# CalMac ferries - grounding risk (the motorhome, not the ferry!)



## Retiring (Jan 28, 2012)

We are off next week on our first major (month long) tour since acquiring our Burstner last year. From Devon up to the west coast of Scotland as far as you can go, then back down the middle.
We'll be doing a little island hopping (Mull & Skye) with CalMac, which we've done before several times in a car: Oban-Craignure, Tobermory-Kilchoan, Mallaig-Armadale.
It's been suggested that you have to be careful about grounding when boarding or leaving a ferry, particularly around low tide, if you have a rear overhang, which we do - about 2 metres from rear axle. 
Can anyone throw any light on this, whether it's a real issue & whether we need to plan ferries around the tides? I guess it might vary according to the slipway; are there any which are especially notorious?
Thanks.


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## Pudsey_Bear (Sep 25, 2008)

They have planks etc to help if it's a problem, just approach the ramp and stop, get them to check the clearance, if they check and tell you to proceed and damage is done take pictures and names of crew, time of ferry etc and claim, if you have a tow bar on, it'll save the back end, but also extend the problem, we had a long overhang on the Laika caught it a few times, but no damage except a bit of scratched tow bar, but it was underneath anyway so we didn't claim.


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## 96299 (Sep 15, 2005)

Only ferry we have been on was the Corran ferry in Scotland and we ground slightly but luckily no real damage, just a few scuff marks. We are going to use it again this year and will insist on the use of planks this time round. :wink2:

Steve


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## nicholsong (May 26, 2009)

Chigman said:


> Only ferry we have been on was the Corran ferry in Scotland and we ground slightly but luckily no real damage, just a few scuff marks. We are going to use it again this year and will insist on the use of planks this time round. :wink2:
> 
> Steve


We too grounded on disembarking from the Corran ferry at the north end. We also have a towbar so I am quite relaxed about it scraping slightly.

I once had a problem when I reversed onto a verge to let two school buses pass and the towbar dug into the soft soil and it was a problem getting out as it acted like a scoop.

To answer the original question, it will depend on a lot of factors like the vessel shape, ramp of vessel, dock ramp, state of tide and whether tisde is Spring or Neap. So a bit impossible to answer, but the company should have some provision to solve the problem. In Greece most companies use thick hessian mats placed where the angle changes.

Geoff


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## MoocherMcGee (Oct 24, 2013)

Kev_n_Liz said:


> They have planks etc to help if it's a problem, just approach the ramp and stop, get them to check the clearance, if they check and tell you to proceed and damage is done take pictures and names of crew, time of ferry etc and claim, if you have a tow bar on, it'll save the back end, but also extend the problem, we had a long overhang on the Laika caught it a few times, but no damage except a bit of scratched tow bar, but it was underneath anyway so we didn't claim.


There have been a few cases reported that the tow bar when grounding actually transfers the effect to the chassis and could actually crease or damage the whole back end.


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## Pudsey_Bear (Sep 25, 2008)

MoocherMcGee said:


> There have been a few cases reported that the tow bar when grounding actually transfers the effect to the chassis and could actually crease or damage the whole back end.


Not sure about that, but the one on the Laika was extremely over engineered, with braces in all directions.


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## bigtwin (May 24, 2008)

I've said it before (in previous similar posts) and I'll say it again, anything that is added to the underside of the vehicle that lowers the contact point will increase the likelihood (frequency) of a grounding contact.
Any grounding contact will transfer loads to the vehicle and, hence, given the increased likelihood, will increase the risk of damage.

Where wheels/rollers are fitted, the owner may feel, psychologically, that less damage is being caused because the scraping is less audible, but the parts of the vehicle to which the loads are being transferred is not suckered by the lack of noise during the load transfer and will feel the full force of the loads irrespective of whether wheels/rollers are used to appease the owner.

Ian


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## nicholsong (May 26, 2009)

bigtwin said:


> I've said it before (in previous similar posts) and I'll say it again, anything that is added to the underside of the vehicle that lowers the contact point will increase the likelihood (frequency) of a grounding contact.
> Any grounding contact will transfer loads to the vehicle and, hence, given the increased likelihood, will increase the risk of damage.
> 
> Ian


Obviously lower point will increase chance of some contact.

