Passerelle on Steroids...

[CMJ]

Hi All,

I’ve been living with the most snappy / jerky passerelle for the last couple of years that’s resulted in the launching and recovering of the tender being a bit nail-biting (understatement) …….so I’ve decided it’s time to tame it.

Onlookers with their own passerelles have commented on how snappy it is too, so I don’t think it’s me being totally incompetent.

Does anyone know if the hydraulic pressure is adjustable and if so, how? I just want to smooth / slow it down!

BTW, it’s an OPACMARE 8998 and the tender’s a mega-heavy jetrib.

Cheers!

 

[PowerYachtBlog]

yes it is if u want to do it slower is possible
but will have to call one of the techs from the brand...

 

[Deleted User YDKXO]

Which model of Opacmare 8998 is it because there seem to be 2 different lifting capacities, 450kg and 300kg? If it's the 300kg version, it's definitely on the limit or over the limit for a jetrib because virtually every jetrib I've seen weighs more than 300kg dry and more full of fuel and stuff. Is the passarelle movement jerky all the time or only when handling the jetrib? If it's the latter, then it might just be the over pressure valve fitted to the lifting ram which is designed to allow oil to bypass the ram if the oil pressure exceeds a set limit. This would produce a jerky movement as the valve would be opening/closing as it sensed the load being applied. Don't forget that even if your jetrib weighs less than the capacity of the pasarelle, the operation of lifting it and it swinging about could put a lot more instantaneous load on the pasarelle than the dead weight of the RIB.
Yes, it's probably possible to reduce the hydraulic pressure in the oil circuit if it's fitted with an adjustable relief valve but I don't see that it would help the situation. In fact all you would be doing is reducing the lifting capacity of the pasarelle until it couldn't lift the jetrib at all
I would suggest that you check which model of passarelle you've got to ascertain the lifting capacity and check it against the weight of the jetrib. If the weight of the jetrib is well under the capacity of the passarelle, then it could be a faulty over pressure valve on the lifting ram circuit. If the jetrib weight is close to or above the passarelle capacity, then you have a problem and you need to change one or other and you might even be damaging the grp on which the pasarelle is mounted

 

[CMJ]

Hi Mike,

Thanks for the help. The passerelle (model 8998/30) has an ID plate on it detailing the max loads, so will check when next down at the boat (prob Friday...I seem to remember that the rib was just within the max limit - not accounting for extra weight though, and the snappiness / jerkiness as clarified below ).....

The Rib (Avon SC320) came with the boat......I've always thought it was too heavy. There's already been some gelcoat cracking at the base of the passerelle but again mainly I think due to the snappiness / jerkiness ...like I say I'll check the max loads though.

I've been unclear in using 'jerky'.....basically it works fine and does exactly what you command it to...however it accelerates from 0 to whatever in less then a blink, and that's what puts excessive loads on things (I've tried to compensate with mooring springs on the Ribs rigging etc)....what I'm hoping to do is adjust it so there is a smooth transition from idle, to movement....and reduce the movement speed slightly to match other passerelles I've seen.

Also, I can't help thinking that I'd be better with a Rib/Outboard combo as would generally be easier to launch and recover I reckon - would miss the fun from the jetrib though.

 

[P4Paul]

Quite often orifice discs are fitted into the lift side of the actuator to moderate speed and it maybe that during assembly or a hose replacement that this has been left out. Speak to your local hydraulic specialist and ask them about the possibility of fitting a flow control valve if its an open centre system or a flow divider if its a closed centre system.

Where about on the South Coast are you? If you are close to us I could take a quick look for you.

 

[Deleted User YDKXO]

According to THIS the 8998/30 model has a 450kg lifting capacity. I believe the SC320 weighs around 300kg with fuel so you are well within the limit of the passarelle capacity which is a relief. Looks like you have a hydraulic problem then. I would contact Opacmare direct and ask them for their UK service agent and get them to have a look at it. Hydraulic problems are normally outside the competence of most boat service companies. If you are cracking the gelcoat on your transom, you really need to get it fixed. Have you checked the backing plate inside the transom moulding? My idiot son once tried to lift our tender with the tie down straps still attached after which some minor gelcoat cracks appeared around the pasarelle mounting. When I checked the backing plate inside, part of it had debonded

 

[CMJ]

Checked the lifting capacity at the weekend, the max according to the plate on the passerelle is 260Kg when fully extended (different to what the Opacmare say in their manual)....also says 260kg in the boat user manual.....perhaps this limit is not based on the passerelle itself, but rather the supports (bathing platform) it sits on.

Also, I checked the Avon Rib manual and it says 250Kg inc. all fuel, battery and oil......so a close call I think but perhaps I should hang-on with this tender rather than trade/swap it for something lighter.

So will continue to try and find out how I can tame the passerelle.....

 

[CMJ]

thanks.......will see if I can get it sorted under warranty first...one thing I note is that there was an option to have flow restrictors installed when new (but no restrictors in this case).