Eliminating Engine Vibrations – Is a Strut Alignment the Answer?

2017 June 5
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by Chris Brown

We recently worked on a 96-foot Ferretti yacht that had run aground and was experiencing considerable engine vibrations. Our field technicians with High Seas Yacht Service inspected the boat and found that the shafts were bent and one of the struts was bent and out of alignment. After pulling the props and shafts, we sent the shafts off to our machine shop, Straight Line Marine for straightening. Once the shafts were back in true, we sent them back to the vessel for re-installation after performing a full strut alignment on the vessel.

Strut alignment is often overlooked when trying to determine the cause of vibrations in a boat. All too often the first or second course of actions are shaft straightening or engine alignment when the root of the problem may lie in the struts. Struts can be out of alignment due to poor factory set-up or a hard grounding causing a bent or twisted strut.

Strut alignments are complex and require special tools and experienced mechanics. Once a strut is removed from the boat it is a major repair and should only be done by specialist in this field.

We begin the process with an optical scope alignment for precision measurements of the misalignment. In order to align the strut, it must be removed or dropped from the bottom of the boat. All strut bolts are removed and a considerable force is applied to break the bond between the strut and the hull. Proper equipment and safety are a major concern since some struts can weigh hundreds of pounds.

Once removed, the strut pad and hull pockets must be ground clean in preparation for installation. Extra jacking holes are drilled and tapped in the four corners of the strut pads to help with fine tuning adjustments. Once preparation is complete, the strut is hung back in its original place and the optical scope is once again used for precision alignment of the strut cutlass bearing.

When the strut is properly aligned, we use ChockFast to inject into the gap between the hull and strut to form a perfect fit with the bottom of the hull.

A strut alignment is typically a one-time project for any vessel unless it is driven hard aground. A properly aligned strut will free-up an engine to provide a smooth ride for comfort and higher speed with lower fuel consumption. For more details on performing a full strut alignment, click here.

Taking Care of our Valued Customers

2017 June 5
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by Chris Brown

When a 112-foot Westport yacht returned to Lauderdale Marine Center, our running gear team dropped in on the vessel for a courtesy visit and health check. The ship was in the yard last year and we did a full running gear job including shaft work and alignment.

Checking Tolerances

Since the yacht was back on the hard, our team checked the cutlass bearing clearance on the shafts to ensure that the shafts were properly aligned. The tool we used to perform this task is called a feelers gauge which are an assortment of fine thickened strips with marked thickness which are used to measure gap width or clearance between the shaft and the cutlass bearings. We also visually inspected the bearing seals.

Feelers Gauge

We were happy to report back to the captain that everything checked out properly and the running gear work that we performed last year was holding true. When you engage High Seas Yacht Service, you can rest assured that we will stand by our work and go that extra mile to keep our valued customers sailing smoothly.

Whether you need both Hydraulics and Running Gear Work – High Seas Delivers

2017 June 5
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by Chris Brown

When an 85-foot Ocean Alexander hauled out at Lauderdale Marine Center recently, the vessel needed repairs on both her hydraulic stabilizer systems and running gear work along with a general re-fit and painting.

The Captain hired us for the hydraulic and running gear work to streamline the process and have the work performed using a single point of contact for the job. Our team of hydraulic technicians at High Seas Hydraulics tackled the routine maintenance on the ABT Trac stabilizer systems, while our running gear mechanics at High Seas Yacht Service pulled the shafts and sent them to our machine shop, Straight Line Marine for straightening. Once the shafts were ready for re-installation, we used an optical scope to ensure precision alignment.

This Captain was on a tight deadline for launching and working with our teams gave him the peace of mind that he would be on his way on schedule. Using High Seas Hydraulics and High Seas Yacht Service for this project made perfect sense for coordination and project management to get the job done right and right on time.

Proactive Measures Can Help Avoid Big Fixes

2017 March 28
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by Chris Brown

When a 126’ San Lorenzo yacht was recently hauled at Lauderdale Marine Center for a number of projects, the captain came to us with vibration concerns with the vessel. Vibration in the running gear can be caused by a number of different issues ranging from bent shafts to misaligned struts or engines to out-of-true props. Our running gear mechanics were dispatched to check out the boat and perform inspections on the various components. We found that the shaft had good run-out, no signs of damage and had recently installed new cutlass bearings, so there was no reason to pull the shafts. We did however, pull the props and sent them out for reconditioning.

The captain of this yacht took proactive measures at the first sign of a potential problem, resulting in a simple fix to a small issue before it became a major job. This yacht should now be ship-shape for future smooth sailing.

Salt Water Corrosion on Aluminum Surfaces

2017 March 17
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by Chris Brown

A 1987 121’ Heesen Yacht, hauled at Lauderdale Marine Center, was showing the wear and tear you would expect on a 30 year vessel. The captain and engineer on this yacht contracted both High Seas Yacht Service and High Seas Hydraulics to perform a number of tasks on both the hydraulic systems and running gear.

As part of the running gear work, our High Seas Yacht Service team pulled the rudders for routine maintenance.

Salt water effects on aluminum

Upon removal of the rudders, we found significant corrosion in the rudder housing in the area of the packing glands. Prolonged exposure to salt water can cause corrosion of aluminum by creating aluminum oxide. The salt does not directly attack the aluminum, but causes an electrochemical attack like a catalyst that results in the corrosion. This is the white deposit that you find on aluminum. The reaction rate is usually fairly slow, but on this 30 year old vessel the salt water had definitely taken its toll.

