Winter Jackstands and Blocking

[lehighsail]

I am somewhat aware of jack stand technique for winter storage on the hard and that the boat rests on the keel and basically supported from tipping laterally by the jack stands. I noticed that sometimes wooded blocks or an additional jack stand is placed under the engine area aft of the keel. Is this something I should ask the yard to do or is it not necessary support the weight of the engine over winter
storage?

 

[DayDreamer41]

While not an expert I don't believe that the stand is there to suppor the motors weight, I know on our 41 the yard puts a stand under the centerline of the hull just forward of the rudder which is at the aft bulkhead. I believe this stand is to help relieve the overhanging load of the aft section of hull, but like I said I am no expert.

 

[dlochner]

The experts on jack stands is Brownell. A trip to their website is instructive.

Jack stands should be placed every 8 feet with a stand under the bow. The weight of the boat should be on the keel and the keel should be supported (blocked) in two places, forward and aft on the keel. Generally jack stands should be placed under supported areas, i.e., bulkheads if possible.

Much of this was learned the hard way on a cold February in 2010.

https://www.boatstands.com

 

[Tally Ho]

3) Hunter 33’s stored at my marina. None have a stand under the motor.

Greg

 

[RoyS]

Sounds like a good idea to me. All the marinas I have been in put a jack stand under the bow but I have never seen one under the stern. There is undoubtedly a lot of unsupported weight there. Good idea.

Edit: "Stern"

 

[Terry Cox]

Jack stands should be placed every 8 feet with a stand under the bow.

Agree, Dave. When the yard hauls our boat they place one additional stand between the back of the keel and in front of the prop shaft. The bow stand is placed in front of the keel and speed transducer. This prevents any fore or aft rocking movement of the boat.

Our boat weighs 35,000 pounds cruise ready. I've watched the travel lift lower our boat's keel onto the block and it is interesting to observe how much the hull flexes/compresses under the boat weight. Amazing how strong they build these boats.

 

[Tom J]

I don't think we should generalize too much on this topic. Every type and model of sailboat has it's own requirements for jack stands and blocking. My Catalina would not do well with supports under the hull just forward of the rudder, since there are no internal supports in that area. The hull would flex, and oil canning would be evident. The owner's manual for my boat specifies where the jackstands should be placed, and I can say with experience that this is very important.

 

[RoyS]

Many of us are not present when the marina places the boat on stands. The yard crews place many boats every day and end up with a routine that may or may not be the best way to stand up your boat. I was in one marina that always placed the stands in exactly the same places year after year by noting the bottom paint differences. Another marina always moved the stands to permit renewing the bottom paint in areas where the stands were the previous year. Aside from being present when the boat is stood up this process is largely out of our control. All of the marinas I have been in over the years can be relied upon to place the keel on a block or two on the ground and one stand under the bow end and either four or six stands on the sides. I would like to see another stand under the stern. On my boat there is more boat behind the keel than in front so why a stand only in front under the bow end? Perhaps the rudder and the prop in the stern area make the selection of a stern location too difficult to become a yard routine.

 

[Tally Ho]

I think the stand under the bow is because the hull is more vertical (pointy) at the bow. I have stands stands behind the keel, almost to the swim platform…

Greg

 

[Morgan donor]

Yards typically charge for each stand used. But it would be wise (in my opinion) to add more stands if:
The mast is not unstepped.
If the ground is not concrete or hard gravel.
If subject to thaw and freeze cycles during winter.
If it's really windy and unprotected from gusts.
If opposing stands are not tightly chained together.
Boats can and do fall over. Seen it. Not mine, thankfully.

 

[Tally Ho]

My marina supplies 6 stands, any more are extra charge. But I usually slip the yard guys a few bucks and they throw an extra set under the boat.

I am always there when they block it (in fact this year, I helped them because they were short-handed).

Greg

 

[Tom J]

I think the stand under the bow is because the hull is more vertical (pointy) at the bow. I have stands stands behind the keel, almost to the swim platform…

View attachment 200169

Greg

I have been in yards that require the bow stand, and others that didn't. Presently, I am in a yacht club, and the bow stand is necessary. Our boats are hauled by Brownell trailer, so that when the trailer is unloaded, the keel is lowered onto blocks and the aft two stands are placed in position behind the trailer. Then the bow stand is placed between the arms of the trailer, and the trailer backs out. The remaining stands are then placed in position.

 

[shemandr]

I've never seen stands under the engine area.

 

[Tom J]

I've never seen stands under the engine area.

Me neither. I'm sure it would damage my boat. I would think it would also take some weight off the aft two stands, which would lessen their ability to stabilize the hull. Once that chain gets tight between those stands, the boat isn't going anywhere.

 

[Morgan donor]

Here's a picture of a stand under the skeg/engine. (just behind the pallet, zoom in)
This isn't a racer with a 1/4" thick glass hull. So it does depend boat to boat where you put stands or cribbing.
Cruiser-racer type as opposed to Racer-cruiser. A sailboat fell over in a northerly storm about a mile away.
On Lake Ontario most everyone pulls the stick for the winter. Its that windy! With a thaw freeze cycle all winter. Belts and suspenders gents!

 

[dlochner]

Once that chain gets tight between those stands, the boat isn't going anywhere.

That depends. There are 2 places to chain the jack stands, at the top beneath the pad and in the middle. Hostar stands place them at the top, a poor place. Brownell stands in the middle.

Securing the stands at the top will allow the stands to walk and dance. Eventually one stand works loose and the rest is ugly. In the case below the keel was improperly blocked, wind caused the boat to rock back and forth, a jack stand danced away and....

would think it would also take some weight off the aft two stands, which would lessen their ability to stabilize the hull.

All the boat's weight should be on the keel. The fore and aft stands simply prevent rocking or tipping fore and aft.

 

[Tom J]

That depends. There are 2 places to chain the jack stands, at the top beneath the pad and in the middle. Hostar stands place them at the top, a poor place. Brownell stands in the middle.

Being based in Massachusetts, I naturally have always used Brownell stands, and they are the best. The yard I store my boat in is gravel, and is frequently under water, but the Brownells keep the boat upright.

 

[DayDreamer41]

That depends. There are 2 places to chain the jack stands, at the top beneath the pad and in the middle. Hostar stands place them at the top, a poor place. Brownell stands in the middle.

Securing the stands at the top will allow the stands to walk and dance. Eventually one stand works loose and the rest is ugly. In the case below the keel was improperly blocked, wind caused the boat to rock back and forth, a jack stand danced away and....



All the boat's weight should be on the keel. The fore and aft stands simply prevent rocking or tipping fore and aft.View attachment 200243

The stands in this picture appear to be home made and don't appear to have any angular cant to them, they also don't appear to have any place to secure a tie chain. The angle iron base is flat which would offer very little resistance to sliding, boat has a nice cover though....

 

[dlochner]

The stands in this picture appear to be home made and don't appear to have any angular cant to them, they also don't appear to have any place to secure a tie chain. The angle iron base is flat which would offer very little resistance to sliding, boat has a nice cover though....

The stands were made by Hostar and were in their second year of service. They were in good shape before the boat fell on them.

In this case, the boat was not blocked properly, note there is only one set of blocks near the keel. A pretty significant wind storm came in off Lake Ontario, winds were in the 30-40 knot range. The boat was being buffeted by the wind and started rocking fore and aft in doing so the jack stands started to shift. Because the stands were chained at the top, the bases could move, which they did. Eventually one collapsed and the boat toppled over, knocking the next boat to the ground which hit the third boat.