Crane Failure with dinghy suspended....?

[Flyguy1967]

We purchased a HF 1500# winch, replaced the wire with Dyneema line and have never had a problem. If you swap out for Dyneema, I would suggest a winch cover as the Dyneema is UV sensitive.

 

[Spinner]

I like the idea of sail boat winches as backups! My big tender is on a Freedom Lift off the transom, but I have a smaller dinghy and a heavy kayak up top which require the crane. Currently I have a 5-1 block and tackle as a backup, but winches sound good too, if I can figure out where to mount them!

 

[ksanders]

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.

Right there is the best answer by far as a backup.

My opinion would be to make the backup line fast and then cut the cable from a protected area.

In reality this will probably never bee an issue. if you have a spare solenoid and do not ignore a crane that is struggling.

 

[Ric]

Crane failure

I had similar concerns about our 750# dinghy. I don't have a full photo, but here you can see the arc of the port davit and the bow of the dinghy. The motor is under the white cover (each of the davits has its own motor). You can see the backup block and tackle, which gives 6:1 advantage. They are available from Gerhauer. Never had to use it (yet) but it'd be easier to control than a come-along under load.

 

[smitty477]

Right there is the best answer by far as a backup.

My opinion would be to make the backup line fast and then cut the cable from a protected area.

In reality this will probably never bee an issue. if you have a spare solenoid and do not ignore a crane that is struggling.

"In reality this will probably never bee an issue. if you have a spare solenoid and do not ignore a crane that is struggling."

I agree here - we likely have lifted and lowered any number of dinghies more than most folks each day/week/year of usage and have never had any issues.
But we did go over everything that we use and make sure it was in good shape - in the last case the davit crane was 20+ years old towards the end and never missed a beat.

 

[Greggnvt]

Crane Winch Failure

Last year when I was pulling my tender on the upper flybridge, about 10 feet up the winch died (AC powered). After looking at it for about a hour, the only thing I could up with was using a come-along and some dock line. Took about 2 hours to finally get it down. The winch was externally mounted - replaced it with a Warn AC winch. Part of the issue was trying to pull it up enough so I could disconnect the old steel winch cable hook. Looking back, I had put off replacing the old winch which was about 10 years old and had seen better days (isn't salt water wonderful!). It still "worked" and there seemed to be other pressing projects.

Gregg

 

[rgano]

While it wasn't a dink crane failure, my boatlift suffered a gearbox casualty today leaving the port side mechanism stuck. The boat had a bit of a list before the squaling of the motor's small pulley against the vee-belt going around it and the much larger gearbox pulley alerted me to the increasing port list of the boat and cradle. I hlt the stop button and then reversed the direction of lift's travel to regain zero list and called for the assistance of the people who reinstalled the lift after Hurricane Michael. They showed up in an hour with heavy chains and hooks to wrap around the fore and aft ends of the port side of the cradle and thence acound the lift's aluminum beam which is secured to the pilings on that side of the slip. They then removed to port side mechanism's vee-bent and gave the gearbox's big pulley a spin by hand to let it start a short 3-4 inch free fall to take up the slack in the chains - scary event.

Unlike the OP's original question about lowering the dink once the liftarb failed, this 12,000 pound boat is going nowhere until a new gearbox is installed at which time we will test the motor and gearbox together as we operate the lift in the UP mode to release tension on the chains.

IF it somehow became imperative to launch the boat (at this point a few feet clear of the water), if would be necessary to rig chain falls to the port side and slowly lower it to the water while touching the down button on the lift to let the other side keep up with the chain falls.

 

[DCDC]

We carry enough blocks and lines to manage a lift failure in various ways with advantage provided by:

> small 12v vertical capstan mounted on the aft deck
> 2-speed winch normally used for our paravanes
> quarter ton mini chain fall
> anchor windlass

Use the existing lift boom and enough blocks to gain a fairlead to one of the above with brake by one or more prussik loops.

