It's my cake day so I thought I might get a few questions answered. I'm curious about the handling of cargo on sailing she of different types in different eras.
I've looked for answers to these questions over the years but I've found it challenging to get succinct or coherent answers.
The cargo carrying capacity of ships (at least English ships) by the 15th century was generally measured in "Tuns". The largest ship mentioned in Bristol port records from the 15th century could carry 511 tuns. The average large Bristol Merchant ship in this century was smaller, perhaps about 300 tuns.
"Tun" originally meant barrel. Roughly a barrel of wine which held 252 gallons and weighed 2,240 pounds.
This word later turned into nautical tons, (which are a measure of volume when applied to ships, not a measure of weight, which is called "displacement").
The word also turned into a measure of weight (the "long ton" generally 2,240 lbs) this was not applied to ships, but was used on land. So, tun meant barrel in the 15th century,, but later meant either the volume of a barrel or the weight of a full barrel.
The cargo of the 511 tun 15th century merchant ship from Bristol is recorded as having been worth 1000 pounds sterling. Carriage by ship (from Bordeaux to Bristol) was charged at about 1 pound per tun. Carriage was extremely expensive. The transport fee for this ship load would have been about 50% of the total value of the cargo.
Loading and unloading - how was cargo loaded and unloaded from ships like galleons and how did those methods differ from ancient galleys, dhows, or longships? Did they use cranes and nets or carry everything on by hand?
A port might have a crane for large objects or a crane could be rigged with pulleys in the spars. Those are the cross beams that hold the sails. Small objects could be loaded by stevedores or sailors. More recent lumber carriers sometimes had doors at the bow and stern. Here's an example
Records - Do records exist of cargo manifests from various eras? Have we ever found a detailed manifest of some Roman gley sailing from Ostia to Alexandria?
Cargo manifests, also known as bills of lading occasionally turn up. More modern examples are more common. One of the other ways to see what ships in a region were carrying is customs tax records. Denmark charged ships a fee known as sound dues for may years to enter the Baltic based on size and cargo.
