Trailering with an Olsson Davit

RichBirk

Well-known member
Joined
Oct 26, 2018
Messages
80
Fluid Motion Model
C-30 CB
Hull Identification Number
FMLT2934C919
Vessel Name
Avellana
We have ordered a R29CB to be delivered in April. Our boat will live in our barn in Oregon, so we will trailer up the freeway to Puget Sound and beyond. We really like the looks of the Olsson ST275 davit for a hard bottom dingy. Does anyone have this type of davit and trailer their boat with the dingy attached? Any concerns with weight on the swim step while underway? Any concerns about extending the overall length on the highway?
Thanks for any suggestions. We really enjoy reading all the info in this site. Very excited to join the Tug community.
Rich
 
I am also interested in whether the ST275 can be used for trailering. I already have the Weaver davits which work well trailering. I have also been looking at the Island davits, winch model, from Kato Marine for our R-29S so I can keep the outboard on the dinghy while afloat. You might check this option out as well. I know it has been mounted on several R-31's. There are pictures on the website of one of the R-31 installations and you can still keep the railing on the swim step. It is removable so I think that I could still use the Weaver davits for mounting the dinghy for trailering. I don't have any info about trailering with the Kato davits.

If you get any information outside the forum, please post it.

For your interest I have attached below a chunk of the email reply to my request for a quote from Kato Marine. They get good reviews from what I can find.

*****************************************************************************************************************************************************

"You are planning to use a Highfield CL 290 AL dinghy with a 9.9 short shaft outboard with the davits. Your boat is currently out of the water until about the end of March.

We try to maintain an extensive database on each boat’s installation (that we know of), so that we can pass this knowledge on the next individual with the same boat. I did check out the very recent davit order we worked on for a 2013 Ranger Tug 29 and it turns out he opted to completely remove the stern rails and install the davits with a custom upper attachment to the boat’s center upper transom coaming, the davits lengthened and base on the transom.

In providing davits for all the other prior installs on the Ranger Tug 27 and 31, their Island davits were attached to the stern rails with rail support to swim platform, as seen in the attached picture of the Ranger Tug 31 installation.

The Island model davits are rated at a safe working load of 300 lbs per davit arm. Keep in mind that 70-80% of the weight of the dinghy is in the transom and carried on one davit arm. Add the weight of the outboard and an allowance for water that may remain in the dinghy, fuel, etc.

Our Island davits are mounted to and rely upon the strength of the stern rail; we reinforced the railing on this boat using tubular supports led forward to the swim platform (see sketch). We employ what we call 'socks' that slip over the bottom of the davit and raise the davits to the desired height. Your davits would be heightened and we need to know the exact height of your rails (from the swim platform) to determine the appropriate length to heighten them. Based on the prior installs, am anticipating between 6-7.5” is the range.

Both of our davit models can be folded when not in use. Because of this fact, it is important to use one of several options to stabilize the davits when in use, by locking them in an outboard position. You will see on our website, www.katomarine.com/saildavits-stabilizers.htm that we offer a range of stabilizing systems to suit different needs and budgets. For a custom fit, the stabilizer is ordered after the davits are installed, the dinghy hoisted and measurements taken. Based on our conversation, it seems our ‘Slip-On’ stabilizer may be a good fit for your needs and have included it in the basic davit system list below.

BASIC DAVIT SYSTEM FOR RANGER TUG 29
Island model davits $1845.00
Single Winch Upgrade (Harken single speed 20 STA & 2:1 purchase) 760.00 per side*
Includes a modified davit arm to accept winch
Heighten davits heightened (6-7.5” estimated) 189.00
Standard 1-1/2" x 3" davit bases included/pair
Standard rail mount w/1-3/8” standoff from rail included/pair
4:1 purchase tackle (Harken blocks with 3/8” line ) included/pair
Transom Rail Supports w/3" bases and alum. backing plates 432.00
Slip-On stabilizer 530.00

*Tyler, I’ve included the winch arm upgrade for one of your davits but you can certainly upgrade both if you so desire. If you got one only, you’d obviously then always be lifting the transom side of your dinghy/motor on the side of the boat that has the davit with the winch available. The other davit would have a much lighter lift but you’d be restricted to always be lifting the dinghy in the same position. You’d find in practice that you can’t use a singular fixed winch (on one davit arm) to lift both sides of the dinghy. For every davit arm you upgrade, you save $60 each as you do not need a cam cleat assembly for that winch enabled davit arm.

Other Options

Additional Stabilizer options
SS100 ‘Fixed’ (choice for adding solar panels) 535.00
CT100 – single 1” s/s cross tube for wire stabilizing (up to 65” span)* 175.00
CT125 – single 1-1/4” s/s cross tube for wire stabilizing (>65” span)* 216.00
*you provide the needed spring lines

Winch Upgrade (Harken single speed 20 STA & 2:1 purchase) 760.00 per side
Includes a modified davit arm to accept winch

Tackle Options (for heavy dinghy or bad back)
6:1 purchase 40mm blocks upgrade 95.00 per side
4:1 purchase 57mm blocks upgrade 63.00 per side
6:1 purchase 57mm blocks upgrade 127.00 per side

Ease of Operation Options
Cam cleat assemblies (essential aid in single handed hoisting) 120.00 pair
Secure-It s/s ratchets w/webbing (securing dinghy when hoisted) 156.00 pair
See video at http://www.katomarine.com/saildavits-dinghy.htm

Shipping and Packaging (Alaska – Kenai 99711) 485.00* estimated
(This is for two (2) shipments as the stabilizer is measured for after the davits are installed).

