Putting an aluminium floored SIB on a trailer

[nelvar]

I was advised not to leave a larger SIB on a trailer or launch trolley as it may sag over time.

However, I am aware that some people tow their SIBs and some leave it on launch trolleys for extended periods.

If you are one of these people, have you seen any ill effects to the SIB, or have you modified your trailer/trolley to increase or improve the surface area that supports the SIB?

I have purchased a launch trolley and am looking at improving the support it currently offers by modifying it with a couple of large webbing slings.

Dave

[The Gurnard]

Originally Posted by nelvar

I was advised not to leave a larger SIB on a trailer or launch trolley as it may sag over time.


Dave

Not sure who told you that but my heavy Quicksilver 4.3m SIB sat on its trailer 365 days per year and never sagged after sitting 16 years. The secret is to support the length of floor of the boat with the trailer bunks just where it meets the tubes. That way there is no weight on the tubes so it wont deform if pressure goes down in the tubes.

I have no experience of leaving it long term on a launch trolley. .. so perhaps that is what they really mean to say.. bunked trailer is fine though..

[jeffstevens763@g]

Surface area support and plenty of it

[_monkey]

Originally Posted by nelvar

I was advised not to leave a larger SIB on a trailer or launch trolley as it may sag over time.

However, I am aware that some people tow their SIBs and some leave it on launch trolleys for extended periods.

If you are one of these people, have you seen any ill effects to the SIB, or have you modified your trailer/trolley to increase or improve the surface area that supports the SIB?

I have purchased a launch trolley and am looking at improving the support it currently offers by modifying it with a couple of large webbing slings.

Dave

My Futura spent all it's life on a SIB trailer, no evidence of problems.

Get an appropriate trailer which supports the tubes and the transom.

[pagick]

Futura mkll with 60hp on it. 3years during summer months it’s on the trailer with no problem. And I check. Transom rests on the bunks as does the aluminum floor. I just let the keel air out so fabric goes slack and let’s bunks contact floor. Also I keep air in tubes that support transom at least 2 psi. It sleeps in my garage when not in use.

[chipko]

Nelvar,

Tried to reply to your pm but strangely couldn't attach any pics, so putting my reply here on the forum. Hope you don't mind, here goes;

Hi Nelvar,

The trolley's (we have a large and small) have been used and modified a few times over the years to suit different boats. We fitted bunks for good support as our sibs sat on these inflated March to November and the trollies only dismantled and folded for storage over winter. The bunks were all made from 38 x 63mm CLS timber and 2400mm long covered with pipe insulation. Tubes always reduced to around half pressure for storage. We also used a cheap hand dolly for ease of hauling by hand over grass, dunes and sand.

The first sib, a Zodiac was aluminium floor so the outer bunks were positioned under the outer edges of the floor next to tubes, and keel fully deflated. Four bunks probably overkill as in reality two would suffice.

For the Aerotec the bunks went under the tubes and the air floor just hung between.

The last incarnation was for a T38. For this the inner bunks ditched and boat supported with single bunks under tubes hard up to floor edges.

We also, at one point, modded the smaller trolley with short bunks. This was good for occasional daily inflation use as could be readily dismantled and folded.

Hope all this rambling makes sense and of some help.

[pagick]

Originally Posted by chipko

Nelvar,

Tried to reply to your pm but strangely couldn't attach any pics, so putting my reply here on the forum. Hope you don't mind, here goes;

Hi Nelvar,

The trolley's (we have a large and small) have been used and modified a few times over the years to suit different boats. We fitted bunks for good support as our sibs sat on these inflated March to November and the trollies only dismantled and folded for storage over winter. The bunks were all made from 38 x 63mm CLS timber and 2400mm long covered with pipe insulation. Tubes always reduced to around half pressure for storage. We also used a cheap hand dolly for ease of hauling by hand over grass, dunes and sand.

The first sib, a Zodiac was aluminium floor so the outer bunks were positioned under the outer edges of the floor next to tubes, and keel fully deflated. Four bunks probably overkill as in reality two would suffice.

For the Aerotec the bunks went under the tubes and the air floor just hung between.

The last incarnation was for a T38. For this the inner bunks ditched and boat supported with single bunks under tubes hard up to floor edges.

We also, at one point, modded the smaller trolley with short bunks. This was good for occasional daily inflation use as could be readily dismantled and folded.

Hope all this rambling makes sense and of some help.

I’d add bunks under transom. That’s the weakest and most important connection. Wood to fabric/hard to soft. And the outboards weight is relentless at trying to pull the wood down to the ground. JMO

[chipko]

Good and valid point.

However, irrelevant to my post. First off on all variants my bunks extend beyond and support the transom. Second, boats all stored without motor attached. Third, towing whilst motor attached, only hand balled or towed at walking speed behind car or tractor on private land/beach.

[nelvar]

Originally Posted by chipko

Nelvar,

Tried to reply to your pm but strangely couldn't attach any pics, so putting my reply here on the forum. Hope you don't mind, here goes;

Hi Nelvar,

The trolley's (we have a large and small) have been used and modified a few times over the years to suit different boats. We fitted bunks for good support as our sibs sat on these inflated March to November and the trollies only dismantled and folded for storage over winter. The bunks were all made from 38 x 63mm CLS timber and 2400mm long covered with pipe insulation. Tubes always reduced to around half pressure for storage. We also used a cheap hand dolly for ease of hauling by hand over grass, dunes and sand.

The first sib, a Zodiac was aluminium floor so the outer bunks were positioned under the outer edges of the floor next to tubes, and keel fully deflated. Four bunks probably overkill as in reality two would suffice.

For the Aerotec the bunks went under the tubes and the air floor just hung between.

The last incarnation was for a T38. For this the inner bunks ditched and boat supported with single bunks under tubes hard up to floor edges.

We also, at one point, modded the smaller trolley with short bunks. This was good for occasional daily inflation use as could be readily dismantled and folded.

Hope all this rambling makes sense and of some help.

Chipko,

that is fantastic, thank you.

My intention, when the SIB arrives, is to inflate, turn it upside down, and work from there to determine the modifications needed to the trailer.

I prefer your rigid bow-to-stern support, as opposed to my original intention of using webbing to provide lateral support.

Once I have completed the trailer, I will post the photos.

Dave