How many people allowed on what size boat?

[keble]

Do I need to /Should I get the max increased by getting the boatbuilder to recalculate for 6 (say)? If so how much should I expect to pay?

I'm really interested in this - bought a new 50' boat and was surprised to find max persons when underway is 4.

Yet I see Glevum hire boats on the G&S seriously overloaded.

Do they pay more insurance?

Would my insurer pay up if I carry 5?

[1066]

Would my insurer pay up if I carry 5?

 

:lol:

[Gary Peacock]

I'm really interested in this - bought a new 50' boat and was surprised to find max persons when underway is 4.

Yet I see Glevum hire boats on the G&S seriously overloaded.

Do they pay more insurance?

Would my insurer pay up if I carry 5?

 

Probably not if it is CE marked.

 

The problem is that narrowboats aren't terribly stable in real boat terms, the maximum number of passengers is dictated by this.

 

If you have power point installed you can have a look at this-

 

STABILITY EXPLAINED

 

If a boat builder does the job properly the maximum number is exactly that and that number is arrived at by calculation and actual physical tests on the completed boat.

 

Ditch crawler builders usually fiddle it and just pick a number that seems right for CE marking, RCD cat D boats are self accessed so no outside body actually confirms stability or any of the other essential requirements.

 

However in the event of an accident the Marine Accident Investigation Branch would take a big interest in asking the builder how they confirmed the stability essential requirement at which point the average ditch crawler builder would be well deep in the smelly stuff.

Edited September 25, 2008 by Gary Peacock

[dove]

We're way off the original posters intentions but in summary

 

for more than 12 passengers regardless of whether they are fare paying or not or whether the bboat is being run as a business or not a whol host of MCA conditions apply, including the requirement for the skipper (who doesn't actually have to steer) to have a boatmaster's certificate of an appropriate level for the vessel.

 

Just dug out the Department of Transport Passenger Certificate for Dove ( when she was Britannia ) for 1992.

For plying smooth waters she was allowed to carry 48 passengers and 2 crew.

On board there had to be, 4 life bouys, 5 fire extinguishers, 2 bilge pumps and 2 buckets ( Ladies & Gents )?

 

Andrew

[alan_fincher]

This all strikes me as faintly ridiculous.

 

Even a pretty large body of 16 stone only weighs 1 cwt, (1 hundredweight), so it would take 10 of of those very large people to make up 1 ton. (Or put another way 200 very heavy people would be needed to produce a "cargo" close to that of a lightly loaded carrying boat).

 

If a boat of any reasonable length, (say 50 feet upwards), has been built so that 10 people will actually make it unstable to the point of being dangerous, then something has gone seriously wrong.

 

On ours, 10 people om the same side would make it list pretty impressively, and it's possible the exhaust pipe would go under, but I'd be mighty surprised if it rolled over.

 

Given that putting stuff on the roof will do far more to affect stability, that people standing more or less on the bottom of the boat, I reckon you regularly see boats piled with enough coal on the roof to be the equivalent of several people being up there. Do these now standards that limit the number of people the boat is designed for also limit how much tonnage of fuel can go on top ?

 

Alan

[keble]

Probably not if it is CE marked.

The problem is that narrowboats aren't terribly stable in real boat terms, the maximum number of passengers is dictated by this.

If you have power point installed you can have a look at this-

STABILITY EXPLAINED

Thanks Gary! Very informative.

Rob

[David Schweizer]

The problem is that narrowboats aren't terribly stable in real boat terms, the maximum number of passengers is dictated by this.

 

I understand what you are saying Gary, but if they were that unstable they would be constantly rolling over, which they are not. Once again we are being subjected to an extreem version of Murphy's Law by over zealous beaurocrats.

[jakey]

ok so we have confirmed that this is a big fat grey area it seems that one should just be semi sensible and make sure the boat is not listing over or dredging the bottom of the canal....and one should pick good swimmers for passengers and have them all scuttle off over the horizon if there is an incident so as to avoid insurance company issues.

[mefloquine]

Hello,
a related question here; my boat is a steel hull 45' widebeam, 200l fuel tank, 250 gallons water tank, 8 x 6V batteries; I have 7 solar panels on the roof, plus several stacks of logs; I have a 10kg anchor plus chain on the front deck, plus more stacks of logs.
I have room for more wood on the roof and deck, but I am seriously concerned about sinking; the affixed plate says the manufacturer's maximum recommended load is 1500kg, I am clearly already way beyond that.
Should I worry? And is there a safe way to determine how much more load the boat can bear?
Many thanks
Annalisa

[larkshall]

Hello,

a related question here; my boat is a steel hull 45' widebeam, 200l fuel tank, 250 gallons water tank, 8 x 6V batteries; I have 7 solar panels on the roof, plus several stacks of logs; I have a 10kg anchor plus chain on the front deck, plus more stacks of logs.

I have room for more wood on the roof and deck, but I am seriously concerned about sinking; the affixed plate says the manufacturer's maximum recommended load is 1500kg, I am clearly already way beyond that.

