Reply
 
Thread Tools Search this Thread
 
Old 22 June 2006, 19:02   #11
Member
 
Nasher's Avatar
 
Country: Other
Town: Principalite d'Chaos
Boat name: The Nashers Revenge!
Make: Ocean & Bombard
Length: 6m +
Engine: Suzi DT200EFI, DT9.9
MMSI: "Mmmmm SI" she said!
Join Date: Jan 2004
Posts: 4,147
Why should I buy something?

Did I not make it clear I would be making any solution myself?

Nasher.
__________________

__________________
RIBBED For extra pleasure.
Member of the ebay Blue RIB cover club.
Member of the Bombard 380 Aerotec club
Nasher is offline   Reply With Quote
Old 22 June 2006, 19:22   #12
Member
 
Hightower's Avatar
 
Country: UK - England
Town: Fareham
Length: 6m +
Join Date: Sep 2003
Posts: 7,855
I wouldn't worry about the stresses caused on a trailer going over a bumpy road. They will be nothing like the stresses created when wave hopping.

Yes. Thrust from the prop is a factor in design of outboard brackets but IMHO the stresses caused by the beformentioned pendulum effect would be cause for concern as Transoms have the strong knees on the inside and not the outside of the hull.

If you follow the RIB manufacturers recommended weight of outboard on transom you can't go wrong.

PS...Trailers have suspension to aborsb shocks....Boats do not!

I wouldn't worry about it Nasher, go spend your money down the Pub/Tank of fuel instead.
__________________

__________________
Andy

Looks Slow but is Fast
Member of the ebay Blue RIB cover club.
Hightower is offline   Reply With Quote
Old 22 June 2006, 19:43   #13
Member
 
Country: Other
Town: San Carlos, Mexico
Boat name: INDE
Make: LOMAC 730
Length: 7m +
Engine: 200 Merc.
MMSI: Please press 1
Join Date: May 2006
Posts: 1,688
Send a message via Skype™ to Limey Linda
Just re-read this thread. I would probably do the same as Nasher and build my own support system. However: please note that hydraulics do NOT provide any shock absorbsion. The ram is a cylinder full of oil and liguids do not compress, only gases. It does not work like a car shock absorber. Still think a stick and a bungee is the simple solution. Although I would be tempted to buy one of those slip on ram thingees for 20quid , just to see how well it worked.
__________________
Running around like a head with it's chicken cut off.
Limey Linda is offline   Reply With Quote
Old 22 June 2006, 20:18   #14
Member
 
Hightower's Avatar
 
Country: UK - England
Town: Fareham
Length: 6m +
Join Date: Sep 2003
Posts: 7,855
I know how hydraulics work! I'm an engineer and work with this sort of stuff every day.

But I don't think you get it.

Last year I broke my transom......I didn't break it on the back of my trailer. I broke it going over the wake of a large high speed ferry. That proves that there are larger forces acting on the transom whilst under-way, at Sea.

Surley if the Hydraulics can take the force of 200hp and support the weight of a 200kg outboard going at 50knotts a simple road trip isn't gonna hurt it. I've never had a support and I haven't yet damaged anything.
__________________
Andy

Looks Slow but is Fast
Member of the ebay Blue RIB cover club.
Hightower is offline   Reply With Quote
Old 22 June 2006, 20:49   #15
RIBnet admin team
 
Nos4r2's Avatar
 
Country: UK - England
Town: The wilds of Wiltshire
Boat name: WhiteNoise/Dominator
Make: Ballistic 7.8/SR5.4
Length: 7m +
Engine: Opti 225/Yam 85
MMSI: 235090687/235055163
Join Date: Jul 2005
Posts: 12,645
RIBase
Quote:
Originally Posted by Hightower
I know how hydraulics work! I'm an engineer and work with this sort of stuff every day.

But I don't think you get it.

Last year I broke my transom......I didn't break it on the back of my trailer. I broke it going over the wake of a large high speed ferry. That proves that there are larger forces acting on the transom whilst under-way, at Sea.

Surley if the Hydraulics can take the force of 200hp and support the weight of a 200kg outboard going at 50knotts a simple road trip isn't gonna hurt it. I've never had a support and I haven't yet damaged anything.

It'd be interesting to see the stress analysis on it if it was possible to gather the relevant data to do one
__________________
Need spares,consoles,consumables,hire,training or even a new boat?

Please click HERE and HERE and support our Trade Members.

Join up as a Trade member or Supporter HERE
Nos4r2 is offline   Reply With Quote
Old 22 June 2006, 21:39   #16
Member
 
Country: Other
Town: San Carlos, Mexico
Boat name: INDE
Make: LOMAC 730
Length: 7m +
Engine: 200 Merc.
MMSI: Please press 1
Join Date: May 2006
Posts: 1,688
Send a message via Skype™ to Limey Linda
Quote:
Originally Posted by Hightower
I know how hydraulics work! I'm an engineer and work with this sort of stuff every day.

