David Napier by David Napier and David Bell: Note 12
12. The 'BRITANNIA' AND 'HIBERNIA'
A contemporary notice of these vessels, corrected as to their length, is to the following effect: The success of steamboats on the Clyde induced some gentlemen in Dublin to order two vessels to ply as packets in the Channel between Dublin and Holyhead, with a view to their carrying the mails. Their dimensions were about 80 feet by 18 feet, being similar in tonnage, scantling and rig to the Government cutters which then performed that service, but were liable at times to be wind-bound for days together. The hulls were built by James Munn, Greenock; and the engines, of twenty horse-power, were supplied by James Cook, Glasgow. It was further announced that "Mr. Cook, whose eminent abilities as an engineer have enabled him to make numerous improvements on machinery, has been very successful in constructing the paddles of these packets, so that one man can easily raise them from five to six feet out of water, while the engine is at work, in the event of a heavy gale making that measure necessary. This arrangement is also of great advantage in a side-wind, as the leeward paddle can be taken up and the windward one lowered, so as always to have an equal hold on the water." These boats having been expressly designed for cross-channel service, where strong beam winds had to be reckoned with, an apparatus such as that described would naturally, in the absence of experience, promise to be of much use. The same idea had suggested itself to Fourness and Ashworth of Hull, and was embodied in their patent of 1788, but it is not known whether they actually tested it on their steamboats. The failure of the arrangement in the later boats implies no discredit to its inventor, being only a disappointment such as frequently occurs in connection with pioneer experiments, and it may have been the presence of this wheel-gear that led to Cook's engines proving so unsatisfactory, so that after a brief period of service the vessels had to be withdrawn.
In respect to speed however the Britannia and Hibernia gave fairly satisfactory results. They left the Clyde in September 1816, and in October the former vessel made the voyage from Howth to Holyhead, a distance of sixty miles, in seven hours; and the return voyage in seven and a quarter hours; these being reckoned admirable performances. Napier's Talbot and Ivanhoe, for the same service, followed three years later.