Boss Enclosed Shaft Systems

The Only Multiple Award Winning Inboard Propulsion Alternative.
The BOSS™ system is the internationally acclaimed Bolt On Shaft System by Seatorque Control Systems.
The BOSS™ is a totally enclosed, oil filled, self contained, shaft and thrust bearing assembly, supplied as a complete unit from transmission output coupling to propeller end. Based on over 14 years of research and development, and covered by numerous Patent applications, the BOSS™ delivers.

Boss Bolt on Shaft SystemRubber mounting to the hull structure, with a flexible connection to the propulsion engine, ensures shaft-line noise and vibration are eliminated at the source. The non-rotating, full length shaft casing and thrust bearing assembly minimizes mechanical losses to only 2%, leaving valuable extra power where you want it… for propulsion. The BOSS™ further delivers unrivaled ruggedness in operation coupled with the lowest underbody drag of any system currently available.

Installation Time Slashed

With the BOSS™ technology, engines and shafts are installed within hours not days, improving production economics by reducing labor costs and shortening line time. 
No time consuming and costly shaft/engine alignments during vessel construction or after delivery. No costly design changes required to existing tooling, hull structure or engine installations.

Driveline Noise & Vibrations Eliminated

By Rubber Mounting the system to the vessel, thrust is delivered to the hull structure not the engine, and noise is contained, not transmitted. The shaft is supported full length within the outer casing, holding the shaft straight and eliminating potential shaft whip, the major cause of vibration. Thrust is eliminated from the engine foundation, increasing the life of engine isolators and reducing engine vibration to the absolute minimum that the isolators can provide.

No Installation Space Restrictions

The BOSS™ fits within the same amount of space as a traditional system and will often take less room when the builder takes advantage of the free engineering support from Seatorque. No space lost under cockpit soles or to aft cabin layouts.

Recommended for High Horsepower Applications

  • No Horse Power restrictions, the BOSS™ is available in ratings up to 3000 HP per shaft.
  • Shaft diameters from 1 inch up to 4 inch in production and up to 6 inch for special applications.
  • No costly, maintenance rich, small, complex, multi engine propulsion packages, just to deliver the horse power needed.

More Power Released for Propulsion, Without An Engine Upgrade

Reduced turbulence through the propeller due to the non rotating shaft casing, plus eliminating cutlass bearings and stuffing boxes allows for an average* of 8% extra delivered Horse Power to the propeller.  

Calculate the cost of upgrading to the next size engine in Horse Power terms, and the BOSS™ makes sound economical sense.

Reduced Drag

A traditional, exposed, spinning shaft produces Active, Vortex, as well as Passive Drag. By eliminating the rotational aspect of a traditional shaft, only Passive Drag remains producing very little in the way of robbed horse power. In short…  

The BOSS™ system equals the lowest drag factors claimed by any other systems on the market.

Peace of Mind

No outdrive type appendages, vulnerable to damage if impacted or bottomed out. No additional gear cases and shafts requiring regular routine maintenance and repair. No costly multiple propellers to damage in the event of contact with debris or worse.

Less maintenance and running cost

  • 3000-Hour, or three-year extended maintenance cycle, only involving changing the shaft oil.
  • Major overhaul is recommended at 10,000 hours or ten years.
  • No leaking stuffing boxes or dripless shaft seals, keep engines and bilges clean and dry.
  • No more costly dockside service for engine re-alignment, or Cutlass bearing replacement.
  • Increased propulsive efficiency ratings result in greater range through fuel economy.

Safety at Sea

No reliance on complex electronic control systems. The BOSS™ is a mechanically engineered solution, providing all the attributes that ocean going vessels rely on, sound engineering principles.

Ease of Operation

 No shaft rattling or banging. Backing down and hard maneuvers are smooth and silent. Arrive at your destination relaxed after a quite passage.

Worldwide Warranty, Service & Spares Support

Full 2-year or 500 hour Limited International Warranty. Worldwide sales and service support. Seatorque carries a full inventory of spare parts, most available worldwide within 24 to 48 hours.

Optional Accessories

  • Purpose Designed, Cast Strut
  • Shaft Temperature Gauge Panel 12v or 24v (Only available on certain Models – Please enquire
  • Owners Spares Kit
  • Seatorque Shaft Oil – Case Qty
*All performance claims herein are approximate representations and are not warranted. Actual results will vary depending on particular vessel parameters and mechanical specifications.