Crane Failure with dinghy suspended....?

[AlanT]

No this has not happened to me (yet?) but it is one of my greatest fears in the category of gear failure.

The thought of having an 800lb dinghy suspended (at any elevation) from the crane with no ability to electrically or manually crank the crane fills me with fear.

The concern drove me to replace both solenoids and remove/service/replace the motor on my last boat. But with a new-to-me boat I am facing the same concern again.

I have thought about carrying tackle on board that would enable me to manually take control of the dinghy if needed. My thinking is that I would need enough mechanical advantage to control lowering the dinghy (either to deck or to water) so I would always be lowering the dinghy, and would not try to spec a tackle with enough mechanical advantage to actually raise the dinghy.

What are your thoughts?

Given an 800lb dinghy I am thinking I would need at least X5 or X6 mechanical advantage. Obviously I would then also need a substantial quantity of suitable rope Just guessing this would be 150' - 250'.

I could set this up with one double block (with becket) and a treble block plus 1/4" polyester rope.

Does anyone have any other suggestions or critique of this?

I haven't yet tackled any upgrade to the current crane, however I do plan to have replacement solenoids on board.

~Alan

 

[smitty477]

I used to carry a 'come along' hand winch like this one on our boat...
https://www.northerntool.com/shop/tools/product_200712271_200712271

We never did end up having any need for it. But we did get to use our dinghy crane to help elevate a friends hydraulic swim step up high enough so he could tie it in place and he could continue a trip without it dragging in the water.

 

[Alaskan Sea-Duction]

I used to carry a 'come along' hand winch like this one on our boat...
https://www.northerntool.com/shop/tools/product_200712271_200712271

We never did end up having any need for it. But we did get to use our dinghy crane to help elevate a friends hydraulic swim step up high enough so he could tie it in place and he could continue a trip without it dragging in the water.

I agree. Northern tools are good, but Harbor Freight is a cruiser's tool heaven.

https://www.harborfreight.com/

 

[AlanT]

I used to carry a 'come along' hand winch like this one on our boat...
https://www.northerntool.com/shop/tools/product_200712271_200712271

We never did end up having any need for it. But we did get to use our dinghy crane to help elevate a friends hydraulic swim step up high enough so he could tie it in place and he could continue a trip without it dragging in the water.

That's is a great suggestion Smitty. I will need to figure out if I could rig it so that the handle would be within reach with the crane swung outboard and, if so it would be a more economical solution by far!

~A

 

[caltexflanc]

You can install a snap shackle which opens under load with a fid attached to a boat hook if the dink gets stuck in midair. But why not just proactively maintain the crane? These are no complex mechanisms at all.

 

[AlanT]

Smitty, another question. Can a come-along be used in reverse, in other words does the pawl allow a load to be lowered under tension? I assume so but I have never used one.

~A

 

[SteveK]

Fair comment to do proactive maintenance. However even then a failure can occur.
I rely on the MacGyver techniques to overcome the unexpected.

 

[smitty477]

I agree. Northern tools are good, but Harbor Freight is a cruiser's tool heaven.

https://www.harborfreight.com/

The Harbor frieght on I looked at had two issues - 1.the gears were not very robust made or their bearings, likely good for a few uses 2. the line lenght was insufficient for our needs.

 

[AlanT]

You can install a snap shackle which opens under load with a fid attached to a boat hook if the dink gets stuck in midair. But why not just proactively maintain the crane? These are no complex mechanisms at all.

Thanks Caltexflanc that is also a good suggestion. I will be proactively maintaining the crane (as I did the last one) but my experience is that anything mechanical can fail and so the concern still lingered on my last boat even after servicing the motor and replacing the solenoids which were the only parts of the crane that I considered failure-prone. ~A

 

[smitty477]

That's is a great suggestion Smitty. I will need to figure out if I could rig it so that the handle would be within reach with the crane swung outboard and, if so it would be a more economical solution by far!

~A

Hello Alan - I remember you from the other board as well. Our plans were to take up the load of the dinghy and lower as much as we could before securing with another line if we needed another 'grab' to go the entire distance.

