Capability Brief · Unclassified

The Long Walk

Live blast and fragmentation exposure on the wrist during the approach. The physics of the cordon, moving with the technician instead of drawn once on a whiteboard.
https://bomb.doctor/app · Garmin watch app
Named for the explosive ordnance disposal walk down range · Physics models named and sourced on every screen
The Problem

Exposure is computed once, then ignored

  • Cordons are static. Safe distances get computed at the incident control point, then the technician walks down range with no live sense of what the distance means at each step.
  • Blast overpressure is now a tracked injury mechanism. The August 2024 Department of Defense memorandum and the fiscal year 2025 defense authorization act require exposure tracking, with explosive ordnance disposal named a priority specialty.
  • Existing tools measure after the event. Worn gauges record the overpressure you already took. Nothing in the kit predicts exposure before you take it.
  • Hands are full on the walk. Whatever the answer is, it cannot live on a phone screen held in a free hand.
Aug 2024
Department of Defense memorandum requiring blast overpressure exposure tracking
FY25
defense authorization act naming explosive ordnance disposal a priority specialty
After
when a worn gauge reports: the exposure is already taken
Before
when this reports: while the distance can still change
The Long WalkUnclassified
The Capability

Charge in, cordon out, exposure live

  • Enter the incident once: location, net explosive weight, fill, casing.
  • The engine computes the rings: the K-factor overpressure cordons, the hazardous fragment distance, and the maximum fragment distance, with trinitrotoluene-equivalent conversion by fill.
  • Push to the watch. On the wrist: distance and bearing to the incident, live overpressure at your current range, fragment hit probability, and the zone you are standing in.
  • Escalation is physical. Crossing into a hotter zone vibrates the wrist. No looking required.
Incident entry with computed rings
Incident entry: rings recompute live as charge parameters change
The Long WalkUnclassified
Feature · Companion

Planning tool in the browser, push tool on the phone

  • Ready check walks the operator through setup: add incidents, set position, connect the watch. Steps check off as they complete.
  • Coordinate formats that match the mission: decimal degrees, degrees-minutes, degrees-minutes-seconds, and military grid reference, with live echo so a mistyped grid is caught immediately.
  • Multiple incidents held at once. The active one can be chosen by nearest range or by highest computed exposure.
  • Metric or imperial, kilograms or pounds, converted at the display edge; the model stays in standard units underneath.
Incident card with ring chips
A 25-kilogram device: inner cordon 186 meters, outer 1510, fragment distances chipped on the card
The Long WalkUnclassified
Feature · Watch

The wrist display is the product

  • Exposure hero face: overpressure and fragment hit probability side by side, zone named above, distance to clear below. The rim ring warms from green to red as danger grows.
  • Cordon radar: the incident at center, cordon rings drawn and labeled, your position plotted at true range and bearing with a breadcrumb trail.
  • Native activity recording with heart rate, saved to the training log like any workout.
  • Waypoint export drops the incident into the watch navigation stack for the built-in map.
Watch exposure face Watch cordon radar
Actual watch captures: exposure face and cordon radar
The Long WalkUnclassified
Feature · Models

The models are written down and testable

  • Airblast decay from published scaled-distance models drives the live overpressure readout.
  • Fragment hit probability is anchored to the hazardous fragment distance definition, with the interior gradient composed from open sources rather than reproduced from any single one.
  • Cordon recommendations reconcile the overpressure standoff with fragment throw, and the governing constraint wins. Where local direction sets a more conservative distance, that distance governs and the app does not attribute it to a public standard.
  • Three technical whitepapers document the cordon model, the exposure and injury model, and the multi-incident assignment logic. Figures are generated from the same code the watch runs, so a model change re-renders the paper.
Fragment hit probability versus range
Whitepaper figure: hazardous fragment hit probability versus range, generated by the same code the watch runs. Illustrative interior; anchored at the hazardous fragment distance
The Long WalkUnclassified
Feature · Common Picture

The walk shows up on the team picture

  • Watch position feed. The watch posts its position to a secure relay every five seconds; the relay converts it to cursor-on-target and the technician appears on the Team Awareness Kit map.
  • Hazard rings on the map. The same bridge pushes the incident point and its cordon rings to the common operating picture, color-coded, so the whole team sees the geometry the technician is walking.
  • Transport-layer security end to end, token-authenticated, on infrastructure the author operates.
  • Optional by design. The feed is off unless the operator configures it; the watch works fully standalone.
Multi-incident assignment map
Multi-incident assignment: which technician takes which device, computed from exposure
The Long WalkUnclassified
Walkthrough

Incident to cordon in under a minute

Animated walkthrough
Recorded against the live planning app: ready check, incident entry with live ring computation, saved incident, direct-install page
The Long WalkUnclassified
Field Test

On the wrist, walking onto a live cordon

  • Real test run. A practice incident loaded, then walked from outside the cordon to standing on the point.
  • The arc plays out on the wrist. Green and clear at 434 meters, the outer cordon alert as the geofence trips, the ring warming through amber, then red inside the inner cordon.
  • The numbers move with every step. At 3 meters the face reads about 6 pounds per square inch and 100 percent fragment probability; at 1 meter it peaks at 26. Same physics as the whitepapers, computed live.
  • The phone rides along. Companion map with the hazard rings drawn, and a geofence-entered notification the moment the outer cordon is crossed.
  • The walk shows on the team picture. The Team Awareness Kit screen was recorded at the same time. As the wrist read red, the map marker stood inside the red inner-cordon ring.
434 m
green and clear, outside the outer cordon
Alert
wrist vibration as the outer cordon geofence trips
3 m
about 6 pounds per square inch, 100 percent fragment probability
1 m
peak readout of 26 pounds per square inch on the point
Readouts from the recorded run. Test footage is not included in this brief.
The Long WalkUnclassified
Distribution and Status

Ships without a store

  • Direct install. Watch builds download from bomb.doctor with checksums and a four-step universal serial bus install guide. No account, no store approval in the loop.
  • Planning mode in any browser today; the same app builds for both major phone platforms, and the store submission kit is ready when accounts open.
  • On the wrist now as a beta on dive-computer and tactical watch hardware.
  • Sequencing is deliberate. Civilian and allied users first; government sales wait for the author's separation date to clear conflict-of-interest rules.
Direct install page
Per-model downloads with checksums at bomb.doctor/garmin.html
The Long WalkUnclassified
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