As indicated in previous posts on the tunnels, molasses was “black gold” to the early economy of Newburyport. Though international trade and ship building was also important, it was the distilling of sugar into rum that was the foundation for Newburyport’s boomtown existence. According to J.J. Currier, there existed as many as 60 of these distilleries within the small borders of the original Water-side community of Newbury-port. Therefore, with so much smuggling occurring to supply these businesses, it must be understood that the primary product passing through the tunnels would have to be rum.
Anyone seeing the geography of the city would understand that transport would need to be done uphill, over “The Ridge” and down the other side. There would be two means of possible transport. One would be “carts” either on wheels or guided by tracks to make it easier to bring the heavy containers through the tunnels; or, and this is more likely, they were “rolled” throught the passageways.
Barrels often have a convex shape, bulging at the middle. This bulge facilitates rolling a well-built wooden barrel on its side allowing it to change directions with little friction, compared to a cylinder. It also helps to distribute stress evenly in the material by making the container more curved. To help in transport, the Barrels have reinforced edges to enable safe displacement by rolling them at an angle (in addition of rolling on their sides as described). Thus, skilled workmen on the wharves could rapidly move the barrels onto ships or onto local carts.
Now in England, the standard rum barrel design and size was established in 1484. The barrel was mandated to hold a quantity of 36 imperial gallons (160 L; 43 US gal).
Someone who makes barrels is called a “barrel maker” or cooper and was a very important skill here in Newburyport. Barrels are only one type of cooperage. Other types include, but are not limited to: buckets, tubs, butter churns, hogsheads, firkins, kegs, kilderkins, tierces, rundlets, puncheons, pipes, tuns, butts, pins, and breakers.
Barrels have a variety of uses, including storage of liquids such as water and oil, fermenting wine, arrack, and sake, and maturing beverages such as wine, cognac, armagnac, sherry, port, whiskey, and beer.
The rings holding a wooden barrel together, called hoops, are generally made of galvanized iron, though historically were made from flexible bits of wood called withies. While wooden hoops could require barrels to be “fully hooped”, with hoops stacked tightly together along the entire top and bottom third of a barrel, iron-hooped barrels only require a few hoops on each end.
The “head hoop” or “chime hoop” is the hoop nearest the extremes of a barrel, the chime being the beveled edge and the head being the flat circular top or bottom of the barrel. The “bilge hoops” are those nearest the bilge, or bulging center, while the “quarter hoop” is located between the chime and bilge hoops.
The stopper used to seal the hole in a barrel is called the bung.
There are pictures at Caldwells in which the barrels were literally covering a football fields worth. Therefore the tunnels to be effective would have to be largely straight and have enough size to get a barrel comfortable down the passage with some room for steerage. We know that the possible origin of these tunnels derived from a period of 1740 until 1815 (to avoid the tariffs from the Molasses Act of 1733) and the likelihood was their construction occurred before the American Revolution.
We know the tunnels were never really designed for human transport simply because there was no money to make from it! Most abolitionists and their human cargo didn’t have the cash, nor would there be any source of justification for such an expensive mining operation. But there was for rum! Not only did a cash resource exist, the use of the tunnels guaranteed a consistent profit not only to pay for the construction but it gave a reliable profit source for years to come.
The tunnels may have been briefly re-opened during the terrible 11 years of the Slave Extradition Act of 1850; but that would have been incidental and not their original purpose.
So, when the tunnels are explored, more than likely the brick was the much smaller ballast brick which can clearly be seen on brick Georgian mansions and was still being used in the Federalist period as anyone can inspect on the buildings around Market Square.