Once the rudders were pulled, we inspected the rudder shafts and found them to be in excellent condition.  However, the repair of the aluminum would cause damage to the lower rudder bearing (bushing) so the vessel opted to have us remove them and fabricate new for installation.  Rudder bearings are machined in our machine shop – Straight Line Marine.  It is convenient to have a machine shop in the same facility, Lauderdale Marine Center, in order to dry fit the part and make repeated passed for a perfect fit. As part of the running gear work on this vessel, we also pulled and refurbished the props on the yacht.

With the proper care, maintenance and service even a 30 year old classic boat can return to the sea for many more years of cruising the world’s oceans.

 

When small problems become big issues

2017 February 28
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by Chris Brown

When a 58’ Kady Krogen trawler recently hauled out at Lauderdale Marine Center, our hydraulics company, High Seas Hydraulics was hired to do routine service on the ABT Trac hydraulic stabilizer system. Our running gear team was also called upon to pull the props and shafts for routine cutlass bearing and seal service.

Damaged threads

Once we dropped the stabilizer fin in order to replace the lower shaft seals, we found the threaded stud on the bottom of one of the shafts was damaged and had signs of thread damage and galling. This was most likely from a stainless steel nut on stainless steel threads that was installed and removed without the proper never seize lubricant. This compromised the re-installation of the stabilizer fin nut so we recommended removing the shaft to repair in our machine shop, Straight Line Marine. Once in the machine shop, we found that the stabilizer shaft was bent 0.080” which is significant for a stabilizer shaft. When we started the straightening process, which involves applying hydraulic force on the high point of the shaft, the stabilizer shaft cracked in two. This was a first – never had that happen before. Under examination of the broken ends, it is evident that a crack in the shaft had worked its way to 20% through – we just finished off the job.

Cracked shaft

This particular vessel is under new ownership so there is limited history as it relates to past problems and repairs. Obviously, this stabilizer was badly damaged at some point in the past. In all likelihood, the boat probably hit something or experienced a hard grounding which lead to a crack in the stabilizer shaft. Over time, these cracks tend to creep and grow.

We were able to source a new stabilizer shaft from the manufacturer and complete the overhaul on the hydraulic stabilizer system.

We have never experienced a stabilizer shaft cracking in two before in our machine shop, but it just goes to show that a small thing such as damaged threads can be a warning sign of bigger issues.

 

Performing a Running Gear Overhaul on a 135 foot Yacht

2017 February 7
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by Chris Brown

As mentioned in an earlier post, we were contracted by the new owner and captain of an older 135 foot Broward Yacht to do a number of running gear and hydraulic projects on the vessel. On the running gear side, we were tasked with removing the shafts, props and rudders to inspect and refurbish the components. From the shaft perspective, we inspected them to ensure they were straight and corrosion free. The machine shop found the shafts were slightly bent and required straightening.  We also installed new cutlass bearings and repacked the stuffing box and performed an optical scope alignment before reinstalling the shafts back in the boat.

As part of our standard maintenance and service process, we removed the rudders to check the bearings and packing glands. In this case, the bearings were in good shape so we did not have to replace them. We just needed to repack the stuffing boxes to complete the work on the rudder service.

Maneuvering the rudders with lifts

However, the challenge with removing and re-installing rudders on a yacht of this size comes with handling them. Each rudder weighs in excess of 800 pounds. In order to do the job right, and safely, it takes precision forklift work. We use two lifts to start the process, one to stand the rudder in a vertical position while the second secures the rudder so that it can be moved back to the boat.

It’s a matter of inches

Maneuvering the rudders to align the rudder shaft with the opening in the boat many times translates into a matter of moving the forklift just fractions of an inch one way or the other.

 

 

 

After considerable team work between the mechanics and the forklift operators, we successfully re-installed the rudders and now the yacht is good to go with a complete running gear overhaul complete.

 

 

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

2017 February 1
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by Chris Brown

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 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.

High Seas Yacht Service upgrades to 2 Ton Crane in its Straight Line Marine machine shop

2017 February 1
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by Chris Brown

To accommodate the growing marine trade at LMC and the potential for larger yachts visiting the yard for service when the new, more powerful travel lift is installed, we have upgraded and enhanced our own lifting capabilities with the installation of a new 2 ton crane along with a new 1/2 ton crane in our machine shop, Straight Line Marine. The new equipment will allow us to extended our shaft fabricating and straightening capabilities to more vessels hauling out at LMC.

How to Identify Tides Seal Assembly Damage

2017 January 29
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by Chris Brown

It is critical to make sure your shaft seal system is getting proper forced water cooling.  If there is a temporary loss of cooling, the internal bearing on the Tides Seal assembly will become damaged or wear out quickly.  Once damaged the seal assembly could spin with the shaft and come loose.  This results in a leaking seal.

Most experienced mechanics will see the leak and recommend replacing the seal.  This can be done easily in the water if you  have a spare seal on the shaft.  However, before changing a seal you should determine if the assembly is damaged.  Placing a new seal in a damaged assembly is a waste of time and a good seal.  It will still leak.

The internal bearing in the Tides Seal assembly should be 0.016″ larger than the shaft.  This keeps the assembly riding on the shaft and within the tolerance of the lip seal.  There is a simple test that you can perform on the Tides Seal in your engine room to determine if the internal bearing has failed or become worn.  As you will see in this video, place your hand under the seal assembly and pull straight up.  If the bearing is damaged or worn, you can lift the assembly 1/8″ or more and water will squirt in.  If the bearing is still within tolerance, it will feel like you cannot move it at all on the shaft.

The adjacent photos show cut-away of the Tides Seals assembly with the internal bearing and shaft.

If you do have a damaged bearing the only option is to replace the assembly.  This means the shaft needs to come off the transmission, slid back and coupler removed.  There are divers that can plug the stern tube to do this in the water if you are well prepared and experienced.