extent of the sorting floors. Trays can be automatically passed from the inner belt to the outer belt. There are escalator belts moving up and down, and trays when destined for another floor automatically pass from the outer belt to the escalator belt. These transfers are necessary, because the duty of a tray is to carry goods from one part of a Clearing House to another by the shortest route. These steel trays, which are mounted on castors, are constantly circulating, by means of the sprocket chains in the alleys, and by means of the truckers, all over the floors of the Clearing House, and are always under automatic control. Therefore a tray, when it moves on the inner belt, the outer belt, or the escalator belt, is always carried on a trucker which seizes it magnetically and holds it in a mechanical grip. When it is travelling along the alley from receiving point to despatch point it is driven by a sprocket chain. Despatch points and receiving points are always marked on the diagram "D" and "R" respectively. They are the ports at each end of the alleys. A tray having been despatched from any point D to a predetermined point R, say, on another floor of the Clearing House, would travel thus: It would travel on the inner belt until it reached the point of contact on the outer belt, where it would automatically pass on to the outer belt. This transference involves a question of differential speed as between trucker and trucker, which it is not necessary to go into ; but the exchange is made without the least jerk. A glass filled with water does not spill a drop of its contents on being so transferred. Having been transferred to the outer belt, the tray will then travel on the outer belt till it reaches the escalator belt, on to which it will be automatically transferred in the same way. It will then be carried up or down as required. It will, on reaching the required floor, be again transferred automatically on to the outer belt of that floor, and travel on it until it reaches the inner belt serving the bay for which the goods are intended. It will then travel along the inner belt until it reaches the desired receiving point. It will then be transferred automatically on to the receiving platform. The receiving platform automatically clears itself, and the tray then travels along the alley, and during this progress in the alley it is cleared and reloaded. During this journey along the alley the workman is able to stop and restart the whole alley-way of trays, or he can stop an individual tray by pulling it out of the rank, and he can put it where he likes, and replace it at will. This tray, having arrived at the despatch point at the outer end of the alley charged with its new load, begins another journey, which may be in a totally different direction from the journey already described. All this time containers are being loaded and lowered on to the waiting trains or motor lorries beneath, according as they are to be despatched by road or rail. The question will be asked: "How come the lorries to be underneath?" The position of the train has been explained. Inside the Clearing House, on the street level, running at right angles to the railway tracks on the level beneath, are twelve broad bridges, each as wide as London Bridge, and between each pair of these bridges is a gap forty-eight feet wide, exposing the rail below. The bridges are supported by girders resting on the main stanchions of the building, and on supplementary stanchions. The motor lorries will stand on these bridges. On these bridges it will be possible to unload and reload 600 motor lorries in ten minutes, always remembering that the containers are removed from the motor lorries by the overhead travelling cranes. The detachable container is thus at all points essential to the scheme. In considering the efficiency of a motor lorry, this is all-important, as by quick unloading and reloading at the Clearing House, practically the whole day can be devoted to useful work on the road. Again, how effective the motor lorry becomes as an adjunct to the locomotive is shown by the accompanying estimate, which should be compared with the estimates on page 75 dealing with this particular journey. HOW A LOAD OF 4 TONS OF GOODS WOULD TRAVEL FROM LONDON (EDMONTON) TO NOTTINGHAM VIA THE CLEARING HOUSE, AND THE COST OF TRANSPORT OF SAME.1 I. 2. 3. From Edmonton to the Clearing House by motor From Nottingham Station to Nottingham by road = 2s. 6d. per ton of goods = Clearing House toll covering transhipment charges at Hire of Container at 4d. per hour for 12 hours 61 8 6 51 O Margin on which to compete with motor lorry 13 O Time occupied on rail, 7 hours, and on road, 3 hours = 10 hours. Speed, 12 miles per hour. There remains to describe the crypt, or lowest level of the Clearing House. It lies thirty feet beneath the rail level. The rail levels are divided into three groups of tracks, the east, the middle, and the west group. The 1 Mr. A. W. Gattie to the Great Central Railway Debating Society. Oct. 26, 1912. eastern group consists of six tracks and seven platforms. On either side of the outside platforms of this group there is a gap revealing the crypt below. Beyond this gap there is a group of twelve tracks, which is the middle group, and then another gap; and the western group consists of six tracks and again a gap beyond. The gaps are fifty feet wide. It will be clearly understood that the gaps in the railway level run parallel with the railway tracks the entire length of the building, and give access to the crypt below. Goods intended for the crypt are lowered by the cranes from any of the levels above into it. Only full loads, or nominally full loads, are lowered into the crypt. With similar (but larger) machinery to that used on the other sorting floors, these loads are manoeuvred into the positions from which they can be most conveniently hoisted on to the trains for which they are intended. There is one detail yet to be given, which will, for ordinary purposes, complete this description. This consists of the shuttle car. These cars are kept at either end of the Clearing House on the railway level on spare rails. They are four in number, each being an ordinary flat railway car, equipped with suitable motors and brakes. They are to be used singly or in pairs, to carry any very lengthy articles, such as girders or scaffoldpoles, or the like, from the north to the south of the Clearing House. They will ply on any disengaged railway track, of which there will be a more than ample margin available. Their function will be to receive an article from one of the southern sets of cranes and carry it into position under one of the northern sets of cranes. Another useful function these shuttles would perform would be to carry a load from one position on a particular train to another position on the same train, or on some other train. This work could be done by cranes, but in this particular instance it would not be economical to use a crane. Provision has now been made for sorting every kind of goods which could possibly be offered to the Clearing House. It has again and again been stated, by ill-informed persons, that the Clearing House will not, and cannot, deal with the heavier classes of goods. This is totally untrue, and nothing has ever been put forward which could give colour to this. The Clearing House will be able to deal with any traffic of any kind, on the proviso that the traffic is delivered in accordance with Clearing House conditions. These conditions have been devised to assist the trader, and not to inconvenience him. It would be possible to write volumes about the mechanical details of the Clearing House, but what has been shown is this: 1. That goods yards can be dispensed with. 2. That the number of trains can be enormously reduced. 3. That, by a mechanical process, goods can be transferred from one train to the other in one per cent. of the time now occupied, and without injury to men, rolling-stock, or goods. It is not the purpose of this book to write a treatise on residual magnetism, uniform acceleration or deceleration, electric lag, volts, amperes, watts, or coulombs, all of which are involved. Such details are obviously only for the expert, who should be, and is, our servant and ally in these matters. It will be sufficient to say that no competent engineer has ever disputed the sound practical engineering principles on which the whole of this machinery is based. It will be of extreme interest to the general publi |