Houseboat Stability

Seattle house barges are a gem of lakefront living and certainly a very special lifestyle for those who choose to love them.  The alure of the custom architecture, the instant access to kayaking or boating, the close knit neighborhoods which make you feel like you are living in a small town, all of these factors draw Seattle residents to Lake Union living and I have very much enjoyed working with these customers.

One issue that has come up on a few surveys of these magnificent floating homes is that of stability.  This is a topic which is often forgotten but of great importance especially during home remodels or for homes which have never had these calculations done.  Vessel stability is quite simply the factors that go into the angle of heel (how the barge leans side to side) and how this relates to final vessel trim as it sits in the water.  It probably does not need to be said that disregard for barge stability can have negative consequences but often stability issues can be easily remedied with a solid plan.

Stability graph for different angles of heel.

There are two main factors to consider when planning for stability, static and dynamic forces

Static – Static forces are  those related to the distribution of the mass of the boat.  Ballast (weight added for stability), structural height and width, weight of building materials, etc.  This is an interesting calculation as we don’t get to take the boat apart and weigh each component so surveyors conduct a heel test with calcuations in order to accurately model the static forces.

Dynamic – These are forces which change over time and might include tank water sloshing, a large number of guests on the rooftop deck or even a winter storm cross breeze pushing on the exterior wall.

Overall there is a lot to consider when dealing with the stability of your house barge.  How the center of bouyancy changes given the shape of the hull, how the center of gravity relates to all else to create the righting arm (the force that rocks your boat back upright).  All of these factors go into calculating a number of figures which inform the current state and safety of the home and reveals great info about the stability of the barge.  If you are super interested about the specific of these then feel free to contact me and I can send you some more detailed info but for now I am trying to prevent this article from becoming a Naval Architecture textbook.

Stability Tips:

  1.  Consider getting a stability survey – I have to say this first of course as getting professional help on this matter is the best way to have a great plan.  Keep stability in mind especially if you are planning additions to your floating home.  A stability plan can help to make sure your project results in a fully functioning and safe home.
  2.  With a shallow draft barge hull that is common for house barges, simply adding more ballast does not always help.  I did some consulting on a very narrow and tall houseboat that the owner had been adding a huge number of concrete sacks to the bilge for ballast but with no change to the shockingly slow roll that the boat had.  With calculations we were able to determine in this case that his placement of ballast was reducing the metacenter of the boat slightly faster than it was reducing the center of gravity.  To paraphrase, his ballast plan was actually a detriment to the stability of the boat.  An easy plan was made to solve the ballast issue.  Ballast is normally as low as it can be and with shallow draft house barges this sometimes means the ballast is under the barge rather than in the bilge.
  3. Ballast should be secure in place.  Loose ballast will tend to shift when it is being most challenged by dynamic forces with the effect of making things a lot worse.
  4. Avoid using uncured sacks of concrete as ballast.  It is a cheap soluction but powder concreate is a chemical which becomes hot and caustic when wet and these factors are not good neighbors for your hull.  I have seen these concrete sacks sitting inside wood hulls with severe degradation in the area where the concrete bag was sitting on the wood hull.  I have also seen lead tire weights in use as ballast and this material can tend to leach toxins into the bilge water where it eventually gets pumped overboard.
  5. Stability considerations are not only for the tall, high risk barges.  If your boat has a fast and uncomfortable roll in weather that tends to make your guests uncomfortable, then a stability plan can actually help slow this roll down while still maintaining ultimate safety.  Recommendations might include ballast, trim weights, outboard floatation, flopper stoppers, and a number of other tactics to dampen the roll.
  6. If you are replacing or doing significant work on an old wood or fiberglass over wood hull then consider replacing the hull with a lightweight and wider footprint aluminum hull.  They last a long time and often this change tends to add significant additional stability AND value to the boat.

If you have questions in general about houseboat life then you can contact Kevin and Linda Bagley at Special Agents Realty, two people who have been a tireless supporter of houseboats in Seattle and knows everything there is to know about them.

