stability of livestock carrier

gululu
10th March 2010, 09:25
Appreciate indeed if anybody can tell me about the unit weight of cattle or sheep to be applied in the stability calculation.
I go through the AMSA marine note 43 and class rules to figer out this issue, but without any result.
Many thanks in advance.

Billieboy
10th March 2010, 11:09
Cattle = one per ton
Sheep = five or six per ton
Pigs difficult, weight is based on age in weeks, if fattened in North Europe.

gululu
11th March 2010, 01:17
Billieboy, many thanks, is that what applied in stability calculation?

Billieboy
11th March 2010, 08:45
Not that I know gululu, they are the approximate weights of European livestock at local farms. It depends where you are loading, as a North African cow will be lighter, an Australian sheep will be lighter etc. There is a company in Breskens, Holland(NL), that owns a large number of specialist livestock carriers, I've forgotten their name at the moment. Try Googling, "specialist livestock carriers", there maybe more information there.

Good Luck.

p.s. The Breskens company is "Vroom and Co". (I just remembered it!)

John Cassels
11th March 2010, 09:05
Would one need to take into account the "free range effect " as opposed to the
"free surface effect " when calculating stability ?.

Billieboy
11th March 2010, 09:29
Don"t make it too difficult John!

gululu
12th March 2010, 03:49
Billieboy, thanks again, i just do a conversion design project, from a container vessel to livestock carrier, it's really a challenge for me cause i know nothing about livestock carrier before, i know such vessel's stability is quite different with normal vessel, to do a loading case calculation, i should know the exactly weight of loads. but i don't know if any regulation specify a certain unit weight of the lives.

p.s. John, as per AMSA's regulation, the shift moment of lives should be taken into account.

Billieboy
12th March 2010, 07:34
Biggest problem with livestock carriers is corrosion. most decks are Corten steel and or acid resistant stainless steel, (316 and 316l).

gululu
12th March 2010, 10:30
Verry interesting, I know the decks are always quite thin such as 6.5mm even 4.5mm. Now a day, owner wanna use alumimum material to instead of normal steel. But the price is quite higher. Alternatively, they may ask for a perfect coating job.

Interalia
13th March 2010, 07:36
Appreciate indeed if anybody can tell me about the unit weight of cattle or sheep to be applied in the stability calculation.
I go through the AMSA marine note 43 and class rules to figer out this issue, but without any result.
Many thanks in advance.

Gululu,

I have had a lot of experience in conversion of small vessels to livestock carriers in Australia. To answer your question Australian cattle, shipped from the north ( Brahman cross) weigh in at anything from 250 kg per head to 400 kg. depending on the season, from the south of Australia they tend to be heavier. They must breed big cattle in Europe!
Sheep and goats around 40 kg plus, camels at about 300 kg depending on age. Donkeys at around 75 kg (there's not much meat on them!)
Look at:
www.daff.gov.au/__data/assets/pdf_file/0003/930108/std4-vessel-preparation.pdf

to find tables allowing deck space per head.

If designing for AMSA take advice from one who learnt the hard way. Follow Part 43 to the letter!!!

Corrosion, in the short term I found not to be a problem, we had steel decks with custom made aluminim pen rails fitted with galvanised bolts and no adverse effects ( though there may have been a bit of voltage between the deck and the rails. But all bolts were sealed with silicon. Point to be aware though is the type of deck coating. After losing several cattle to splayed legs - slipping while rolling - eventually we devised a deck coating of a mixture of two pack epoxy mixed with three different grades of blasting grit.

Re stability, from a practical ( seaman's) point of view it is interesting to note that in heavy weather the cattle will lie down thus reducing their CG marginally on each deck.

I was involved with livestock here from 1994 to 2003, so the rules may have changed a bit but will be happy to give you and further help that I can,if I can.
Cheers
Interalia

Billieboy
13th March 2010, 09:05
Gululu and Interalia, Very Sorry, I've made a big mistake I was thinking 1000Kilos but it was obviously 1000lbs! The sheep were also in lbs, so it's two cattle or ten sheep to the ton!

