Ballast in small boats ?

D

Dick Sargeant

Well-known member
I have almost finished reading the Endurance a story about Ernest Shackleton who was stuck in the arctic for over a year. As some of you know, this chronicle is hard to imagine even with modern equipment. At one point, Ernest leaves 22 guys on an Island and goes for help about 800 miles away with 4-5 others on a 22 foot wooden boat........having to navigate the most treacherous piece of ocean, maybe on earth. One of the things that they did with this heavy wooden double ender, which could be rowed or sailed, was to put a big load of rocks on the inside which they sometimes had to adjust to suit conditions. It was a complete miracle, of course, that they made it but it got me to thinking about ballast.

I know one commercial tuna boat, I think it's a 41 foot lowell, that has ballast tanks that they fill when on anchor to smooth things out but this is a big boat capable of running at speed through 10 foot waves.

The only time I ever heard about weight added to a duck boat was for the bow of a sculler but, again, I wonder if weight added below deck would make a small boat safer in rough conditions ?

sarge
 
There are some very big differences in the desired handling characteristics of a planing hull boat versus a displacement hull vessel. Many of these are related to how the hull is loaded, as well as how much load the hull is carrying. Powered duckboats, employ planing hull designs.
 
Sarge~

Interesting thoughts and questions.

The James Caird (Shackleton's boat) was ballasted for the same reason most displacement sailing vessels are ballasted - to keep the center of mass low enough to counteract the forces on the tall rig. In the days of wooden ships - which did not have floodable ballast tanks - stone was the most common ballast - but bricks often did double duty as ballast and as valuable cargo. (And, one thing I learned during my days in Invasive Species management - most of the aquatic invasives in the Great Lakes arrives in the ballast tanks of ships from the Black and Caspian Seas. The freshwater - taken on in the Caspian - in the tanks provides a way for freshwater organisms to survive the trip across the salty Atlantic.)

I have also seen ballast in layout boats (the Great Lakes style) - and even the Horal Scooter (the 2-man layout skiff I wll be restoring next) has several lead ingots it uses under the afterdeck while gunning. This idea is, of course, carried over from the old batteries that used the cast iron "wing ducks" to trim the box so it was almost awash.

Even in planing hulls, the placement of "moveable ballast" - which includes humans, all sorts of gear, fuel, anchors, etc, needs careful consideration. I think this is especially so with some of the taller blinds now in use.

Although not ballast per se, I do like a heavier hull in heavy seas. My Great South Bay Scooter is heavy - no doubt from the 'glass skin - and gives me great peace of mind in a big chop. Its motions are slow, easy and predictable, not quick and jerky as a light boat can be.

Finally, before adding or carrying ballast in any sort of gunning boat, I would want to be sure that it did not compromise the floatation.

All the best,

SJS
 
There are some very big differences in the desired handling characteristics of a planing hull boat versus a displacement hull vessel. Many of these are related to how the hull is loaded, as well as how much load the hull is carrying. Powered duckboats, employ planing hull designs.
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It would be more accurate to say; Powered duckboats, employ both, planing hull designs and displacement hull designs.
 
Steve - I forgot that the Caird, one of 3 extra "lifeboats", was actually built as a displacement sailing vessel. Also, one of the crew built up the sides and added a deck with pieces taken from the icebound mother ship. Those additions would surely have raised the center of gravity and, coupled with the mast, needed to be offset by a lot of stones. I guess the fact that they somehow made it got me to thinking of extra ballast as a magic ingredient instead of a description for added weight. True enough, any added weight can and does affect the center of gravity and performance.

Thanks for the info about the great lakes, very interesting.

I am looking forward to launching my 2320 Parker this spring and getting offshore to fish. One of the features that I really like is that you step down about a foot to enter the house. I liked this because it means I can easily reach roof mounted rod holders and it's easier for me to go around for on and off my mooring. The larger benefit, however, will be that the house is lower and less affected by wind and a little less of an effect on the gravity center........than it would be if higher. My best opportunity to smooth the ride will be a full fuel cell and moderate speed.

Dick
 
The only time I have put anything in a boat was when I worked in Alaska set netting when I was 19. We ran 16' aluminum skiffs. It was windy and then it started gusting hard. My Boss estimated at least 60. He had us bail water into the boat to keep it from flipping from the wind until we could get some fish in it then bail it back out. The wind was coming from the shore so there wasn't much in the way of waves otherwise that would have been a recipie for disaster. He made it very clear that this was not a normal thing to do.
 
When I was a kid I spent all my summers at the family camp on the shores of Lake Superior. One of the first boats I assisted in building was a Grand Banks Dory, planks on ribs. We would use this to access the sailboat we kept moored about 100 yards offshore and then tow it on our frequent trips around the lake, rowing to shore in the many sheltered bays we visited. We did have a sailing rig for the dory but rarely used it. The leeboards were a pain to use and got in the way when not sailing.

On the windy days we would often place a few large stones in the bottom of the dory, adding what I would estimate was 200 lbs of weight. This weight was used to both balance the dory and to provide some mass to help resist being pushed around in the surf and wind. Launching into the waves and rowing out from shore was always easier with a little more mass.

On a side note, that dory always looked awesome with all three rowing stations occupied. We didn't think twice about rowing five miles for no particular reason other than exploring. The exuberance of youth!
 
Dick does this mean I can forgo my exercise program and resume being the ballast for the Don Warren?
Be kind, now...lol.

Best - Paul
 
Dick does this mean I can forgo my exercise program and resume being the ballast for the Don Warren?
Be kind, now...lol.

Best - Paul
Paul - I was hoping that someone would come up with a great new idea for adding weight to a BBSB and then we could get you to volunteer a vessel from your fleet as a test boat........after installing a periscope !

Seriously, reading Endurance again has made the few rough days that I have had offshore seem very tame by comparison. I still can't believe what those guys were able to survive.
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