I fostered a great interest in this question while stationed up in Juneau, Alaska for the US Coast Guard.  One heavy snow storm up there resulted in two houseboats having major stabity issues due to rooftop snow load and the additional weight this caused up high on the barge.  After the snow was removed and the houses made right again I was able to help these owners create a plan to keep their homes safe for the future considering all dynamic loads to be expected in Alaska.  This is a topic for which I have great passion and If you have questions about houseboat stability then feel free to contact Eric at Tasman Boat Company.

Winter Warmth Aboard, Sometimes a Little Too Hot

With Seattle winter in full swing and a couple of cold snaps of snow already in the log book it pays to talk about space heaters.  It is common for boat owners to use cheap little electric heaters to keep their boat interior dry and to prevent frozen pipes.  The fire department and your insurance agency would like to remind you that plugging in a space heater into a power strip not rated for such high amp loads is a highly risky action.

powerstrip

Power strips aside, any space heater should be of high quality, have a wide and stable base, should shut off automatically when tipped over, and not be a risk for falling paper or other combustible goods catching fire.

As a surveyor and a former US Coast Guard marine investigator, I have seen all too many of the cheap foreign space heaters catch fire all on their own.  The culprit of these fires was not what you would think (the heater element) but rather the overheating of the poorly constructed printed circuit board which controls the unit.  So I would recommend that you get a high quality unit or better yet intall a marine electric heater system onboard to maximize safety.

Happy boating!!

Eric…

Pre-underway Checklist

I have been asked about what specifically needs to be done in order to get a boat underway in order to maximize safety, minimize issues and help the crew enjoy the day.  Unfortunately the answer to this question is as diverse as the number of boats on the water but I will start with a general list for sailboats mainly because most of the recent questions came from new sailboat owners.

This list is a work in progress and will be updated periodically.

Things you should keep in order at all times:

  • Charts of the area to be navigated, navigation gear and knowledge
  • Vessel registration and all safety gear (PFD’s, fire extinguishers, flares, horn, etc)
  • Inspect your anchor rode for wear and make sure the stainless siezing wire holding the shackle is in good order.
  • A means to recover crew from the water (lifesling, boarding ladder, etc)
  • Test bilge pumps
  • Navigations lights in working order
  • Boat hook
  • First aid kit
  • Engine gauges are in good working order, depth sounder functioning
  • Tools appropriate for anything you might need to work on while underway
  • Sunscreen, hat, polarized sunglasses
  • Appropriate clothing to keep warm (it is often quite a bit cooler out on the Puget Sound than in town)
  • Binoculars
  • Drinking water

Prechecks:

  • Float plan – Let someone who cares about you know where you are going, when to expect you, what communications devices you have and what to do if you don’t report in.
  • Check weather report
  • Inspect running and standing rigging, remove sailcovers and inspect sails
  • Open raw water seacock
  • Open fuel supply valve
  • Inspect engine belts, hoses, evidence of new leaks
  • Check engine oil each time before starting, check marine gear oil and fuel injection pump oil about every 2nd or 3rd time starting the motor.  Check belt tension.  Verify coolant levels and top off as needed.
  • Turn off shorepower switch inside boat and at the dock and disconnect shore power cord.
  • Turn battery switch to the appropriate setting for starting
  • Turn on engine instruments if this is on a seperate switch
  • Activate any appropriate fuel lift pumps as required for your boat
  • Preheat engine as required by manufacturer
  • After engine starts check for raw water flow at exhaust, stop engine if no flow and repair as needed.  Then check gauges and inspect motor now with motor running to verify that all looks normal.
  • While motor is warming up you can spend some time bringing online the VHF radio, autopilot breaker, stow the shorepower cord, unlock the helm, remove instrument covers, unlock hatches and lockers, verify manual bilge pump lever location, brief crew on the plan, do a dockside marine transmission test.
  • Always remember to check up and down the marina fairway for other boats before casting off lines.

