Blockade Running Ships
It became apparent that the design of the local Clyde river steamers, with their shallow draughts and small size, made them well suited to the shallow approaches of many southern American ports and their speed meant that they had a reasonable chance of running the blockade. Although they were clearly not designed for the Atlantic crossing, the scale of the potential profits to be made from running even small cargoes meant that there were plenty of speculators willing to try to get them across when demand outstripped the supply of larger ocean-going vessels.
The blockade runners had to be fast and reliable in any weather situation in order to be successful. Sailing ships were therefore ruled out as they were dependent on the wind and fast steam ships were used for this risky task. Having made a three-day crossing from the neutral ports of Nassau or Bermuda, and having been blacked-out and painted off-white or battleship grey, they attempted to use their superior speed to charge through the lines of blockading Union gunboats and gain the protection of Confederate shore batteries. At the time of the American Civil War, many of the more suitable ocean-going vessels had already been acquired or were unavailable.
Several local contemporary newspapers described the Iona II as being a gun-runner or a vessel carrying gun powder.
“If report speak true, she was intended for a blockade runner, for which her long, low built and rare sailing qualities admirably fitted her. By all accounts she was one of those slippery craft numerous enough at the present time along the American coast, in every way calculated to show her tail to the squadron blockading the Confederate ports.” North Devon Journal 4 February 1864.
Ferry to Blockade Runner
To prepare it for the Atlantic crossing the Iona II’s luxurious fittings were removed and the hull structure was reinforced. The Board of Trade inquiry reported on the £3,282 (about £270.000 today) worth of alterations that were made in November 1863 in the yards of J. & G. Thomson Ltd.
• saloon decks were replaced with temporary deckhouses
• side lights plated over
• additional deck stringer plate added
• bulwark was raised from 3'6” to 4’3”
• stanchions were strengthened and increased in number
• addition of two schooner rigged masts with all the associated fittings
These alterations to strengthen the long, thin hull of the river steamer were considered sufficient by a ship surveyor to cope with the increased wave heights and rough weather conditions of the open ocean. Schooner masts were added because, despite being filled with coal, steam engines at this time were relatively inefficient and most steamships would have required the assistance of sail to actually make it across to America.