So sorry, it must be thirty years since I weighed a cow at the market in Carmarthen.

gululu
13th March 2010, 12:49
Interalia and Billieboy, you all are vey kind. Both of those advices give me a lot help.
The project I'm just handling is a 4500TEU container carrier convert to a livestock carrier, as a junior naval architect with no any experience, it's really a challenge for me. The classification society treat livestock carrier as a cargo ship. The stability booklet which is one of the most important documents should be Class stamped and kept on board. We all know for a normal cargo ship, they have a typical deadweight, for example, a 50,000dwt bulk carrier can carrier about 50,000 tons of cargo. When I prepare the stability booklet, I just put 50,000 tons weight and it's VCG, LCG take into account the lightship's parameters, then calculate the intact and damage stability under the different loading cases (full-load departure / arrival, ballast departure / arrival, docking condition and etc) and compare with the IMO rules to show the vessel have enough stablity in any voyage case. But as you said above, the unit weight of lives is not a constant. It makes me confused, The owner only told me they propose to carrier 20,000 cattles or 100,000 sheeps, or a combination of both. I don't know what's the right typical weight should I apply in the stability booklet. That's the real question for me.

JoK
13th March 2010, 16:27
As a bystander who will conceivably never deal with lifestock carriers, interesting thread!

Interalia
13th March 2010, 23:05
Gululu,
As with most stability problems, there is often a lot of aproximation with the weights and/or centres of gravity. For instance, where is the centre of gravity of a 300 kg animal? ( I went up to a farming area with a tape measure and measured a few steers and made a good guess!)

I should tell you first that I was not the naval architect who calculated all the stabilty but was heavily involved in the design work and conversion of 1500 tonne vessels -1200 head of cattle-(two converted one proposed only) and also sailed as Master of them , so stability was of great concern to me.
My method of attack was to determine the total deck area available for livestock (excluding the hospital pens), and using an average weight per animal - say, 300 kg,and using the table on the webstie I gave earlier in reply determine the total number of cattle per pen or deck. This will give you a weight to apply to the whole deck and apply an approximation of the CG for each deck. Choosing a middle of the range unit weight per animal will give a bit leeway either side of the probable true weight

Location of fodder is important, bearing in mind that the quantity of fodder reduces during the voyage ( we used pelletised fodder in bags stowed on upper deck, manually distributed by the crew) while fresh water is consumed at a high rate. After a very fast learning curve we installed three Reversed Osmosis units to make a total of 40 tonnes FW daily, sufficient to keep all FW double bottoms almost pressed up. Remember I am talking about much smaller vessels than you are dealing with.

Then to add to the interest, on a ten or twelve day voyage a good stockman would manage to make a weight gain in the cattle amounting to up to 10 kg per animal, depending on the weather. So there is an overall weight increase in the livestock decks during the voyage. As you realise, stability at the middle or end of the voyage is just as critical as initial stability.

Another concern is the presence of free water on the livestock decks during daily wash down This can be a considerable amount of SW and so provision needs to be made to get it off the decks as soon as possible eg with submersible sludge pumps installed in sumps.

As an aside, the first voyage of the first conversion resulted in the vessel having a severe list due to slack or empty tanks and, refering to an earlier thread about first ballasting the LOW side to lower the KG, believe me that is the only way to go!

As with any high sided vessel, with the wind near the beam there will, of course, be a considerable amount of wind heel, and consequently the cattle, of sheep will migrate to the low side. That is why the width of the pens are limited by AMSA.

AMSA in Canberra are very approachable and I'm sure they can give you advice - they want you to get it right - and as I am now retired, I'm happy to offer you what help I can - it's a waste to keep experience locked up in only one brain!

Cheers,
Interalia

John Cassels
14th March 2010, 10:50
Why try to calculate the CG of every animal ?. Surely the weight is transferred through
the feet so no matter how big , fat , high the beast is , the CG will always be at deck
level.
If the animal is lying down, having a kip or just travel weary there will then be a slight
rise in it's CoG.

Lancastrian
14th March 2010, 17:09
Surely the weight is transferred through
the feet so no matter how big , fat , high the beast is , the CG will always be at deck
level.


Surely not?

LOADING WEIGHTS
GG1 = (w x d)
(Final displacement)
where d is the distance between the CG of the mass added and the CG of the ship.
Which is why it is unwise to stand up in a small boat!