Yanmar 1GM Rebuild

So the current challenge for me is to get a 1980’s Yanmar 1GM running.  I got this engine by helping a client remove it from his recently acquired 1930’s Dutch built wooden sailboat and the owner before him had really abused / neglected this quirky but popular little workhorse for a number of years.  For those that don’t know, the 1GM is a single cylinder diesel motor which can be found in a number of small sailboat in the US and abroad.  They have some known issues but overall they work well if you take care of them.  And taking care of this specific example is exactly what did NOT happen.  When my client had this boat shipped in it was with the hope of getting rid of this motor in favor of a nice electric setup and it was clear why.  The motor was caked in rust (Yanmar paint is known to fail fairly easily), did not run and it was clear that it lacked full compression.  We got the engine out no issue except for the siezed engine mount nuts which meant that the motor came out with the mounts still attached.  Now that I have broken the motor down here is the list of items wrong with the motor:

Failed paint – Yanmars have a thick metalic paint which seems particularly prone to fracture and rust.  Combined with the cast block and you don’t really have a recipie for an engine that will forgive lack of maintenence.  This will need to be cleaned up and repainted.

Thermostat completely siezed with rust – The thermostat was completely rusted and fouled with deposits such that there is no consideration that it might be saved.  Into the garbage it goes!

Clogged cooling channels – This is a common issue with the Yanmar GM line.  No real damage to be seen as a result of this but it sure is a pain to get all of the deposits out.  I did not find any rusted through parts of the head channels which was good since it does happen.

Carbon scale in the exhaust ports – Carbon scale essentially gets baked on to the inside of your engine and is more difficult to clean that getting burned cassarole off of a baking pan.  I used a chisel very carefully on the surface of the carbon to see if I could get it to fracture which most of it did.  Lastly a dremel tool with a sanding brush light enough to not damage the metal made quick work of the leftover carbon.  This is an issue that only gets progressively worse over time such that eventually the motor will have so much backpressure that it will not run.

Exhaust valve erosion and carbon buildup – Because the exhaust valve had been fouled with carbon it was allowing the explosions to blow past the partially open valve.  This sacrifices engine power but also causes a burned valve via hot gas erosion and fatigue.  A new exhaust valve is so cheap that I will most likely just get a new one but I am at least attemping to see if I can lap the seat with a nice silve edge all around the valve and seat contact seal.  Doubt it but it is fun to try.

Exhaust bend mounting face on the head is rusted and will not seal – This is the gasketed joint between the head exhaust outlet and the exhaust elbow.  It is held on by three bolts at basically 9, 12 and 3 o’clock while 6 o’clock is unsupported.  I have no idea why they did this as there is room for a 6 o’clock bolt but I digress.  At the 6 o’clock position there was a past water leak coming from the unsupported side which turned the seal face into a rusty mess.  This probably means that the head itself is done for by most standard but ultimately I am not interested in paying hundreds of dollars on a new head and am more interested in making the old one work for the challenge and engineering of it all.  In my mind there is no real reason why a thick sturdy pipe can’t be welded on in order to be rid of the pesky rusted seal face.  If it needs service in the future then it can be ground off and I am totally ok with this versus buying a new head.

Exhaust elbow – This is a famously pesky part on these engines, pretty much guarenteed to fail like clockwork every 4 years.  And at only $300 a pop from Yanmar (granted it is a double wall tube but I still think that is a lot).  I am planning to duplicate the same thing in a more durable setup and simply weld it straight to the head.  It pays to mention that in order to weld to a head you have to know what you are doing or you will certainly just crack it.  For those of you who own this engine it is advised that you remove the exhaust elbow every two years and really just consider replacing it.  Failure of the water and exhaust mixer causes water to spray backward into the head with often pretty disasterous results and it is best to just avoid this.  You can find quality aftermarket examples in stainless steel for about a hundred bucks.

Overall a fun project engine and one which I plan to get chugging for about a hundred bucks.  It won’t be perfect but the goal right now is to consider installing it in our 14 foot cocktail launch built in the 1940’s, no round the world cruises with this motor.  The launch currently has an air cooled gas flathead engine which is unbelievably loud and despite being a reliable engine this noise is something that I would like to get rid of even if it means dumping the Kohler engine.  I have looked into mufflers made for it but the engineer seems to only think this will take care of about 20 db of sound so we have only gone from 747 engine noise to only a race car engine noise level, yea!!!  With a small water cooled diesel the motor could be mounted inside a sound proof enclosure where the engine noise goes out through a water muffler and the mechanical noise gets taken care of by the insulated enclosure.  And maybe, just maybe, my cocktail guests will be able to take off the hearing protection and actually converse with each other!!  One can always hope.

Happy boating to all!!!

Eric…