Archive | Naiad

Bringing New Life Back to an Older 112’ Westport Yacht

We are seeing a growing number of new owners of older 112’ Westports. This “Made in America” production boat has a lot to offer but many of these vessels are purchased without a solid maintenance history. Nevertheless, their new owners/Captains still want to bring them back to life.  In order to do that, sometimes a total refit of the vessel is required.

One of these new owner refits spent a few months at LMC getting a full paint job, mechanical upgrades, interior work and hydraulic systems overhaul and refurbishing. Our capable team of hydraulic technicians was tapped to handle all the hydraulic projects.

Starting with the Naiad stabilizer system, we did a full rebuild including removing the shafts and bearings.  The entire stabilizer actuator system was also rebuilt back to new.  The stabilizer shaft had some corrosion in the lip seal area from sitting too long in salt water so our on-site machine shop, Straight Line Marine, performed a cladding repair.

We then moved on to work on the entire hydraulic central system where we performed a full hydraulic fluid flush, cleaned and pressure tested the heat exchangers and changed all the filters.

In the engine room, we found that we needed to change a large number of the hydraulic hoses.  Hydraulic hoses have a 10-year life and can cause huge problems when they fail on the high-pressure side so it is very important to inspect and replace them during routine service.

We also did a little work on the bow thruster, installing new seals in the lower leg, adding fresh gear oil and testing the hydraulic motor.

Stainless steel ring on main gear

Our team did a full rebuild on the single Maxwell 4500 windlass on the bow, down to the gear box including installing new seals and bearings.  As part of the rebuild, Straight Line Marine also fabricated new stainless steel rings for the main gears to help prevent future gear oil leaks around the lip seals. We also replaced the small Maxwell 2500 capstans in the stern with new electric units due to the cost of installing new versus re-building these smaller units.

We found the steering system to be in good shape.  There were no leaks on the cylinders so these were left alone.  We did, however, replaced a few hoses and upgraded some of the ball valves to stainless steel to help prevent future corrosion.  Finally, we changed the fluid and filters.

This was a big job from start to finish but our talented hydraulic technicians, supported by our in-house machine shop, were more than capable of tackling every hydraulic system from bow to stern and everything in between.

Repair, Service and Maintenance for Vosper Stabilizers

It is not uncommon to find Vosper stabilizers in many older yachts and ships. What is uncommon these days is to find a company that specializes in the repair, service and maintenance of the older units. VT Motion, the company that supplied Vosper stabilizers, was acquired by Naiad in 2009 and absorbed into its Naiad Maritime Group.

Increasingly, we hear from many ship’s captains and owners that when they seek to maintain their Vosper stabilizers, they are often urged or even forced to upgrade and replace these stabilizers with newer models. It seems that the major stabilizer companies are shying away from Vosper in lieu of recommending a major upgrade – an upgrade that can be expensive and time consuming.

At High Seas Hydraulics, we specialize in the repair, service and maintenance of all types of stabilizer systems including Vosper, Naiad, Quantum and others. If you are looking for expert hydraulic technicians to work on your stabilizer systems, whether older models like Vosper or newer ones on the market today, look no further than High Seas Hydraulics.

 

Whether you need hydraulic repairs, running gear work or shafts straightened – High Seas Family of Companies is here to serve

It’s not unusual for mega yachts to haul out at Lauderdale Marine Center requiring extensive work on multiple parts of the boat. That was the case for a 135 foot Broward yacht when she came into the yard. The Captain of the yacht approached High Seas with a laundry list of requirements that included hydraulics and running gear jobs. High Seas is unique in the sense that we have the expertise to work on both areas, providing a central point of contact that can help to design the most efficient work flow through coordinated schedules.

For this yacht, we were hired to:

  • Perform a full NAIAD 505 service with shafts out and new bearings
  • Do a full rebuild on the Hydraulic Steering System including removing the HPU and replacing hoses
  • Reinstall PTOs on new generators with new hoses
  • Refurbish the steering cylinders
  • Remove rudders for a bearing inspection and repack stuffing boxes
  • Remove shafts for new bearings, packing and alignment
  • Complete removal and rebuild of Maxwell 11000 windlasses

In coming posts, we will walk through the steps we took to make this yacht ship shape again.

Stabilizer shaft cladding to repair corrosion found during 10 year service process

A 130 foot Westport Yacht was recently hauled at Lauderdale Marine Center for routine service and maintenance. While in the yard, High Seas Hydraulics was contracted to overhaul the stabilizers and perform a standard 10 year service process on them.

Stabilizer shaft cladding

Once the stabilizers were removed, we found that the stabilizer shafts were corroded to the point that we needed to call on our machine shop, Straight Line Marine, to perform a process called shaft weld-overs, also known as cladding (or incorrectly “metalizing”). Shaft weld-overs or cladding is the process of repairing a worn or damaged area on a shaft.   Stainless steel shafts can be damaged by excessive wear in contact areas, such as bearings or seals, due to long life or misalignment. Shafts can also be damaged from crevice corrosion or stray current corrosion.

Typically, if the wear is smooth and less than 0.010″ deep it is acceptable. Any crevice corrosion, stray current corrosion or wear in a lip seal area must also be repaired since lip-seals such as Naiad or Tides Seals need a smooth surface to maintain water tight integrity.

Stabilizer shaft on lathe

When repairing a shaft, it must be placed in a lathe and have the damaged area turned down to remove the damaged area.  Never more than 0.125″. The area is built back up using semi-automatic MIG welding while slowly turning in the lathe. After cooling, the shaft is turned back down to close to the original shaft diameter.

Expert weld-overs cannot be detected by eye or feel once complete.