Should I worry? And is there a safe way to determine how much more load the boat can bear?

Many thanks

Annalisa

Annalisa, your bound to be asked by someone, what width is your widebeam?

[mefloquine]

Boat width is 10'

Thanks

Annalisa

[David Mack]

Hello,

a related question here; my boat is a steel hull 45' widebeam, 200l fuel tank, 250 gallons water tank, 8 x 6V batteries; I have 7 solar panels on the roof, plus several stacks of logs; I have a 10kg anchor plus chain on the front deck, plus more stacks of logs.

I have room for more wood on the roof and deck, but I am seriously concerned about sinking; the affixed plate says the manufacturer's maximum recommended load is 1500kg, I am clearly already way beyond that.

Should I worry? And is there a safe way to determine how much more load the boat can bear?

Many thanks

Annalisa

 

1500Kg is probably just an arbitrary number more or less plucked from thin air by the boatbuilder. In any event, if this is a 'safe load', it will be in addition to full water, fuel and toilet tanks.

 

The risks of overloading are twofold: capsizing or just sinking.

 

Narrowboat-style widebeams are pretty stable by nature, so unless you propose to keep all your logs, anchors and other worldly goods on the roof, and have no ballast I can't see you being at risk of capsize. The only example I am aware of was a small narrow beam day-hire boat, which had about 12 people sat on the roof and executed a tight turn. Your situation is nothing like that.

 

And as long as any hull vents, drain outlets etc. are well above water level, then there is no risk of the boat sinking. But do check that your weedhatch has at least a couple of inches clearance above water level and has a watertight seal under the lid.

[Arthur Brown]

According to the nature of the waterway, it would be sensible to match the numbers of souls on board match the number of life jackets etc.

[Rose Narrowboats]

Narrowboats are actually very stable (in terms of self righting) so long as the ballast stays put. Weight up high - i.e. coal etc. on the roof will make them more tender (prone to rolling) but as a qualified naval architect point out to me recently while we were discussing this, when the boat gets to a certain angle all the stuff that shouldn't be there - and quite possible some people who should - will all slide off and the boat will likely right itself.

 

Most day boats (our included) carry 12 people and are normally only 30-35 feet long.

 

The big concern is for narrowboats is downflooding - you put too much weight in the wrong place and water starts running in through deck drains etc, quite possibly without you noticing until you have too much water in the boat and then you are in trouble, either in terms of stability or more likey lack of bouyancy. I was present at some testing carried out on a certain design of 50' boat (with the bow door offset to one side) five or six years ago and we were all very surprised to discover that four people sat in the wrong place on the fore-end was enough to have water running down into the cabin.

 

This is also why a maximum load is recommended - to ensure a reasonable freeboard to hull prenetrations such as scuppers, skin fittings and engine exhausts.

Even a pretty large body of 16 stone only weighs 1 cwt, (1 hundredweight), so it would take 10 of of those very large people to make up 1 ton. (Or put another way 200 very heavy people would be needed to produce a "cargo" close to that of a lightly loaded carrying boat).



Alan

Passenger boats are usually quite heavily ballasted for stability in the first place. Consider the Zoo Buses such as Water Ouzel (which is a little woolwich) - she looks half loaded when empty.. The next consideraton is that passengers move in a way that most cargo does not: "Oooh, look at that over there...."

[Paul's Nulife4-2]

Question : How many people allowed on what size boat?

 

Hi Is there any general rule here? I mean can one load up a 20' boat with ten people hanging off the roof and at either end? I would hate to get dirty looks from seasoned boaters if I were to attempt that

I guess there a weight restriction per boat in KG? based on when the boat is totally empty ie. no kettles or plates on board?

Cheers

Newby.

I've currently got a 42x11ft Sea Otter and -

https://www.dropbox.com/s/qkq104secyo25rw/IMAG0868.jpg?dl=0

[thunderbird]

Narrowboats are actually very stable (in terms of self righting) so long as the ballast stays put. Weight up high - i.e. coal etc. on the roof will make them more tender (prone to rolling) but as a qualified naval architect point out to me recently while we were discussing this, when the boat gets to a certain angle all the stuff that shouldn't be there - and quite possible some people who should - will all slide off and the boat will likely right itself.

 

Most day boats (our included) carry 12 people and are normally only 30-35 feet long.

 

The big concern is for narrowboats is downflooding - you put too much weight in the wrong place and water starts running in through deck drains etc, quite possibly without you noticing until you have too much water in the boat and then you are in trouble, either in terms of stability or more likey lack of bouyancy. I was present at some testing carried out on a certain design of 50' boat (with the bow door offset to one side) five or six years ago and we were all very surprised to discover that four people sat in the wrong place on the fore-end was enough to have water running down into the cabin.

 

This is also why a maximum load is recommended - to ensure a reasonable freeboard to hull prenetrations such as scuppers, skin fittings and engine exhausts.

Passenger boats are usually quite heavily ballasted for stability in the first place. Consider the Zoo Buses such as Water Ouzel (which is a little woolwich) - she looks half loaded when empty.. The next consideraton is that passengers move in a way that most cargo does not: "Oooh, look at that over there...."

