parsecs in a week (breaking more laws of physics).

We give the Suleiman a 2G Impulse drive and a J-2 jump drive. We add jump fuel for 3 parsec to help it survive if a misjump occurs. 

Power     

Right now there aren’t that many choices to do for power but the empty row on the design sheet will eventually hold some kind of energy storage banks. Simply choose if you go with a fission or fusion powerplants and the number of EPs it must produce (or MWs if the dTon=5 m3 option is used). A legit design should have enough power to support everything except the Surface fixtures segment (sensors and weapons if you will). Our Suleiman has “Protected radiators” noted for its powerplant but your design may instead say “Vulnerable radiators”. If a ship has more than 2 EP per 100 dTon (more than 50 MW per 500 m3 hull if dTon = 5m3 is used) the powerplant must have extendable radiators and those are less armored than the rest of the ship. This is automatically reflected in the ships ratings. In reality, all ships will have vulnerable radiators, even the space shuttle with its puny power output must extend the cargo doors are cooling fins when in orbit.   

Well, this is all for now, in the next installment we will cover Payload, Crew and Surface fixtures. Feel free to ask questions here at the blog or through e-mail.  

So long and keep the solar wind to your backside.

I’ve decided to publish the design system for Intercept so people can start using their own ships in space combat. The design system is mostly done so one can start designing all the ships from the Traveller universe. Note however that my interpretation of tech level progression differ from the standard Traveller one, it also differs from GURPS Traveller tech level progression. The changes mostly affect the lower TLs in order to allow fission and fusion powered ships with semi-realistic capabilities and sensor signatures. If you want to play what-if scenarios from the Atomic Rocket site you can whip up some nuclear rockets with really shitty signatures and play dogfights in Earth orbit. Oh, there are no plasma or fusion guns in the design system for obvious reasons.

Once upon a time a long time ago I decided to get rid of the silly 1.5 squares used by Traveller deckplans back in the eighties. I treated them as being 1×1 m and 2.5 m high and as two deckplan squares equals one dTone my new dTon became 5 m3 which I built my original design system on. That system is long gone but in the new system you can choose if you want to build ships with dTons (displacement tons) and EP (energy points) or go with my m3 and MW ratings. The designs will perform, cost and behave the same regardless, it is just a matter of taste.

The design system consist of two excel worksheet; one for the data and one for your design. The Data.xls must be opened before the Ship.xls sheet is loaded so it can read data from Data.xls. The Ship.xls sheet can be named as you like to hold your Beowulf, Suleiman or Donosev etc. All values needed for Intercept space combat are calculated as are price, tonnage etc. The worksheets are protected so you cannot ruin anything by accident (and you can also not see how crappy I am at fiddling with Excel). The Ship.xls is already filled in with my take on how a Suleiman type S scout should be, best damned player ship if you ask me (Cassandra Monastera, Ulrika Loke and Gvoudzon concur).

If you download the Intercept bundle you get the rules, maps etc including the design system excel sheets.