Breakwaters, revetments and reclamation measured tide to tide. The window opens at low water, the armour and the toe are flown inside it, and the built profile is read against design before the next barge is loaded.
Capture · Mission 21
The sheet above is a drawing of this. 11 capture waypoints, and every finding called as the aircraft reaches it — scroll sets the target, the mission keeps its own pace, and the page waits for it.
Sector · Coastal
Low water opens for two hours and ten minutes, twice a day. The sortie is armed on the falling tide, runs the seaward face to the roundhead, watches a 6.5-tonne unit set into the pack, reads the reclamation clarifying basin-length by basin-length — then the unit walks the exposed armour and captures the joint gaps the tide is about to take back.
The toe is visible for two hours a day, and only on the right tide. Miss the window and the next honest look at the underlayer is a fortnight away, by which time it has 40,000 tonnes sitting on it.
The capture is scheduled against the tide table rather than the working day. Missions arm on the falling tide and fly the exposed profile at low water — every window, on every section, whether or not anyone is on the causeway.
Rock armour is placed by grab off a barge in a swell. Whether the armour layer holds its specified thickness over the underlayer is a question nobody can answer standing on the deck.
Each exposed layer is surfaced at 1.6 cm and sectioned against the design profile every 20 m of chainage: crest level, slope, toe position and layer thickness read to ±0.3 m, all on chart datum.
Armour is bought by the tonne and placed by the barge load. The claim is a delivery ticket plus an assumption about how much of it ended up inside the design profile.
Volume between two surfaces, converted at the quarry's bulk density, is what gets claimed. The 480,000 tonnes on the record are the tonnes inside the section, and the frames travel with the claim.
480k t
Rock armour placed and counted
±0.3 m
Built profile against design
2/day
Low-water windows flown
The program runs on the tide table, not the working day. Missions arm on the falling tide, fly what the low water exposes, and put it on the record before the sea or the next barge covers it.
2×/day, armed on the falling tide
The exposed face, the toe and the underlayer are flown at low water, every window, whether or not anyone is on the causeway. The armour that will be underwater by 08:00 is on the record by 07:00.
1.6CM · 1.9KM IN 34MIN · LW 06:12Every flight, before the next barge loads
Each surface is cut against the design profile every 20 m of chainage — crest level, slope, toe position and layer thickness, all on chart datum. Rock placed blind from a barge is read to ±0.3 m.
SECTIONS CH 20M · PROFILE ±0.3M · CD DATUMEvery window over the fill, as the platform rises
The hydraulic fill behind the wall is surfaced on the same flights as the armour, so the platform's rise is measured against the same section and the same datum as the rock that retains it.
FILL 246,000M³ · CUT 18,600M³ · P-27Claim week, off the same surfaces
Volume between two surfaces, converted at the quarry's bulk density, is what gets claimed. The 480,000 t on the record are the tonnes inside the design profile, and the frames travel with the claim.
ARMOUR 480K T · CLAIM WK · EVIDENCEDYou don't. The capture is scheduled against the tide table rather than the working day — missions arm on the falling tide and fly every low water, two windows a day, with nobody needed on the causeway.
WINDOWS 2/DAY · ARMED ON TIDEThat is the whole program. The toe at CH 1+420 read 0.4 m under profile at 07:05, and by 07:50 two barges were re-tasked, not argued with — a fortnight before 40,000 t would have buried the question.
TOE CH 1+420 · −0.4M · READ 07:05Each exposed layer is surfaced at 1.6 cm and sectioned against design every 20 m of chainage. Crest level, slope, toe position and layer thickness read to ±0.3 m on chart datum, layer by layer as the bund comes up.
PROFILE ±0.3M · CH 20M · P-27The rock in the section. Volume between two surfaces, converted at the quarry's bulk density, is the claim — 480,000 t placed and counted, every tonne inside the design profile, evidenced frame by frame.
ARMOUR 480K T · EVIDENCEDThirty-four minutes for 1.9 km of armour. The mission arms at 05:40 on the falling tide, the window shuts at 07:50, and the toe reading is on the record in between — with time left for the tide to do the rest.
1.9KM · FLOWN 34MIN · WINDOW 2H10Read against the same section: 246,000 m³ of fill and 18,600 m³ of cut on P-27, on chart datum like everything else, so the platform and the breakwater that holds it are never on two different records.
FILL 246,000M³ · CD DATUMThe difference between two epochs of the same 1.9 km, both on chart datum. The waterline is a measured line with a date on it rather than a memory of where the beach used to be, so retreat and accretion read as metres along the chainage — on the same section the armour was claimed against.
SHORELINE · EPOCH Δ · CD DATUMRead overnight on a section like P-27: two low-water flights, the tide table, the armour ledger and the design profile on chart datum. Three of the 27 profiles wake up to it.
05:40 · CAUSEWAY · CH 1+420
SEQUENCE
The window runs 05:40 to 07:50 with low water at 06:12 — fly the toe at CH 1+420 first; it read 0.4 m under profile yesterday, and both barges hold until the new diff lands.
CITES: TIDE TABLE LW 06:12 · TOE CH 1+420 · P-27
07:20 · SECTION P-27 · TOE
TOLERANCE
The armour layer holds ±0.3 m against design on every 20 m section except the toe at CH 1+420 — the underlayer gets its look this window, a fortnight before 40,000 t would have covered it.
CITES: FLIGHT 06:12 · SECTIONS CH 20M · ±0.3M
06:55 · CLAIM · CH 0+00 → 1+900
EXPOSURE
The armour claim is the rock inside the section: 480,000 t evidenced between surfaces at the quarry's bulk density, with the frames attached — a survey, not a stack of delivery tickets.
CITES: ARMOUR DIFF · 480K T · CLAIM WK
One calendar for every autonomous capture on the portfolio
MISSIONS ON A CYCLEThe site in three dimensions, measurable by anyone who opens it
MESH 40M FACES · DEM 5CMEarthworks quantities and stockpile volumes reconciled against design
VOLUME ±1.8% · NIGHTLYClaims assembled from the record, defended by frames
CLAIM WK · EVIDENCEDFigures are a specimen record, drawn to the platform's own conventions.
Send us a section and a tide table — we will arm on the falling tide, fly the low water and hand you the built profile against design before the next barge loads.