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10 corrections, most recently by SheffieldPark - Show corrections

ENGINEERING.

AVIATION NOTES.

By METRE.

Container Railway Car.

In order to reduce the time required for loading goods, the New York central lines have introduced what is termed a "con- tainer railway car." This is a car with low sides, and it is designed specially for carrying a number of containers constructed to fit the car floor. These containers might be described as light, steel safes, which after being loaded with freight by   the consignor would be carried to the station in a motor-lorry and there would be   lifted by cranes and deposited on the car. Ordinary cars are built to take five containers. This method, of course, making, for very rapid loading and unloading, adds largely to the capacity of the   rolling-stock equipment.

In a paper read before the American Society of Mechanical Engineers, Mr. Walter C. Sanders, an officer in the equipment   department of the New York central lines, said that the cars were introduced last year by Mr. A. H. Smith, who is the pre-     sident of this group of railways. It was hoped that mail, express, and freight rob- beries, and breakages, delays in checking and handling would be greatly reduced by this system. Loss of and damage to freight had grown so much in recent years that it was now one of the heaviest leaks in the transportation industry.

The container car, Mr. Sanders went on to say, would reduce the cost of packing and crating, for goods packed ¡n paste- board or even in ordinary paper would be protected from breakage, theft, and water or weather damage. The locked containers could remain either on station platforms or else at the stores of the shippers for   unloading or loading whenever this might be convenient, and in this way there would be no demurrage of costly rolling-stock. At present there were three container cars on the New York Central group which were used carrying mail matter and valuable freight, such as silks and woollens. Three new mail cars of improved design were being constructed, and the introduction of refrigerator and tank container cars was under consideration.

For goods that are carried on an   express car attached to passenger train, the containers are somewhat smaller to meet the requirements of the express consignment business. A 61ft. 3in. car will carry   nine express goods containers. The size is 9ft. by 6ft. by 7ft. 4in, and the door is 6ft. by 3ft. The carrying capacity is 7,000lb.  

Whether it is the railway company or the shipper that supplies the containers is not stated. Presumably it is the shipper, at any rate, it will be when the   system is introduced on a large scale, for otherwise there might be serious inconvenience, due to the demurrage of containers.  

The New York central lines have made

a most interesting experiment, and so far the experience with the container-car system goes to show that its success is     assured.

Aeroplane Catapults.

The United States naval authorities are experimenting with catapults for launching aeroplanes from warships. The catapaults   are in the form of turntables, and   the most suitable type can be installed on any ship. This, it is considered, is the best answer to bombing aeroplanes attacking naval craft, for here "dog will eat   dog." A« the turntable catapult can launch ' a plane in any direction, there ss-ould bb"no'need for the ship to locate formation when helping to repel an aero- plane attack. The propelling power for the catapult is compressed air.

The Arctic Steamer Quest.

The arctic steamer Quest, chartered by the late Sir Ernest Shackleton for his antarctic expedition, though only 111ft. in length all over, has a range of 9,000 miles with 200 tons of coal in her bunkers. She was built in Norway in 1917, and was in- tended for sealing. The hull, which is   enormously strong, is constructed of pine and white oak, with steel reinforcements of the bows. The boiler is of the "Scotch" type, and the engine is a two-cylinder com-

pound. The little ship is equipped with an aeroplane and a wireless plant.

Giant Turbo-Alternator Seta,

In an article by "Professor W» Seiche], published in a German technical journal, it is said that turbo-electric generators may be built in s¡7.ca up to 160,000 kva., and the most serious obstacle in the. way of accomplishing such constructions lies in tho diflïculty of the transportation of such huge machines by railroad, necessita- ting their assembling and, in particular, winding on the spot of installation, a pro cess not always attractive. .

The use of giant machines of 100,000 kva. at 1,000 r.p.rn*' is suggested ' in a central station with six units, one being a standby. Such a plant would have a normal load of 400,000 kiv. anil a peak load of 500,000 kw., svith a total output per year of, Buy, 2,000,000 kw. hr. Five such central stations would have been sufficient to satisfy the entire demand for electric power in Ger- many. For steam .turbines driving these generators aro suggested double units with steam admission m the middle, 10 gauge to 17 atmos. pressure at the turbine inlet and 20 atmos. pressure on the boiler, with a steam temperature of 350 degrees Centi- grade at the turbine inlet valve.