Howevr i am not really understanding your comment and McGee's comment about transfer of the load from the towbar to the chassis, and possible damage to the vehicle.

I cannot believe that the stresses on the chassis will be worse than those imparted to the chassis through compression of the suspension, and possibly down to the bumpers, that a hard drive over a speed bump would produce.

Surely the design and certifications for the chassis would take account of such stresses.

We need an automotive design or certification engineer to pronounce.

Geoff


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## bigtwin (May 24, 2008)

Geoff,

My point is simply that lowering the lowest point of the vehicle (as a result of adding tow bars and the like, particularly if they extend beyond the back of the vehicle) increases the frequency of grounding - it is more likely that an impact will ensue.

Furthermore, for a give tilt of the vehicle (height that the front wheels are above the rear wheels) the force applied will be greater than would otherwise be the case.

What I am not pronouncing on is whether or not the margins in a given design are likely to be threatened. But the fact is, is that any product has a design basis (the parameters that the product is designed to withstand) and that if the user exposes the product to circumstances that exceed the design basis, failure may very well be likely (dependent on how extensive the margins are (x2, x5, etc)).

As I said, I am not in a position to know what margins are included in the design of a given motorhome, but increasing the frequency at which a grounding occurs, and at loadings that may exceed the design assumptions, cannot be a good thing to do. I'd certainly prefer to hear a graunching noise on an umodified vehicle than on one with a post-production reduced ground clearance.

A couple of final points:

1 - the loadings imparted by road shocks are damped and are exerted at points of the vehicle designed to take these loadings (the design basis will, most likely, include a defined bump profile, height and impact speed) - I don't know what the standards are in this area but if you expose the wheel to a 'bump' that falls outside this range (or at encounter speed greater than the design basis (I.e hitting the bump harder)) the risk of failure is increased.

2 - imagine that a couple of wheelbarrow type handles were extended from the rear of the motorhome, and, if you were strong enough, you were to lift the motorhome using these handles, it is likely that you would be applying forces to parts of the motorhome not specifically designed to cope with these forces.

I don't know if this clarifies or not.

Ian


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## nicholsong (May 26, 2009)

Ian

Unless my understanding is wrong, the only place that the extra load would be applied to would be the chassis to which the towbar is bolted and unless that were subjected to a force great enough to actually bend it then none of the body of the motorhome would be subject to any force.

I am of course open to being corrected.

Geoff


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## erneboy (Feb 8, 2007)

I doubt that much attention is paid in chassis design to dealing with upward forces. It'll be all about bearing weight and dealing with the forces exerted by a tow bar should one be fitted in my view, Alan.


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## nicholsong (May 26, 2009)

erneboy said:


> I doubt that much attention is paid in chassis design to dealing with upward forces. It'll be all about bearing weight and dealing with the forces exerted by a tow bar should one be fitted in my view, Alan.


Surely they must take into account upward forces on the chassis if the suspension is compressed and the weight is on the bumpers?

Geoff


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## erneboy (Feb 8, 2007)

OK Geoff I should have said at the extreme rear of the chassis.


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## Retiring (Jan 28, 2012)

Well thanks for all the comments! Glad I started a technical discussion about forces exerted on chassis etc. I'll keep that in mind but we have no tow bar or other accoutrements under the vehicle. It's also been suggested that having air suspension fitted is helpful but it seems a rather costly exercise, unless there are other benefits? (Though not as costly as bending one's chassis, perhaps) 

But I guess the answer is to check out the slipway beforehand, talk to the ferry and dock crew if there is any risk and, as always, take it slowly, with someone (perhaps my good lady) outside ready to shriek at me to stop if needed.

I'll let you know what happens.


