NYK Tail shaft conservation in Kobe, Japan

Execution time: 4½ days. Carried out by 2 Cocoon engineers.

Conserved parts: 1 propeller. 1 tail shaft of 3 same LNG tankers.

In the bustling port of Kobe, a strategic project unfolded, commissioned by Fuji Trading Co. LTD on behalf of NYK.

The mission?

To secure the longevity of crucial spare parts for LNG tankers over their extensive economic and technical lifespan of 30-40 years.

This case study showcases the successful implementation of the Cocoon Mothballing System for the preservation of a propeller and tail shaft from three of the same LNG tankers, stored in the open air.

Let’s dive into the details of this environmentally friendly, cost-efficient solution.

Challenges Met and Overcome:

We had to shield the workplace so that the immediate area was not affected by our work and that the cars would not get covered in spray dust, Cocoon is almost dry after only 20cm. We installed special work tents to prevent this.

Since Kobe is located in a Typhoon area and these parts are 8 metres from the quay, we opted to apply extra layer thickness so that the Cocoon can withstand this force of nature even better.

We placed the air dryer in the crate so that it cannot be hit by the waves and is extra high from the ground.

The client’s primary objective was to find a simple yet effective preservation solution for the propeller and propeller shaft, ensuring their availability and functionality for the tankers’ entire lifespan.

Two Cocoon engineers undertook the project in Kobe, Japan, overcoming unique challenges posed by the location and project conditions.

Implementing the Cocoon Mothballing System:

To safeguard the propeller shaft, the Cocoon Mothballing System was meticulously applied, employing the following steps:

  1. Spacer Hoses: Spacer hoses were installed to maintain a gap between the Cocoon skin/envelope and the surface, ensuring optimal preservation conditions.
  2. Cocoon Foil: Cocoon foil was applied, providing a protective barrier.
  3. Reinforcement: Connection seams of the Cocoon foil and steel foundation plates were reinforced, guaranteeing a robust and secure enclosure.
  4. Cocoon 550: Multiple layers of Cocoon 550 were applied, further enhancing the system’s protective capabilities.
  5. Air Circulation System: An air circulation system, consisting of PVC pipes, was connected, facilitating the regulated flow of air within the cocooned area.
  6. Air Dryer: An air dryer was strategically placed to maintain optimal moisture levels, preventing any potential damage.

Addressing Unique Site Conditions

Working within the constraints of the project site, which was situated approximately 8 meters from the quay in a car park, the Cocoon team took extra measures to minimize disruptions and protect the surroundings.

Worksite Screening

To ensure minimal disturbance to the immediate surroundings, the worksite was securely screened off. This prevented spray dust from reaching nearby cars, as the Cocoon system dries quickly after only 20cm.

Special Work Tents

Special work tents were installed, providing an additional layer of protection against potential spray dust and safeguarding the integrity of the preservation process.

Adapting to Environmental Challenges

Considering the port’s typhoon-prone location and the propeller and propeller shaft’s proximity to the quay, the Cocoon team proactively reinforced the preservation system:

  • We Enhanced Layer Thickness: Extra layers of Cocoon were applied, fortifying the system’s resilience against the forces of nature, including the region’s typhoons.
  • Elevated Air Dryer: To shield the air dryer from waves and ensure its safety, it was positioned inside a crate at an elevated height above the ground.

Successful project completion

With meticulous planning, efficient execution, and regular client interactions, the project progressed seamlessly.

The Fuji Trading team visited the worksite daily, witnessing the progress and addressing any additional requirements.

Ultimately, the customer expressed utmost satisfaction with the final outcome—a secure, cost-effective, and environmentally friendly preservation solution for the propeller and propeller shaft.


The NYK Tail Shaft project in Kobe exemplifies the effectiveness of the Cocoon Mothballing System in preserving critical spare parts for the LNG industry.

Overcoming site-specific challenges and environmental factors, the project showcased the system’s simplicity, cost-efficiency, and environmentally friendly nature.

The success of this endeavor ensures that these spare parts, the propeller and propeller shaft, will remain in optimal condition throughout the economic and technical lifespan of the tankers, which spans an impressive 30 to 40 years.

Need help? Feel free to contact us!

We’re aiming to establish an LNG storage site in Singapore area (Malaysia), Middle East (Dubai) and at customer request in other location.

The storage depot consists of halls and outdoor storage and are accessible by water so that screws and other large component can be supplied and removed.

If you are interested in the above location, I would like to get in touch with you so that this can be realised.

Alexander van der Zee

Alexander van der Zee

Owner, Cocoon Holland B.V.

We are a company located in Hoofddorp, a town nearby the airport, and we also have our dedicated storage facilities in Drachten, the north of The Netherlands where we store spare parts of LNG carriers. Our company has existed since 1972, meaning we are a well-known party, especially in the LNG sector. Cocoon is weatherproof, perfectly applicable to any organic form and is extremely low in weight.