 

[smitty477]

Smitty, another question. Can a come-along be used in reverse, in other words does the pawl allow a load to be lowered under tension? I assume so but I have never used one.

~A

Yes - at least the one we had back 12 years ago did. The one we had I did used to lower some larger tree branches and the stop was spring loaded. Cfrank the load off the stop, push the release button, lower the load a full swing, and repeat each time you want to go down another length.
Did take some time but as I said we never used it on the boat.

 

[SteveK]

Smitty, another question. Can a come-along be used in reverse, in other words does the pawl allow a load to be lowered under tension? I assume so but I have never used one.

~A

Yes it has two pawls and can be worked carefully in reverse. But a read of product has a warning about do not use in the vertical position.

 

[Alaskan Sea-Duction]

The Harbor frieght on I looked at had two issues - 1.the gears were not very robust made or their bearings, likely good for a few uses 2. the line lenght was insufficient for our needs.

Well they are cheap and quality......depends! But if you drop the tool in the salt water, no big deal....LOL

 

[TWedd]

A chain fall or chain hoist might be a better solution. easier to operate than a come a long plus the chain used to raise/lower the load can allows the operater to be several feet away from the actual hoist. Distance depends on the model of the chain fall. they come with different lengths.

https://www.northerntool.com/shop/tools/product_200756083_200756083

 

[Comodave]

I have a chain fall that allows 16’ of lift or drop. It is somewhat slow but in an emergency that is ok.

 

[smitty477]

A chain fall or chain hoist might be a better solution. easier to operate than a come a long plus the chain used to raise/lower the load can allows the operater to be several feet away from the actual hoist. Distance depends on the model of the chain fall. they come with different lengths.

https://www.northerntool.com/shop/tools/product_200756083_200756083

If you do not mind more weight and costs there are all types and quality of portable winches out there powered by 12 and 120 volts sources.

 

[RickyD]

Well, I drop my dinghy at the dock as I have an end tie and tie to port with my davit swinging to starboard. Then I tow the dinghy so I don't have to try to drop the dinghy when it is rough. Here is something else. Ok, we are talking an emergency, right? Well I use Dyneema cable on my davit hoist. If I have to, I can cut the dinghy loose and drop it. Like I said, emergency.

 

[KnotYet]

A simple and 'yachty' back up to electric crane motors is a single or two-speed
sailing winch in parallel to the motor cable(s). Small yacht braid and a cleat and voila.
You can even have a self tailing version. These are available used at very low prices.
Heck, I have a half-dozen left over and gathering dust from a former life.

 

[KnotYet]

Well, I drop my dinghy at the dock as I have an end tie and tie to port with my davit swinging to starboard. Then I tow the dinghy so I don't have to try to drop the dinghy when it is rough. Here is something else. Ok, we are talking an emergency, right? Well I use Dyneema cable on my davit hoist. If I have to, I can cut the dinghy loose and drop it. Like I said, emergency.

I agree with your 'in an emergency' statement.
Always have a means to cut any cable or line readily available.

 

[GoneDiving]

I'm looking to replace my 3:1 tackles with two 3 speed boat winches with dyneema cord.

Simple, cheap and easy enough for my 14yo to use.

 

[rgano]

I like some of the solutions, but approaching the problem in the simplest form, it appears you want to be able to take the eight off of your stalled hoist line and transfer that weight to another line which would allow a controlled descent. The simplest descent control would be a stout and convenient cleat with an "s" turn (we did this with multi-ton landing craft control lines in the Navy). You would not need a lot of tackle beyond a single snatch block and a way to secure it at the end of your boom.

Now for the transfer of the load, you need to be able to hoist the load an inch or two using possibly a second, co-located snatch block. I come-along seems like the answer to just keeping it simple and non-electric.

 

[guy with a boat]

The solenoids are just remote switches. If one of those dies, jump the circuit to lower the tender. It’s possible but difficult to use all the crane functions this way. Assuming it is electric/hydraulic, plan c is to slowly open a hydraulic fitting and let the pressure (and fluid) out so the tender lowers. Any of these measures beats more stuff on the boat, in my book.