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## 96299 (Sep 15, 2005)

Forgot to say but, when we ground on the Corran ferry, we was being watched by a crew member:surprise: Don't trust them, ask for the plank:wink2:

Steve


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## nicholsong (May 26, 2009)

Chigman said:


> Forgot to say but, when we ground on the Corran ferry, we was being watched by a crew member:surprise: Don't trust them, ask for the plank:wink2:
> 
> Steve


You mean the two other planks:wink2: - the longer ones:laugh:


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## 96299 (Sep 15, 2005)

nicholsong said:


> You mean the two other planks:wink2: - the longer ones:laugh:


Gutted - cant believe I didn't think of that, I'm normally on the ball:laugh:

Steve


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## Jezport (Jun 19, 2008)

Bare in mind that a lot of the longer vans have chassis extensions. So all the force of a grounding will go through the points where the chassis is bolted to the extension. This is where problems can occur.


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## 96299 (Sep 15, 2005)

Jezport said:


> Bare in mind that a lot of the longer vans have chassis extensions. So all the force of a grounding will go through the points where the chassis is bolted to the extension. This is where problems can occur.


Yep so true.

Steve


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## nicholsong (May 26, 2009)

Jezport said:


> Bare in mind that a lot of the longer vans have chassis extensions. So all the force of a grounding will go through the points where the chassis is bolted to the extension. This is where problems can occur.


Are they only bolted or are they welded? I know welds can suffer shock degradation over time.


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## 96299 (Sep 15, 2005)

nicholsong said:


> Are they only bolted or are they welded? I know welds can suffer shock degradation over time.


They are bolted. That allows for movement:frown2:

Steve


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## nicholsong (May 26, 2009)

Chigman said:


> They are bolted. That allows for movement:frown2:
> 
> Steve


'Movement' - as in slight scraping of the towbar?:wink2::laugh:


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## bigtwin (May 24, 2008)

You are correct Geoff.

You rightly say that "unless that were subject to a force great enough ....". As I said earlier, I am not pronouncing on whether the margins are threatened only that you are increasing the frequency/magnitude of the encounters.

Ian


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## erneboy (Feb 8, 2007)

nicholsong said:


> Ian
> 
> Unless my understanding is wrong, the only place that the extra load would be applied to would be the chassis to which the towbar is bolted and unless that were subjected to a force great enough to actually bend it then none of the body of the motorhome would be subject to any force.
> 
> ...


A chassis is designed to flex, but not by being lifted by the tow bar or by being heavily grounded at the rear, unless it's a specialist vehicle, Alan.


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## Jezport (Jun 19, 2008)

nicholsong said:


> Are they only bolted or are they welded? I know welds can suffer shock degradation over time.


Bolted only


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## Pudsey_Bear (Sep 25, 2008)

How many instances are there of the vans arse falling off through grounding of a tow bar versus damage to the rear lower valance or bumper?


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## 4maddogs (May 4, 2010)

I use the Oban to Craignure ferry very frequently and it has never been a problem. I have seen large MHs boarding but again no problem. Fishnish to Lochaline is OK too, but I can't vouch for the Tob to Kilchoan ferry.

Just have a wonderful time and have a pint in the Mish for me!

MH are generally well catered for, but do observe the rules for driving and always give way to locals!


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## nicholsong (May 26, 2009)

4maddogs said:


> MH are generally well catered for, but do observe the rules for driving and always give way to locals!


Even if one knows local reg numbers how can you read a plate when one sees another vehicle 2-3oom away?:-s


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## Pudsey_Bear (Sep 25, 2008)

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nicholsong said:


> Even if one knows local reg numbers how can you read a plate when one sees another vehicle 2-3oom away?:-s


Locals are the ones who glare at you, usually not in brand new cars, they tend to be hire vehicles, but not always.

Our policy for single track roads is to give way to all others, we're on holiday, they might be late for work, picking up kids etc, why make them wait, I only use their roads, then have to live with them, it also give me a chance to have a better look at the scenery instead of snatched glances.


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## nicholsong (May 26, 2009)

Kev_n_Liz said:


> Locals are the ones who glare at you, usually not in brand new cars, they tend to be hire vehicles, but not always.
> 
> Our policy for single track roads is to give way to all others, we're on holiday, they might be late for work, picking up kids etc, why make them wait, I only use their roads, then have to live with them, it also give me a chance to have a better look at the scenery instead of snatched glances.


