Reply
 
Thread Tools Search this Thread
 
Old 20 April 2010, 07:52   #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
Not quite sure how to say what I want to.

But with a twin axle suspension trailer, as you go over the apex at the top of a slip or similar, the weight is still spread a little as one axle goes light and the other compresses.
With solid axles all the weight would transfer to one axle for a short time.

The weight transfer could be enough to rip the coupling up off the towball and the boat and trailer would launch itself.

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 20 April 2010, 11:47   #12
RIBnet supporter
 
Erin's Avatar
 
Country: UK - Channel Islands
Town: A large rock
Boat name: La Frette
Make: Osprey Vipermax
Length: 6m +
Engine: 200 Suzzy
Join Date: May 2004
Posts: 2,830
Quote:
Originally Posted by Nasher View Post

The weight transfer could be enough to rip the coupling up off the towball and the boat and trailer would launch itself.

Nasher.
That sounds like a fun day out. Might go down and watch Martini II being launched if it's suspension less. To give moral support obviously... not just to have a laugh
__________________
Erin is offline   Reply With Quote
Old 20 April 2010, 13:07   #13
Member
 
martini's Avatar
 
Country: UK - Channel Islands
Town: jersey
Boat name: Martini II
Make: Arctic 28/FC470
Length: 8m +
Engine: twin 225Opti/50hp 2t
MMSI: 235067688
Join Date: Jun 2005
Posts: 3,021
Quote:
Originally Posted by Erin View Post
That sounds like a fun day out. Might go down and watch Martini II being launched if it's suspension less. To give moral support obviously... not just to have a laugh
Thanks for the offer, you can stand behind me and see me back

Nasher, I think I get what you're saying but the axles are so close together I don't think it would make that much difference to the nose weight. Still raises a good point though, on an uneven surface or apex etc., without suspension theres more chance that 1 axle would be taking much more load than the other and quite easily exceeding its capacity.

Rogue Wave, this trailer is also one of Phils, built by SBS with air brakes and leaf springs. It uses landrover size 7.5R16 wheels with commercial 12 ply tyres.

I know it exceeds the capacity of my rangerover and the only brake on it now is the hand brake but it still seems to stop and drive fairly well. All completely illegal of course but as the weight of the whole rig is probably just over 7.5t I'd need an HGV licence in order to comply

I'm now waiting for SBS to get back to me with a price for complete new axles same as original with leaf springs. Probably the safest route and saves having to modify the trailer to take any different systems.
__________________
martini is offline   Reply With Quote
Old 21 April 2010, 05:52   #14
Member
 
Country: UK - Wales
Town: Southampton
Boat name: DynaMoHumm/ SRV/deja
Make: Avon8.4, 5.4 & 4.777
Length: 8m +
Engine: Cat3126 Yam 90 &70
MMSI: 42
Join Date: Dec 2003
Posts: 6,556
Quote:
Originally Posted by martini View Post
Thanks for the offer, you can stand behind me and see me back

Nasher, I think I get what you're saying but the axles are so close together I don't think it would make that much difference to the nose weight. Still raises a good point though, on an uneven surface or apex etc., without suspension theres more chance that 1 axle would be taking much more load than the other and quite easily exceeding its capacity.

Rogue Wave, this trailer is also one of Phils, built by SBS with air brakes and leaf springs. It uses landrover size 7.5R16 wheels with commercial 12 ply tyres.

I know it exceeds the capacity of my rangerover and the only brake on it now is the hand brake but it still seems to stop and drive fairly well. All completely illegal of course but as the weight of the whole rig is probably just over 7.5t I'd need an HGV licence in order to comply

I'm now waiting for SBS to get back to me with a price for complete new axles same as original with leaf springs. Probably the safest route and saves having to modify the trailer to take any different systems.
yeah thats the trailer I have but without the leaf springs, the bogey I'm talking about comes with leaf springs and is the same wheels axles brakes as yours.

I really like my trailer but I can't get an airbrake unit for my Pajero, so I'm getting a custom built jobbie, hopefully!

You could go legal if you wanted to with one of the kits made by these lovely people.

http://www.erentek.co.uk/conv-kits.htm

I havem't been to the yard where the bogey is for a couple of months but I will have a look tonight
__________________
Here it comes again, I don't stand a chance
Soul possession, Got me in a trance
Pullin' me back to you - Deja Voodoo
Rogue Wave is offline   Reply With Quote
Old 21 April 2010, 11:53   #15
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
Quote:
Originally Posted by Nasher View Post
With solid axles all the weight would transfer to one axle for a short time.

