CHAPTER IV.
A MARVEL OF MECHANISM.
“Thetime is coming when it will be cheaper for a working man to travel on a railway than to walk on foot.”
So prophesied George Stephenson some few years before his successful competition at Rainhill; and by his success on that fateful day, he had brought the time appreciably nearer. The directors of the Liverpooland Manchester Railway no longer debated as to what form of traction they should adopt.
But Stephenson did not rest on his laurels. Every new engine showed some improvement. The “Arrow” sped over Chat Moss at about 27 miles an hour, on the occasion of the first complete journey along the line, on the 14th of June, 1830; and when, on the public opening of the railway on the 15th of September, 1830, Mr. William Huskisson, M.P., was unhappily knocked down by the “Rocket,” George Stephenson himself took the maimed body in the “Northumbrian,” fifteen miles in twenty-five minutes—that is, he drove the engine at the speed of thirty-six miles an hour.
The sad death of Mr. Huskisson has often been referred to, but we may tell the story again, following the account given by Mr. Smiles, who had the advantage of the assistance of Robert Stephenson in the preparation of his biography.
The engines it appears halted at Parkside, some seventeen miles from Liverpool, to obtain water. The “Northumbrian,” with a carriage containing the Duke of Wellington and some friends, stood on one line, so that all the trains might pass him in review on the other. Mr. Huskisson had descended from the carriage and was standing on the rail on which the “Rocket” was rapidly approaching. There had been some coolness between the Duke and Mr. Huskisson, but at this time the Duke extended his hand and Mr. Huskisson hurried to grasp it, when the bystanders cried “Get in! get in.”
Mr. Huskisson became flurried and endeavoured to go round the carriage door which was open and hung over the rail; but while doing this, the “Rocket” struck him and he fell, his leg being doubled over the rail and immediately crushed. Unfortunately he died that evening at Eccles Parsonage.
This sad event cast a gloom over the otherwise rejoicing day; but the wonderful speed at which the wounded man was conveyed, proved a marvellous object lesson as to what the locomotive could accomplish.
In the “Planet,” put upon the line shortly after the opening, the cylinders were placed horizontally and within the fire box. The engine drew eighty tons from Liverpool to Manchester against a strong wind in two and a-half hours, while on another occasion with a company of voters, it sped from Manchester to Liverpool, thirty-one miles, in an hour. But next year the “Samson,” which was still further improved, and the wheels of which were coupled so as to secure greater grip on the rails, hauled 150 tons at twenty miles an hour with a smaller consumption of fuel.
The locomotive had now become one of the wonders of the world. Since then its speed has been doubled. But all the improvements (with possibly one exception—that of the compound cylinder which is at present only partially in use) have been more in details than in principles. Thus the 70 or 80 ton express engine, which covers mile after mile at the rate of a mile a minute without a wheeze or a groan, is not very different essentially from George Stephenson’s locomotives, though its steam pressure is very much higher.
There are, for instance, the multitubular boiler, the furnace surrounded by water and communicating with the boiler, the horizontal cylinders acting directly on the driving wheels, and the steam-blast by which the waste steam is spouted up the chimney, creating a draught in the furnace.
These may be regarded as the more important of the essential principles, although there is diversity of details, more especially for the different work required. But the steam pressure is now much greater. Let us glance at a typical English locomotive. You might not think it, but the machine has about five thousand different parts, all put together as Robert Stephenson said “as carefully as a watch.”
At first sight you will probably not see the cylinders. The tendency in many engines now seems to be to place them inside the wheels, for it is urged that the placingof the heavier parts of the mechanism near to the centre lessens oscillation, and protects the machinery more effectually. Against this, it is said that the placing of the cylinders in that position increases the cost and the complication of the driving axle, and renders the pistons and valves more inaccessible for the purposes of repair. Both forms have their advocates, and the outside-cylinder form may be seen on the London and South-Western and some other railways, while the inside may be seen on the North-Western and others.
The boiler is of course the long, round body of the locomotive, and in English machines it is placed on a strong plate frame. Then as to the driving-wheels. Express engines, such as the splendid “eight-feet singles” of the Great Northern, have often, as the name implies, but one large driving-wheel on either side, and for great speeds this form is held to possess certain advantages. Certainly the performances of Mr. Patrick Stirling’s expresses would indicate that this is the case.
With steam raising the safety valve at a pressure of 140 lbs. to the square inch, the engines will whisk a score of carriages out of King’s Cross up the northern height of London at forty miles an hour, and then without a stop rush on to Grantham at near sixty. Standing on the platform at King’s Cross, with a large part of the immense driving-wheel hidden below you as it rests on the rail, you do not realise its tremendous size. Yet, let the engine-driver open the throttle, as it is called—that is, turn on the steam to the cylinders—and that huge wheel will revolve, and with its neighbour on the other side, haul after them that heavy train of carriages, and, gathering speed as they go, they will soon be rushing up the incline at forty miles an hour, and then on at sixty. It is a marvel of mechanism!
But then the compound engines that Mr. F. W. Webb, the engineer of the North-Western, builds for that Company can also perform remarkable things.The compound is the great modern improvement (some engineers might doubt whether improvement be the correct word) in the locomotive, effecting, it is said, an economy of from ten to fifteen per cent. in fuel. Now the compounding principle has been developed to such an extent in marine steam engines that it revolutionised steam navigation. But the application of the principle has not been so great in the case of the locomotive.