 

[kernr]

Crane failure

AlanT -

So, I have read all of the thread here to date and I just do not see a clear simple answer to your dilemma about crane worries. On our GB 47 it would not be easy to balance overboard and operate a come-along to raise then lower the dinghy. It doesn't look like a 6:1 set of pulleys is going to allow you to raise a 800 lb dinghy (BTW our is also about that weight) - lowering with a cleat to check the line would work. Unfortunately I think we need to figure out how to get it up 3" or 4" first. The sailboat winch is a great idea but I am not sure where I could mount a winch with the proper backup under it.

Have you decided what to do? Right now I do not see a clear answer. Let me know your thoughts because I would also like to have a solution other than maintaining ones electro/hydraulic winch.
Thanks,
Bob

 

[KnotYet]

AlanT & Bob, could you post a photo of the crane setup you have? It might help us help you.

 

[BandB]

Speak to the crane manufacturer. Many of them have manual solutions to be used in the event of failure. If they don't sell one, they can at least advise you on what might work.

 

[AlanT]

AlanT -

So, I have read all of the thread here to date and I just do not see a clear simple answer to your dilemma about crane worries. On our GB 47 it would not be easy to balance overboard and operate a come-along to raise then lower the dinghy. It doesn't look like a 6:1 set of pulleys is going to allow you to raise a 800 lb dinghy (BTW our is also about that weight) - lowering with a cleat to check the line would work. Unfortunately I think we need to figure out how to get it up 3" or 4" first. The sailboat winch is a great idea but I am not sure where I could mount a winch with the proper backup under it.

Have you decided what to do? Right now I do not see a clear answer. Let me know your thoughts because I would also like to have a solution other than maintaining ones electro/hydraulic winch.
Thanks,
Bob

Bob, there were a good few thoughtful suggestions in the responses. Thanks to everyone that chipped in with their suggestions!

The cheapest is the idea of using a come-along which (if deployable) would get me the 3-4" of lift that I would need to disengage the crane hook. Then lower the dinghy on the come-along. There are two problems with that approach however:

1/ If the crane seized with its length of cable exposed less than the length of the come-along, it would not be possible to hook it up.

2/ It might not be possible to reach the come-along with the dinghy half-way lowered. At that point the crane boom is perpendicular to the boat and out a good ways. This is something I can test next time I drop the dinghy.

The suggestion that I really like is one that I will look into first. I may be able to secure a small self-tailing two-speed winch to the top (or to one side) of the crane boom. I am pretty sure that the boom is wide enough to easily support the footprint of a smallish winch (5" diameter base). I would obviously need a backing plate and the room to mount it clear of anything inside the boom.

The idea of using the anchor windlass is also very attractive (and free if it worked!), however it would impose an enormous side load on the crane boom. I think even if I could fairlead a line to the windlass 50' away, with tension the boom would be pulled forward to the point that it would wedge the dinghy against the side of the hull. Adding an additional line to hold the boom aft would be necessary and create too much complexity IMO.

Finally I will be servicing the crane this spring. It needs paint as well as having the motor looked at and checking all wiring/solenoids and securing any point-of-failure parts.

I do have a sneaking suspicion that if I mount that winch, it would pretty much ensure that I never have a problem with the crane!!

~Alan

 

[kernr]

crane worries

KnotYet -

I do not have great photos of the operation, however, I have a few of the crane next to the dinghy so that you will get the idea. Basically the dinghy always goes over the Starboard side of our boat and the cable is generally about 3 1/2 feet away from the boat thus the difficulty in handling a come-along. It is a pretty standard set up for this GB Model.

Bob

 

[tozz]

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

The two most recent failures I've heard of locally have been the remotes themselves and not anything to do mechanically. I have thought about ordering a spare remote but haven't pulled the trigger yet.

 

[AlanT]

The two most recent failures I've heard of locally have been the remotes themselves and not anything to do mechanically. I have thought about ordering a spare remote but haven't pulled the trigger yet.

