Domain · Hydrodynamics & drivetrain
Marine propulsion
Marine propulsion is unforgiving: every kilogram, every decibel, every cubic centimetre shows up in range, signature, and yard time. 4XD treats the under-keel world as a full system — structure, shaft line, appendages, and power density — not a catalog of parts.
Conceptual under-keel study · lighting is the product surface
Design principles
- 01
Hull–appendage–propulsor as one conversation
- 02
Power density without theatre packaging
- 03
Service paths that yards will still respect in year five
- 04
Disclosure stages that protect IP while inviting the right partners
Active stack
Marine & propulsion work
Stages and disclosure levels stay explicit. What you see matches what we can say.
Harbor Drive
Compact marine drivetrain topology
A drivetrain architecture meant for harbor and coastal envelopes: high torque at low speed, tight packaging under the waterline, and service paths that yards can actually execute.
Quiet power density for constrained hull envelopes — fewer compromises between range and payload.
Keel Node
Structural interface for modular platforms
A modular structural node family so appendages, sensors, and propulsion packages share a repeatable load path instead of one-off steel poetry every time.
One honest mechanical language across prototypes that used to refuse to talk.
Wake Shear
Appendage flow package for cleaner stern wake
Geometry and surface treatments aimed at organizing stern flow before it hits the propulsor. Measured first as hydrodynamics, then as system-level efficiency.
Less wasted energy in the wake means more range for the same installed power — or quieter power for the same range.
Shaft Line X
Low-signature shafting & bearing stack
From strut to stern tube: a stack that prioritizes alignment stability, serviceability, and acoustic hygiene under real hull flex.
Bearing, alignment, and seal choices that treat vibration as a first-class design input, not a late surprise.
Pulse Casing
Thermal-mechanical enclosure family
Enclosures and thermal paths for dense power electronics and actuators where salt air, shock, and access all have opinions.
Containment geometry that earns trust before it earns a datasheet.
Build with us under the line
Suppliers, yards, and partners who care about fit — not just brochure power curves.