R.M.S. Campania Construction and Launch - Part II
This page covers the following topics on the Construction and Launch of the Cunard Campania: The Launch, Engine and Boilers, Circulating Pumps, Propellers, Starting Gear
The "Campania" was launched on Sept. 8th, 1892. Unqualified success attended it, as a result of the most complete and thoughtful preparations made by the staff of the Fairfield Works.
While launching, the ship appeared to be, and was indeed, under perfect control up to the moment of taking the water, without any signs of "taking charge" or the ominous cracking, so frequently a source of anxiety to the uninitiated ; and yet, the declivity fixed upon was such, that immediately the last dog-shores were knocked out there was no stoppage of the vessel for the slightest period of time.
She at once started on her career, slowly at first, and majestically, but not less surely, and, gaining speed every second, was safely afloat in the Clyde, amid the plaudits of the assembled hundred thousands of interested spectators who thronged the banks on both sides. Everything worked so satisfactory that the " Campania" was moored in the Fairfield Dock, which runs at right angles with the river, within 4o minutes of the launch.
The "Campania" was most appropriately released from her position on the ways and named by Lady Burns, of Castle Wemyss. As in the case of the " Umbria" and "Etruria," the Directors have gone to ancient Italy for the name of this vessel and its sister ship. In the case of the "Campania," it is a felicitous name, promising much to the shareholders, for that ancient province on the west coast of Italy was distinctive from all other provinces for its fertility, yielding in abundance corn, wine, and oil.
The " Campania," after her launch in September, was berthed under the 130 ton sheerlegs, which were designed and constructed at Fairfield, to have her machinery placed on board, and, in pursuance of describing the work as it progressed, we shall now describe the Engines and Boilers.
Engines and Boilers
The construction of the engines was practically completed within twelve months of the order being placed -- it represented about 6o,000 indicated horse-power for both ships. The greater part was not only erected in the workshops, but was placed in the vessel within the year -- a performance which at once testifies to the splendid organisation of the staff in the Fairfield engine department.
In the arrangement of the engines there are five cylinders-2 high-pressure, 1 intermediate, and 2 low-pressure, but the great advantage of well-balanced parts of the 3-crank engine is maintained by placing the high-pressure above the low-pressure cylinders, one pair of high-pressure and low-pressure being at the forward, and the other pair at the after-end of the engine, with the intermediate cylinder in the centre. The adoption of five cylinders, too, reduces the diameter of each low-pressure cylinder to more moderate dimensions.
The diameter of the cylinders are as follows ; -- high-pressure (2), 37 ins.; intermediate (I), 79 ins. ; and low-pressure (2), 98 ins. The stroke of piston in each case is 69 inches.
The details of the engines were soon determined upon, and patterns made, for within five or six weeks from the signing of the contract, or, to be precise, on September 15th, 1891, the first casting was delivered at the Fairfield Works. It was one of the cylinder liners : these liners are all of cast iron. The last of the castings and forgings were delivered about the end of February, and the whole of the machinery finished by the end of March.
The two engines were completely erected before the end of June. The height of them from the base of the engines to the top of the cylinder is 47 feet. As will be seen, the Fairfield Company have adhered to the type of the bedplate, column and condenser, which has been adopted and proved satisfactory in so many of the notable vessels that they have constructed. The bearing surfaces are large in all cases, as will be seen from the illustration.
It is scarcely necessary to state that all the cylinders are steam-jacketed, and are fitted with automatic steam traps for the return of water to the hot-well. The condenser is rectangular in section, and fitted with 3/4 in. brass tubes, and is built up in three parts, and divided into two portions, so that each low-pressure engine has its own condenser.
The Circulating Pumps
At the back of the condenser there are two air and two circulating Pumps, each driven by a lever from each of the crossheads of the fore and aft engines. From the crossheads, also, are worked pumps for lifting the water from the condenser to the feed heater.
The circulating pumps and engines are four in number, and have been constructed in such a manner that they will be equal to the work of circulating while working on the compound principle with steam at the full pressure, exhausting into the low pressure steam chest, or condenser, at the option of the engineer, and, at the same time, with such an arrangement of the cylinders that, by a simple hand-slide valve, both cylinders may receive the high-pressure steam whilst pumping from the bilge, and therefore working to suit the maximum requirements.
By this method economy is effected while circulating, and the full power can be obtained for bilge pumping, the size and weight of the engines being at the same time considerably reduced. It is the first time that the system has been adopted for work of this kind, but it seems likely that it will be largely adopted in future.
Returning to the main engine, it may be noted first that the high-pressure pistons are fitted with Ramsbottom rings, while the intermediate and low-pressure pistons have each one ring, fitted with Downie's packing. The piston and connecting rods are made from steel ingots, that used for each of the connecting rods weighing, rough, 25 tons, this being reduced to to tons. Maclellan's composite triple expansion packing is also used, as supplied by Messrs. George Maclellan & Co., Glasgow Rubber Works, Glasgow.
The whole of the shafting was supplied by Messrs.Vickers, Sons & Co., Ltd., of Sheffield. The crank shaft is 26 in. in diameter, and each of the three interchangeable parts weighs 27 tons, so that with the thrust shaft, which is 14 feet long, the weight of each crank shaft is about 1 to tons. Each thrust bearing has 14 rings of the ordinary horse shoe type. These bearings are in the recesses at the after-end of the engine room bulkhead, but are tied direct to the foundations of the engines.
The propeller shafts are each 24 ins. in diameter, and are fitted in about 24 ft. lengths,' each length having twa bearings. The pillow blocks are of cast iron lined with white metal. With the bossing out of the stern it has been rendered possible to dispense with the usual outside shafting, and this enables the propeller shafts to be carried in the stern tube, as in the ordinary single screw steamer.
The Ship's Propellers
The stern bushes are of the usual design, brass lined with lignum vita, the shaft being sheathed at the bearing to suit. The propeller bosses are also -of Vickers' steel, and the blades are of manganese bronze, cast at Fairfield.
Each blade weighs about 8 tons, and a simple calculation brings out the interesting fact, that had pennies been used, five and a half millions would have gone into the casting of the six blades. At the after end of the propeller shaft there is fitted one of Dunlop's governors, while governors have also been fitted to the marine engines.
Another safeguard is provided in the form of an emergency gear fitted in connection with the steam and hydraulic starting and reversing gear. This emergency gear is such that the engines are stopped automatically if a predetermined rate of speed is exceeded.
The Starting Gear
The starting gear is of a well-known type introduced some 20 years ago. The engine consists of a steam cylinder in which a piston and rod by one stroke handles the links, the movement being controlled by a water cylinder with automatic valve gear. The novelty in connection with this gear is the addition of a governor, by the operation of which, when a shaft breaks, or dangerous racing takes place, the links will immediately be shifted into mid gear.
It is well known that any attempt to control the speed of triple-expansion engines, without operating on the distribution of steam in each cylinder, has, up to the present, not been satisfactory. With the ordinary governor, therefore, valves on each cylinder are necessary, and considerable complication is the result.
It has, therefore, been considered much better to have marine engines strong enough to race up to say 5o to too per cent. on their normal speed, and after that to stop them or to bring them to dead slow. The engineer's attention is at once called, and proper steps can be taken. One or two recent accidents, notably that to the " City of Paris," suggested the necessity of something being added to the reversing engine which, while simple, would be unfailing in action. Accordingly, the " Paris" was fitted with such a governor as is now adopted on the Cunarders, and, after prolonged tests, in which it frequently stopped the engines in excessively bad weather, the " New York" was also fitted, and now the engineers in charge are free to leave the reversing handle with confidence.