Briefly, the principle is this—the steam is sent out from the boiler at a high pressure, say 160 to 180 lbs. to the square inch, and is used in one or in a pair of high-pressure cylinders, and then used again, by means of its expanding power, in a larger, low-pressure cylinder. Mr. John Nicholson, of the Great Eastern Railway, suggested a compound locomotive before even the compound marine engine had been made, and his design was successful; but in 1881 Mr. Webb, of the North-Western, patented a compound locomotive, with two small high-pressure, and one large low-pressure cylinders, the latter twenty-six inches in diameter. Placed between the front wheels, the bright boss of this cylinder may be seen in shining steel as it flies over the rails.
The argument is that the compound burns less fuel and is more powerful than a non-compound of the same weight; but against this is launched the objection that the compound is more expensive to build, to repair, and to maintain. Still further it is argued, that a fast-speeding locomotive has not the time in its hurrying life to expand its steam in the tick of time between each stroke of the piston.
THE COMPOUND LOCOMOTIVE “GREATER BRITAIN.”By kind permission of Mr. F. W. Webb, L. & N. W. Railway.
THE COMPOUND LOCOMOTIVE “GREATER BRITAIN.”
By kind permission of Mr. F. W. Webb, L. & N. W. Railway.
Mr. Worsdell’s compounds on the North-EasternRailway have but two cylinders, one high and the other low-pressure. The one is eighteen and the other twenty-six inches across. Instead of the steam alternating between the two cylinders, it all passes first to the high-pressure and then, through a pipe in the smoke-box, to the larger low-pressure cylinder. Theselocomotives, it is said, are not under the objection alleged against the other compounds—viz., that they have more parts, and are more costly to build and maintain. Yet it is claimed for them that they are more economical and more powerful than non-compounds.
When doctors disagree who shall decide? The cost or speed might decide; but at present it seems doubtful on which side the balance does really fall. Engines of the three types have done splendid work. A Worsdell compound, built by Mr. Worsdell, of the North-Eastern Railway, is reported to have rushed down the incline to Berwick one day at seventy-six miles an hour for some miles at a time. Then the “Greater Britain,” a massive North-Western compound engine, turned out at the Crewe works in 1891, and weighing seventy-five tons, can whirl along with ease a heavy twenty-five coach express at an average of over fifty miles an hour, with a comparatively small consumption of fuel.
This locomotive was described in theEngineernewspaper as the most remarkable that had been built in England for several years. Its axle bearings are of great length, and its parts are very substantial, so that it ought to keep out of the repairing shops for long spells of time. It was specially planned for both fast and heavy passenger traffic to Scotland, and its work on its trial trip was so good that it was confidently expected it would answer expectations. In working, the engine has been found to develop great speed and power, easily running at over fifty miles an hour with what is called a double train—viz., twenty-five coaches, behind it. Indeed, it has run at fifty-five miles with this heavy train. Its stated speed ranges from thirty to fifty-five miles an hour, with a low consumption of fuel.
This last is a matter of very great importance to engineers and railway directors; and when we state that, according to Mr. Bowen Cooke, the North-Westernengines altogether burn 3095 tons of coal per day, any small saving per hour would be eagerly welcomed.
Now, it is claimed that the compounds have consumed about six pounds of coal per mile less than others on the same work, and that they also haul along loads which would require two of the other type. If so, the saving in the North-Western coal-bill must be enormous.
BACK AND FRONT VIEW OF THE LOCOMOTIVE “GREATER BRITAIN.”
BACK AND FRONT VIEW OF THE LOCOMOTIVE “GREATER BRITAIN.”
A great feature in this engine is a combustion chamber placed within the barrel of the boiler. This chamber catches all the gases from the furnace, and causes the heat generated by them to be used to the utmost for the production of steam. Though heavier than any engine previously built, yet it is so made that no greater weight than usual rests upon any of thewheels, thus throwing no extra strain on the railway or the bridges. The two couples of driving-wheels are placed before the furnace, and an additional couple of small wheels behind the furnace, and beneath the foot-plate where the driver and fireman stand. The weight therefore is evenly distributed, with another pair of wheels to bear the burden. The front wheels are fitted with the radial axle-box patented by Mr. Webb, so that, although the engine is of great length, yet it can speed round curves with perfect safety.
Yet this engine, though one of the most remarkable developments of the locomotive, is in essence and in principle but very like the “Rocket.” The difference lies in its innumerable details, exhibiting so much engineering skill and ingenuity, in the compound cylinders, in higher pressure steam, and in its marvellous power and speed combined.
On the other hand, the Great Northern runs daily from Grantham to London at fifty-three and fifty-four miles an hour average; while it was reported in theEngineerof the 10th of March, 1888, that a Great Northern train from Manchester to London, when running from Grantham to London, covered one mile in forty-six seconds, that is, at the rate of seventy-eight and a-quarter miles an hour, and two miles following each other were run in forty-seven seconds each, that is, seventy-six miles an hour. We doubt, indeed, if any railway in the world can show regular faster daily running than some of the Great Northern expresses between London and Grantham. The average speed of their Manchester train over this ground is slightly over fifty-four miles an hour. Then there are the Great Western expresses, the “Dutchman” and the “Zulu,” at only slightly less speeds, to say nothing of the fine performances of the Midland. We may take it, therefore, that the compound locomotives, excellent as their work has been, have not really beaten their rivals in point of speed.
Compounds are used largely on the North-Western,the Great Eastern, and the North-Eastern, and should they prove to be really more economical in working, while maintaining at least equal power and speed with their rivals, we have no doubt but that they will prevail.