Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 11-01-2016, 13:04   #1
Registered User
 
TMT2's Avatar

Join Date: Dec 2012
Location: Cruising US East Coast/Caribbean
Boat: 1975 Gulfstar M53
Posts: 158
Hydraulic Davit Question?

Any hydraulic davit experts out there? I have a nice set of hydraulic davits on the stern of our Gulfstar M53. They are fully functional but it's time to inspect/test/service the unit. My intent is to hang a 10ft/500 lb Avon Center Console RIB for coastal/inland cruising (25hp Yamaha, plus fuel/battery and steering console unit). Photo of davits is attached. For those who abhor sailing with dinghy on davits - rest easy...we lift the RIB onto the fore-deck for off-shore transit with our mast crane (another CF post).

Ignoring the solar array that I have mounted to the top-side of the davits...does anyone recognize the maker of this davit unit? I have been unable to identify a manufacturer? On a long-shot, perhaps some savvy cruisers have the same set-up? I am comfortable with the solid mounting arrangement as there are large aluminum backer plates on the inside of the transom plus the well-secured locking eyes at the gunnel for secondary stability. What I don't want to do is "test lift" the RIB and blow a lift cylinder creating a hydraulic spill in the water not knowing the lift rating of the unit? Reaching out as a stab in the dark for someone that may be able to ID the unit?

Any help would be appreciated.

TMT2
__________________

__________________
TMT2 is offline   Reply With Quote
Old 11-01-2016, 13:06   #2
Registered User

Join Date: Nov 2013
Location: Nice, France
Boat: Hunter Marine 38
Posts: 281
Re: Hydraulic Davit Question?

No photo
__________________

__________________
sailormed is offline   Reply With Quote
Old 11-01-2016, 13:06   #3
Registered User
 
TMT2's Avatar

Join Date: Dec 2012
Location: Cruising US East Coast/Caribbean
Boat: 1975 Gulfstar M53
Posts: 158
Re: Hydraulic Davit Question?

OK...Figured out that the photo needed to be in "attach files" versus videos.
Attached Thumbnails
Click image for larger version

Name:	IMG_0465.jpg
Views:	157
Size:	425.0 KB
ID:	116549  
__________________
TMT2 is offline   Reply With Quote
Old 11-01-2016, 13:39   #4
Registered User
 
TMT2's Avatar

Join Date: Dec 2012
Location: Cruising US East Coast/Caribbean
Boat: 1975 Gulfstar M53
Posts: 158
Re: Hydraulic Davit Question?

Ironic...Just heard from previous owner...custom rig - all the way. Have what I need (based on tube thickness calculation, frame is 800+ lbs/cylinders are compatible/ pump may be undersized - will research) ... but happy to share/describe our setup with others if interested.

TMT2
__________________
TMT2 is offline   Reply With Quote
Old 12-01-2016, 15:52   #5
Registered User
 
funjohnson's Avatar

Join Date: Mar 2010
Location: Currently Indiantown FL
Boat: 37' aluminum pilothouse "Elements"
Posts: 1,846
Re: Hydraulic Davit Question?

Are your solar panels on cabinet slides? Do you have a second row under the upper set?

Sent from my LG-V410 using Cruisers Sailing Forum mobile app
__________________
MJSailing.com - Written Blog
Youtube MJ sailing - Vlog
funjohnson is offline   Reply With Quote
Old 12-01-2016, 16:10   #6
Senior Cruiser

Cruisers Forum Supporter

Join Date: May 2013
Location: Oregon to Alaska
Boat: Wheeler Shipyard 83' ex USCG
Posts: 1,699
Re: Hydraulic Davit Question?

If you're concerned with spills, there are several bio hydraulic oils available. They leave no sheen and are affordable for small users.
Many commercial boats have gone to them. Better commercial suppliers carry them, probably Ebay, too.
__________________
Lepke is offline   Reply With Quote
Old 12-01-2016, 16:31   #7
Registered User
 
TMT2's Avatar

Join Date: Dec 2012
Location: Cruising US East Coast/Caribbean
Boat: 1975 Gulfstar M53
Posts: 158
Re: Hydraulic Davit Question?

Funjohnson,

The solar panels (4x130W) fold from the outside-in. A king-board "drawer/stainless slide" arrangement provides support for the panel "wings" when deployed.

TMT2


Sent from my iPhone using Cruisers Sailing Forum
__________________
TMT2
1975 Gulfstar M53 (Ketch)
https://www.takemetheresailing.com
TMT2 is offline   Reply With Quote
Old 12-01-2016, 16:32   #8
Registered User
 
TMT2's Avatar

Join Date: Dec 2012
Location: Cruising US East Coast/Caribbean
Boat: 1975 Gulfstar M53
Posts: 158
Re: Hydraulic Davit Question?

Lepke,

Thanks-I didn't know that...I will research your suggestion.

