MV Shahrastani — Water Ingress Detection on an LPG Carrier Main Engine
20 days of live LOTUS Beacon data that revealed sustained water contamination, validated the purification response, and confirmed the oil’s recovery — on a vessel already fitted with a shipboard monitoring system.
Installation
How LOTUS Beacon Was Deployed
LOTUS Beacon was installed on MV Shahrastani as part of Petredec’s pilot programme for continuous main engine oil condition monitoring — a panel-mounted Connect installation with full ECR integration.
Main engine — across the lube oil cooler
Panel-mounted with local display showing live readings to crew
Wired to ECR · PC with DAQ and processing software
Tie-back to ASTER cloud completed · pilot phase signed off
Note: MV Shahrastani was already fitted with ACONIS — a shipboard oil monitoring system. This case study includes a direct comparison between LOTUS Beacon, ACONIS, and shore lab results.
Reference
Fresh Oil Reference Values
| Oil | Viscosity @40°C | Density | Dielectric | BN |
|---|---|---|---|---|
| Main Engine System Oil (fresh) | 99 cSt | 876.75 kg/m³ | 2.23 | 6 mgKOH/g |
All in-service readings are temperature-compensated to measurement temperature.
Chronology
How the Event Unfolded
Elevated water readings flagged immediately
Water saturation at 28% and moisture at 1,811 ppm — well above acceptable limits. Viscosity at 78.87 cSt (below fresh oil baseline of 99 cSt @40°C), indicating a water dilution effect.
Readings sustained — not a transient spike
Water saturation remains 19–24%, moisture 957–1,562 ppm across multiple consecutive days. Sustained readings rule out measurement artefact and confirm genuine contamination. PC rebooting noted 15–17 Jun but local sensor readings continue uninterrupted.
Purification response — readings begin improving
Water saturation falls from 20% to 13%. Moisture drops toward 768 ppm. Dielectric constant begins declining from 2.35 → 2.31, tracking toward fresh oil value of 2.23 — confirming water removal is working.
Recovery confirmed — all parameters normalising
Water saturation at 10%. Moisture at 663 ppm. Dielectric at 2.29 (approaching fresh oil value of 2.23). BN at 12.4–14.7 mgKOH/g — above new oil spec of 6. Zero ferrous and non-ferrous wear debris throughout.
Full Data Log
Daily Monitoring — June 2025
Local LOTUS Beacon readings. All viscosities are kinematic (cSt), temperature-compensated to measurement temperature.
| Date | Viscosity (cSt) | Density (kg/m³) | Dielectric | Temp (°C) | Water Sat (%) | Moisture (ppm) | BN | Ferrous | Non-Ferrous |
|---|---|---|---|---|---|---|---|---|---|
| ↑ Water ingress period — elevated contamination | |||||||||
| 11 Jun | 78.87 | 875.08 | 2.35 | 48.25 | 28% | 1,811 | — | — | — |
| 12 Jun | 76.00 | 847.00 | 2.35 | 48.98 | 24% | 1,562 | — | — | — |
| 13 Jun | 73.71 | 874.22 | 2.34 | 49.37 | 21% | 1,334 | — | — | — |
| 14 Jun | 76.49 | 874.54 | 2.34 | 48.85 | 23% | 1,453 | 12.41 | — | — |
| 15 Jun | 76.50 | 874.49 | 2.34 | 48.96 | 21% | 1,389 | — | — | — |
| 16 Jun | 76.51 | 874.36 | 2.34 | 49.11 | 19% | 1,237 | — | — | — |
| 17 Jun | 78.75 | 847.67 | 2.33 | 48.70 | 20% | 1,310 | — | — | — |
| ↓ Purification response initiated — recovery period | |||||||||
| 18 Jun | 84.35 | 875.47 | 2.33 | 47.82 | 20% | 1,301 | — | — | — |
| 19 Jun | 84.43 | 875.39 | 2.32 | 47.89 | 19% | 1,195 | — | — | — |
