Long-Term Humidity Control for Container Ships in Lay-Up

Wilhelmsen Ship Management operates, stores and repairs commercial container ships across a global fleet.

Vessels are periodically laid up in safe harbours for six to eighteen months between operational cycles, and that idle period is where the moisture damage happens.

Results at a Glance

• 36 units delivered to a global fleet
• 7+ years running without fault
• 6 to 18 month lay-up periods covered
• Scaled from a trial order after performance was confirmed

The Challenge

A vessel under way is ventilated, heated by its own machinery and constantly attended. A vessel in lay-up is none of those things.

Sealed spaces in a tropical harbour become condensation traps.

The exposures during lay-up:

• Condensation and corrosion inside control systems
• Moisture damage to navigation and electrical components
• Humidity accumulating in sealed bridge and control spaces with no air exchange

Replacing marine navigation electronics after a lay-up costs far more than controlling the air they sit in.

Our Solution

Moisture Cure recommended the AMDZ-136 commercial dehumidifier for the application.

It was selected for:

• High-capacity moisture extraction relative to the enclosed volumes
• Durability in enclosed, salt-laden shipboard environments
• A compact form factor that fits shipboard access and space limits

What began as a small trial order scaled to 36 units once performance was confirmed across the first vessels.

Delivery involved travelling to Malaysia, negotiating directly with the client’s team on site and overseeing installation across the fleet.

Results and Impact

Reported outcomes:

• 36 AMDZ-136 units delivered and operating without fault
• Bridge and control space humidity managed successfully across multiple laid-up vessels
• Systems still running reliably more than seven years later
• A Port Macquarie based supplier delivering into a global fleet operation

“We felt like David facing Goliath, but we delivered, and the systems have been running flawlessly for over seven years.”

Moisture Cure project team

Lay-Up Is a Different Problem to Operation

An operating vessel manages its own internal climate as a side effect of running.

Lay-up removes every one of those mechanisms at once.

What changes when a ship goes idle:

• Machinery heat disappears, so internal surfaces track ambient and reach dew point overnight
• Ventilation and air conditioning are shut down, ending air exchange in enclosed spaces
• Spaces are sealed against weather and intrusion, trapping whatever moisture is already inside
• Nobody is aboard to notice condensation forming on control and navigation equipment

Six to eighteen months of that cycle is enough to write off electronics that were serviceable on the day the vessel was laid up.

Related Solutions

• shipbuilding and marine humidity control. Lay-up protection and build-phase control share the same corrosion mechanism.
• defence equipment storage moisture management. Long-term preservation of idle high-value assets follows the same principles.
• AMDZ-136C3 ducted dehumidifier. This is the current model of the unit supplied to the fleet.

Protecting Vessels and Assets in Lay-Up

Idle assets deteriorate quietly, and the bill arrives at recommissioning.

Contact Moisture Cure Commercial for lay-up and long-term storage humidity control.

Contact Moisture Cure Commercial for expert sizing advice on your application.