In the previous post, we looked at the signal network constructed to link Hilton Head to Folly Island, as detailed by Colonel Edward Serrell. Closing that post, I mentioned the arrangements to run telegraph wire across Light House Inlet, which would provide a wire link right up to Fort Putnam at the north end of Morris Island. In that regard, Serrell added the following note to his report:
The following drawings represent the booms used to obstruct the water communications between our positions on Morris and Folly Islands and the enemy. For obvious reasons, their positions are not designated at this date. Plates XVIII, XIX, and XX represent in plan, elevation, and cross-section the method of construction. I consider Plate XX the most desirable form to use. No boat or other floating body can pass over it without first submerging the logs and frieze, and, if turned upside down, the obstruction still presents itself. Great attention has been paid to this matter. Many hundred yards of booms like these have been constructed and put in place.
Here are those plates, in sequence:
Like Serrell, I find the third example (Plate XX) most desirable. Just looks like some thing you’d rather not get a boat stuck upon. In addition to boats, there was a fear the Confederates would float torpedoes or other devices down with the tides to break up this wire link. For that reason, Serrell was rather sensitive about detailing the location of the booms. Furthermore, he didn’t detail any functionality, if any, to allow Federal ships to pass through the boom and beyond to Light House Creek.
Serrell does not provide a date at which the boom was placed. There are references to wire communication between Major-General Quincy Gillmore’s headquarters on Folly Island and the breaching batteries on Morris Island during the siege of Battery Wagner. Perhaps the three variations are indications of a long trial and error period, running from summer to the late fall.
The wire run across Light House Inlet was part of a communication network that ran from the Department of the South’s rear headquarters in Hilton Head right up to the very front lines operating against Confederate defenses.
Messages could pass from Morris Island to Hilton Head in just over a half hour, given fair weather. And with some adjustments, the Federal signal officers hoped to reduce that to less than twenty minutes. I’ll look to First Lieutenant Franklin Town’s report later on this month, to highlight those improvements.
(Citations from OR, Series I, Volume 28, Part I, Serial 46, pages 257.)