TMT2


Sent from my iPhone using Cruisers Sailing Forum
__________________
TMT2
1975 Gulfstar M53 (Ketch)
https://www.takemetheresailing.com
TMT2 is offline   Reply With Quote
Old 17-05-2016, 12:37   #9
Registered User
 
TMT2's Avatar

Join Date: Dec 2012
Location: Cruising US East Coast/Caribbean
Boat: 1975 Gulfstar M53
Posts: 158
Re: Hydraulic Davit Question?

After many hours of research and a bit of trial and error...the aforementioned davit system lifts and holds our 500 lb AB Rover 340 center console RIB with a Yamaha 25HP 4-Stroke.

For those inclined to opine on davit usage - we do lift the RIB onto the fore-deck for off-shore passage (covered in another thread). I was surprised that the boat didn't "squat" at the stern when I hoisted up 500 lbs! She didn't even flinch.

Now onto the task of eliminating "swing" under the davits. Since the RIB is a center console, cinching/snugging the RIB up to the davits is not an option. Cross ties or ratchet straps won't give me 360 degree rigidity. I am thinking about rigid, adjustable (turn-buckled) aluminum or stainless braces (crossed) to connect from each opposing davit arm to the RIB hull (interior) to prevent swing? Anyone seen, used/have experience or ideas with this technique?...Suggestions?
Attached Thumbnails
Click image for larger version

Name:	RIB Diagram side.png
Views:	81
Size:	60.6 KB
ID:	124510   Click image for larger version

Name:	RIB Diagram Top.png
Views:	80
Size:	41.4 KB
ID:	124511  

__________________
TMT2 is offline   Reply With Quote
Old 24-05-2016, 11:33   #10
Registered User

Join Date: Oct 2009
Location: Boise, ID
Boat: AMF Force 5 -- 14ft long
Posts: 23
Re: Hydraulic Davit Question?

Rigid supports should work. I'd make sure to bungee the rigid supports to the davit arms, so they are above the boat while the boat is being raised. Then lower them into the boat and secure to the boat.

Sent from my SM-G900V using Cruisers Sailing Forum mobile app
__________________
jason902 is offline   Reply With Quote
Old 20-06-2016, 05:22   #11
Registered User
 
TMT2's Avatar

Join Date: Dec 2012
Location: Cruising US East Coast/Caribbean
Boat: 1975 Gulfstar M53
Posts: 158
Re: Hydraulic Davit Question?

Sharing final photo of my project - appreciate all the help from forum members!

TMT2
Attached Thumbnails
Click image for larger version

Name:	RIB Mounted 1.JPG
Views:	88
Size:	119.9 KB
ID:	126595   Click image for larger version

Name:	RIB Mounted 2.JPG
Views:	84
Size:	134.6 KB
ID:	126596  

__________________
TMT2 is offline   Reply With Quote
Old 20-06-2016, 09:19   #12
Registered User
 
leftbrainstuff's Avatar

Join Date: May 2011
Location: San Francisco and Australia
Boat: Liberty 458
Posts: 1,978
Re: Hydraulic Davit Question?

Does the whole frame and arch pivot? Looks custom.

Looks like a lack of triangulation. Low cycle fatigue will likely be the failure mode. Keep a close check on any cracking or buckling at the hydraulic cylinder attachments. Especially after any sea state is experienced.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app
__________________
leftbrainstuff is offline   Reply With Quote
Old 20-06-2016, 09:35   #13
Registered User
 
TMT2's Avatar

Join Date: Dec 2012
Location: Cruising US East Coast/Caribbean
Boat: 1975 Gulfstar M53
Posts: 158
Re: Hydraulic Davit Question?

Leftbrainstuff...The entire davit assembly lowers/raises to/from the waterline. The remote control key fob switch is a nice feature. I agree - I will watch for low-cycle fatigue. I've solved the swing issue with cross-bars and ratchet straps that snug the RIB against the davit arms along the RIB rub rail. We'll give it some coastal testing and make adjustments as we go. Time will tell...perhaps by the time I get it perfect - I will buy a new aluminum RIB, a new 4-stroke... and shave about 170 lbs off of the load.

TMT2
__________________

__________________
TMT2 is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Want To Buy: Simpson S175 Davit Parts or Complete Davit Dockhead Classifieds Archive 1 06-07-2015 02:47
Hydraulic Steering Question Celestialsailor Construction, Maintenance & Refit 39 13-10-2013 11:13
Hydraulic steering question F51 Construction, Maintenance & Refit 4 07-03-2013 20:02
Dinghy davit question Dulcesuenos Auxiliary Equipment & Dinghy 10 10-01-2013 16:53
Hydraulic Steering Cylinder Question ... Cheechako Construction, Maintenance & Refit 12 01-10-2012 21:45



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 13:06.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.