NE of the most important and difficult problems confronting naval engineers and Admiralty Departments today, is the storage of fuel and the expeditious coaling of warships. The increased dimensions of war vessels and attendant coal capacity, combined with the growth of navies, renders the storage of large quantities of coal imperative, and the rapid charging of the vessels' bunkers desirable to maintain efficiency. Storage on quays presents many disadvantages, for not only is much valuable space occupied that could be turned to much more profitable account, but the task of discharging the fuel therefrom to vessels is attended with many difficulties, since the facilities of handling are necessarily somewhat limited.

In order to overcome, if possible, these disadvantages, the British Admiralty re

cently decided to test a new type of floating coaling depot equipped with the latest facilities for transshipping coal to war vessels. For this purpose a contract was placed with the Temperley Transporter Company of Bishopsgate street, London, for one of their patent depots with a capacity of 12,000 tons.

The Naval Department were stimulated in their action by the frequent difficulty experienced in getting the hard Welsh steam coal aboard by means of hoppers, owing to the large pieces bridging over the openings and thereby stopping the run or flow of the coal. With the new equipment, this difficulty has been completely overcome.

It is possible to moor the depot at any convenient spot in the harbor, thus leaving the quays unoccupied for other more valuable work. Greater storage capacity within a defined space is secured, while there is no breakage in loading the coal. Furthermore, owing to the fuel being

stored under cover, its calorific value is not deteriorated by atmospheric conditions, as is the case in storage upon dry land, while the coal is more easily accessible and is used up in rotation, so that there is no possibility of encountering areas of stale fuel. With this depot, more rapid filling of the bags or skips is assured, since shoveling operations are entirely dispensed with, and it is possible to maintain a stock of 10,000 bags filled with coal ready for emergency coaling. A higher rate of delivery has also been obtained, ranging from 600 to 700 tons per hour, while two or more vessels can be coaled simultaneously-a most important consideration in naval operations.

The hull of the depot, some 400 feet in length, follows the design of a large, flat-bottomed, straight-sided vessel with a bluff bow and stern, and is of strong and simple construction throughout. Practically the whole of the craft is devoted to coaling purposes, there being only a small space in the bow for the accommodation of the crew and stores, while the engines and boilers are placed in the extreme stern. The depot is subdivided by six transverse water-tight bulkheads, into seven compartments. The five central compartments contain the coal hoppers, of which there are ten in number, divided into two sections of five on either side by two longitudinal bulkheads which extend centrally throughout the entire length of the vessel. The space between these longitudinal bulkheads affords a clear gangway from one end of the vessel to the other, and gives access through openings to the space beneath the hoppers. It also supplies a clear space through which the bags of coal are hoisted up by the transporters placed centrally above them on the deck, at any desired points throughout the length of the depot.

There is a space between the floor of the depot and the bottom of the hoppers. In the latter are provided a number of trap-doors with movable chutes of special design, to enable the men to tap the coal from below, and for regulating the speed of the coal-flow into the bags.

The dangers arising from the presence of coal dust and foul gases which might possibly gather in the bottom of the vessel, are entirely removed by an

moved is not wasted by discharging into the atmosphere, but is ultimately delivered back into receivers in the hoppers for subsequent collection in bags or any other purpose that may be desired. The suction of these exhaust tubes induces a downward current of fresh air, so that there is always a sweet atmosphere in the lowest parts of the depot. On the deck there are three rows of very long hatchways provided throughout the entire length of the holds, the middle row being over the central passage for the discharge of the coal in bags, and the side rows over the hoppers on either side for delivering coal into the depot.

A railroad track extends longitudinally over the middle gangway, upon which travel four towers carrying the "transporters" for loading the depot and dis

charging the coal into the warships moored alongside.

All the operations of the transporters -such as traversing the railroad track on the deck of the depot, raising or lowering the overhanging arms of the beams, raising or lowering the derricks with their portable transporters, hoisting and transporting coal, etc.-are carried out by means of electrically-driven winches which are carried on raised platforms above the horizontal transporter, so that the engineer in charge has a clear and commanding view of the whole operation.

