Putting the Heart into Shackleton

As you know, if you read my blog, I chose fixed ballast for Shackleton.

 Possible advantages may include:

  1. Simplicity (fixed and always present)
  2. Lower center of gravity (placed directly onto the bottom of the hull)
  3. Lower maintenance (no water intrusion into the hull)
  4. No mussel transport (big deal in Idaho…mandatory inspections at state lines)
  5. Increased storage (not that anyone needs more storage in a Scamp)
  6. Safer (impossible to forget to fill with water)
  7. Quicker (nothing to fill & top off)
  8. Adjustable (by cutting 3/4″ dummy blanks to take the place of the steel)

Possible disadvantages may include:

  1. Steel plates may rust (but I don’t think they will because I epoxied them with graphite)
  2. The steel plates could clank around inside the vault and gain momentum (I built the vault very tight to the steel.  I then added nylon straps around the steel to keep them off each other and to provide a bit of a bumper effect.  These straps also allow me to lift out the steel plates if needed)
  3. I may get condensation in the vault (I’ll need to keep an eye on this and possibly drill a few holes through the vault for proper ventilation if it becomes a problem.  The nylon straps also provide a slight air gap around all the plates)
  4. Heavier trailering weight (not much though…like hauling around your skinny buddy in the trailer, approx. 175 lb.)
  5. Inadequate hull strength (I epoxied an additional 3/4″ bottom plate directly onto the 3/8″ hull, and then filleted this plate to all the surrounding bulkheads to tie it in place.  The sides of the vault were built onto this bottom plate)

Enough talk…let’s see the photos

DSC00421This is looking down into the vault.  The lid has been places onto the hinged hatch cover.  You can see the stainless thumb screws and washers on the non skid.  Yes, the lid fits through the hatch…but just barely.  And, yes I did have this figured out ahead of time…but just barely.

DSC00422If you look very closely, you can see the head of the center board pivot bolt at the far right side of the storage compartment.  I reversed the head position of the CB bolt for easier access.  This will allow me to keep an eye on the CB bolt.

DSC00425Behold the mighty six steel plates.  This is the moment of pure and utter reverence…please offer up a minute of silence here.  Notice the nylon straps going around each plate. They provide a cushion between the plates and allow me to lift them out of the vault if needed.  Otherwise, it would be next to impossible to remove the plates.  They weight around 27 lb. each.  Notice how tightly they fit.  Possibly another moment of silence may be in order.  The top also snugs down onto the nylon straps, so in the event of a capsize, the plates are held securely in place.  I’m feeling some serious love here!

DSC00426 Notice the cut out on the right side of the vault lid.  This allows me to pull the CB pivot bolt without removing the vault lid.

Summary:

It felt a little symbolic dropping the weights down into the vault today.  Sort of like I was breathing life into Shackleton.  I wanted to share this moment with you so you could revel in the joy that both boat and builder felt at this time.  I can feel things coming together for Shackleton.  I’m hoping to have everything completed within another 2 -3 weeks.  I’ll keep posting my progress.

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Building “The Vault”

The decision to utilize fixed ballast creates a few unique issues.  Will the boat be strong enough to handle the added weight once outside the water?  Will trailering the boat with this added weight create an issue?  Simply put, will it work or will it fall apart?  Simeon suggested I email the designer and pose these questions prior to moving forward.  I felt this was good counsel, so I drafted a quick email, not knowing if I would even receive a reply.  Well, the reply came.  John’s only advice was to tie the bottom of The Vault into the bulkheads on all sides.  And, he felt my design was “on the right track”.  With this reassurance, I moved forward.

Several issues needed to be resolved:

  1. I knew the ballast needed to be accessible and removable.  What if it gets wet?  What if I need to service the BH area?  What if I want to remove some weight?  Hence, the design had to allow me to tweak, dry and access the ballast.  So, I had Jennifer sew up straps from nylon webbing to facilitate easy removal.  These sleeve around the individual plates and allow a great hand hold.
  2. I knew the plates could not move or gain momentum.  The weight needed to be absolutely stationary.  So, I built a box that didn’t allow any movement.  I epoxied this box to the bottom of the hull between BH 4-5.
  3. I knew, based on John’s advise, I should fillet the box into the surrounding bulkheads for added strength.
  4. I knew I had to allow access to the CB pivot bolt for servicing of the centerboard.

