Kiwiprops™

  • Increase font size
  • Default font size
  • Decrease font size

KFP - Spare Blades

 

We are frequently asked as to the merit of ordering a spare blade or spare blade set when purchasing a propeller.

Kiwiprops are unique in that they have been designed using the predictable material attributes of composites to sacrifice a blade or blades when the unit impacts a substantial foreign object.

This will eliminate damage to the drive train by way of shaft, coupling and gearbox failures.

Any rotating machinery that is brought to a sudden stop and is connected to an engine which has a heavy flywheel - typically rotating at ~ 2500 rpm and driving via a reduction gear will generate sufficient torque upon impact with an immovable foreign object eg floating timber to almost invariably damage what is always a very expensive drive train.

Rope wraps will not damage the unit - but may still damage the drive train. We have examples of sheets becoming caught, stalling the engine and breaking the entire gearbox from the bell housing of the engine with no damage to the propeller.

We believe that the loss of blades at US $ 110 each is a preferred outcome to the alternative - namely expensive drive train damage.

The blades can even be easily changed underwater with the simplest of tools and the utility of this sacrificial approach has been proved time and again.

We do not charge freight on blades ordered and shipped with the propeller - so there is a substantial saving in ordering at least a spare blade with the original order coupled to the benefits of having it onboard if ever required.

Vessels going offshore or to remote coral or ice areas or operating in areas with sunken logs would be advised to carry a spare set of 3 blades. The design of the unit with injection molded composites makes this approach economic.

All spare blades are shipped with a full set of fittings: Pitch screw, grease screw and neoprene seal. All blades are fully backwards compatible. Any blade will fit any propeller. (Current 50 % glass content blades have a higher mass than the earlier 35 % glass blades and should not be mixed due to the slightly differing mass)

Unless requested otherwise we ship spare blades ordered subsequently with 18 deg (ie minimal) pitch set on the blades as unless we are advised of the current setting we can not be sure the pitch has not been altered by the owner or previous owner to what we originally supplied. Obviously the pitch must be the same on each blade to avoid vibration.

Blades ordered with the propeller are shipped with the same pitch as the propeller.

On balance we would suggest users order at least one spare blade with their propeller order and if operating in a high risk area of ice, corall or floating timber a set of three spare blades.