Let’s assume it’s full of gold coins, wouldn’t that amount to a half a ton or more?
A cubic foot of gold weighs more than 1000 lbs. Worth like $20MM.
Gold has a density of 19g/cm^3.
Let’s say the interior of the chest has a volume equivalent to 404050cm. That’s 64000 cm^3.
Let’s say 3/4 of the interior of the chest is gold. The rest is air. So that’s 48000cm^3 of gold.
48000cm^3 * 19g/cm^3 = 912000g.
So your pirate chest would weigh about 912kg, give or take 5-10 kilograms of wood and other metals in the chest itself, provided the gold coins were pure gold. (24k) They usually weren’t; other metals were mixed in to make the coin more durable.
England still uses the “crown gold” standard for minting new gold sovereigns. It was introduced in the 1500s by Henry VIII, I think, so I guess that could be the type of gold crown reasonably expected to show up in a pirate chest. Crown gold is 22 karat (91,667%) gold, with the rest strictly copper. Copper has a density of about 8,96g/cm^3. Roughly, that would decrease the weight of the chest by about 4%.
So the chest would weigh in at about 875 kilograms. Or about 1930 pounds. Man, gold’s heavy.
(Apologies for any mistakes - I just came off night shift and I’m going cross-eyed.)
One of my pet peeves is that film makers rarely seem to represent the real difficulties of handling heavy objects. From the suitcases that are clearly empty to the gold bars in the Italian job, even if they make some attempt, they abandon reality for effect.
I do recall that Three Kings (1999) made a noticeable effort to show that the gold being stolen by the GIs was rather heavy. But their effort was mainly noticeable because most other films don’t make that same effort.
Apologies for continuing the hijack.
And don’t forget Kelly’s Heroes (1970). When the gold was being removed each man carried one case at a time and many men were in use. The Yanks had their truck and the Germans had theirs. I thought it an accurate portrayal of the weight and difficulty of transporting gold.
On a similar note, a standard attache case found handcuffed to your skeleton wrist after your plane crashes in the Caribbean will contain less than a million dollars in crisp US $100 bills packed in tight.
Let us also not forget that gold was not that common even back in the day. Most coins were silver, and a pirate’s treasure chest would be predominantly filled with Ag, not Au. That’s gotta save you what, a pound or two? 
A stack of 1000 US bills is a bit smaller than two standard red clay builder’s bricks. But much lighter. So $1M in $100s is 10 such stacks or about 20 brick’s worth. I bet you can get 6 full stacks in an attaché case, and maybe a 7th if you can break it up. But not much more.
bob++
As I recall, the impossibility to carting away so much gold was why the filmmakers of Goldfinger changed from the book’s plot of stealing the contents of Fort Knox to irradiating it to reduce the world supply of the stuff and thereby make Goldfinger’s own gold more valuable.
As well they should.
Funny you should say that. I remember that movie as being the most egregious violation of gold-weight in Hollywood. They pack, like, 20 bars into one fabric suitcase and they hold bars by their fingertips.
But we know a couple pirates can carry it quite a distance over rough terrain [surely you’ve seen those movies!]. Based on this I am thinking 150 pounds.
Again I don’t think some of you have seen many pirate movies: it’s not just gold; it’s also jewels…
Ironic username / post combo.
And don’t forget when Pinky and the Brain successfully managed to break into Fort Knox, only to realize that even a single gold bar is well beyond the carrying capacity of a pair of mice.
Yes, that was a rare dose of reality - it’s not as if, even back in the dark ages of 1965, that someone could take a stolen cargo consisting of truckloads of gold, safely make it to the Canadian border, and then be home free. Unless he then buried it in the snow… 
However, it did include Pussy Galore and Plenty O’Toole.
As far as I know, Flemming never actually said in the book, how GF planned to shift it.
At today’s prices, I think $15 billion of gold would weigh in at around 4,000 tons (US)
Plenty O’Toole was in Diamonds are Forever, which incidentally reminds me of another adaptation-improvement. In Charles Templeton’s 1975 novel The Kidnapping of the President, the hostage-takers demand a ransom of, as I recall, 12.5 tons of gold. In the 1980 film adaptation, this is modified to the equivalent in diamonds, which has the advantage of being far more portable, though probably not nearly as negotiable.
The problem’s certainly acknowledged in the book, though Goldfinger rather skates over some of the details in addressing the Mafia bosses:
He then notes that he’ll “initially” be using the railways himself to move his share and asks that he have unimpeded access to them.
I have a recollection that when they tried to lift said fabric suitcase, it immediately tore. But I might be remembering it wrong or mixing it up with another movie.