The photos below show what I came up with.  

DSC00003 These webbing straps not only provide a great hand hold, they also cushion the plates from each other.DSC00006 The Vault proper.DSC00008All parts received 2 coats of epoxy.  DSC00010The bottom of The Vault, showing how it’s screwed into the sides. DSC00004The top edge of the sides were drilled to receive a 5/16″ threaded lag.DSC00005Stainless threaded lag with thumb screw and washer.DSC00002By using two nuts, tightened against each other, you simply screw them in.  I applied epoxy to the hole and lag threads prior to insertion.  DSC00001This allows convenient access to the lid of The Vault.  DSC00013Epoxied to the bottom of the hull and surrounding bulkheads.DSC00010I cut a portion of the lid back to allow access to the CB pivot bolt.DSC00014  If you look closely, you can see the CB access cutout on the left side of the lid.DSC00044I purchased an extra long stainless CB pivot bolt.  I wanted the finished bolt to be solid shaft without the threaded section.  This bolt cut easily with a hack saw.  I softened the edges with a metal file.

DSC00010I choose to epoxy the wooden plate to the CB case and decided not to make it removable.   I felt it would be easier to seal the bolt hole, than the entire wooden plate.  I then cut the bolt a little long.  My thinking here was to allow room to silicon the bolt shaft to the wooden plate while still allowing full access to the bolt head for easier removal and service of the centerboard.

The fixed ballast idea felt good to me.  Others have utilized water for ballast and I’m sure many are very happy with their systems.  If you are wanting a different way of accomplishing ballast, maybe this system can be of interest to you.  If not, water seems to be a simple solution.

Now placing my attention on BH 3-1 and access hatches.  

Fixed Ballast for Shackleton

Water or fixed ballast?

Scamp is designed to take on approximately 175 lb. of water as ballast.  I never felt quite right about this design characteristic.  Though I appreciate the concept of water ballast in larger sailboats (where weight savings can be over 1,000 lb.) I question whether the benefits are realized in small sailing vessels. If you want the lightest trailering rig possible, then water ballast proves to be advantageous.  However, to me, Scamp is such a light sailboat, that to add fixed ballast doesn’t seem to present any real problems or huge disadvantages.

Some of the draw backs of water ballast may include:

  1. Drilling a hole in the bottom of the boat to bring in water.
  2. Maintaining the water tank from algae or microbial growth.
  3. Transporting invasive larvae (think quagga mussels here.)
  4. Sealing the water tank from surrounding water tight compartments inside the boat.
  5. Accessing the drain hole each time you sail.
  6. Toping off the water tank with additional water (gravity doesn’t’ completely fill the water chamber) each time you sail.
  7. Draining the water tank after each sail.
  8. Drying the water tank from residual water after each sail.

Some of the advantages of fixed ballast may include:

  1. Never forgetting to fill the ballast tank before setting sail.
  2. No maintenance, with dry ballast I can fix it and forget it.
  3. No water sloshing around to potentially destabilize the boat.
  4. Dryer cockpit sole.  I know I would spill water each and every time I top off the water tank with a pitcher of water.
  5. Lower center of gravity.
  6. Adjustable by adding or removing additional plates as needed.
  7. Storage of additional heavy gear in this same BH area.

For these reasons, I’ve decided to add 150 lb. of fixed ballast in Shackleton.  Why 150 lb.?  I’m simply guessing that 150 lb. fastened directly to the bottom of Scamp is worth at least 175 lb. of water dispersed over the entire water tank area.  With these ideas rattling around in my head, I visited Pacific Steel for my ballast needs.  DSC01000DSC00991DSC00998DSC00997DSC00004 I had them cut 6 pieces of flat bar, measuring 3/4″ x 6″ x 20″.  Each of these plates weigh 25 lb.  This will give me 153 lb. of ballast in the bottom of my boat.DSC00002Cleaning up the rough edges.   DSC00005DSC00006  Coating all sides with two coats of graphite epoxy.  I will then build a wooden box to hold the plates.  This box will be glued to the bottom of the hull.

Summary:

I’m hoping these changes will simplify and quicken my sailing experience.  Anytime I can simplify my life, I’m usually happy with the results.  Hopefully these changes will bring about similar results.

Box design to follow.