Intermediate Strut Alignment

Intermediate Strut Alignment

We are working on another Horizon that is in need of a strut alignment.  This vessel has a cutless bearing in the forward end of the stern tube, an intermediate strut and a main strut.  With three bearings supporting the shaft, the need for an accurate alignment increases.  The minor bends in the shaft when the intermediate bearing is out a small amount will cause vibrations at the higher RPMs.  In this case, both port and starboard intermediate struts were out of alignment to the tube and main strut.  Realignment of these struts is not a huge job if the shafts are removed.  The strut bolts have very good access and since it is only the small intermediate strut it is relatively light and easy to handle.  As with all strut alignments, it starts with adding jacking screws to the corners of the pad and threaded rod in the strut bolt holes.  Using the Optical Scope Alignment system , we can align the strut within a few thousandths of an inch.

Once the strut is in place, a solid bedding compound locks it permanently to the bottom of the hull.  Finally, drill the strut bolt holes and bed them in 5200 to finish the job.

Intermediate Strut Newly Aligned

A strut alignment is not a big job if done when the shafts are out.  Next time you need to have routine maintenance on your running gear (replacement of cutless bearings and shaft seals) make sure you work with a company that is an expert with running gear.  Hiring a specialized expert will gain you the extra repair items that the average mechanic might miss.

You might be surprised to find out that a small vibration can be cured and is not just ordinary.  Give us a call and we can talk about more details on your next project.