Charleston’s ship channels – then and now

During our visit to Charleston last week, the Aide-de-Camp and I walked the Sullivan’s Island beach near sunset.  During our walk, our study of the harbor was interrupted as this big white thing passed:

IMG_5883

That’s the Carnival Ecstasy outbound on a cruise to some tropical ports of call.  One escort boat paces to the stern.  There was a larger pilot boat on the other side.  We kept tabs on the liner’s progress as she worked out the channel to the sea.

2016-03-19 Charleston 090

The cruise liner is 150 years removed from the days of coal-fired steamships that attempted to run out of Charleston during the Civil War.  Sailors of those blockade runners might not recognize the modern diesel engines powering the liner.  For that matter, maybe the concept of luxury cruises might seem odd to the Civil War sailors….

But one thing that would look familiar are those boats tending to the big ship.  I wrote about the problems getting ocean going ships over the bar at Charleston on several occasions, in particular how that limited options during the crisis days at Fort Sumter.  During the war, the US Navy kept numerous armed tugs in the blockading force off Charleston.  These light-draft and maneuverable vessels were invaluable for working in the shallows and also for assisting the larger ships through the narrow confines of the channels.  Recall that during the Civil War the approaches to Charleston harbor offered four channels:

CharlestonApproachesWartimeColor

Of all the wartime maps of Charleston, I like this one best.. and not just because of the colors.  The US Coast Survey produced this map in 1865 by direction of Rear-Admiral John Dahlgren.  Annotations on the map supported Dahlgren’s reports filed at the end of the war.  So we see notes about the locations of significant wrecks, torpedoes, harbor obstructions, and batteries.

But look at the channels.  Charleston had four:

  • Main Ship Channel – coming up from the south in front of Morris Island.  The Federal ironclads used this channel to attack Fort Sumter on April 7, 1863. And later the Federals maintained a presence in the channel, first as they worked against Battery Wagner then later for operations against Fort Sumter.
  • Swash Channel – Somewhat a secondary route directly over the bar.  Federals often posted tugs or light draft gunboats in the Swash Channel overnight on blockade duty.
  • North Channel – Also a secondary route.  Used often by the blockade runners in the first half of the war (as evidenced by the wreck of the Georgiana.
  • Beach Channel, better known as Maffitt’s Channel – Running along Sullivan’s Island, this became the preferred channel for blockade runners.

Now let’s consider how the entrance to Charleston looks… from under the water… today:

CharlestonApproachesModern1a

I’ve called out some key points in red on this navigational chart.  Note the locations of Forts Sumter and Moultrie, still watching the passage of vessels at the harbor entrance.  But other than that, a lot of changes – above and below the water.

We see Morris Island Lighthouse on the lower left.  That’s not the location of the wartime light, but rather a postwar light built in 1876.  It servers to depict how much Morris Island has retreated. Keep in mind that the coastal survey teams documented rather alarming changes to Morris Island between the pre-war and 1863. So don’t get the idea that barrier island’s erosion is all a 20th century thing.  Barrier islands shift and move… that’s what they do.

Looking under the water, notice that Charleston now has just one channel.  Two jetties reach out from shore to help stabilize that channel.  For ships entering harbor, the first leg of the passage is the “Fort Sumter Range,” on which the vessel’s bearing is directly at Fort Sumter.  The Corps of Engineers maintains that channel to a depth of 49 feet mean low lower water (MLLW) but has plans to deepen that to 52 feet.  MLLW?  Yes, the “The average of the lower low water height of each tidal day observed over the National Tidal Datum Epoch.”  It’s a low tide thing.  Wonder what Dahglren would say about a 52 foot deep channel into Charleston for his ironclads?

Note the locations of the wartime channels, marked in red, on the modern chart.  Only a remnant of the Main Ship Channel remains in front of Fort Sumter.  Maffitt’s Channel is but a memory.  The modern channel splits the Swash and North Channels (and my annotation of those two channels there is somewhat a ballpark estimate… both channels wandered around a bit even during the war).  Some of these changes were prompted by all the activity off the coast in the 1860s.  Certainly the number of wrecks, to include the stone fleet, had some impact.  But the biggest issue was four years in which no channel maintenance was conducted.  After the war, Charleston needed a deeper channel.  Jetties built in the 1870s widened out the Swash Channel.  Now in the 21st century ships are getting bigger and thus the project to make it 52 feet deep, at low water.

Oh… and by the way, for that project to deepen the channel, the Corps of Engineers has conducted a “cultural resources assessment.”  On page 23 of Appendix O of the report, the Army has determined at least one anomaly within the channel deserves attention.  As a precaution, the Army will have “an archaeologist onboard the dredge when operating in the vicinity of the anomaly.”  Furthermore, “Remote sensing surveys will be conducted in all areas proposed for widening to ensure that incidental damage to any such resources will be avoided. It is anticipated that no cultural or historic resources would be affected by the project.”

Some other points of reference, since we are out looking at those waters.  Notice Rattlesnake Shoals remains a hazard to navigation out on the northeast approaches.  Walk down to the lower left of that shoal and you see a box outlined on the chart:

CharlestonApproachesModern2

The chart indicates, in Note A, that we should refer to Chapter 2, US Coastal Plot 4, specifically part 165.714.  There we find the coordinates for a trapezoid and the following warning:

In accordance with the general regulations in §165.23 of this part, all vessels and persons are prohibited from anchoring, diving, laying cable or conducting salvage operations in this zone except as authorized by the Captain of the Port.

And what prompted such regulation?  Just off from lighted buoy #16 is where the H.L. Hunley was found.

One more bit of history comes by way of the notes on this chart.  Track to  “Danger Area (see note B)” just below the Hunley‘s box.  Note B states:

Area is open to unrestricted surface navigation but all vessels are cautioned neither to anchor, dredge, trawl, lay cables, bottom, nor conduct any similar type of operation because of residual danger from mines on the bottom. Anchorage in the designated area is at your own risk.

Minefields in that area (and others marked on the chart) date to the World Wars. So more than just Civil War history to consider.

And that history has me reflecting on changes… changes to the harbor entrance that we can document.  Often our thoughts about changing battlefields remains above the surface as we look at topology.  Things like new roads and development tend to obliterate what was heavily contested ground in the 1860s (as Phil recently wrote about).  But for some battlefields, there is another dimension to consider.  The waves on the surface of the ocean off Charleston still rise and fall just in 1863…

IMG_5892

But what is beneath those waves has changed drastically.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s