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All figures below are reproducible from the CSVs in this folder using ../scripts/summarize_campaign.py. Savings are the weather-aware-vs-weather-blind fuel/CO₂ saving in percent, over the status == ok instances. The full matrix is 12 routes × 4 seasons × 2 years = 96 instances per vessel.

Weather-routing savings (%)

Vessel metric n mean median p90 max
S175 route-only 91 5.04 1.91 14.58 39.82
S175 joint route+speed 91 11.01 8.82 19.75 45.56
KVLCC2 route-only 67 6.14 3.91 16.07 26.25
KVLCC2 joint route+speed 66 10.95 10.00 20.21 29.69
JBC route-only 66 4.55 1.82 15.09 26.81
JBC joint route+speed 65 9.57 7.82 17.30 30.33

The S175 slow-steaming (cube-law) component alone is mean 6.03 %, median 6.93 %.

S175 route-only saving by basin (n, mean, median, max %)

Basin n mean median max
N. Atlantic 6 10.88 12.15 17.98
NE Atlantic 7 8.86 8.29 12.83
N. Pacific 6 10.10 6.69 32.48
NW Atlantic 16 6.32 2.62 39.82
Indian 16 5.08 3.64 14.58
S. Atlantic 16 3.87 0.00 25.07
W. Pacific 8 2.92 2.16 8.04
Tasman 8 0.42 0.20 1.47
North Sea 8 0.00 0.00 0.02

Savings concentrate where a strong weather gradient meets a resistance-sensitive operating point; calm or laterally-constrained routes save little, a heavy storm tail saves substantially.

Cost-objective divergence (min-cost vs. min-fuel, same route & weather)

On the ECA-affected lanes the two objectives diverge: cost-optimal routing trades a small fuel increase for a voyage-cost reduction by shortening time on the pricier ECA-compliant fuel.

Vessel diverged (of 96) mean cost saving max cost saving mean fuel change
S175 31 +2.36 % +10.9 % +1.48 %
KVLCC2 24 +2.15 % +10.0 % +0.64 %
JBC 20 +1.34 % +9.6 % +0.97 %

Feasibility

status == ok instances (route computed) of 96:

Vessel ok / 96 Notes
S175 96 / 96 all feasible
KVLCC2 75 / 96 deep draft (20.8 m > Suezmax 20.1 m) makes some lanes infeasible irrespective of weather
JBC 76 / 96 deep draft (16.5 m > Panama 15.2 m) likewise

Of the ok instances, a further subset have a weather-blind baseline that is itself infeasible (the storm exceeds the engine MCR or seakeeping limit at the service speed): these carry no defined saving percentage and are excluded from the saving statistics above (hence n = 91 / 67 / 66 for the saving rows, below the ok counts). On these "storm-enabled" voyages, weather routing does not merely save fuel — it enables the crossing at all.

Scale and runtime (reference workstation)

Quantity S175 min-fuel
Waypoints per instance 17 – 1003
Router solve time per route median 183 s, mean 335 s, range 39 s – 24 min

Provided so methods can be compared on computational cost as well as savings.