Bow Heavy

[Delfini]

1980 Albin 36’ single engine with 4 kw gen forward of the engine
Fuel tanks each side 300 gallons water in stern laz.
Even with empty fuel and water tanks full bowsits 6” low.
100’ 3/8” chain in bow
I can only conclude it was built that way but am not willing to accept that conclusion just yet.
Any other bow heavy have a take on this one?

 

[rslifkin]

The question is, does it actually sit low in the bow (as far as deck drainage, etc.) or is the painted waterline just wrong?

 

[psneeld]

I think the 36 and 40 Albins suffer from lack of buoyancy forward. I load mine as heavy aft as I can...including a dingy on the swim platform....it helps.

 

[Lepke]

Not the most efficient way to run, it could be stealing 1/2 knot. I'd try to ballast down the stern. Maybe some lead bars, bricks, cement blocks where they would fit. I have bricks in my stern and cement blocks along the keel.

 

[Art]

Not the most efficient way to run, it could be stealing 1/2 knot. I'd try to ballast down the stern. Maybe some lead bars, bricks, cement blocks where they would fit. I have bricks in my stern and cement blocks along the keel.

How many lbs. ballast in your big Wheeler?? Just wondering...

 

[rslifkin]

As an interesting note, being a little bow down may help fuel burn at low speeds. My boat gets faster at my standard slow cruise RPM as I burn off fuel and the stern gets lighter (bottom angle changes and less submerged transom to drag through the water).

 

[Comodave]

We had a 46’ with a cockpit that was a bit bow down. Ours wasn’t 6” more like 2 or 3”. Nothing drained correctly. I added 1400 pounds of lead ballast in the lazarette and it was almost correct. It took way more weight than I thought it would. Maybe load a bunch of weight in the stern temporarily and see how much weight it will take to make it right. 55 gallon drums filled with water will work as a test.

 

[catalinajack]

Not the most efficient way to run, it could be stealing 1/2 knot. I'd try to ballast down the stern. Maybe some lead bars, bricks, cement blocks where they would fit. I have bricks in my stern and cement blocks along the keel.

For lead, try 25# bags of reclaimed shotgun lead. Easy, sort of, to move around.

 

[Nomad Willy]

One of the advantages of a double end boat is that being pointed at both ends means equal flotation at both ends.
I’ve noticed many bow down trawlers over the years but seldom said anything because I didn’t want to insult anybodies boat or the skipper.

I concluded that it would be hard to steer a boat that was bow down. Especially quartering and running down wind and wave. A pointy bowed SD trawler quartering a stern sea will be at a significant disadvantage w their overly small rudders. And most all trawlers are SD.

And I determined that stern down was much better than bow down. My own Willard was stern down some but I never “fixed” it for a number of reasons. Mostly because down stern is better than down bow.

But finding a fixed weight load aft is hard to do as the only one’s available are relatively small except the engine/s. But being heavy aft is not a balanced boat either. Also you don’t want excessive weight at either end or both ends. The ability of a boat to turn depends mostly on the ability to yaw and the ability to yaw is most optimized w most all the weight amidships. But there’s downsides to that too.

Balance of trim on a boat is important or very important depending on boat design and weight distribution.
Many boats have large fuel or water tanks aft in the Lazerette. My Willard had large water tanks aft and same size fuel tanks amidships. But the W30 was very full aft and not so much fwd.i. So between the tanks the weight would be much more desirable at approximately 25% of the way aft of center. Of course there are other heavy items aboard like batteries and ground tackle. Both batts and ground tackle can be adjusted to weigh more of less or be moved to better balance the boat. But most all 30-45’ boats are custom designs as per a specific customer and frequently heavy items are put in bad for balance places. But it’s like powering, once you buy the boat it’s very hard to “fix” an imbalance situation.

One of the easiest fixes for a bow down boat is to lighten up the ground tackle. Get rid of the very heavy all chain rode and use a combo rode. Use a good sized high performance anchor, a short but heavy run of chain and a realistic nylon line (long) no heavier than required.
A seaworthy boat is safer than a super heavy anchor rode.

