Bow Thrusters of North America
Home    –    Service    –    Products    –    History    –    Contact    –    Example of Installation

Products > Stabilizers and Control Systems > NAIAD Roll Stabilizers > Model 254

Model 254


Model 254


For vessels from 55-85ft (16-26m)

The NAIAD Model 254 Fin Actuator Assembly is designed for efficiency, power and rugged reliability. It is supplied completely factory tested under pressure, assembled and ready for installation including all required hardware and fittings. Unlike other systems, no disassembly is required for installation. NAIAD Fin Actuator Assemblies are recognized the world over as the industry standard for excellence.

The hardened and passivated stainless steel fin shaft, supported by dual heavy-duty tapered roller bearings within a reinforced cast and machined housing, features a precision-machined self-locking taper for secure connection with the fin on one end, and a high capacity splined connection to the torque arm on the inboard end. This installer-friendly design allows the Assembly to be mounted in any convenient angular (360°) orientation. The powerful double acting hydraulic cylinder rapidly and accurately positions the torque arm, shaft and fin, as commanded by the stabilizer's control system, using hydraulic servo valves with closed-loop continuous direct-acting fin position feedback. Double lower shaft seals mounted in a stainless steel retainer keep the factory-applied severe duty marine bearing grease in and seawater out. Guaranteed leak proof, NAIAD seals benefit from the extraordinarily precise machined fits obtained in NAIAD's state-of-the-art manufacturing facility. The Model 254 is built to last and is virtually maintenance-free.

Standard Fin Sizes: 3 sq.ft. (0.28 sq.m), 4.5 sq.ft. (0.42 sq.m), 6.0 sq.ft. (0.56 sq.m), 7.5 sq.ft. (0.70 sq.m), 9.0 sq.ft. (0.84 sq.m).
Fin Attachment: Precision machined oversized self-locking taper.
Main Shaft: 2.5 in. dia. (63.5 mm) heat-treated stainless steel.
Fin Actuator Housing Material: High-strength ductile iron; 2.5 times stronger per square inch than aluminum.
Upper AND Lower Bearing: Heavy-duty tapered roller bearings by Timken (TM), the best in tapered roller bearings.
Lower Seal: Two double-lip seals for maximum seawater protection. Easily accessible in a 316 stainless steel retainer.
Upper Seal: Double-lip, spring-loaded seal for maximum grease retention. The double-lip design also provides protection of the fin actuator against external contaminants.
Lubrication: Pre-packed with high quality Lubriplate (TM) water-resistant grease for lifetime maintenance-free service.
Hydraulic Connections: SAE O-ring ports and (JIC) 37° fittings (not pipe fittings) for leak-free service.
Hydraulic Cylinder: Custom engineered for NAIAD stabilizer applications in collaboration with a world leading cylinder manufacturer. Double acting. Steel body construction with high strength tie rods for heavy-duty service. Self-regulating shock reducing cushions. Teflon seals throughout.
Cylinder Mounting: Head Trunnion mount allows most compact Fin Actuator design. Trunnion freely pivots in dual high capacity roller bearing assembly.
Maximum Working Pressure: 3000 psi (207 bar)
Cylinder Bore Diameter: 2.00 in. (50.8 mm)
Rod Diameter: 1.00 in. (25.4 mm)
Rod End: Spherical rod ends with a permanently bonded fabric liner for maximum wear protection.
Rod End Pins: Through-hardened, ground and passivated stainless steel.
Torque Arm: Cast and heat-treated high strength alloy steel, cadmium plated for corrosion resistance. Honed bore for precise Rod End Pin fit.
Shaft-Torque Arm Connection: Oversized clamp-type spline for maximum torque capability.
Overall Weight: 150 pounds (68.0 kg)
Overall Dimensions: See dimensional drawing.
Fit & Finish Throughout: High 'yacht' quality, painted, plated and polished.


NAIAD Model 254 Dimensions

Copyright © Bow Thrusters Of North America
Site design by Solar Flare Studios with Tommy Solomon as Creative Producer