But I don't think you get it.

Last year I broke my transom......I didn't break it on the back of my trailer. I broke it going over the wake of a large high speed ferry. That proves that there are larger forces acting on the transom whilst under-way, at Sea.

Surley if the Hydraulics can take the force of 200hp and support the weight of a 200kg outboard going at 50knotts a simple road trip isn't gonna hurt it. I've never had a support and I haven't yet damaged anything.

It would appear that we should take Mr. Highpower's engineering advice and do nothing to protect transoms etc. while trailering. "you pays your money and takes your choice" I do not think so; but that is just an opinion from a 60 year old engineer that has owned 10 boats and trailered well over 10k. miles ?????
__________________
Running around like a head with it's chicken cut off.
Limey Linda is offline   Reply With Quote
Old 23 June 2006, 07:50   #17
Member
 
Country: Other
Town: Stanley, Falkland Is
Boat name: Seawolf
Make: Osprey Vipermax 5.8
Length: 5m +
Engine: Etec 150
Join Date: Mar 2006
Posts: 3,688
I don't know anything about engineering but one might reasonably assume that RIB manufacturers make their transoms strong enough to take the specified engine weight in whatever situations the boat might be found in whether wave hopping or on a trailer? Lots of engines falling off would be bad for business....

What I can say is that there are no sign of problems with mine and it has been trailered by previous owners on roads that are much rougher than any found in the UK (unsurfaced gravel and clay), and it has even been towed quite some distance off road by the previous owner, which would be more thumping and banging around than most ribs would ever see trailered on tarmac roads. The trailer has no suspension and is fitted with four 7.50x16 Land Rover wheels which do not give an especially smooth ride. I think the guy I bought it from said he just used to lower it on to the locking frame and then put a ratchet strap around it to take the load off the hydraulics. No apparent problems (famous last words!)
__________________
BogMonster is offline   Reply With Quote
Old 23 June 2006, 20:01   #18
Member
 
Hightower's Avatar
 
Country: UK - England
Town: Fareham
Length: 6m +
Join Date: Sep 2003
Posts: 7,855
Quote:
Originally Posted by Limey Linda
It would appear that we should take Mr. Highpower's engineering advice and do nothing to protect transoms etc. while trailering. "you pays your money and takes your choice" I do not think so; but that is just an opinion from a 60 year old engineer that has owned 10 boats and trailered well over 10k. miles ?????
HighPower.....I like it!

Let's just get one thing straight please.

I don't tell people what to do at all Linda. I let them make their own minds up. I can however offer advice though experience or knowledge or even offer opinions if it helps.

If people want to design and build or buy a peice of kit that they think will add protection to their transoms and outboards, that's fine. I however have not the need for such a device and have never had a problem with any boat I have owned.

I did however have a small fishing boat with no hydraulic T&T that I had to trail with a piece of wood jammed between the saddle and skeg (which is what Nasher is kind of talking about), but that was to give clearance between the skeg and road whilst trailering and nothing more.
__________________
Andy

Looks Slow but is Fast
Member of the ebay Blue RIB cover club.
Hightower is offline   Reply With Quote
Old 27 June 2006, 14:00   #19
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
Quote:
Originally Posted by Hightower
But I don't think you get it.

Last year I broke my transom......I didn't break it on the back of my trailer. I broke it going over the wake of a large high speed ferry. That proves that there are larger forces acting on the transom whilst under-way, at Sea.
No it doesn't.

All it "proves" is that your transom failed while on the water, rather than on the road. Can you state for sure that all damage occured at that point in time, or could it have been weakened on the road, to fail when you hopped the wake?

jky
__________________
jyasaki is offline   Reply With Quote
Old 27 June 2006, 14:31   #20
Member
 
Country: Other
Town: San Carlos, Mexico
Boat name: INDE
Make: LOMAC 730
Length: 7m +
Engine: 200 Merc.
MMSI: Please press 1
Join Date: May 2006
Posts: 1,688
Send a message via Skype™ to Limey Linda
Quote:
Originally Posted by jyasaki
No it doesn't.

All it "proves" is that your transom failed while on the water, rather than on the road. Can you state for sure that all damage occured at that point in time, or could it have been weakened on the road, to fail when you hopped the wake?

jky
A VERY, VERY good point. When it comes down to it why take the risk of not independently supporting the outboard, particularly from bouncing. Some boats maybe stronger than others, but "who knows".
__________________

__________________
Running around like a head with it's chicken cut off.
Limey Linda is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 18:16.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.