 

[Blissboat]

One of the easiest fixes for a bow down boat is to lighten up the ground tackle. Get rid of the very heavy all chain rode and use a combo rode. Use a good sized high performance anchor, a short but heavy run of chain and a realistic nylon line (long) no heavier than required.
A seaworthy boat is safer than a super heavy anchor rode.

Agree with this approach. If the OP tries this, he might then store the rest of that chain in the lazarette. That way the weight is where he wants it, and the chain is aboard if he needs to bend it on to the rode.

If I was going to add weight to any part of my boat, I'd try to do so with heavy items that could also serve a purpose.

 

[C lectric]

Albin 36 or similar? Three friends had them. Yes they all were bow down.

Still good boats. I agree about the ballast at stern using lead.

To experiment also a bunch of water filled 5 gal. would help zero in on weight needed. and whole lot cheaper.

Also agree about examine the anchor rode for lightening possibilities.

 

[Delfini]

The fly bridge does slope forward. And when I hauled out last spring, I studied the waterline /moulded hull lines. Waterline certainly looks like it’s correct.
I’ll move the chain and play with the weight but with 300 gallons of water ( 2400 lbs )
In the stern tanks I probably have my answer.
Thank all for the input.

 

[Comodave]

Just make sure that the deck you are going to set 300 gallons of water on can bold the weight or else reinforce it temporarily.

 

[FF]

"As an interesting note, being a little bow down may help fuel burn at low speeds. My boat gets faster at my standard slow cruise RPM as I burn off fuel and the stern gets lighter (bottom angle changes and less submerged transom to drag through the water).

This is what the USN has found , slightly bow down is more efficient.

Their hulls are usually slimmer than TT though.

 

[SteveK]

Bow down at rest, but where is the bow at hull speed? Are you leveling a docked boat or one underway.

 

[RT Firefly]

Greetings,
Mr. SV. Have another coffee. From the picture, it looks like under way.

 

[rslifkin]

I just noticed, it says that's with low fuel. What happens when you fill the fuel tanks? Some boats have a poor distribution of variable weights like tankage. On mine, the fuel and water tanks are all aft, so with full tanks, it's stern heavy. As you burn off fuel and use water, it eventually becomes slightly bow heavy. The holding tank is a little forward of midship, so as that fills it also shifts the weight further forward.

 

[SteveK]

Greetings,
Mr. SV. Have another coffee. From the picture, it looks like under way.

I will go get another. Meanwhile explain this

Even with empty fuel and water tanks full bowsits 6” low.

ETA: Back with 2nd cup. The picture in post 1 is of a boat underway at idle or a bit more. At that speed my bow heavy GB sits much like at rest. At hull speed the aft is squatting and as far as I can tell bow is up. I think they were meant to sit bow heavy at rest so at speed they are not pointing to the sky. JMO

 

[Art]

Our Tolly has twin engines well placed in boat cog location [i.e. side to side and fore aft] with 100 gal aluminum tanks to either side of each. Fuel full or anywhere toward empty seems to not interrupt trim angles, in general. 77 gals of water [two 37.5 gal plastic tanks] are to either side of boat under beds in stern master stateroom [starboard queen, port twin]. They empty simultaneously so no side trim is affected. However, full as compared to near empty water tanks in rear does create up to a 500 +/- weight difference regarding fore to aft trim. For planing the trim tabs keep boat angle adjusted. For just below hull speed [our usual cruising speed] I leave trim tabs full up and notice little to no difference regarding water weight stages.

BTW - We have no actual ballast weights in the Tolly. Except too may selections of tools and parts that I keep under the V beds and in closet and on shelves in front state room. So yes... our boat is usually just a bit forward loaded for trim waterline!

 

[Nomad Willy]

I just noticed, it says that's with low fuel. What happens when you fill the fuel tanks? Some boats have a poor distribution of variable weights like tankage. On mine, the fuel and water tanks are all aft, so with full tanks, it's stern heavy. As you burn off fuel and use water, it eventually becomes slightly bow heavy. The holding tank is a little forward of midship, so as that fills it also shifts the weight further forward.

rslifkin,
Good thinking but shy in that assumes the ballast/trim was right in the first place.

