Thursday, June 27, 2013

18th Century Travel Speeds by Ship

Bonhomme Richard and Serapis
One of the biggest headaches in writing a long, sprawling series that includes a lot of historical action is figuring out logistics. For example, how long would it take to get from here to there using the modes of transportation of the time? Unfortunately, that isn’t always spelled out in the historical record, especially when your hero or heroine is going somewhere other than the sites of the various incidents described in your research materials.

I know how long it took Howe’s army to get from Head of Elk on the Chesapeake to the site of the famous battle along Brandywine Creek, described in Crucible of War. That information appears in one of my reference books. But how long would it take Elizabeth to get from Philadelphia to Bemis Heights, north of Albany New York? And first of all, what route would she take? And what about weather and terrain along her route that might slow her down?

See the problem? Inevitably you resort to making an educated guess.

Now that I’m about to embark on the naval aspect of the war, I’m confronted with the need to know how fast a sailing ship would travel from one port to another. Naturally it would depend on the overall design, size, and tonnage of the ship, plus weather and wind speeds. And you have to keep in mind things like the depth of the water. Can you get a vessel of a certain size through that channel or will it run aground? To calculate that you need a good chart of the sea roads, and the times of the incoming and outgoing tides on that particular day. All of which are readily available . . . not.

ARGH!! I’m beginning to sound like a pirate. Which, as a privateer, is basically what Carleton has become by the end of Crucible of War, so I guess I really need to start thinking like the captain of a privateer. In Valley of the Shadow, Carleton’s ships have to sail from Marblehead, above Boston, to the New Jersey coast to pick him up with his party, and then back up to New York harbor, where Elizabeth is being held. It’s imperative for me to know how long it would realistically take them to sail that distance in ships designed for speed and stealth.

Doing a web search didn’t turn up much to help me figure out travel speeds of 18th century warships, and most of what I did find was contradictory. I finally decided to go with the information I found on the AllExperts website, at least as a general guide. This was very useful in putting together my timeline.

Following the contemporary accounts listed in the first section below, the author then deduces travel speeds.
Account of a London to Boston voyage = 3,280 miles / 50 days transit time

Comments in Ben Franklin's biography regarding a bet on the speed of the packet Lutwidge = 14.95 miles / hour

Account of the sailing vessel Red Jacket’s voyage from New York to Liverpool = 3,473 miles / 13 days transit time

It's all pretty sketchy as there were obviously no decent measurement tools available at the time let alone interest in recording such details. Plus factors like speed differences between naval ships of the line, revenue cutters, privateers, passenger or cargo vessels, etc. and indications of stops or weather variations are not accounted for. So working through the data I did find the following speed values are indicated.

1st Case 3,280 miles / 50 days = 66 miles per 24 hours     2.73 miles / hour

2nd Case 14.95 miles / hour

3rd Case 3,473 miles / 13 days = 247 miles per 24 hours   11.13 miles / hour

4th Case 210 miles / 2 days = 105 miles per 24 hours     4.38 miles / hour

The average of these speeds is: 8.30 miles per hour. Obviously the larger ocean transiting vessels (other than the 1st Case) were able to pile on more sail and make better use of the open ocean for better speeds. So if we go with the average speed indicated by these values, the sailing times between the ports you mention are as follows.

Boston to Hyannis Port 61 miles @ 8.30 mph =   7.35 hours  0.31 days

Boston to Charleston (S.C.) 822 miles @ 8.30 mph = 99.04 hours 4.13 days

Boston to Nassau, Bahamas 1,247 miles @ 8.3 mph = 150.24 hours  6.26 days
Following the author’s calculations allowed me to come up with a reasonable conjecture as to the time frame needed for Carleton’s ships to get to the rendezvous off the New Jersey coast, and then back up to New York. It’s at that point when the real fun begins!

In a later post, I’m going to cover travel on land and the time required for getting to and from different points, depending on the mode of travel.

I hope this gives you a little more insight about the process of writing historical fiction . . . and why it takes a couple of years for me to complete each volume!