John Cassels
14th March 2010, 18:32
Same principle as carcasses stowed on hooks. Weight acts from the hook and not from
the CG of the carcass.
The well known formula for shift of G as in yr last is only valid where the animal has not
yet developed sea legs and where the CG is not in a vertical line with a point that
intersects the diagonals between all 4 legs.

Lancastrian
14th March 2010, 20:41
Same principle as carcasses stowed on hooks. Weight acts from the hook and not from
the CG of the carcass.
The well known formula for shift of G as in yr last is only valid where the animal has not
yet developed sea legs and where the CG is not in a vertical line with a point that
intersects the diagonals between all 4 legs.

Obfuscation! Suspended weights are a different case -
"Effect of suspended weights
For a suspended weight, whether the vessel is upright or inclined, the point through which the force a gravity may be considered to act vertically downwards is g1, the POINT OF SUSPENSION."

I do hope you are not going to argue with Messrs Kemp & Young.

John Cassels
14th March 2010, 21:34
Would never dream of going against the teachings of K & Y. However , I must reiterate
that the principle is the same.
Kemp and Young only prove my point re suspended weights and here we have a
situation where the weight of the animal is acting on the deck via the hoofs. It then
follows that the vertical C o G of all animals on a particular deck will in fact be acting on
that deck itself. There is therefore no need to calculate individual V C o G.

As Interalia has already stated - in heavy weather animals will lie down . This will have a
slight detrimental effect on the vessels GM as the VCoG will slightly increase.

If animals have been seasick in heavy weather then the initial transfer of stomach contents to the deck will have a very slight beneficial effect on the GM ( how much would depend on whether the animals were standing up or had already collapsed on the
deck when the incident took place) but may be offset by any free surface effect caused.

In short , there are very many factors which can affect the stability of
livestock carriers . A cow could easily be trained to stand up in a small boat
in such a way that it would keep it's CoG in a vertical line projected up from
the initial CoG of the boat.

Lancastrian
14th March 2010, 22:30
Reductio ad absurdum. When calculating the effects of loading, you take into account the CG of the cargo, even if in this case it is a variable.

Cisco
14th March 2010, 22:39
Reductio ad absurdum. When calculating the effects of loading, you take into account the CG of the cargo, even if in this case it is a variable.

except when it is hanging on a hook.....

CG of a cow ( or most other beefs excluding bulls) is not at half height but more likely at about 11/16th height.... not much weight below the knees.

Cisco
14th March 2010, 22:44
A cow could easily be trained to stand up in a small boat in such a way that it would keep it's CoG in a vertical line projected up from the initial CoG of the boat.
I don' think you could train a cow to do anything.... thats why you don't see them in circuses.

In argentina it appears to be the norm to stand up in dinghies in sheltered waters.. bit of a macho thing I think... doesn't seem to bother the stability.

John Cassels
14th March 2010, 23:20
except when it is hanging on a hook.....

CG of a cow ( or most other beefs excluding bulls) is not at half height but more likely at about 11/16th height.... not much weight below the knees.

All very correct and concise. The question is -from which point does
this weight act ?. On the hoof , perhaps ?.

John Cassels
14th March 2010, 23:40
I don' think you could train a cow to do anything.... thats why you don't see them in circuses.

In argentina it appears to be the norm to stand up in dinghies in sheltered waters.. bit of a macho thing I think... doesn't seem to bother the stability.

Well , I once saw a cow that was trained to walk and say "Moo " and this all
without any promting or extra encouragement or even in a circus.

It was so impressive , one can easily imagine that small boat stability would
present little problem to them.

Cisco
15th March 2010, 00:32
I have just been conducting an experiment in my shed. a piece of plywood.. about 2 foot by 2 foot.. balanced on a bit of 2" x 1".
I asked Daisy to take part in this experiment but she just said 'mooo' .. not in her job description.
So I placed 100kg of me on the ply.... bent from waist several times as if touching toes.... I wish... platform remained steady .. did not tip forward at all but did , due to flexing of my calves , tip back once or twice... away from my mass.
I go with the hoof being the CofE.

randcmackenzie
15th March 2010, 00:33
Think again John.