Tyler, your shipment would be in two parts. Once you’ve installed the davits and rail supports, we then have you hoist your dinghy with outboard, make a few minor tweaks for create a temporary bridle, then measure for your stabilizer. The stabilizer we custom size for you and comes in a separate shipment.

We provide all the fasteners with exception of any hull or deck hardware (as we would not know the length needed for your particular boat). We also provide a comprehensive installation package with each set of davits and remain available by phone to assist you. It is important to us that each installation goes well."
 
Kenaithab - Thank you for your reply. I called Olsson today and he assured me that we could trailer our boat with the dingy attached provided it was well strapped to the cleats on the boat. We have decided to NOT get the swim step rails and want to leave our motor attached to the dingy. We have never had a nice dingy before and are looking forward to having it easily available to use. This option also gives us a good view out the back of the boat.

The pictures we see of the R29 underway look like the swim step is right at the water. My concern: Is 200 lbs too much weight and how does it affect performance at cruising speed?

We won't get delivery on our boat until April so we have time to decide. Lots to look at during the boat show season.
 
We run the Olson davit on our R29CB and love it. We still have visibility to the stern and leave our 9.9 hp Yamaha attaches to the dingy and it has remained secured and comfortable on the swim step. We use tie downs to secure the dingy to the vessel on long journeys for piece of mind. We have been through some tuff weather with our setup and have been happy with the outcomes.


Sent from my iPhone using Tapatalk
 
We have a set of Olsson Davits, model RS-4 on our 2016 R-27 IB.
No stern rails on the swim step.
The previous owner had them installed. I like them for the capability of leaving the 6 HP OB attached to the 7'10" Achilles R IB.
With the dinghy mounted horizontally, I have better visibility to the rear.
I have not trailered the boat since we just purchased it.
Bill
 
RichBirk":1unmla2k said:
We have ordered a R29CB to be delivered in April. Our boat will live in our barn in Oregon, so we will trailer up the freeway to Puget Sound and beyond. We really like the looks of the Olsson ST275 davit for a hard bottom dingy. Does anyone have this type of davit and trailer their boat with the dingy attached? Any concerns with weight on the swim step while underway? Any concerns about extending the overall length on the highway?
Thanks for any suggestions. We really enjoy reading all the info in this site. Very excited to join the Tug community.
Rich

Several comments for you... and I do like the Olsson ST275 davit system and its looks and easy block&tackle for lowering/raising.

1) Adding weight (possibly as much as some 300 lbs) to the stern will cause greater fuel burn. It's the worst possible place to add weight.

2) The swim step on the R29CB will be awash once the boat is underway at about 10 kts, and progressively more so at hight speeds.

3) With following seas or when decelerating from high speed the swim step can be overwhelmed with water and this could cause the dinghy on the Olsson ST275 davit system to float up some.

4) The dinghy in its up position will hide some of the rear view, but not as bad as having the dinghy in a vertical position. Part of the best stern wave IMO is the portion just immediately aft of the stern.

5) It's quite likely that when underway that water spay etc will enter the dinghy and add more weight to be carried at the worst part of the boat.

6) Even though the dinghy is not vertical its forward angle will still create wind drag.

7) The dinghy will add overall length to the boat that will increase docking fees base on the overall feet required for docking, and this may very well also mean having to use a longer slip at permanent marina moorage compared to not having the dingy.

8) If you fish with down riggers with the dingy installed you will have the added and unwanted interference of the dinghy when pulling in your catch, and beware of hooks attaching to the dinghy causing punctures etc.

9) If you intend to install a full cockpit enclosure be sure to have cutouts for allowing the block&tackle to thread through to the transom.

10) Not sure about how the transom flip seat will work with the Olsson ST275 davit system in place.

11) I have no comment to add related to trailering as that is not something I do with my boats.

12) When you dock 'mediterranean style' with the dinghy installed how would you get onboard as the complete beam of the swim step is occupied with the dinghy ?

Good luck.... 🙂
 
OK - Now that we've had the boat for nearly 6 months and 360 hours on the engine and over 1000 miles on the trailer - here are some of what we have experienced.

Chose a 9.5' Highfield hard bottom boat with 15 horse Suzuki outboard. Admittedly maxed out both length and weight for the davit but wanted to be able to fish and explore as well as have the horsepower should I for some reason lose the main engine. Fuel injection and electric start are really nice. The weight of engine is more than I would like on the same side as all those batteries, but so far have been able to load the boat to off-set that.

Most of our travel is at about 7.5 mph. Exceptional fuel efficiency and It's good to know we can live cheaper on the boat cruising than at home.

We've seen some ugly water - Queen Charlotte Sound - but dinghy rode well. Two strap ties as suggested by Craig secured it well.

Had to add a second drain plug to the port corner of the dinghy transom as rainwater or splash can fill the dinghy quickly - even on the road. It works well.

Dinghy does add a little to the overall length. We report it as 33' and no one has questioned it. The one exception is Washington State Parks. They must go by what is on the documentation certificate when buying a park permit - 29'.

Have no plans at this time to add a cockpit enclosure. Transom seat is flipped to the back most of the time to allow for more access in the cockpit, but would be a boring view should someone choose to sit there.

We're on our way to Sequim this Sunday afternoon to launch. Will be taking our 2.5 Hp outboard instead of the 15. I expect everything will tow and travel easier.

Josh at Olsson Davit has been wonderful to work with.
 
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