Sometimes the Chicken Wins


Location: Tuntamus (Madel Cauldron)
Date: 6921-11-13
Habitat: Tuntab High Orbit Three (“Senmarville”)
Defining Event: Complete structural failure
Accident Number: LM6921-443
Damage: Total
Casualties: 23,147

Presented to the Inter-Worlds Commission on the Accord on Free Space

The events of the Tuntab High Orbit Three habitat disaster have deep roots in existing conditions on the habitat, which will be summarized following the proximal cause analysis.

While both the quantity and severe damage to the wreckage prevents this analysis from being as detailed as this Commission might wish, the earliest specifically identifiable contributory event took place on the night previous, at E-14:11:31, when a local management computer for the station’s domestic electrical grid detected demand on the local power grid for which it was responsible and was unable to meet this demand – part of a pattern of ongoing grid instability – and thus began load shedding. Various remote attempts to restore service over the next few hours proved unsuccessful, with ongoing grid instability causing incoming power connections to trip as soon as they could be brought on stream.

At E-11:10:22, the electrical control room containing the local management computer was entered by an individual using the security codes of a station administrator (one not recorded as having operational training), and power restored manually from station main bus B, an alternate source which had previously failed, and the automatic cutouts locked in the on position. This procedure violated all established safety regulations and operational protocols.

This resulted in load exceeding design parameters being borne by the superconducting cable connecting the associated electrical substation to main bus B, which several hours later (E-2:20:16) explosively overheated at a previously worn spot on the cable as it entered the 37.5°30 sub-level 2-5 machinery room, igniting a lubricant fire therein.

This fire went unnoticed for over an hour. Alarms sounded in the 37.5°30 emergency control center, but this center was, again in violation of all established safety regulations and operational protocols, unmanned. The fire thus had the opportunity to establish itself, and the alarm was not relayed to the station operations center until E-1:05:48. Even then, response was slowed by the ongoing efforts to correct the problems with the electrical grid (as shown by the operations log), but ultimately emergency response teams were dispatched to extinguish the fire now raging on the lowest level of the machinery room.

While the fire on the lowest level had largely been extinguished by E-0:13:11, flames had broken through in several areas into the next level, including along various pieces of unstopped or inadequately stopped electrical ductwork and service passages, including a branch from the duct conveying various outgoing power lines to the machinery room’s subordinate grids to the super-high-tension relay substation on sub-level 4. When the fire became established in this area and heated the oil-insulated transformers, the resulting flashover and electrical short-circuits, at E-0:02:61 reignited fires on all levels of the 37.5°30 machinery room (and may have ignited minor fires elsewhere on the station; see full addendum), but this fire was swiftly extinguished by the station’s automatic response, sealing the area (although at least three spacetight doors failed to seal fully, having been manually propped open or disconnected) and venting it to space.

More serious consequences, however, were felt elsewhere. The electrical consequences of the short-circuits in the 37.5°30 machinery room were transmitted immediately to all parts of main bus B; while the immediate reason is unknown due to a lack of physical evidence the bus isolation breakers failed to open at any point between the machinery room and the station’s fusion plant. In the face of the sudden demand spike this caused, the three fusion reactors feeding into bus B tripped offline and initiated SCRAM procedures. While this was the correct response from the point of view of reactor protection, all portions of the station dependent on main bus B were immediately deprived of main power.

The electromagnetic bearing supporting the station’s major habitable torus should not have been affected by this. As all vital systems are, it was powered, by design, from multiple essential-services buses cross-fed from multiple main buses to prevent exactly this type of incident. However, at some point in the recent past, and again in violation of all established safety regulations and operational protocols, the primary magnetic rings had been rewired to all feed from main bus B. While not established directly by the evidence, maintenance records exist of a recent replacement of worn cabling for the bearing; it seems most probable that the rewiring to B was done due to a lack of available replacement wire (see below), and the maintenance records falsified accordingly. The operations log does indicate warnings logged of the lack of power drain from the ess bus spurs involved, but no action appears to have been taken on these by station operations.

Thus, at E-0:00:03, the non-moving inner surface of the magnetic bearing lost axis and made contact with the rotating rings, immediately undergoing catastrophic delamination. Shortly thereafter, at E-0:00:00, the resulting increase in friction and transfer of angular momentum tore the station apart, with all regions aft of docks & locks (fortuitously separated by an early debris impact) being subjected to g-load far in excess of their structural limits.

Inhabitants of this region, which included the major habitable torus and annexes, were given neither time nor opportunity to escape the station, and no survivors were reported from this region. The 1,982 survivors were all recovered from the docks & locks region, from nearby workshacks, or from EVAs being carried out at a distance from the station.


To fully understand the root cause, it is of note that Tuntab High Orbit Three was, at the time of the incident, in the third month of ongoing industrial action by the local operations and maintenance technicians, whose grievance was that station administration and operations were not ensuring that proper maintenance was performed in a correct and timely manner, or with replacement parts of adequate quality. In response to this, the Technical Association had required its members to cease performing any maintenance or associated work, which included even such activities as unloading, or permitting to be unloaded, maintenance or emergency supplies.

The Commission has therefore determined the probable causes of this incident to be:

  • Inadequate historical maintenance of station systems.
  • Dereliction of duty by responsible maintenance personnel.
  • Operation of technical systems by unqualified personnel.
  • Performance of maintenance by unqualified personnel.
  • Violation of safety regulations and operational protocols on an unprecedented scale.
  • Failure to properly inform habitat population of the safety status of the habitat.
  • Failure to evacuate in accordance with safety regulations.
  • Sophont error.

In closing, the Commission would add that, in their opinion, the true root cause of the Tuntab High Orbit Three incident was the belief of the station adminstration, operations, and technical staff that they could afford to play flinchy-flinchy with the prospect of a cascade failure in service of their own goals, something that no member of the operations and technical staff of any habitat should have contemplated. As such, the Commission recommends a complete revision of the training and licensure requirements for all those licensed to practice in these areas, with particular emphasis on the ethical obligations of those who, by virtue of their control of infrastructure, hold their populations’ lives in their hands.

The Commission also recommends to the League Ministry of Habitation that an immediate review be carried out of all habitats within League space with respect to establishing their historical and future compliance with all applicable safety regulations and operational protocols, with special powers to require the relicensure, retraining, or dismissal of any individual found to be, wilfully or otherwise, not in compliance with these, and the relicensure or receivership of any habitat administration or management company knowingly encouraging, tolerating, or provoking such practices.