The actual Chatham Chest built in 1625, to keep the 6d's which was deducted monthly from all seamen's wages. It has five locks and a disguised keyhole in the top, all to keep the accumulated fortune under the control of those who collected the money.
 A Corrody was the earliest form of pension practiced in England.
When Biddel gives this promise, he's referring to the “Chatham Chest.”
Established in 1590 by Sir John Hawkins and Sir Francis Drake, it helped convince young men to enlist to the navy, despite the grim fate of former sailors.
What tolled the “Chatham Chest” was nine months of sea war against the Spanish Armada; nine months of active service in small ships.
Many of those who didn't perish in battle, came back to England suffering from ship fever (probably Typhus.) The death toll was such, that young men were looking elsewhere for work.
Sir John Hawkins and Sir Francis Drake, fearing that there would be no new recruits to the navy, established the “Chatham Chest,” promising that it will provide pensions to disabled seamen.
If you wonder where the money came from, well, it was deducted from the salaries of the seaman. You didn't expect Sir John Hawkins, Sir Francis Drake or Queen Elizabeth to pay for it, or did you?!