Gear Oil Maintenance, Thruster | Harbour Tug

Customer case

System — Thruster

Vessel: Harbour tug “VB PORNIC”
Thruster: AQUAMASTER US 1401 AZIMUTH Starboard Thruster
Gear oil: EPONA Z 100 (marine mineral gear oil)
Viscosity: 100.7 cSt @ 40 °C
Oil volume: 850 litres


Entry of seawater into the gear oil of the thruster of the tug (starboard side). The mineral oil was contaminated from high level of seawater (0.39%) and sodium particles (22 ppm). Since the next inspection in the dry dock was scheduled in 6 months, our customer was urgently looking for a solution to continue vessel operation.

Gear oil filtration, thrusters, harbour tug

Harbour tug “VB PORNIC”

Solution: CJC® Thruster Filter

A CJC® Thruster filter consisting of Desorber D5 and oil care system 15/25 was installed. The installation of the CJC® Thruster Filter in the offline circuit ensures continuous dewatering, fine filtration and maintenance of the gear oil (24/7/365). Water — free, emulsified and dissolved — as well as wear particles and oil degradation products (varnish, acids) are removed from the gear oil very efficiently.

Water separation capacity: > 150 ml/h
Dirt holding capacity: approx. 1.1 kg
Filtration degree:3 μm absolute, 1 μm nominal
Filter material: 100% natural fibres (cellulose)

gear oil filter for thrusters, harbour tug

BEFORE — without gear oil maintenance

Result of gear oil maintenance

Weekly oil samples were taken to follow the oil condition and trend. After a week, the CJC® Thruster Filter had removed the water from the gear oil — the water content in the oil dropped from 3,904 to 163 ppm. According to Noria Corporation, this corresponds to a lifetime extension factor of 5-6 for the oil and equipment. The recommended water content in the gear oil is < 300 ppm. Moreover, the CJC® Thruster Filter removed solid particles from the gear oil — wear debris such as iron (FE) and copper (CU) were lowered from 29 and 4 ppm down to 17 and 1 ppm; the sodium/salt content (NA) decreased from 22 to 13 ppm. The content of these impurities should not exceed 25 ppm as recommended.

Oil samples

gear oil maintenance, thruster, harbour tug

BEFORE — without gear oil maintenance
Water: 0.39%
Sodium: 22 ppm

gear oil maintenance, thruster, oil sample with cjc thruster filter for oil care

After 3 weeks with CJC® Thruster Filter
Water: 0.05%
Sodium: 14 ppm

Water content in gear oil, thruster, gear oil care
Particle content in gear oil, thruster, gear oil care

Savings and Benefits

The installation of the CJC® Thruster Filter results in the following advantages for our customer:

  • cost-intensive emergency inspection in dry dock avoided
  • oil filling service life and thruster components extended by 5 to 6 times
  • oil change avoided and 850 litres of gear oil saved
  • permanently clean and dry gear oil ensured – free of water, wear particles, and salt crystals/sodium

By avoiding the oil change and drastically extending the service life of the oil filling in the future, the CO2 footprint of the tug improves – a valuable contribution to BOLUDA’s strategic goal of becoming a CO2-neutral company.

Improving the CO2 footprint

Longer oil change intervals lead to high savings and, at the same time, protect the environment and resources:

  • less fresh oil
  • less waste oil, and CO2
    approx. 2,210 kg less CO2 per saved oil change*)
*) The thermal disposal of waste oil produces approx. 2.6 kg of CO2 per 1 litre.

Customer comment

Regional Technical Manager, Mr. Olivier GLOAGUEN:

“The CJC® Thruster Filter allows us to keep the tug in operation until the scheduled dry dock inspection in 6 months. The results of the oil analyses are clear and clearly demonstrate the effectiveness of the CJC® Thruster Filter.”

Contact your maritime technical salesperson now

You would like to know more about the customer case? Let us start a conversation

Receive detailed information on the oil analyses, savings and calculations and a personal consultation specifically on your thruster, your gear oil and your requirements and goals.

Write or call me.

Andreas Mann
Andreas MannKey Account Manager - Marine Segment
Mobile: +49 (0)151 12 88 38 05
Fax: +49 (0)40 855 04 79 – 20