Do you know of any available stability information based Inclining results for flat bottomed narrow beam canal boats?

[Arthur Brown]

the 75 kilo assumption for the average passenger was out of date in the 60s.

 

I'd suggest that 85kg is more likely.

[Rose Narrowboats]

No. When I asked this question, I was asked first to define what I meant by stability - there are different sorts apparently....

 

A lot of work has been done over the last few years to try to come up with a simple practical test and matching theoretical calculation on the basis that narrowboats aren't that complicated or that different from one another but I haven't seen a conclusioin yet.

 

I have a stability test and calculation for one of our tugs which is (literally) Greek to my and my friendly naval architect (who did stability calcs on big ships for a living at one point) can't understand how they derived some of the information either!

[Giant]

This is all quite interesting. Our boat was built to carry 100 tons and predates the RCD. How many people can we have aboard?

[Ange]

Lovely bit of grave digging! Not complaining at all - just interesting to see posts from the likes of Gary Peacock who suddenly disappeared. Hope he's OK.

[patty-ann]

My boat has plaque stating max 6 persons.

[Phil Ambrose]

An old mate if mine runs a double decker trip boat on the Broads, it's a catamaran hull,60ft x 15ft ish and has to get inspected annually with a stability test bi-annually. The stability test involves loading one side of the upper deck with the weight equivalent of maximum passenger load. He "borrows" the sand from a pal at Jewsons.

Phil

[Naughty Cal]

Practicality is just as much of an issue as the paperwork. Too many people and it becomes a nightmare moving around the boat to work locks etc. (never mind getting a beer or going for a pish!). I reckon about one person per 10' of boat is about right, otherwise you'll be treading on each other's toes. And don't forget, if you argue with anyone, there's nowhere to go!!

By your calculation NC should only carry 2.3 people max.

 

Sealine calculate it at 6 max for Cat C rating and 8 max for Cat D rating.

 

I think we will stick with the manufacturers recommendations.

[magictime]

the 75 kilo assumption for the average passenger was out of date in the 60s.

 

I'd suggest that 85kg is more likely.

 

I'm not sure what 75 kilo assumption you're referring to, but if the assumption is that all passengers are adults, with a 50/50 split between men and women, 75kg is still about right.

 

http://www.telegraph.co.uk/news/earth/earthnews/9345086/The-worlds-fattest-countries-how-do-you-compare.html

[rjasmith]

It's funny that this old thread from 2008 has got resurrected and attracted a lot of new discussion

(well done Annalisa!).

 

I too miss Gary Peacock's stuff and it was good to read it again although a great pity that all those links to Ledgard Bridge's defunct website no longer work. His posts helped me understand some of the basics of the RCD when I was getting started.

 

For anyone who is interested the RCD requirements for stability and buoyancy are specified in ISO 12217 Part 1 (Non sailing boats longer than 6m). This document is 70 odd pages long!

 

IMHO this ISO is the most complicated to understand of all the RCD ISO suite and requires a boat to pass a set of assessments which lead to the Max Crew Limit and Max Load figures to be entered on the Builder's Plate. The accuracy of these figures assumes that the boat builder has done it all properly of course!

 

The pass can be either worked out by calculation using some fairly horrific maths (best done using bespoke software on a computer), or more easily by physical tests on the boat in water.

 

Maybe it will help if I quote the two main requirements of the ISO because this might help anyone who wants to do it to get some idea of whether their Builders Plate is right.

 

The two tests applicable to a Cat D (Inland Waters) boat are the "Downflooding Height" test and the "Offset Load" test.

 

The proper procedure for each test is quite long-winded and the procedures have been changed 3 or 4 times in the last 5 years or so but I'll try to give a rough idea.

 

1. The Downflooding Height test is to show that no place where water could enter the hull sinks to below 0.4m (16") above the waterline in level trim under max load (mainly the crew but also with full tanks and all stores etc). For this test the crew need to be the equivalent of 75Kg per person. Add more and more such people until you reach the minimum worst case height. Provided connections of drainpipes etc are in accordance with other RCD stds, the height of eg sinks etc inside the boat will help ie it's not just the height of a skin fitting.

 

2. Offset Load. The full procedure in the std is quite complicated and anyone trying it should be very careful. The aim is to prove two things using increasing nos of crew members who this time need to be the equivalent of 85Kg per person. The crew need to be placed at the worst case deck extremities of one side to check that the angle of heel does not exceed about 12° (varies slightly with boat length). The low side must also not have any downflooding openings less than 0.01m (4") above the waterline. The test has to be repeated for the other side.

 

Once you've done all this, the crew limit is the least no of "people" (bearing in mind the average weight thing!) that cause any of the limits to be reached.

 

For the full description of these requirements and tests you MUST refer to the ISO itself and you could do this by joining Manchester City Library (open to anyone living at a UK address) and using their free link to BSOL to read it .

 

Probably no help at all to post all this!!!

 

Richard

Edited June 5, 2015 by rjasmith