You don't need a spare remote. The remote is a simple switch. you can open it up and jump the terminals if you ever have to. If you throw it overboard you can do that same with the terminals on the female plug that it plugs into.
~A

 

[BandB]

I would still call 800-770-0455. There might just be a hidden way under the shroud. If not, at least commonly used methods.

 

[kernr]

Crane failure

BandB -

You probably have the best idea going before we try any of these other schemes. Will do.
Thanks
Bob

 

[kernr]

Crane worries

AlanT -

Thanks for your thoughts on a crane failure.

I also agree that even on my smaller trawler the side loads of coming at it from the Windlass would be too great. The two best ideas are to call the vendor (I wrote Advantech an email and they are pretty good at getting back) to get their recommendation and a winch that has a good location to get some backing under it in place. When I hear back from Steelhead I will let the readers see the response.

Thanks Again,
Bob

 

[kernr]

Crane worries

All -
Well I called the crane manufacturer and they sent me a schematic (see attached) for a crane similar to mine (see attached) showing the valve that if opened would allow the linear winch to collapse (hopefully slowly) and the dinghy would come down. So, I thought that is really cool. And having taken my linear winch apart last year to clear a jam I became pretty intimate with how my crane works. So, I thought some more about it because the Counter Balance Valve that he mentioned is on the inner most end of the linear winch. Guess what - there is absolutely no way to get at this valve while the crane is under load. When I asked him about the access to this valve he stated that I was correct and there is really no way to lower the crane - for a total loss of power to the crane. Jumping the solenoid is still a possibility - if you have access under load to those.

Oh well back to the drawing board. It was a good thought BandB.

Bob

 

[smitty477]

All -
Well I called the crane manufacturer and they sent me a schematic (see attached) for a crane similar to mine (see attached) showing the valve that if opened would allow the linear winch to collapse (hopefully slowly) and the dinghy would come down. So, I thought that is really cool. And having taken my linear winch apart last year to clear a jam I became pretty intimate with how my crane works. So, I thought some more about it because the Counter Balance Valve that he mentioned is on the inner most end of the linear winch. Guess what - there is absolutely no way to get at this valve while the crane is under load. When I asked him about the access to this valve he stated that I was correct and there is really no way to lower the crane - for a total loss of power to the crane. Jumping the solenoid is still a possibility - if you have access under load to those.

Oh well back to the drawing board. It was a good thought BandB.

Bob

I do not see the pump or any feed lines to the hyd winch.

 

[kernr]

Crane worries

Smitty477 -

Basically, at the very end of the linear winch there are two hydraulic lines that connect up to winch. These lines go back to the solenoid in the pedestal below base of crane. From there the hydraulic lines (2) run about 15 feet to the Hydraulic pump, motor, and reservoir. Under the forward end of the fly bridge. See attached depiction of the hydraulics and power.

Bob

 

[TWedd]

Come a long is not practical for the reach reasons stated above. A chain hoist, or chain fall solves the reach to operate issue.
It is also more compact and will allow a shorter distance between connection points.
Finally, lowering a load with a come a long is a long, tedious process-Chain hoist is very easy in comparison.

In my opinion after using both for years in my professional career, a come a long is an accident waiting to happen, when compared the ease and safety of a chain hoist.

Just my .02 worth. If you ever use a chain hoist, you would probably never use a come a long again. I haven't.

 

[RickyD]

The two most recent failures I've heard of locally have been the remotes themselves and not anything to do mechanically. I have thought about ordering a spare remote but haven't pulled the trigger yet.

Yes, I have had this happen twice as I have two davits. Each time it was not a critical situation. My sun deck top davit remote died and I ordered and received a new one. $12 from China, I know I should be embarrassed. Then my bow mounted davit has a robust remote and I opened it up and replaced a broken switch that I had as an extra three position switch. With my old boat, I always have to be prepared to replace switches.