| 20 Jun | 86.13 | 875.51 | 2.32 | 47.67 | 15% | 968 | 12.21 | NIL | NIL |
| 21 Jun | 88.45 | 875.89 | 2.32 | 47.31 | 15% | 957 | 12.41 | NIL | NIL |
| 22 Jun | 90.23 | 876.92 | 2.32 | 46.44 | 13% | 768 | — | — | — |
| 23 Jun | 100.07 | 877.12 | 2.31 | 45.77 | 11% | 684 | — | — | — |
| ✓ Recovery confirmed — parameters trending to normal | |||||||||
| 24 Jun | 97.21 | 877.12 | 2.31 | 45.91 | 12% | 791 | 12.40 | NIL | NIL |
| 25 Jun | 121.56 | 880.74 | 2.31 | 41.75 | 13% | 822 | 14.70 | NIL | NIL |
| 26 Jun | 115.84 | 879.12 | 2.30 | 43.45 | 11% | 680 | 14.69 | NIL | NIL |
| 27 Jun | 129.29 | 880.67 | 2.29 | 41.68 | 9% | 562 | 14.45 | NIL | NIL |
| 28 Jun | 104.37 | 877.43 | 2.29 | 45.23 | 11% | 703 | 14.65 | NIL | NIL |
| 29 Jun | 100.42 | 877.21 | 2.29 | 45.64 | 11% | 682 | 13.68 | NIL | NIL |
| 30 Jun | 94.19 | 876.25 | 2.29 | 46.99 | 10% | 663 | 12.40 | NIL | NIL |
Key observation: As water saturation and moisture content decreased, the dielectric constant declined from 2.35 → 2.29, approaching fresh oil value of 2.23. This independent parameter confirms the water removal was real and complete.
System Comparison
LOTUS Beacon vs ACONIS vs Shore Lab
MV Shahrastani was fitted with ACONIS and subject to periodic shore lab analysis. Here’s how the three systems compared on key parameters:
Water Activity (aw) — lower is better:
BN (mgKOH/g) — higher is better:
The lab water reading of 0.50 aw was from a sample taken 2.5 months prior. By the time this result was available, the contamination event had already occurred and partially resolved. LOTUS Beacon detected it daily, in real time, with no delay.
Analysis
Key Technical Findings
Water ingress confirmed — not oil aging
Low initial viscosity (73–78 cSt vs fresh oil 99 cSt) alongside high water readings confirms water dilution, not oxidative thickening.
Dielectric tracks the recovery
Dielectric fell 2.35 → 2.29 in parallel with moisture reduction — an independent corroborating signal of successful purification.
No mechanical wear detected
Zero ferrous and non-ferrous wear debris throughout. Contamination was caught and treated before any mechanical damage occurred.
BN well above condemnation limit
BN of 12.4–14.7 mgKOH/g — well above new oil spec of 6 mgKOH/g. Alkalinity reserve remained healthy throughout the event.
Outcomes from the MV Shahrastani Deployment
- ✅ Contamination detected in real time — water saturation of 28% and moisture of 1,811 ppm flagged from day one, with continuous tracking through the full recovery period.
- ✅ Intervention validated by data — LOTUS Beacon showed the purification working in near-real time, giving the CE confidence the treatment was effective before any lab result was needed.
- ✅ No mechanical damage — zero wear debris throughout. Contamination was caught and resolved before it could cause liner, bearing, or ring damage.
- ✅ Superior to existing systems — LOTUS Beacon water activity (0.10 aw) was more accurate than ACONIS (0.14 aw) and far ahead of the stale shore lab result (0.50 aw from 2.5 months prior).
- ✅ Pilot successfully completed — Petredec confirmed successful pilot completion. Outcome: scaling LOTUS Beacon across the fleet.
Continuous Monitoring That Works Alongside Your Existing Systems
LOTUS Beacon provides daily oil condition data — viscosity, density, dielectric, water activity, BN, and wear debris — even on vessels already fitted with shipboard monitoring.