Though the weight of a container is applied through its base, the C of G is taken at one third height - or it was in my day.


Similarly, the C of G of a tank was taken at half height, even though the sounding could be below that, a useful margin I used to keep in my sleeve in Seatrain days.

Interalia
15th March 2010, 00:43
Why try to calculate the CG of every animal ?. Surely the weight is transferred through
the feet so no matter how big , fat , high the beast is , the CG will always be at deck
level.
If the animal is lying down, having a kip or just travel weary there will then be a slight
rise in it's CoG.

John,
The CG of an individual animal is, as Cisco puts it, somewhere in the top half. The weight of the beast is transfered to the deck through it's legs, but the distance of its CG to the deck is variable depending whether it is standing up or lying down. Imagine a deck barge with a tower crane on deck - height say 20 metres with a ten tonne cabin at the top. The CG is somewhere in the region of the cabin. Now lower that cabin somehow to the deck of the barge, leaving the legs of the crane still at 20 metres high. The CG of the crane is now much closer to the deck.
As pointed out, loads suspended on hooks are a different situation, but we tried not to do that on a LIVEstock carrier.

Of course I am only experienced with Australian cattle and wouldn't their weight act in the opposite direction to European cattle?

Interalia
15th March 2010, 01:24
If animals have been seasick in heavy weather then the initial transfer of stomach contents to the deck will have a very slight beneficial effect on the GM ( how much would depend on whether the animals were standing up or had already collapsed on the
deck when the incident took place) but may be offset by any free surface effect caused.

Cattle when they're seasick don't vomit - imagine what it would be like with four stomachs - would it happen in parallel or in series?
Of course reaction to seasickness at the stern of the animal is a bit different.

John Cassels
15th March 2010, 10:14
Think again John.

Though the weight of a container is applied through its base, the C of G is taken at one third height - or it was in my day.


Similarly, the C of G of a tank was taken at half height, even though the sounding could be below that, a useful margin I used to keep in my sleeve in Seatrain days.

Roddy , that's the whole point. A container does not move ( that's what we
hope anyway) so when the vessel heels , the force acting from the CoG moves to the side.
When a livestock carrier heels , the animals sway with the ship therefore
keeping their CoG always in a vertical line acting through the bisection
point of the diagonal lines between the hoofs.

Lancastrian
15th March 2010, 10:21
Come on JC. Whilst the thread has produced some amusing banter, your original statement at #15 was wrong. Even the other guy can't get you out of that.

John Cassels
15th March 2010, 10:36
Come on JC. Whilst the thread has produced some amusing banter, your original statement at #15 was wrong. Even the other guy can't get you out of that.

OK , you win.

Andrew Craig-Bennett
16th March 2010, 02:56
I'm glad we have that settled.

Cisco
16th March 2010, 03:41
Come on JC. Whilst the thread has produced some amusing banter, your original statement at #15 was wrong.

No it wasn't....


it is much the same as beef on the hook, the deck head height is used as 'worst case'.. a tight stow of beef on the hook will act as a solid mass. Likewise a tight stow of beef on the hoof will behave as a solid mass and , having just run the tape over a representative sample of my cows, would have a CofG of 1.1 to 1.2 metres above the deck. A single cow able to move with the roll will be as described by John.

Getting back to the 'standing in a dinghy ' scenario... if the C of G was acting through the body's centre then when people stand in the dinghy it will capsize.. it doesn't.. just so long as they stand steady. Trouble starts when standing people start moving around in the dinghy, transfer weight to gunwhale etc etc....

Got to run... off to do my bit for the Argentinian economy..

Interalia
16th March 2010, 09:11
.

it is much the same as beef on the hook, the deck head height is used as 'worst case'.. a tight stow of beef on the hook will act as a solid mass. Likewise a tight stow of beef on the hoof will behave as a solid mass and , having just run the tape over a representative sample of my cows, would have a CofG of 1.1 to 1.2 metres above the deck. A single cow able to move with the roll will be as described by John.

Getting back to the 'standing in a dinghy ' scenario... if the C of G was acting through the body's centre then when people stand in the dinghy it will capsize.. it doesn't.. just so long as they stand steady. Trouble starts when standing people start moving around in the dinghy, transfer weight to gunwhale etc etc....


