Rosatom-Antonov K37 TNTRL

First developed and flown near the end of the 22nd century, the venerable K37-TNTRL has become the de-facto workhorse of The Ring. Its simple and robust design has proven over the decades to have the kind of reliability and maintainability that's vital to the thousands of captains and crew who call these well-loved vessels home.

The K37-TNTRL, sometimes affectionately known as the “Tarantula” and often abbreviated to just “K37”, was initially designed as a short-haul mining ship, although their modular design has proven extremely adaptable in the decades since the model's introduction. Despite their technological obsolescence, today a K37 can be effectively refitted to suit interplanetary travel, light combat duty, mining, cargo hauling, and even light duty mobile mineral refining. The sturdy reconfigurable hardpoints aren't quite suitable for mounting high power military grade kinetic weapons, but they otherwise handle almost any equipment you might imagine fitting to a craft of this size, including mass drivers, microwave emitters, mining lasers, and much more besides.

The K37 is compact but sturdy, measuring just over 32 meters long and weighing 37 tonnes when dry. The design is highly modular, but all configurations share a few key elements. The fuselage, crew module, nuclear reactor, cooling system and main drive are effectively standard across all models, offering a baseline specification that specialist builders can develop on.

At the heart of every K37 is a purpose-built nuclear reactor, with thermal power provided by an assortment 1) of Rosatom's SO6 “Sunshard” fuel rods. Thermal energy from the reactor is used to heat liquid water for use as both engine propellant and working fluid for the onboard 100MW turboelectric generator. Due to the extremely high temperature and pressure achieved inside the reactor core the propellant exists in a supercritical state, yielding relatively high propulsion performance despite the simple design.

The high operating temperature of the Sunshards enable relatively compact cooling solutions to be used, and the reactor's entire waste heat output can be dissipated through a series of graphene radiators on the outer walls of the reactor module. Although this isn't recommended due to the large thermal stresses applied to the radiators, a reactor running hot at over 4000K can dissipate 4GW through this array. Waste heat from other ship systems is negligible compared to that of the reactor, so the rest of the ship is cooled by a heavy 'skirt' of heat-pumped radiators which serve both as a cooling surface and a protective layer for the more delicate reactor cooling behind it.

The main drive of the K37 is a relatively simple bimodal nuclear thermal-electric rocket, using a large Lorentz-effect electric boost stage powered by a magnetoplasmadynamic generator, as well as optionally using direct thermal power from the reactor. For long-distance cruising the drive can operate in a so-called “high gear”, where thrust is provided mainly by the Lorentz accelerator, powered by the onboard closed-cycle turbine to minimise propellant waste and maximise exhaust velocity. For operations inside the rings however, the main drive will shift into a low gear where the propellant mass flow is increased significantly to buy extra thrust, at the cost of exhaust velocity. While in high-thrust mode, the K37's combination of nuclear-thermal thrust and electromnagnetic exhaust velocity can push several gee of acceleration when lightly loaded, and even carrying its own mass in cargo and fuel a K37 can exceed 1g at full burn. While propellant usage at these thrust levels is prodigious, the drive is still far more economical than simple chemical thrusters - even a modest 30T of propellant is more than enough for a good miner to fill their cargo hold with ores and get back to station with propellant to spare!

A K37 commonly carries a crew of three, though in emergencies it can be operated by a single busy pilot. The crew facilities of most K37s reflect this, being relatively short on amenities and little space in the standard model, though “caravan” refits which convert the cargo hold into a larger living space aren't unheard of!

Prices range from E$35,000 for a cheap but serviceable used hull, and up to E$174,999 brand new.

Particulars

  • Manufacturer: Rosatom-Antonov
  • Length: 32m
  • Beam: 16m
  • Mass (standard configuration, dry): 33200kg
  • Mass (standard configuration, wet): 63200kg
  • Mass (full load) ~275,000kg

Notes

  • “low stress” is pretty high for k37. military ones will break it off, but both emd14 & erfmd17 will make it
  • For on-board systems it uses a standard high-pressure turbine. Thrusters have built-in MPD generators for their own electricity needs.
  • MPD needs quite a lot of power to start up. Turbine just needs pressure. [Supercapacitors are not enough] when you are cold in the waters. K37 is designed to be re-bootable.
  • Radiators the ship have are perfectly capable of dispersing up to 4GW of waste heat in peak. Under normal operating conditions they radiate out 1-2GW. Bigger radiators pose a risk in the rings, they are used by interplanetary craft. K37 also cools itself considerably by exhaust
  • Bulk of the cooling on K37 comes from heat-pumped radiators. You can radiate a lot of heat with 3500K. It's interplanetary-capable - but ships that are not expected to ever go near the Rings indeed use classic radiator fins, as they are just much simpler and less prone to failure.
  • K37 comes with built-in camper compartment. Crew lives there for days to weeks when interplanetary.
  • Ship features high-temperature heat pumps to dump all the heat out to high-temperature radiators; since radiation has T^4 having radiators operating at 3500K means they can radiate insane amounts of heat.
  • Main engine pushes with 750kN
  • K37 uses moving fuel rods design due to lower mass. There are numerous failsafes built into the reactor, but they are rarely actively maintained by private owners and many of them just don't work on a century old ship.
  • Also, keep in mind that center of mass of the ship shifts depending on your cargo and remass available.
  • Lore-wise, the ship has pyrotechnically detachable reactor, that's just one of the systems that is almost certain to be broken or removed on used k37.
Rosatom-Antonov K37 TNTRL Operation Manual: The cold boot sequence
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