ENGINES OF THE “GREAT BRITAIN.”
From the Model in the Victoria and Albert Museum.
ENGINES OF THE “HELEN McGREGOR.”
From the Model in the Victoria and Albert Museum.
It was not until 1852 that the Cunard Company were so thoroughly convinced of the capabilities of either iron ship-building or the screw propeller as to give both a trial. Four iron screw steamers were then built, and these were the first owned by this line which were fitted with accommodation for emigrants. The next year six more iron screw steamers were added, and connection formed with the chief ports of the Mediterranean; and when the Crimean War broke out a number of the Cunard ships were employed as transports. But from one reason and another the screw propeller had not found general favour among passengers. The vibration it caused, its unpleasant “racing” in bad weather, and the new motion as compared to that of the old paddle-wheel, allied to the usual obstinate temperament, showed that the earlier type had still to be retained for a while. Following on the medieval custom, the stern of these early steamships was still regarded as the place of honour, and the saloon passengers were accordingly placed abaft the machinery, which was amidships. Thus placed, the traveller was doubtfully privileged, for the close proximity of the propeller made life on shipboard exceedingly trying to the nerves, and there were many who, having voyaged in the old ocean-going sailing ships, looked back with mixed feelings to the longer but less nerve-racking journeys. The strain on the early screw engine was very considerable when the vessel was pitching fore and aft into the Atlantic seas. Being of comparatively small size, its movements in such circumstances were far more lively than in a modern, lengthy liner, which is able to stretch over a longer span. Consequently, as the bow came down into the sea and the stern rose out, the propeller was much more prone to race wildly, and the gearing, such as we saw in the engines of the Great Britain, was not infrequently unable to endure the terrible strain to which it was put. It was for this reason that the screw engines were afterwards made direct-acting.
The Cunard Company decided to build their next ship of iron, but with paddle-wheels. This was the Persia, launched in 1856, a vessel of 3,300 tons burthen, with accommodation for 250 passengers. But she was even surpassed by the Scotia, which was built in 1862, and is interesting as being the last and the finest paddle-ship which was ever made for their Atlantic service. An illustration of this vessel will be found [opposite page 130]. She was fitted with the greatest luxury of the time, to carry 275 cabin passengers, had seven water-tight compartments, and a double bottom, so that even if she should have had the bad luck to run ashore she would still most probably be able to endure. Nowadays most steamships are fitted with this excellent arrangement, which was first adopted in the Great Eastern, through the ingenuity of Brunel, to which we shall refer presently. But the Scotia turned out to be also a fast boat, and materially altered the time spent in crossing the Atlantic; she lowered the record to just two hours under the nine days. Her engines were of the familiar side-lever type, and were the finest examples of their kind that were ever made. The cylinders were 100 feet in diameter, and steam at 20 lb. pressure was supplied by eight boilers with forty furnaces, the speed attained being 13½ knots per hour; her daily coal consumption was 159 tons. She could carry 1,800 tons of coal, and was exceedingly strongly constructed. We can obtain some idea of those paddle-wheels [shown in the illustration] when we remark that they were no less than 40 feet in diameter. She was afterwards turned into a “telegraph” ship for use in cable-laying, and her paddles changed for twin screws. It was not until about 1896 that her water-tight bulkheads were put to practical use; for as the result of an explosion on board of vapour from spirit her bow was blown out of her, and the water began to rush in. Her collision bulkhead was also damaged, but happily the second bulkhead saved the ship from foundering.
THE “SCOTIA” (1862).
From a Painting. By Permission of the Cunard Steamship Co.