Bunch of dudes tried making a Bronze age boat, but it sinks
35 replies, posted
[img]http://news.bbcimg.co.uk/media/images/60202000/jpg/_60202528_60202526.jpg[/img]
[quote]
The band was ready, the champagne was on hand, Time Team's Tony Robinson was there to record the historic event, and the crowds gathered to watch as a half-size replica of Dover's Bronze Age boat prepared to take to the water.
The only problem was, it started to sink.
A team of craftsmen and archaeologists had been working for several months to build the replica boat, using the same tools and the same methods as their ancestors would have used when the original boat was built more than 3,500 years earlier.
But time was against them. They only completed the task a couple of hours before the launch was due to take place and there was no time to test it.
A team of rowers, complete with life-jackets, were waiting to go on board, but they were not needed.
As the boat was gently lowered into the water at Dover Marina, it soon became clear there was a problem.
It started listing to one side, and after a few minutes it had to be hoisted back out again. Water had got into the boat, and now, as it made its way back on to dry land, water was dripping out of it again.
But the team, though disappointed, were undeterred, and said they would continue their work.
"We are hopeful that we can think again and make the boat good," said archaeologist Peter Clark who has led the project.
"We have come an awfully long way in the past three and a half months and we think we are nearly there."
Paying tribute to all those who had worked on the boat, Mr Clark named it Ole Crumlin-Pederson after a Danish archaeologist who had worked on the project, but died before it was completed.[/quote]
[url]http://www.bbc.co.uk/news/uk-england-kent-18049714[/url]
That's sad
Sounds like someone didn't do the math properly.
It's like when you've got an assignment for high school / college / whatever, if you rush to get it finished on the last day, it will be terrible.
Kind-of their own fault.
[QUOTE=V12US;35963682]Sounds like someone didn't do the math properly.[/QUOTE]
[quote]...using the same tools and the same methods as their ancestors would have used when the original boat was built more than 3,500 years earlier.[/quote]
I bet ancestor ghosts are dead from laughter.
[QUOTE=Asgard;35964106][/QUOTE]
It's not like they didn't have math back in the day. Math isn't some kind of novel, modern invention.
[QUOTE=V12US;35964132]It's not like they didn't have math back in the day. Math isn't some kind of novel, modern invention.[/QUOTE]
Yes, but I very much doubt that engineers back then did algebra to figure out the volumes of their boats and the ratio of whatever the fuck
They just took hammers and made shit out of dumb materials
[QUOTE=DireAvenger;35964214]Yes, but I very much doubt that engineers back then did algebra to figure out the volumes of their boats[/QUOTE]
How would you be able to use algebra that way?
I saw a documentary where they made longboats just like the Saxons used and they sailed pretty well.
[QUOTE=DrasarSalman;35964239]How would you be able to use algebra that way?[/QUOTE]
To calculate the volume and thickness of the boat to keep a certain amount of people afloat.
Gravity exercises a downwards pointing force on the boat and the people inside and buoyancy counteracts that force. The trick is to make sure that force is large enough by calculating the volume of the boat that will be underwater:
[img]http://puu.sh/uQvE[/img]
[img]http://puu.sh/uQqY[/img]
Where Fg is the force of gravity and Fb is the buoyancy force. The gravity is directly proportional to the total mass of the boat (m[sub]b[/sub]) and the people inside (m[sub]p[/sub]), g here is Earth's gravitational constant averaging 9.81 m/s[sup]2[/sup].
The buoyancy force is proportional to the volume of the water occupied by the boat (V[sub]d[/sub]), the density of the water (p[sub]w[/sub]) and the gravitational constant.
These forces need to cancel each other out so that the boat has no vertical movement, which means the following equation needs to be solved for the displaced volume:
[img]http://puu.sh/uQss[/img]
The gravitational constant g cancels out:
[img]http://puu.sh/uQsF[/img]
(That means that your boat will behave the same on other planets!)
Finally solving for the displaced volume:
[img]http://puu.sh/uQt1[/img]
That means that if you have a boat that weighs 50 kg (regardless of material) and two persons weighing 140 kg together:
[img]http://puu.sh/uQtG[/img]
A volume of 0.19 cubic meters will be displaced. If you assume your boat is about 150 cm long and 50 cm wide, your boat will need to be at least 25 cm high for water to not leak in and sink your boat (1.50*0.50x0.25~=0.19).
Archimedes would roll around is his grave for these guys.
They could make these calculations 287 BC.
Reminds me, when I made an Ice-Cream age summer home.
[QUOTE=DireAvenger;35964214]Yes, but I very much doubt that engineers back then did algebra to figure out the volumes of their boats and the ratio of whatever the fuck
They just took hammers and made shit out of dumb materials[/QUOTE]
I dunno man, you'd be surprised what our ancestors were capable of, as humans we've had math down pretty well for well over a couple thousand years
[QUOTE=Furioso;35964473]I dunno man, you'd be surprised what our ancestors were capable of, as humans we've had math down pretty well for well over a couple thousand years[/QUOTE]
Exactly. People think that either 1) Our ancestors are stupid, or 2) the modern generation is stupid. We're not all that different to our forefathers or ancestors in terms on intellect, only in understanding and learning. imo, anyway.
