Davits

[N4712]

We just got all the hoses replaced on our davit, and were going keep the olds for spares. Anyways if a hose was to break, is there a safety feature to prevent it from plummeting down and screwing a lot of stuff up? Our model is a 1300lb Aritex Davit with 10ft telescoping boom.

 

[Forkliftt]

I'm not familiar with your specific system, but what you are asking about is called a "velocity fuse".

 

[N4712]

I'm not familiar with your specific system, but what you are asking about is called a "velocity fuse".

Ahhh, I think we have those on it. I googled those and there're like round things that screw in to an block. we have a block on the bottom the cylinder for the boom, and can't tell if the swing and winch cylinder have one too, as there not visible.

 

[River Cruiser]

On equipment like hydro cranes they use a load check valve. It will keep the boom from dropping if a line, hose or oring were to fail. If you have one it will be mounted on the cylinder, it restricts the flow of oil out of the cylinder without the control valve being shifted to send oil to the other side of the piston. May look like this:

 

[Shoalwaters]

The little valves described will do the trick if you have an hydraulic failure. Most of the hydraulic davits I have seen move the hook up and down by a block and tackle working in reverse and driven by an hydraulic cylinder. Needless to say, the hook and its load will drop like a stone if the cable breaks, regardless of any fail-safes on the hydraulic side of things. Keeping the cable washed free of salt deposits will help it live a long and happy life. Unfortunately access to the block and tackle assembly can be well nigh impossible without dismantling the davit. A Bertram sportfish of my acquaintance had a new Marquip davit installed on the foredeck. I asked Marquip how to keep the davit healthy as that location gets liberally doused with sea water. Their answer was to put the boom all the way up, the cable all the way out, and squirt a water hose into the top of the boom. YMMV.

 

[N4712]

On equipment like hydro cranes they use a load check valve. It will keep the boom from dropping if a line, hose or oring were to fail. If you have one it will be mounted on the cylinder, it restricts the flow of oil out of the cylinder without the control valve being shifted to send oil to the other side of the piston. May look like this:

Yep, we got'em. They look like that except in SS.

 

[N4712]

The little valves described will do the trick if you have an hydraulic failure. Most of the hydraulic davits I have seen move the hook up and down by a block and tackle working in reverse and driven by an hydraulic cylinder. Needless to say, the hook and its load will drop like a stone if the cable breaks, regardless of any fail-safes on the hydraulic side of things. Keeping the cable washed free of salt deposits will help it live a long and happy life. Unfortunately access to the block and tackle assembly can be well nigh impossible without dismantling the davit. A Bertram sportfish of my acquaintance had a new Marquip davit installed on the foredeck. I asked Marquip how to keep the davit healthy as that location gets liberally doused with sea water. Their answer was to put the boom all the way up, the cable all the way out, and squirt a water hose into the top of the boom. YMMV.

Thanks for the tip, Well do that. And ours is just as you mentioned with the hydro cylinder with block.

 

[N4712]

Here's a pic I got today, pretty sure that's it.

 

[River Cruiser]

Here's a pic I got today, pretty sure that's it.

looks like one to me.

 

[N4712]

looks like one to me.

Ok, I thought so.