 

[Barabus]

If it were me, I would use a come along with Dynema line over steel cable as back up. They are all going to say not for overhead lifting since that is a specific OSHA or other standard. The 4x4 crew runs some nice gear.

I’ve had this one in my Amazon wishlist for 4x4 in snow self rescue for awhile. No connection just to give you an idea.
https://www.amazon.com/dp/B08B6DLWX...olid=1YM1Y1CH656LK&psc=1&ref_=lv_ov_lig_dp_it

 

[KnotYet]

I'm looking to replace my 3:1 tackles with two 3 speed boat winches with dyneema cord.

Simple, cheap and easy enough for my 14yo to use.

You may know this but a small diameter winch will have a higher mechanical advantage.
Most 3-speed winches I've seen have pretty big winch drums.
Obviously, the extra gearing will make up for that but may not be necessary.

 

[KnotYet]

If it were me, I would use a come along with Dynema line over steel cable as back up. They are all going to say not for overhead lifting since that is a specific OSHA or other standard. The 4x4 crew runs some nice gear.

I’ve had this one in my Amazon wishlist for 4x4 in snow self rescue for awhile. No connection just to give you an idea.
https://www.amazon.com/dp/B08B6DLWX...olid=1YM1Y1CH656LK&psc=1&ref_=lv_ov_lig_dp_it

I've used these big boys and they are bad-ass! Pricey but worth it if you need that much pull.

 

[Iggy]

I have a chain fall that allows 16’ of lift or drop. It is somewhat slow but in an emergency that is ok.

Yes, a chain fall.

What about the windless? Some have a drum than a line could be wrapped around and be used as a winch. Of course you would need the right setup.

Just a thought..................

 

[Jeff F]

I carry one of these guys. Very useful.

https://superwinch.global/collections/superwinch-utility-winches-1/products/superwinch-winch2go

Here's an improvised hoist I set up to change the mounts on my generator. Just anchor the box to something and hook up to 12v.

I also carry a lithium booster pack that could power it for emergency use.

 

[DDW]

A multi part tackle isn't going to do much with an 800 lb dinghy. You can only pull about 50 or 60 lbs horizontally so you'd need a 16 part tackle and that is not practical. A small sailboat winch, between a #20 and #28 would do what you need, with some sweat. The numbers on those winches refer loosely to the power ratio, 1 lb on the handle gets you 20 lbs on the line for example (minus some friction). So applying 50 lbs to the handle of a #20 will apply 1000 lbs (or a bit less) to a line. A self tailing one you do not have to hang onto the line so two hands to crank. Two speed ones have two power ratios depending on which way you turn the handle. Three speed are only available in large and expensive versions. They are FAR more reliable than anything electric on a boat. Something like this would be the premium unit.

 

[mvweebles]

Let's face it. Depending on where you are and the duration of your cruise, loss of a crane could really cramp your schedule. A come-along or chain fall may provide the mechanical advantage on paper, but if your boom end isn't high enough to accommodate the extra 2-feet or so, you'll be close but not close enough. Any solution should be tested.

As Rgano states, belaying the dinghy down with a line on a cleat is easy and straightforward. Raising 800 lbs with multi-part block and tackle may not be easy. With each added part, friction means there's diminishing returns on mechanical advantage. 5-6 part is probably the max practical system.

The good news is the nicer boom systems have very nice winch drives and are relatively reliable. But if you're using a trailer winch contraption such as the Rule, it will rust and eventually fail, likely within 5 years or so.

I personally went with an Andersen 2-speed #28 sailboat winch on my pipe-davit crane. It's incredibly slow, so I use a cordless drill with winch adapter. But I also went with an aluminum RIB and a pull-start tiller steer OB. 300 lbs total. Not a place I wanted to add complexity. My good friend with a $1.5m boat with full power crane lifting a 15-foor center console RIB thinks I'm nuts.

Peter

 

[boathealer]

My Dutton-Lainson StrongArm AC winch has a hand crank handle that, unless the gears are completely hosed, will allow a VERY slow emergency manual operation.