Proper Blocking of Yacht

On my recent 43 haul out I'm pretty sure there was only 3 on each side. Total weight 48k.

A Cabo is built strong.....can put about 3-4 blocks down the keel (or hull bottom) and 3 stands a side is fine....... Generally on most all yachts, all weight is resting on the keel, the stands are to keep them from falling over.

This older post caught my attention. How do you figure 25%-35% of the weight is on the keel???? ALL the weight is on the keel. The side stands simple keep her from falling over. I'm sure there are rules based on length for how many keel blocks to use + side stands. Recently had my 55' Hatteras convertible hauled. They put 4 blocks under the keel and 7 stands down each side.

This, I concur all of the weight is on the keel.

No, I've seen keels crushed on boats from not enough blocking on the sides, even well-built boats. Contact the manufacturer, there are specific places to block a boat. Do not put all the weight on the keel unless the manufacturer says that is proper.

There are boats that are designed to take their full weight on their keel, usually smaller boats, or large boats designed for grounding.

The marks for straps usually indicate solid structural points, balance to even the load on the hoist, and places to avoid lifting on components under the hull like intakes and shafts. They are a compromise.

Keel blocks usually go under your bulkheads or transverse frames for proper load bearing.

The boat stands can bear some weight if you over crank them, but are usually hand tight for stability. 3 per side on a 40 is plenty, plus however many keel blocks that align with bulkheads, probably not more than 3 or 4 in your case. Ultimately, the yard is responsible and the good ones are a bit conservative. Let's see a picture when you have it hauled out.

Don't forget to have the stands chained from port to stbd, to prevent any accidental "slippage".

The side stands should not be adjusted with the full weight of the boat on them, if it is even possible. Perhaps with enough grease and muscle. Normally the keel is lowered to the cradle or ground, it is blocked to take the weight evenly at structurally strong points, and then lowered to rest on the keel with some of the weight. Then the side stands are adjusted to the hull, then the boat is lowered the rest of the way. On larger boats there is enough flex, that a lot of weight ends up on the side stands as the hull relaxes. How much is usually more of a guess at most boat yards. It would be nice if they put a nautical engineer on the task but they don't.

If the boat is on straps, the flatter the bottom, the more weight is on the chines. You want to put the side stands at the bow tight, and the side stays at the stern loose, before relaxing the straps.

I used to haul and block boats as a kid, sometimes 40 to 60+ footers. We still had a lot of big wooden boats then, the big ones flexed a lot.

Generally, if there are professionals in a yard performing a function that could have some liability attached, I keep my mouth shut and leave it up to the yard, their insurance company and God. On one boat that I ran, an 80' custom M/Y, the keel had a tendency to deflect upwards when in the slings or blocked. So much, that the floorboards between the engine stringers crowned in the center. From the point where I discovered that, I had to advise the yards about the best procedures to prevent damage, which included having a diver run the straps between the hull and shafts, adding more jack stands, and minimizing the weight resting on the keel.The boat traveled a LOT, so I had plenty of opportunity to hone my people skills in the way of providing advice. Generally, it went pretty well, except on an occasion with loading the thing on a float-on, float-off ship. The loadmaster very icily told me they knew what they were doing . He was really P.O'd when he had to flood the ship back down to improve the blocking.