Hydraulic swim platforms " REVISITED "

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Robski97

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Anyone have a nautical solutions lift on there vessel. Was hot on one brand lift then ran into some people that had em and lets just say im now into plan B mode.

Rob
 
Bill,
I guess my post wasn't clear. Nautical is what i'm looking at currently. Previously it was a different brand.

Rob
 
Ah, I see. I have not used Nautical Structures lifts. But FWIW I have had their davits on a few boats. And found them to be very well made and have had great luck with their customer service people.
 
I have a 2001 Cruisers 4450 with a nautical structures transom lift on it. This season I had to replace both hydraulic rams. I believe the rams on the boat were original (though I'm not the original owner so I can't be sure except for the last five years.) The replacement rams weren't too cheap at about $1200 a piece but seem to be of high quality and good workmanship. I believe right now, after the replacement, the lift is slightly out of adjustment as it seems to be going up and down faster on port than starboard, though I think this is an adjustment issue more than anything wrong with the lift. My boat was fitted with the swim platform lift from the factory, if I had it to do over I'd seriously consider a cradle lift behind the swim platform. The advantages I see are that then the swim platform is clear to be used without the dinghy in the way and if you have issues with the lift getting stuck down you only have the structure of the cradle in the water instead of an entire large, solid and heavy swim platform in the water. It's worth noting I had that exact issue this season that required having the boat hauled and a fork lift under the platform in order to have the platform raised and run back to a yard that was capable of fixing it. I've had a couple of yards who have done maintenance on the lift comment that the nautical structures lifts are much better made than the tnt and they see many fewer problems with them. My experience is that in five seasons I've had one problem, that problem was the failure of a seal in a likely 10 year old hydraulic ram. I don't feel like that's too bad.

Ben
 
Ben,
Can't thank you enough for the post ! I'm told there is a manual pump to raise the platform incase of failure . Also the rams are power up and power down . So in case of hydraulic failure the rams would not release. There is also a lock that engages . So there's double protection .

Rob
 
Rob,

All of those things are accurate except for one fact. In my case the failure was a seal in one of the hydraulic rams. The seal failed on the up cycle of the platform. This caused all the hydraulic fluid in the system to be discharged through the seal and the system to lose all pressure. This meant that no amount of manual pumping was going to get the platform up. Also, in this case the seal was good enough on the way down to hold the pressure, but not on the way up. This failure pattern is one of the few I can see in which you would end up with the platform down but I can tell you first hand it is possible.

Ben
 
Ben,
Fully understand. My point was the platform wouldn't lower when fluid was lost. ( which most platforms would ) Also if the pump failed u could manually raise the lift. If there's no fluid , yes I would not expect it to be able to be raised. I just liked the back systems and the redundancy of not having it lower accidentally.

Rob
 
HaveADay said:
I have a 2001 Cruisers 4450 with a nautical structures transom lift on it. This season I had to replace both hydraulic rams. I believe the rams on the boat were original (though I'm not the original owner so I can't be sure except for the last five years.) The replacement rams weren't too cheap at about $1200 a piece but seem to be of high quality and good workmanship. I believe right now, after the replacement, the lift is slightly out of adjustment as it seems to be going up and down faster on port than starboard, though I think this is an adjustment issue more than anything wrong with the lift. My boat was fitted with the swim platform lift from the factory, if I had it to do over I'd seriously consider a cradle lift behind the swim platform. The advantages I see are that then the swim platform is clear to be used without the dinghy in the way and if you have issues with the lift getting stuck down you only have the structure of the cradle in the water instead of an entire large, solid and heavy swim platform in the water. It's worth noting I had that exact issue this season that required having the boat hauled and a fork lift under the platform in order to have the platform raised and run back to a yard that was capable of fixing it. I've had a couple of yards who have done maintenance on the lift comment that the nautical structures lifts are much better made than the tnt and they see many fewer problems with them. My experience is that in five seasons I've had one problem, that problem was the failure of a seal in a likely 10 year old hydraulic ram. I don't feel like that's too bad.
Click to expand...
Ben, Can you share how the yard gained access to the Port side RAM? Our 4450 has the same TNT lift that failed in a similar manner to yours. The guys can get to the starboard RAM but no luck so far with the Port side.
 
I doubt Ben is still around to reply 15 years later :).

TNT platforms like all platforms have the rams outside the boat so they should be very visible and accessible

They are also powered by a single hydraulic pump which powers both rams

The problem with TNTs is that unlike Nautical Structures they don’t have locks so when you loose hydraulic pressure because of a leak at the cylindrers or hoses the platform will drop. NS have locks that engage when the platform is up and are disengaged by auxiliary cylinders when you press down

This is why the manual for TNTs states that your tender should be tied to the boat wi the a row line in case of a malfunction under way. Confidence inspiring…

Indeed while the pump has a manual hand pump function, it s only good in case of a motor failure.

A few years ago, I had a hose pop while under dropping one side of the platform and the 15’ tender. Thankfully it happened in reasonably calm waters on the Bahamas bank and we were able to launch the dinghy and use the aft deck capstan to raise it back up. Had it happen an hour earlier in the Gulf Stream and 6 foot seas it would have been a different story

Since that day when crossing in open waters I use heavy duty ratchet straps between the heavy pins in the frame and the cockpit cleats to make sure it will not drop in case of a hose failure
 
Pascal,

Thanks. We do keep heavy duty ratchet straps on board specifically for the possibility of RAM failure.

The TNT rams do extend well up into the transom and are only accessible from inside the aft cabin. Starboard was easy enough as it is behind the mirror over the vanity seat. Port is less so as it looks like the headboard/stair cover has to come off. I used an endoscope to see inside and the current attack is to remove the lowest stair cover in the aft cabin.

The reason we need access to the tops of the rams is to remove the locking pins that will allow the whole ram to come out so we can have all of the seals replaced.
 
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