Under AMSA and Australian Standards for Export of Livestock a (say) 300kg animal is to have minimum of 1.11 square metres of deck space; this is not a tight stow, leaving the cattle room to move about to take their turn at the fodder and water bins. Cattle transported by road in a truck are a different story - they may be considered a tight stow.

On the 'standing in a dinghy ' scenario I agree that as long as the people stand steady there will be no capsize. But when the dinghy / livestock ship is acted upon by an external force such as wind, swell ....

Lancastrian
16th March 2010, 10:39
Quite so. Even if they are standing steady on the centreline, they are increasing the KG of the dinghy from what it was when they were sitting down, and the effect of their mass is not acting on the bottom boards.

John Cassels
16th March 2010, 10:54
Actually , it should be quite simple.

All livestock intending to make the trip should be given a quick basic course in elementary
stability which would include being able to roll with the ship and so keep their CoG from
moving. When required , they should know when to lie down ( not sit down as
Lancastrian would have it) so lowering their CoG.
When feeling seasick , they should be ready to aim for scuppers - so avoiding any free
surface effects.
A basic exam should follow the course - answers can be made by a nod ( for yes) or a
shake( for no) of the head.

Any animal not meeting the required standard would be refused passage.

Billieboy
16th March 2010, 12:56
There may be a language problem there John, Spanish, Kiwi or plain Outback; perhaps a short linguistcs course could be patched in, on the train, from the farm, to the loading port?

gululu
20th March 2010, 07:26
I found a very interesting movie at Discovery Channel named "Mighty Ships "Berux", it's may helpful.

NoMoss
20th March 2010, 10:35
There seems to be a lot of bull going on here.

lgrania02
20th March 2010, 11:13
Do not know too much about the stability of livestock, but I do know they were the only vessels that I made a conscious effort to board and leave on the windward side when they visited Jeddah. I was once told that with a mortality rate of about 3% a ship with 100,000 sheep aboard coming from Australia would be throwing a dead carcass overboard about every 15 minutes on average! Hard to believe but maybe true.

livex
27th March 2010, 06:54
Loading of livestock vessels is monitored by AQIS and to a lesser extent by AMSA.
AMSA these days does not police load density,water ,feed etc.

The role of AMSA is vessel condition and inspection and subsequent issuance of the ACCL(australian certificate carriage livestock)under MO43 .
Livestock carriers operating from Australia must be IACS class only.
There is less than 30 vessels(amsa compliant) that are able to serve the Australian trade.
The vessels servicing the Australian trade are in excellent order and are mostly european owned and managed.
VROON is by far the biggest player then SIBA.
The most recent newbuild is the MV OCEAN SWAGMAN operated by SIBA.
She was launched in feb 2010 and is the most advanced livestock carrier in operation.

All loading and stock densities are enforced by AQIS.
To formulate load area =av weight(one hd) .0034 + .09 x total hd = m2 required

water requirement = net kgs cargo x 12% x voyage length + 3 days.

Cattle are fed hay pellets that are mostly 5/8 in diameter and are stored in bulk or handled in small 35 kg bags.

feed requirement = net kgs cargo x 2% x voyage length + 20%.

Indonesia is world largest buyer of Live cattle importing more than 700,000 from Australia in 2009.Nearly all cargo are discharged at Jakarta or Panjang.
The busiest Australian port for cattle is Darwin.
Fremantle,Townsville and Broome do substantial numbers.

Fremantle is the main sheep port.

kevinmurphy
3rd April 2010, 12:29
Having worked on livestock carriers in the 80's, the average weight of the animals is obtained from weighing the lorries arriving at the port at a weighbridge, or from the holding area, day before loading we would mark the pens with the allowed number from the weights given, all carefully calculated from Aussie govt rules, then Mate did his stability based on the weigbridge data.
On passage, an allowance was made from food and water consumed being turned into sh!te, which from memory was 60% (but it was a while ago), we did daily calculations on passage.
rgds
Kev

NEWCON
20th April 2010, 04:34
Is damage stability calculation (probabilistic) a requirement for Livestock carriers.