Small Hovercraft Boltholes

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Items in italics aren't known to the characters beforehand! Other stuff may or may not be known (depending on the team's placement date).

 

     Many of the Project's teams are placed in boltholes -- hidden, blast-proof underground bunkers. Not all boltholes are the same; they vary in size, access points, installed equipment, and construction styles.

     All bolt holes are built from steel-reinforced high-density concrete, with a synthetic lining on all interior surfaces for insulation and to improve airtightness, to absorb neutrons and to reduce moisture infiltration and other contamination of the interior. Once the bolthole's occupants and equipment are in place, it is filled with nitrogen gas at about 15% above local atmospheric pressure. At least one large bucket of desiccant (usually silica gel) is placed in the interior to reduce the humidity.

     Along the sides of the bolthole are liquid nitrogen storage tanks (dewars). They automatically vent nitrogen if the interior air pressure drops to less than 10% over normal atmospheric pressure for the bolthole's altitude, or if commanded by the monitor. Each tank is about 1.4 meters tall, and 1 m on each side; they weigh 60 kg when empty; the exterior is made of stainless steel. They have power cords and control cables plugged into the floor; there is a heavy-duty manifold on one side (for filling the tank, venting into the bolthole automatically, venting the tank manually for whatever reason, or venting to the exterior on monitor command). 

The nitrogen dewars are not shown on this plan, for some reason.

If five cryoberths are present, the fifth one goes where the table is located in this plan.

 

das Hoverbunker ... external elevation of the entrance end

 

The Monitor

 

     A simple electronic system monitors the VLF radio, conditions within the bolthole, the status of the cryoberths, and the status of the vehicle fusion reactor which powers the bolthole systems. The cryoberths, radio and monitor draw less than 3000 watts of power. The wakeup procedure requires several hours to complete (and draws a few kilowatts of power for each cryoberth).

     Environmentally, the monitor watches temperature, air pressure, toxic agents, radiation count, a smoke detector, and orientation. If the interior temperature exceeds 27° Celsius for 24 hours, or 40° Celsius for 1 hour; if the air pressure is not at least 10% above local (pre-War, anyway) atmospheric pressure for 24 hours; if the smoke detector goes off; or if the orientation detector signals a 5 degree tilt for more than 2 minutes, the monitor system will initiate the cryoberth wakeup process.

     If the fusion reactor indicates that less than 15% of its fuel remains, the monitor will initiate wakeup of the team.

     If a critical number of the cryoberths have signaled a "fault" status, the monitor system will initiate wakeup on the remainder. For a team of 8 persons or less, the critical number is "half". If any of the cryoberths have the wakeup process started manually (there's a switch on the outside of each berth) the monitor will initiate wakeup on all of them -- unless whoever's waking them up uses an MPID to over-ride the "team wakeup" process. If the monitor detects the team-specific wakeup signal on the VLF radio, it'll start the wakeup process on all berths (this may not be true for some teams outside the Recon branch).

     In any case, if the wakeup process for one or more berths is initiated, the monitor will open the manifold valves from a rack of oxygen tanks (each about 2 meters long, 86 kg empty), and open the automatic valves on the nitrogen storage tanks to feed into an external vent. The monitor will attempt to keep the bolthole at least at 5° Celsius (all that oxygen escaping and nitrogen venting will really cool it down) by commanding the vehicle reactor to generate heat. Air pressure in the chamber will go to about 1.2 atm (about as much as being under 2 meters of water), or a bit more, depending on how much nitrogen is still present, the normal external air pressure, and any large leaks. The monitor will remotely turn on the vehicle's AutoNav or computer, set the time and date, and pass along information about the reason for the activation process (including any data received over the radio). The cumulative radiation amount within the bolthole will be passed along also.

     The monitor uses something like the sensor on an M1 CBR kit to detect agents in the bolthole, with the same 75% chance of detection. If it senses something toxic, it does not affect whether or when the wakeup takes place, but will turn on a warning signal in each berth during wakeup -- a nasty electronic buzz and lamp with the words "DANGER TOXIC AGENTS PRESENT". It's up to the unlucky Project members to figure out how to deal with that ...