In slack times the men engaged on the depot can be occupied in filling the reserve supply of 10,000 bags with coal, which is stored in the space underneath the hoppers. It is possible to accommodate 1,000 tons of coal in this manner; and when a vessel comes alongside for quick coaling, this reserve can be employed to distinct advantage, as it is simply a question of hoisting the charged bags as fast as possible, and coaling can thus be considerably accelerated-to about 100 tons per hour above the normal. The value of this available storage capacity can thus be realized, and consti

A

N interesting transporter bridge or aërial ferry has recently been constructed at Newport in England, connecting the old town on the western bank of the River Usk with the new town on the eastern bank. This bridge is electrically operated, and, as shown in the accompanying illustrations, is similar in construction to the electric aërial ferries at Duluth, Minnesota, and at Rouen and Marseilles, France. It cost about onethird of a million dollars. Of this amount the foundation piers and anchorages cost over $100,000; the steel superstructure and traveling apparatus, about $150,000; and the electrical equipment, motor house, and shore abutments, as well as the Eastern pier and lattice girder span, about $30,000.

About a century ago, these two old English towns were connected by a fivearch stone bridge. This was finally widened, and cantilever footpaths constructed on both sides, in 1866. About

1890, other improvements were made, and a subway scheme was also considered. A transporter bridge was recently constructed at Bilbao, Spain, and its great success caused it to be considered the best solution of the difficulty. After inspecting also the Rouen transporter, this type of electrically-driven aërial ferry received parliamentary sanction in the year 1900; and, two years later, tenders were obtained for the work.

The Newport bridge consists of a horizontal railway track supported by a bridge spanning the river at such a height as to allow the tallest ships using the channel, to pass underneath without striking their upper masts. The span is 645 feet from center to center of the towers, and 592 feet between the faces of the piers. The clear height to the underside of the stiffening girder from high-water mark, is 177 feet at ordinary spring tide; and the height of the tower from the pier cap or level of the approach road, to the saddle, is 241% feet. It may be stated that the distance be

tween the centers of anchorages is 1,545 feet, and the distance from the center of the tower to the center of the anchorage 450 feet.

An electrically-operated car or traveling frame runs on the bridge, and is so arranged that it can move freely in a longitudinal direction, its motion being arrested or reversed at will. This traveling frame and service platform weighs 16.3 tons, while the suspension cables

SUSPENDED CAR CROSSING THE RIVER.

weigh 2.9 tons, and the car 31.5 tons, making a total weight of 50.7 tons. The structure was designed for a load of 65 tons in addition to its own weight, and this platform or carrier is suspended from the traveling frame, being hung at the level of the bank of the river to be crossed.

The car is lighted by electricity, and is propelled by means of steel wire ropes wound on a drum worked by two electric

motors. These motors are installed in a steel-frame building placed over the approach road at the eastern end of the bridge. Each has a capacity of 35 brake horse-power, series controllers being utilized, worked from the pilot-house, for the necessary electrical control. Insulated conductors connecting this apparatus are installed from the pilot-house to the traveling frame, where they are connected up to underrunning trolleys. A third controller is provided, from which the bridge can be worked in case there is an accident to the overhead electrical equipment. The controllers are in duplicate in the pilot-house; and an automatic circuit-breaker and various other electrical instruments are also provided.

The maximum rate of travel of the service platform is ten feet per second; and an elastic or movable buffer is provided at each river-wharf space of the fixed structure, in order to absorb the momentum of the car and prevent shock. There is a lattice girder span, as shown in the accompanying illustration, supported on a separate pier, connecting the car with the shore abutment at the eastern end of the bridge. The steel wire cables have a minimum tensile strength of 63.5 tons.

This bridge has an easy stairway extending from the ground to the platform level on each tower; and the stability of the tower against overturning is at a minimum when it is standing as an isolated structure. It is stated that wind pressure of 56 pounds to the foot on the side facing the wind was allowed for in the calculations, and one-half this amount on each of the leeward faces.

The electrical operation of the ferry is said to be entirely satisfactory, thousands of passengers being carried daily, with large quantities of freight and many

teams.