The weight transfer could be enough to rip the coupling up off the towball and the boat and trailer would launch itself.
That happens, on occasion, even with suspension. Usually at ramps with a an abrupt change from flat to a steep slope. One more reason to make sure your safety chains are up to snuff.

Seems to be more prevalent with triple axle trailers, but has happened to twin axles as well.


Solid-mounted axle, I'd worry more about tires than bearings (though they probably wouldn't last too long either) or boat. Any energy from the trailer bouncing would have to be absorbed by the tires, and it wouldn't take a whole lot of bounce to put them way beyond their load rating.

My $.02US;

jky
__________________
jyasaki is offline   Reply With Quote
Old 21 April 2010, 12:59   #16
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
Quote:
Originally Posted by jyasaki View Post
That happens, on occasion, even with suspension.
I have some quite rough ground on the approach to the house and my twin axle Ifor Williams trailer regularly has one or other axle off the ground if lightly laden - it doesn't take much. A ton of fuel in it sorts it out though
__________________
A Boat is a hole in the water, surrounded by fibreglass, into which you throw money...

Sent from my Computer, using a keyboard and mouse
BogMonster is offline   Reply With Quote
Old 21 April 2010, 13:25   #17
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
Quote:
Originally Posted by jyasaki View Post
That happens, on occasion, even with suspension. Usually at ramps with a an abrupt change from flat to a steep slope. One more reason to make sure your safety chains are up to snuff.

jky

Hi jky

We don't tend to do safety chains over here, we have breakaway cables that are meant to break and apply the handbrake at the same time.
I've a funny feeling they are not legal here, but am probably wrong.

On the other hand I'm not sure how I feel about having the boat and trailer attached losely by a strong chain whilst I try to slow down from motorway speeds. I'll need to think on that one and let you know.

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 21 April 2010, 13:47   #18
RIBnet admin team
 
Poly's Avatar
 
Country: UK - Scotland
Boat name: imposter
Make: FunYak
Length: 3m +
Engine: 2 stroke YAM 20 HP
MMSI: 235089819
Join Date: Sep 2005
Posts: 10,114
Quote:
Originally Posted by Nasher View Post
Hi jky

We don't tend to do safety chains over here, we have breakaway cables that are meant to break and apply the handbrake at the same time.
I've a funny feeling they are not legal here, but am probably wrong.

On the other hand I'm not sure how I feel about having the boat and trailer attached losely by a strong chain whilst I try to slow down from motorway speeds. I'll need to think on that one and let you know.

Nasher.
Nasher chains are only used here on unbraked (i.e. < 750 kg) trailers.
__________________
Poly is offline   Reply With Quote
Old 21 April 2010, 15:09   #19
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
Quote:
Originally Posted by Polwart View Post
Nasher chains are only used here on unbraked (i.e. < 750 kg) trailers.
Ta

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 April 2010, 11:42   #20
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
Quote:
Originally Posted by Nasher View Post
Hi jky

We don't tend to do safety chains over here, we have breakaway cables that are meant to break and apply the handbrake at the same time.
I've a funny feeling they are not legal here, but am probably wrong.

On the other hand I'm not sure how I feel about having the boat and trailer attached losely by a strong chain whilst I try to slow down from motorway speeds. I'll need to think on that one and let you know.

Nasher.
Off-topic reply...

I think we've been over this before.

In the US, braked trailers have both a breakaway cable (to actuate the brakes should the trailer get loose) and safety chains (to prevent the former scenario. (Non-braked trailers have just the chains, naturally.)

I've never had it happen, but know a couple of people who have: ideally, should the hitch fail, the trailer tongue drops into the cradle of the chains (they're crossed to run left trailer to right side of tow vehicle and vice versa), keeping the tongue from pole vaulting the trailer ass over teakettle. One guy said he had no problem getting to the side of the road and stopping; the other said he swerved all over, but got stopped safely.

Bottom line: Don't know if it's better or worse, but given the number of non-functional braking systems on trailers over here, I gotta think the safety chains are a good thing.

jky
__________________

__________________
jyasaki 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 10:08.


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