Finished product

Maintaining your stabilizer systems – what to look for before they fail!

A 100 foot Marlow yacht was recently hauled at Lauderdale Marine Center for routine maintenance that included her running gear, hydraulics, topside paint and other services. The captain turned to High Seas Yacht Hydraulics for the ship’s hydraulics inspections on her stabilizer and our sister company, High Seas Yacht Service for her running gear.

marlow v2The boat had a Naiad stabilizer and hydraulic system. During our inspection of the stabilizers, we found evidence of grease passing through the inner seal housing. This is a maintenance requirement that should be performed every 2-3 years or sooner based on the grease pushing past the inner seals. That is a sign of the outer seals failing and allowing water to pass through into the bearing housing. Typically, this is due to normal operation, wear and tear, but can be the result of inferior seals that were used when the technician is not properly trained in the servicing of these stabilizers. 

To remedy the situation, you must first hydraulically remove the fins, top plate assemblies, upper and lower seal housings and actuators. The next step is to clean and inspect all bearings and races, replacing bearings if needed. The actuators would then need to be reassembled, pack seal housings with grease and install upper and lower seal housings. Finally, we re-install the fins, top plate assemblies and set fin indicators (potentiometers) to the proper level. 

Generally, hydraulic systems should be inspected before any significant trip. Service, oil and filter changes should be completed at least every 2-3 years. Hydraulic oil breaks down even when the boat is sitting idle and not being used often. As far as major service goes, we feel that depends on operating pressure and temperature readings while the systems are engaged. Also another indicator of a potential problem is when filters are changed and debris is found in them.  This could be a sign of pumps possibly starting to fail. 

 It is vital to follow your manufacturer’s recommended service intervals and use quality parts and trained technicians to service these highly-used and valued pieces of equipment. 

 

 

 

Pressure Testing NAIAD Stabilizer System Heat Exchangers

Pressure testing NAIAD Stabilizer heat exchanger

Pressure testing NAIAD Stabilizer heat exchanger

In a previous post, we detailed the steps of flushing a NAIAD Stabilizer hydraulic tank off of a 100 foot Azimut yacht as part of rebuilding the entire system. The Naiad hydraulic fluid tank has a heat exchanger built inside that uses circulated sea-water to keep the hydraulic fluid cool. In this project the hydraulic fluid was turning a burnt orange color as seen in the sight glass which is an indication that the fluid was running hot.   We removed the tank and removed the heat exchanger for descaling. A final critical step in the process is pressure testing the unit before it is re-installed in the tank and back in the vessel.   If the unit fails it will mix sea-water with the hydraulic fluid with disastrous results.

We use a pressure testing system that starts with city water pressure and is boosted by a pump to 70 to 100 lbs. of pressure.  The boosted pressure is held in place by a valve. We then monitor the pressure gauge to see if the pressure holds.  If the pressure drops over an hour time then we know we have a leak.

If we detect a leak then the entire core needs to be replaced.

If no leak is detected, we proceed with the re-assembling and re-installation of the tank and add new hydraulic fluid to finish off the job.

NAIAD Shafts; Common Problems – Unique Solutions

Newly cladded NAIAD Stabilizer shaft

Newly cladded NAIAD Stabilizer shaft

One of the most common problems we see on mega yachts is crevice corrosion and wear on stainless steel shafts, whether those shafts are propeller, rudder or NAIAD stabilizer shafts. Stainless steel shafts can be damaged by excessive wear in contact areas, such as bearings or seals due to long life or misalignment. Shafts can also be damaged from crevice corrosion or stray current corrosion.

The solution to these problems can range from cladding the existing stabilizer shafts or fabricating entirely new units. Cladding or shaft weld-over, is the process of repairing a worn or damaged area on a shaft.  This type of work is done by our on-site machine shop, Straight Line Marine, which is the only shop in Florida that is ABS approved to perform this type of work on propeller shafts.  Replacing a large NAIAD stabilizer shaft would cost thousands of dollars, depending on the size.  However, the cladding repair is less than a thousand dollars.

This was the case on a 145 foot Trinity yacht that we were working on rebuilding its NAIAD Stabilizer System. When pitting or crevice corrosion becomes too extensive, it prevents the lip seal from establishing a tight fit thus allowing sea water in or oil to leak out of the system.

We removed the shafts, cladded them and installed new lip seals in the NAIAD Stabilizer and the owner was good to go.

Upgrading a NAIAD Stabilizer System for better Fit and Performance

NAIAD Stabilizer lower bearing housing

NAIAD Stabilizer lower bearing housing

While performing routine lip seal maintenance on a NAIAD Stabilizer System on a 120 foot Custom Yacht; we found excessive amounts of corrosion on the external side of the housing. The corrosion was so bad we could not remove the plates in order to replace the seals.

An important component to the comfort and safety of any vessel, the principle behind NAIAD fin stabilization is to counteract the tendency of a vessel to roll with an equivalent and opposite righting moment applied in exactly the proper phase and proportion. These righting moment forces are typically generated from a pair of underwater fins, although other control surfaces are also available. Wave forces are thus prevented from aggravating the vessel’s natural tendency to roll.

Specially design hydraulic press

Specially designed hydraulic press

Once the fins were removed from the NAIAD Stabilizer, the corrosion on the shaft and in the bearings was so significant that the shaft could not be removed using the most common methods.  In order to get the shaft out, we built a special hydraulic press to drive the shaft out of the boat. With the shafts out, we then worked with NAIAD to upgrade the system to the next larger size unit.

Upgrading to the next size required a new housing which required fiberglass modifications to resize the hole in the hull.

What started out as a routine job turned into a complete replacement and modification to the yacht in order to guarantee continued high performance and comfort at sea.