 

[Nomad Willy]

I will go get another. Meanwhile explain this


ETA: Back with 2nd cup. The picture in post 1 is of a boat underway at idle or a bit more. At that speed my bow heavy GB sits much like at rest. At hull speed the aft is squatting and as far as I can tell bow is up. I think they were meant to sit bow heavy at rest so at speed they are not pointing to the sky. JMO

That works fair until you’re plowing along w stern seas. Much of the time.

 

[Nomad Willy]

Since many have fuel tanks amidships the water tanks aft designers may have concluded water is cheap .. skippers will be more inclined to keep them full minimizing bad trim re bow down attitudes.

The 36 GB has {as I recall) engines rather far fwd. Thats invited by a fwd mounted helm station and on a 36’ boat two FL’s is quite a bit of weight.
I personally haven’t noticed GB 36’s being bow down though. Perhaps they have fuel and water both in the stern or some other nice fix. Any GB owners comments?

 

[SteveK]

Since many have fuel tanks amidships the water tanks aft designers may have concluded water is cheap .. skippers will be more inclined to keep them full minimizing bad trim re bow down attitudes.

The 36 GB has {as I recall) engines rather far fwd. Thats invited by a fwd mounted helm station and on a 36’ boat two FL’s is quite a bit of weight.
I personally haven’t noticed GB 36’s being bow down though. Perhaps they have fuel and water both in the stern or some other nice fix. Any GB owners comments?

Engine/trans start at galley sink and end aft end of hi lo table. They are forward of center. Fuel tanks either side and middle forward of head wall, still forward of center. Two water tanks in lazerate trim when full, otherwise bow heavy at rest.
Underway at hull speed stern squats from prop thrust so trim is good.
As I said before designed to look level when water tanks full or underway at cruise speed.

 

[Mako]

Obviously the engine is correctly placed and the saddle fuel tanks are COG neutral and the aft water tank would only help the trim issue. Perhaps its the heavy generator located forward and probably sitting right behind the forward stateroom.

I think before spending money to add lead ballast (more weight) to the boat, it might be better to put that money towards relocating the genset. Also what are the battery location(s)?.

There's a difference between curing the problem and putting a bandaid on it.

 

[Nomad Willy]

The problem remains that one end being wide and full or (square) there’s tremendous flotation (support) for weight. Where’as the fwd end may start to get skinny amidships. So even 1/4 of the way aft from the stem the boat only has a fraction of the volume below the WL to support weight. The CG needs to be more than a bit aft of boat center. That does vary boat to boat but I suspect many boats fail to have the weight and hull volume below the WL centered. Boats shouldn’t be bow down at rest and floating on their lines at cruise speed. Such a boat will not respond gracefully or even safely when being tossed about on waves.

 

[SteveK]

Eric, I must respectfully disagree. Since this is very common with GB for decades, if the designers thought you were correct they would have made modifications.
Previously I had planning hulls and they had the CG aft of center, so again the engineers must have worked the design for optimum layout.
I do agree if there is more chain weight than originally designed a few hundred pounds forward may well leverage the boat more than the same weight at the stern.
This may also explain why twins burn more fuel than the same single due to weight location designed for a single.

 

[Giggitoni]

IMHO, 3/8” chain is a little over kill for a 36’ boat. Heavy. Try nosing up to the dock. Run your chain out on the dock and see if your bow rises.

Post #2 is worth exploring.

 

[markpierce]

IMHO, 3/8” chain is a little over kill for a 36’ boat. Heavy. Try nosing up to the dock. Run your chain out on the dock and see if your bow rises.

Post #2 is worth exploring.

Got 3/8-inch chain (200 feet), but I'm still bow-light with full tanks. (Engine midship, fuel slightly behind, and water tanks toward the stern.) But never extremely out of balance.

 

[BruceK]

I`d like to see a pic at a scintillating 8 knots/hull speed. That`s the test, imo.

 

[Lou_tribal]

When bow is light I get few box or wine bottles to add weight, usually these don't last long and compensate for fuel burn [emoji1]

L.