 

[smitty477]

Smitty477 -

Basically, at the very end of the linear winch there are two hydraulic lines that connect up to winch. These lines go back to the solenoid in the pedestal below base of crane. From there the hydraulic lines (2) run about 15 feet to the Hydraulic pump, motor, and reservoir. Under the forward end of the fly bridge. See attached depiction of the hydraulics and power.

Bob

Perhaps the correct fitting of an emergency bleed fitting on the lifting side of the hydraulic line would do.

 

[smitty477]

Come a long is not practical for the reach reasons stated above. A chain hoist, or chain fall solves the reach to operate issue.
It is also more compact and will allow a shorter distance between connection points.
Finally, lowering a load with a come a long is a long, tedious process-Chain hoist is very easy in comparison.

In my opinion after using both for years in my professional career, a come a long is an accident waiting to happen, when compared the ease and safety of a chain hoist.

Just my .02 worth. If you ever use a chain hoist, you would probably never use a come a long again. I haven't.

Our come along was never needed but a quick test showed us that we could easily reach the middle of the hoist when our 5'8" beam RIB was along side.
Attaching to a ring in the davit was also easy as the comealong was fairly light, ratcheting the 20"+ handle was also easy as it was not far away.

Chain falls of what weight and materials carried on a boat for an emergency that should likely never happen?

If it is that important of an issue just bring along a spare portable electric hoist - lighter and mush easier to use than any other solution.

 

[BandB]

All -
Well I called the crane manufacturer and they sent me a schematic (see attached) for a crane similar to mine (see attached) showing the valve that if opened would allow the linear winch to collapse (hopefully slowly) and the dinghy would come down. So, I thought that is really cool. And having taken my linear winch apart last year to clear a jam I became pretty intimate with how my crane works. So, I thought some more about it because the Counter Balance Valve that he mentioned is on the inner most end of the linear winch. Guess what - there is absolutely no way to get at this valve while the crane is under load. When I asked him about the access to this valve he stated that I was correct and there is really no way to lower the crane - for a total loss of power to the crane. Jumping the solenoid is still a possibility - if you have access under load to those.

Oh well back to the drawing board. It was a good thought BandB.

Bob

Sounds like a design flaw but glad you had the conversation and found out what you did.

 

[guy with a boat]

In the extremely unlikely event that there is a failure in mid lift that can’t be fixed inside the remote or at the solenoids, crack a hydraulic fitting and lower it to the water. For one-time use in a pinch, any fitting that turns can be a pressure relief fitting. Wrap it first in an oil diaper and you won’t even have much of a mess.

 

[tozz]

You don't need a spare remote. The remote is a simple switch. you can open it up and jump the terminals if you ever have to. If you throw it overboard you can do that same with the terminals on the female plug that it plugs into.
~A

Yep. That’s the other thing I’ve been meaning to do. Grab the wiring map.

 

[Simi 60]

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'.

Our tender, outboard, fuel etc weighs in at around that
We have a decent set of transom mounted davits and hand cranked winches
Nice and simple

Tender is raised with a manual 3 speed trailer winch (1 each end) and 2:1 block (down and back up to top and locked off) using 1/4 inch dyneema
https://www.ebay.com.au/itm/3-Speed...49ceac91b401118f8e14|ampid:PL_CLK|clp:2334524

Never need to use the lowest gearing

 

[Shay]

Crain Failure

Dingy crane failure was one of my concerns also. I was afraid it would fail when conditions were bad. My dingy only weighed about 500lbs. I used a 6 purchase block and tackle sailboat boom vang and 3/8 rope. I practiced raising and lowering the dingy and it was all I could handle. My arrangement required me to pull the rope in a horizonal direction, pulling down would have been much easer. I included a cam cleat to allow taking a break. Even though I used good quality sail boat hardware the friction of the pullies added way more resistance than I expected. I never had to use the block and tackle for handling the dingy but did use it a few times when I needed the mechanical advantage.

Another option I considered, and it may work for a heaver dingy, was to fabricate a quick attach bracket for a boat trailer wench fitted dyneema so it could be routed through a pully on the end of the boom.

Shay