     All of the extra air pressure will place about 30 tons of force on the exit door; once it starts to slide open, there will be a shriek and hiss for a couple seconds, building to a full-throated whistling organ-like roar for forty-five seconds or so. Everyone's ears will pop very painfully as the pressure drops. The noise is pretty loud outside, too; there won't be a condensation cloud (the air coming out of the bolthole is very dry) but it'll blow any loose material away from the doors.

     As all the berths open, the monitor and radio will self-destruct. If you're listening, you might hear a faint pop-and-sizzle sound.

 

Configuration

 

     This bolthole variant is designed for a single small hovercraft -- the Pequod, Gull, or Flying Dutchman designs. The interior is an arch 4 meters in radius, 10.5 meters long (527 cubic meters).

     A heavy steel sliding door closes off one end of the bolthole; the door opening is 5 meters wide. The door itself 7 meters wide, 3.5 meters tall, and 14 centimeters thick (armor value 18); it weighs 27 tons. There are flush-mounted shackles on the interior surface of the door, and on either side of the doorway opening, to allow the door to be moved by block-and-tackle.

     At the rear of the chamber is a niche, with a ladder leading up 2 meters to a heavy steel hatch. This is an emergency exit -- the shaft above the hatch was mostly filled with pea gravel and sand by the Project after the bolthole was constructed. The floor of the niche is a steel grille, covering an empty concrete well of about the same volume as the amount of pea gravel filling the shaft above. When the hatch is unsealed, the pea gravel falls down through the grille into the well. If the escape shaft doesn't quite empty on its own, the team has pioneer tools to assist in opening the emergency exit. There are eight nitrogen dewars, and twenty-eight oxygen tanks.

     Note the effects above regarding air pressure ... very exciting if a cofferdam is opened first. The cofferdam hatches each have about a ton of air pressure on them, so getting the hatches open will be quite a chore if there's still pressure in the bolthole.

 

Installed Equipment

 

     Besides the monitor and radio (destroyed when the team awakens), the standard bolthole contains:

 

• a rather crusty-looking 5-gallon dessicant bucket
  

• 28 empty, heavy frost-covered oxygen tanks, with a computer-controlled manifold valve

• 8 empty, frost-covered nitrogen dewars, labelled "LIQUID NITROGEN"
  

• a scorched and smoking VLF radio/monitor station

• a 10-meter long interface cable, connecting the monitor to the vehicle computer

• a cheap folding "banquet" table, with:
  

• in many cases, the bolthole prep team will have left cheap terrycloth bathrobes and/or cheap slippers on the table

• four or five body bags

• four shovels

• on and under the banquet table is the team's gear (weapons, standard equipment, and so forth) 
  

• four or five cryoberths, with letters "A", "B", "C", "D", and (if needed) "E" painted on the panel end of the berths

• personal effects boxes are stored in a niche in each cryoberth

• a periscope, with a manual ratcheting mechanism to raise it

• a large hand crank for opening the vehicle door, mounted to one side of the doorway (opposite the periscope). It takes a lot of turns to open the door. There is a locking ratchet to keep the door from being pushed open from the outside.
  

• four wooden blocks supporting the hull of the hovercraft (if it doesn't have its own jacks)
  

 

Conditions Upon Activation

 

     In most circumstances in the campaign, the air will be cold (about 5° Celsius - or about 41° Fahrenheit), incredibly dry, with a lot of odd chemical smells (including burnt computer parts and wiring). Each cryoberth has two bluish electroluminescent "night lights", one inside the lid and one on the exterior "panel" end, that come on when the lid unlocks. A regular light bulb on the bolthole ceiling (24 volt, 150 watt lamp that looks kind of like a motorcycle headlight) will be going "pop" and dying as the cryoberth lids open; a few electroluminescent nightlights (also 24 volts with military connectors, but otherwise like the ones used in childrens' nursery rooms) stand out against the darkness here and there.

     None of the team's or vehicle's canteens, jerry cans, etc. contain any water.

... except in the reactor, and only a very little there.

     There's no latrine, and the team members' bladders are very empty, but the dessicant bucket looks sort of available ...

     In actual wakeup scenarios, the synthetic insulation/sealant lining on the walls, ceiling and floor will be discolored, blistered and possibly cracked in places.