The Hamiltons get a new prop shaft after 9,500 hours on their Nordhavn 52

Dirona Shaft © Peter Jansse

Back in December, James and Jennifer Hamilton, the globe-circling, high-tech cruising couple from Seattle, passed the 9,500-hour mark on the single 265-hp John Deere engine that drives their Nordhavn 52. That was in the North Atlantic. Since then they cruised to Ireland and then England, where, starting on Jan. 9, they decided to replace the cutlass bearings on the rudder shaft and on the wing and main prop shafts as well. They were at Saxon Wharf in Southampton.

Hamilton gives a blow-by-blow account of what happened next, with pictures, all on their website (mvdirona.com). Here's the short version:

• They loosened the rudder bolt so they could inspect the rudder bearing.

• They removed the prop so they could change the cutlass bearing. The prop had not been off the boat since they bought it in 2010.

• Then they found rust and deep pitting in the main shaft. It was an Aquamet 17, badly corroded. Nordhavn now uses Aquamet 22 shafts in their new 52s. They needed a new shaft.

• They saw failure in the cutlass bearing.

• They replaced the Gori wing engine prop.

• They removed the rudder foot to check the bearings; the lower bearing needed to be replaced.

• They had a new lower rudder bearing fabricated at E. French & Son, a local shop.

• They installed the new prop shaft and replaced the rudder cutlass bearing.

After pulling the boat and the shaft, they found that the issue involved the prop shaft run-out; there had been some metal transfer from the old shaft taper onto the side of the coupling, which prevented the shaft from fitting accurately. They eliminated it and relaunched on Feb. 8.

Finally, the Hamiltons cruised up to London, where they are now. The shaft is running within tolerance.

They plan to cruise to Norway this summer and return to the U.S. in 2020. Stay tuned!

Quick Links:

• mvdirona.com/2018/04/cutlass-bearing-replacements
• nordhavn.com