We are different to our ancestors becuase back then you had to know how to hunt/build/farm/fight to survive, nowdays we don't to learn any of these things becuase we just just get someone else to do it for us.
[QUOTE=ReligiousNutjob;35963694]It's like when you've got an assignment for high school / college / whatever, if you rush to get it finished on the last day, it will be terrible.
Kind-of their own fault.[/QUOTE]
What if we forced to kill them to make them get the job done faster?
worked in the old days and shit got done right.
Funny how you guys blame it on math rather than the skill of the craftsmen.
They didn't use their own design and used old methods of sealing the boat, which is most likely where the problem occured considering it didn't sink. It just took on water through the seals and/ or joints.
[QUOTE=sami-pso;35964819]Funny how you guys blame it on math rather than the skill of the craftsmen.
They didn't use their own design and used old methods of sealing the boat, which is most likely where the problem occured considering it didn't sink. It just took on water through the seals and/ or joints.[/QUOTE]
Obviously they used old methods, that was kind of the point.
[QUOTE]Paying tribute to all those who had worked on the boat, Mr Clark named it Ole Crumlin-Pederson after a Danish archaeologist who had worked on the project, but died before it was completed.[/QUOTE]
Kind of sad that he never got to see his boat finished, even if it did fail.
Overv, I salute you.
and just like their ancestors, they're forced to use trial and error before they find success
[QUOTE=Overv;35964387]To calculate the volume and thickness of the boat to keep a certain amount of people afloat.
Gravity exercises a downwards pointing force on the boat and the people inside and buoyancy counteracts that force. The trick is to make sure that force is large enough by calculating the volume of the boat that will be underwater:
[img]http://puu.sh/uQvE[/img]
[img]http://puu.sh/uQqY[/img]
Where Fg is the force of gravity and Fb is the buoyancy force. The gravity is directly proportional to the total mass of the boat (m[sub]b[/sub]) and the people inside (m[sub]p[/sub]), g here is Earth's gravitational constant averaging 9.81 m/s[sup]2[/sup].
The buoyancy force is proportional to the volume of the water occupied by the boat (V[sub]d[/sub]), the density of the water (p[sub]w[/sub]) and the gravitational constant.
These forces need to cancel each other out so that the boat has no vertical movement, which means the following equation needs to be solved for the displaced volume:
[img]http://puu.sh/uQss[/img]
The gravitational constant g cancels out:
[img]http://puu.sh/uQsF[/img]
(That means that your boat will behave the same on other planets!)
Finally solving for the displaced volume:
[img]http://puu.sh/uQt1[/img]
That means that if you have a boat that weighs 50 kg (regardless of material) and two persons weighing 140 kg together:
[img]http://puu.sh/uQtG[/img]
A volume of 0.19 cubic meters will be displaced. If you assume your boat is about 150 cm long and 50 cm wide, your boat will need to be at least 25 cm high for water to not leak in and sink your boat (1.50*0.50x0.25~=0.19).[/QUOTE]
This reminds me how the collective intelligence on even FP alone is enough to rival many universities and yet much of it goes to waste...
[QUOTE=Master Kief-117;35972181]This reminds me how the collective intelligence on even FP alone is enough to rival many universities and yet much of it goes to waste...[/QUOTE]
You sir, have never seen the OIFY.
[editline]16th May 2012[/editline]
Just realised that that could make up for the liberal arts section of the university.
Maybe they shouldn't make boats out of heavy bronze then.
People who rate dumb are too stupid to realize it was a joke.
[QUOTE=draugur;35972649]Maybe they shouldn't make boats out of heavy bronze then.[/QUOTE]
uhm
Guys, do you [I]honestly[/I] think they couldn't work out simple buoyancy formulas for this? I severely doubt it. These are very intelligent people, and it probably was a craftsmen error. I can guarantee you that if they were trained to built old boats from their childhood, this wouldn't be a problem.
[QUOTE=draugur;35972649]Maybe they shouldn't make boats out of heavy bronze then.[/QUOTE]
this comment needs to be preserved for posterity
[QUOTE=Master Kief-117;35972181]This reminds me how the collective intelligence on even FP alone is enough to rival many universities and yet much of it goes to waste...[/QUOTE]
This shit is fairly common in most college math calsses
They lacked the viking spirit.
[QUOTE=sami-pso;35964819]Funny how you guys blame it on math rather than the skill of the craftsmen.
They didn't use their own design and used old methods of sealing the boat, which is most likely where the problem occured considering it didn't sink. It just took on water through the seals and/ or joints.[/QUOTE]
They said one-half scale.
It's a surface-area to volume issue. As you shrink the boat, the mass of the hull material increases relative to the internal volume (which determines bouyancy). i.e. it's easier to make big things float.
I'm not saying that the thing didn't leak. The article isn't terribly specific about [i]why[/i] it sank. Just that it's a possibility that it simply wasn't buoyant enough, due to a miscalculation.
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