It's called an armed merchantman.
Q Ship
A merchant vessel outfitted to fight is commonly referred to as a "privateer." These ships were typically merchant ships that were armed and authorized by a government to engage in warfare, particularly against enemy vessels. Privateers operated during times of conflict, capturing enemy ships and cargo, and were often motivated by profit, as they could keep the spoils of their captures. This practice was a legal form of piracy sanctioned by letters of marque issued by governments.
The ships were called privateers. The authorisations were called letters of marque.
Privateers or Merchant Mariners help win the Revolutionary War. To add to this, they issued Letters of Marque to privately owned, armed merchant ships and Commissions for privateers, which were outfitted as warships to prey on enemy merchant ships
Both sides wanted to keep U.S. shippers from supplying their enemy.
arm the merchant ships
Frederick C. Matthews has written: 'American merchant ships, 1850-1900' -- subject(s): History, Merchant marine, Merchant ships, Ships
Privateers or Merchant Mariners help win the Revolutionary War. To add to this, they issued Letters of Marque to privately owned, armed merchant ships and Commissions for privateers, which were outfitted as warships to prey on enemy merchant ships
Merchant ships did (and still do!) travel all over the world, wherever there are sea ports.
Roger Villar has written: 'Merchant ships at war' -- subject(s): Armed merchant ships, British Naval operations, Falkland Islands War, 1982, Merchant ships
103 merchant ships were sunk in world war one
Congress denied President Wilson the right to do what with merchant ships?