My experience has been that most cars and even vans wait for us - maybe because we are in quite a large 'A' Class MH. I have sometimes flashed them to come through and find they are still waiting for us. Maybe they are never sure whether we have left enough room for them to pass us.:laugh:


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## Pudsey_Bear (Sep 25, 2008)

nicholsong said:


> My experience has been that most cars and even vans wait for us - maybe because we are in quite a large 'A' Class MH. I have sometimes flashed them to come through and find they are still waiting for us. Maybe they are never sure whether we have left enough room for them to pass us.:laugh:


Yes we find that, so I just pull in on sight of approaching vehicles, same for following ones too.

You can't be too courteous in someone elses country.


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## 4maddogs (May 4, 2010)

nicholsong said:


> Even if one knows local reg numbers how can you read a plate when one sees another vehicle 2-3oom away?:-s


Ha ha! No-one zooms anywhere on the single lane roads😄


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## Retiring (Jan 28, 2012)

Well, we survived! Our first serious trip. Ferries were fine, absolutely no grounding problems on Oban to Craignure or Mallaig to Armadale. Tobermory to Kilchoan was a little more challenging. We were first in the queue & I had a word with the guy off the ferry who couldn't have been more helpful. They even brought the ferry a little closer in to reduce the ramp slope. He checked the rear all the time & afterwards said we just touched but didn't leave a mark & I didn't hear or feel it. At Kilchoan we needed a plank (oddly only under one side) which worked fine. 
What was a closer call (for a novice like me) was getting off the Oban ferry at Craignure. We were at the back, tight up against large lumps of ferry metal on the port side & at an angle. So starting off was a bit tight but, to cap it all, some numpty had abandonded their 4x4 (or so it seemed) to the right of us & it was as tight as you can get squeezing through. But these ferry guys really know their stuff. You forget your mirrors (they're folded in anyway) & just watch his hands. I reckon about 2" each side at one point. Good training, though.
The trip was great, no problems & we really loved the time with the vehicle, even though the weather prevented much eating outside. Five nights at Camusdarach (Local Hero) were superb. We took to some good windy roads & yes, the pulling in to let others pass is of course much appreciated. 
The coolness kept down the midges: we saw only 48 of them & were eaten only twice. The midge hats were never worn.
The tourist route to Lochinver, past Stac Pollaidh & Suilven (which sadly were absent on account of cloud base) is fun, we were a foot short of the maximum length for the road & meeting an oil tanker just outside Inverkirkaig was a little tight, but again, these guys really know their stuff.
We cut the trip a bit short (timewise, not distance) in the end on account of the weather, so didn't stay at Sango Sands, though Smoo Cave is well worth a visit. Scourie is a lovely site. The wild site at Sheigra (near the Sandwood Bay walk start) has an extremely rough access so we stayed overnight by the adjacent burial ground, no problem.
1996 miles in all. A good start. Can't wait for France in September.
Grand Tour: https://goo.gl/4NZPrV


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## jiwawa (Jun 22, 2007)

That sounds fantastic, Retiring - I take it you'r retired by now?!

May I just add re the grounding that I've found it helpful to approach the dip at an angle if possible, never head on.


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## Retiring (Jan 28, 2012)

JWW...
I was planning to be retired by now but being self-employed and having one of those, what do you call them, silly little things, of little consequence, even less value......duh.....ah...pensions, that's the word, that didn't live up to original expectations, when the phone rings and work beckons, it's a bit too tempting to say no thank you. But of course making a decision to travel off away for big chunks of time does give me the upper hand. It's a pretty perfect semi-retirement scenario, so far. 
I'd quite like to change my handle on here to something more fitting - it was a moment's madness than led to calling myself retiring. Can it be done or do I have to reincarnate myself?

I can't quite get my head around the geometry of approaching a ramp at an angle - doesn't it make the upper side of the back even closer to the ground?

Richard


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