Triangulation is the first hard wall in IRON NEST. Up to Calibration Fire the game hands you a grid reference and asks only that you convert it. From the second operation onward the grid reference disappears and two observers start reading bearings at you over the teleprinter, and it is entirely on you to turn those numbers into a point on the map.
The drill, in order
- Plot both spotters first. Blue markers on the map show observer positions. Match the marker number to the observer number in the order text before you draw anything — this is the single most common way a mission is lost silently.
- Draw from spotter 1. With the yellow pencil, click the spotter's position and drag outward. The line reports distance and bearing as you move it. Pull it to the edge of the map and rotate until the bearing matches what the observer reported.
- Repeat from spotter 2. Same tool, same method, second observer.
- Read the intersection. Where the two lines cross is your target.
- Re-measure from the nest. Draw a third line, this time from the IRON NEST marker to the intersection. That bearing is what goes to the guns.
The mistake that ruins the shot
A spotter's bearing is the bearing from the spotter. It is not the bearing from your turret, and it never should be copied straight onto the gun.
The two only coincide if the observer is standing exactly where you are, which never happens. Copying the reported bearing directly produces a shot that is confidently, precisely wrong — and because you cannot see outside the nest, nothing tells you why. The correction that comes back will look like a ranging error rather than a plotting error, so operators often "correct" themselves further off target.
The size of the error is not small, either. Two positions a short distance apart can differ by tens of degrees on the same target, and the difference grows as the target gets closer to either of you. Working through a solution on the calculator on this site makes this concrete: enter any realistic pair of positions and compare the observer's reported bearing with the gun bearing it derives.
When the observer gives distance instead of bearing
Some reports arrive as a range rather than an azimuth. Switch from the pencil to the compass — the blue tool on the clipboard, below the pencils — and scribe an arc at the reported distance from that observer. Two arcs, or one arc and one bearing line, resolve to the same intersection.
Mixing the two report types in one solution is normal rather than exceptional. What matters is that each measurement starts at the observer who reported it, whichever tool you used to draw it.
Three ways the geometry fails
Not every pair of bearings produces a usable target, and recognising a bad solution before you fire saves a shell and a correction cycle.
The lines are parallel. Two bearings that never cross usually mean one report has been attributed to the wrong observer. Re-read both, check the marker numbers, and redraw rather than trying to force an intersection near the map edge.
The lines cross behind an observer. A bearing is the direction an observer is looking, not a back-azimuth. If the only intersection sits behind one of them, one bearing has almost certainly been reversed by 180° somewhere between the tape and the clipboard.
The lines cross at a very shallow angle. Two observers on nearly the same line of sight produce an intersection that is technically valid but extremely sensitive to small errors. When the geometry is this poor, a one-degree transcription slip moves the target a long way, and a ranging round is worth the requisition.
The checklist before you fire
| Step | Confirm |
|---|---|
| Observer identity | Marker number matches the number in the order |
| Bearing source | Line originates at the observer, not the nest |
| Intersection | Both lines actually cross, not merely converge off-map |
| Gun bearing | Re-measured from the IRON NEST marker |
| Charge | Selected for the nest-to-target distance, not the spotter-to-target distance |
The last row catches more misses than any other. Distance for charge selection is measured from your guns, exactly like bearing, and it is easy to carry the observer's range forward without noticing because it is already written on the card.
Why this is a transcription problem, not a maths problem
Nothing in this drill is arithmetic you could not do on paper. The difficulty is that you are doing it from a tape you cannot re-read at leisure, onto a card you will act on minutes later, while a turret that takes real time to move sits between you and the result.
That is why the order of operations above matters more than speed. Plotting observers before drawing lines, labelling as you go, and writing the solution down before you traverse are habits that survive under pressure. Improvising the order is what produces a confident, wrong answer.
Practise it free
The demo runs the same fire-control loop with procedurally generated objectives, so you can drill this without owning the game. Run the same target ten times and time yourself from teleprinter to first round — under pressure, the plotting order above is what stops you transposing digits.
A useful exercise is to compute each solution twice: once on the clipboard as the game intends, and once on this site's firing solution calculator. The calculator does the geometry exactly, so any disagreement between the two is your own error, and seeing which step it came from is more instructive than simply getting the right answer.
What this page does not cover
Charge selection tables — which powder charge suits which range — are unconfirmed here. Those values are measured from the live build and shift with patches, so this site does not reproduce a table it has not verified.
Correction procedure after the first round lands is also unconfirmed beyond the principle of applying corrections to the recorded solution rather than re-deriving from scratch. The Steam discussion boards are where operators work these out, and the official Discord carries developer answers on the underlying mechanics.