Finally, a Stern Tube Bearing Guaranteed to Last the Life of the Vessel!

Lifetime Bearing Wearlife Guarentee

Our COMPAC bearing system is proven to last!  We have references on 550+ commercial vessels that use seawater lubricated shaftlines and we are backing that up with a lifetime bearing wearlife guarantee.

Thordon is offering this guarantee because of the proven performance and wear life with the COMPAC propeller shaft bearings operating in commercial vessels over the last 25 years.   Using the proven principles of seawater lubrication, Thordon’s COMPAC propeller shaft bearing system will reduce your operating and maintenance costs with its reliable performance.  We don’t believe in selling spare parts!  The 100% pollution free system is future compliant and has zero environmental impact.

Get on board and find out for yourself why Thordon is the proven choice.

“It's a No Brainer! A seawater lubricated shaft means there is less to worry about.”

– Andy Wright, Fleet Operations Director | Technical Operations,
Holland America Group | Serving Princess Cruises

COMPAC System Strip

COMPAC Lifetime Bearing Wearlife Guarantee

The Thordon seawater lubricated COMPAC bearing is guaranteed to meet Classification Society propeller shaft bearing wear specifications for the lifetime of the vessel or Thordon Bearings will supply new bearings free of charge.*


Commercial newbuild ship owners of Classed ships with stern tube (single/twin screw) with shaft diameter of 300mm (12”) or greater. The program excludes vessels such as naval/coast guard/government vessels.  COMPAC conversions may also be considered on a case by case basis.


The ship owner must clearly specify the complete COMPAC system (see below) to the shipyard in order to qualify for the lifetime bearing wearlife guarantee. There will be a full technical signoff by Thordon Bearings prior to issuance of the lifetime wear life guarantee.   A copy of the specification is available from Thordon.

COMPAC Propeller Shaft Bearing System:

The COMPAC propeller shaft bearing system specification includes:

a) COMPAC propeller shaft bearings for shafts of 300mm (12”) or greater

b) Thordon Water Quality Package

c) Shaft liners

d) ThorShield shaft coating

e) Forward seal (SeaThigor or Blue Water or seal approved by Thordon Bearings)

Items a, b, c, and d must be supplied by Thordon. Item e must be approved by Thordon before issuance of the guarantee. If bearing carriers are a required part of the design, they would also be supplied by Thordon Bearings.

* What is the Guarantee?

The Thordon seawater lubricated COMPAC bearing system is guaranteed to meet Classification Society propeller shaft bearing wear specifications for 25 years or Thordon Bearings will supply new bearings free of charge. The guarantee is limited to the supply of replacement bearings delivered to the ship. It does not include replacement of any other Thordon supplied components nor any drydocking or installation costs.  Standard operating parameters as specified by Thordon Bearings (for example – system maintenance, minimum water flows, etc.) must have been provided and maintained by the ship owner.

The guarantee is limited to the owner of the ship. If the ship were sold, the balance of the time outstanding on the guarantee can be transferred to the new ship owner for a fee (25% of price of fully machined set of bearings). The guarantee would be issued by Thordon Bearings directly to the shipowner or his designate and would not be offered through the shipyard.

Thordon is offering this guarantee because of our confidence in Thordon COMPAC propeller shaft bearings and the proven experience and wear life of COMPAC bearings operating in commercial vessels in the last 35 years.

Propeller Shaft Bearing



Thordon COMPAC is a high performance water lubricated bearing system primarily for “blue water” operating conditions. Specially formulated with a low coefficient of friction to reduce startup friction and eliminate stick-slip,

Learn More

Shaft Coating



Thordon's ThorShield propeller shaft coating system provides corrosion protection against seawater. This toughened, 2-part epoxy coating is up to nine times more flexible than existing shaft coating products.

Learn More

Water Quality Package



Thordon Water Quality Package is designed to supply seawater to the propeller shaft bearings for lubrication and cooling while condition the seawater by removing suspended solids.

Learn More

Shaft Seals

Seal installed on Hudson low res (crop)


The Thordon SeaThigor Seal is a mechanical face seal for 300mm (11.8") to 750mm (29.5") water lubricated propeller shafts found in yachts, cruise ships, merchant ships and naval vessels. The SeaThigor has evolved from a design first tested in 2003 and improved during the next decade.

Learn More


Technical Papers


Class Society Requirements For Extended Shaft Withdrawals



The final (fully finished) sizing of a Thordon elastomer or ThorPlas bearing can be determined by using the Thordon Bearing Sizing Calculation Program.

You cannot run the Thordon Bearing Sizing Calculation Program Version 2017, Release 10 without a User Registration Number. Once you have a User Registration Number you can download the Program below and enter it when prompted.

Click here to Request a Bearing Sizing Program User Registration Number

If you have a Bearing Sizing Program User Registration Number, you can download the program here


Find My Thordon Contact

Our Newsletter

View All Recent News

  • News Thumbnails 320x160_NW19-Mar

    Thordon Marine NewsWorks 2019

    Thordon’s web-based newsletter specifically developed for marine users of oil-free and grease-free bearings. This newsletter includes feature articles about our Lifetime wearlife guarantee on COMPAC propeller shaft bearings, our continued success on Viking Cruise ships, our accomplishments with COMPAC and SeaThigor on Canadian Coast Guard vessels, the Elmer A. Sperry Award as well as other awards Thordon received for our innovative products.
    Learn More

Recent Marine News

View All Recent News

  • ThordonNews-COMPACWarehouse-thumb

    MSC Cruises Returns to Thordon to Keep the Seashore Clean

    Oct 16, 2019
    Thordon Bearings has received an order to supply a water-lubricated propeller shaft bearing solution to Fincantieri’s Monfalcone shipyard for installation to MSC Seashore, the third Seaside Class cruiseship to which Thordon’s COMPAC system has been specified. The order follows the in-service performance success of COMPAC installations aboard the 154,000gt sisters MSC Seaside and MSC Seaview, delivered in 2017 and 2018, respectively.
    Learn More
  • News-Thumbnails-320x160_OilPollution

    Continued Use of Oil Lubricated Shaft Seals Counterproductive to Environmental Legislation

    Jun 20, 2019
    Media reports indicating the potential volume of lubricating oil polluting the world’s seas and oceans due to shaft seal damage or failure should send a clear message to Administrations that this frequently overlooked source of pollution needs to be quickly addressed.
    Learn More