Shipyards and marine construction sites face some of the toughest electrical challenges anywhere — delivering power safely and reliably across constantly changing environments. Whether you’re energizing welding stations, cranes, or onboard systems, temporary power has to work — from ship to shore, day after day.

To keep your power flowing, here are four questions we hear most from engineers, project leads, and maintenance crews — and what we’ve learned from helping them solve it.

1. How is shore power distributed on ships and piers?

Docked vessels often draw power from the shore — or, if needed, from a generator nearby. That high-voltage feed (typically 480V) gets stepped down through portable power distribution units (PDUs) into usable outputs for tools, cranes, lighting, and onboard systems.

Because layouts change daily, crews rely on mobile, stackable PDUs built from weather-resistant NEMA 3R enclosures to create flexible “power zones” that move with the project. It’s a setup designed for mobility — and built for the constant motion of shipyard work.

2. Which cables and connectors hold up in marine environments?

Salt, vibration, and constant movement can quickly wear down ordinary connections. That’s why every component — from the cable to the coupler — has to pull its weight.

The marine standard usually includes:

• Heavy-duty cable assemblies with molded ends, internal strain relief, and corrosion-resistant contacts
• IEC 60309 Pin & Sleeve connectors, plus other options common in a marine-environment such as CS-type, and Camlock
• Cable protectors for safe routing across docks and decks, preventing tripping hazards and abrasion from forklifts or cranes

Understanding IP Ratings

Power systems in marine environments are constantly exposed to the elements — so ingress protection (IP) ratings matter. An IP67 rating means the device is fully dust-tight and can withstand immersion in up to one meter of water for 30 minutes.

That level of protection makes IP67 products a trusted standard across shipyards, marinas, and industrial sites where equipment faces spray, rain, or temporary submersion.

While some applications call for higher ratings like IP69K, designed for high-pressure washdowns, IP67 remains the practical, field-proven choice for most outdoor power distribution. It delivers reliable protection where consistency and uptime matter most — keeping your system stable in a constantly shifting environment.

3. When do I need a custom power unit?

Off-the-shelf PDUs handle most day-to-day needs — usually offering standard 5-20R duplex outlets and a few passthrough options. But when your project lives near water or involves diverse loads, a custom marine PDU can be the difference between smooth sailing and constant resets.

Custom marine PDUs are built with IP67-rated outlets for dependable ingress protection in wet or high-humidity conditions. Each receptacle is individually sealed, equipped with a weather cover, and protected by its own mini circuit breaker to guard against overcurrent. These turnkey builds cut installation time, simplify wiring, and perform reliably with moisture, heat, and movement — all at once.

A few proven examples:

• HEB362U — Compact and portable, this one-tier 20A PDU is a favorite for marinas, service docks, and small vessels. Just plug in, power up, and go — every outlet is GFCI-protected and sealed against weather.
• 649230CU — When you’re powering cranes, welders, or heavy equipment, this double-tier Camlock-fed unit is built to perform. With eight 50A CS-type receptacles and breaker protection on every line, it handles high-load marine operations with steady reliability.

4. Can the same equipment work on ships and shore?

Yes — when it’s built for it. Every Walther PDU features a durable NEMA 3R enclosure that resists rain, corrosion, and impact — perfect for pier-side use. For direct spray or washdown areas, IP67-rated outlets seal out dust and water.

Together, those ratings help ensure safe, reliable performance whether you’re docked, underway, or working pier-side.

The Bottom Line

Temporary power isn’t an afterthought — it’s critical infrastructure. Walther Electric designs systems that keep work moving: from standard off-the-shelf PDUs to fully custom, marine-grade units built to your exact requirements.

Learn more about marine and shipbuilding power systems: Marine & Shipbuilding Markets

Shop PDU models: Portable Power Distribution Units (PDUs)