In view of the great consumption of fuel and water of condensation, it is obvious that economically such big plants should be located only near a large coal supply and also near a large river. As- suming that coal would be delivered 300 days in the year, this would mean that 7,500 tons per dav would have to bo re- ceived into the" plant and be distributed cither to the boiler rooms or to the bun-

kers.

The general conclusion to which the . author comes is that at present the limit to tlie size of electrical generators is set mainly by the demand for power.

Old Files Renewed.

It is stated in the "Scientific American" that old files may be renewed by, first clean- ing them svith a" "file card" and afterwards placing them in a mixture of'4oz.'of wash- ing soda and one quart of very hot water, in which mixture they 'are then scrubbed with n brush to remove oil, dirt, ic. The acid mixture to which the files. are then transferred, consists of 4oz. of sulphuric acid in one quart of water. It should be remembered that .when diluting sulphuric acid with water sudden heat is dix-loppd such that if the svater is poured upon the acid dangerous spattering will occur. Tho acid should always be poured rato_ the water very slowly and the solution stirred with a piece of wood or a glass rod. The old files remain covered in the solution for fromalo to 12 hours, after which tlicy are thoroughly wushed in water, dried, and

oiled.

American Air Mails

The ? following particulars concerning aerial mail btrvices in the United States have been forwarded by. the Society of the Australian Ahciaft Owners:- t .

In May, 1U1S, aerial mail services svere established in the United States of Amer- ica, After the first year's operations, the control of the services was handed over by the War department to-the Postal de- partment. At the same time, thc'cbaigc for aerial correspondence was reduced from six cents un ounce to two "cents, which is the mtc of postage on letters carried by

train.

Twelve mouths later, n icport ss-as issued which showed that a profit of 10,000 dollars had been made; that the cost per mile had dropped to 50 cents: and that the-savinp of time now effected over the fastest rail- road train between Ness' York and Chicago would enable the l'ostnl department to make a su\ ing in space equal to more than tsvice the .cost of an air mail service on

that route.

As aerial mail services are now*about to sturt operations between Adelaide and Sydney and Brishane, it is interesting to note that the U..;ted States report re- ferred to contains the following state-

ment:

"The success of the aeroplane in carry- ing the mail, toitcthur ssith the great de- velopment that Ima taken- piacu lu speed, and quantity of mail that can be carried, ninl.es it ininrolialilu that air'transporta- tion, whether hy Government or commer- cial liuih, will ever be stopped; but will ¡nereus».' from year to year, ,by leaps and bounds, especially over long distances."

There is now a complete service opera- ting daily across the whole width of the American continent, reducing the travel-   ling-time between New-York and San Francisco by 24 hours. It is claimed that the Transcontinental Air Mail is un- equalled by any other aerial undertaking elsewhere. During the year ending 30th June last, more than 23,000,000 letters were carried over a total distance of 540,244 miles, at less than it would have cost to transport and deliver them by rail. No additional postage is charged.

Answers to Correspondents.  

T. McC. (Colac).-- It would he better for you to write for the particulars. As far as suggesting practical new uses for rubber is concerned, you would have a formidable table for many hundred

suggestions are sent in.

"NaiW (Willi-uurtown).-1. With a very anal! hiirli-preMure cylinder, recels in^ steam for nearly full stroke, .»uti would, uf course, reduce tile ranire of temperature lu tliat cylinder, ami the lot-bcs.due to raupe. But there lost»* would still occur in the losv-prudsure cylinder Another objec- tion ia tli-.il: the eii/lnc would not be efl-y to bal ance. '2. The latent Ia. and 0.- ateaiuera have quad-

ruple expansion engines.

"Novice" (Yarraville).-- In starting from cold ti i* i '.-luiuit pipe and laporíacr are cold, and van. not be rs-1 to hrat the mixture. You could ttart by *ii;)pl,\ :nir p- tro] to the float chamber, cr effie by heating the chamber with a primus.

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