The Wonders of Refrigerated Railway Transport
THE COLD STORAGE WAREHOUSE AT VERONA was built in 1931, and is among the largest of its kind in Europe. The circular hall in the middle of the large three-
THE use of snow and ice for cooling and preserving foodstuffs has long been known, though the manufacture of artificial ice is only a hundred years old. In hot countries, snow falling during the winter on the mountains was formerly collected in large pits dug into the ground, covered with layers of leaves and brushwork, and finally with earth. In this primitive though efficient way the snow was preserved and made to last through the warm season. Even to-
The oldest documentary evidence of the use of ice is contained in an ancient collection of Chinese lyrics, the Shih-
The manufacture of artificial ice is a comparatively modern invention, for which credit is due to British scientists. In a paper read at the Royal Society in 1662 Robert Boyle showed the way to artificial refrigeration and indicated various cooling mixtures for freezing water. The investigations of the great Faraday carried the matter further, but it was not till 1834 that Perkins patented the first refrigerating machine. This was based upon the use of ether. Since then the refrigerating industry has made enormous strides, particularly during the last forty years. It is no exaggeration to say that few other inventions have influenced the economic and hygienic conditions of the world to a similar extent.
When we buy in England fruit and vegetables out of season, or other perishable goods from the Dominions, such as New Zealand lamb or butter, South African eggs, and Canadian cheese, we probably never give a thought to the difficulties that had to be overcome in transporting such goods across the seas, or even across the comparatively short distances of the European continent. Few of us realize what profound studies and exhaustive investigations were necessary before fresh fruit, whether hard-
Italy has for centuries supplied many European countries with fresh fruit and vegetables. But what was once the privilege of the wealthy, who alone could afford peaches, grapes, or even oranges, has become in these days accessible to a much wider public. This is due to the progress of the refrigerating industry, which maintains the goods in a perfect condition over long periods and obviates expensive transport by special fast trains. It is not, therefore, surprising that a country that derives much of its wealth from the products of the land should have devoted particular attention to the important question of refrigerated transport of fruit and vegetables.
The main railway system of Italy is State-
This Italian structure for research is considered to be one of the most remarkable of its kind at present in existence.
The new building has a length of 84 ft, a width of 36 ft, and an internal height of 18 ft 9-
The walls are 8-
The purpose of the isothermic cells is to investigate the insulating properties of refrigerated and isothermic trucks and containers, and at the same time the conditions of the loaded goods in different atmospheric conditions. It is, therefore, necessary to reproduce these atmospheric conditions artificially by heating or cooling the cells to the desired temperature. Temperatures vary in Italy to a degree unknown in England. While, for instance, the temperature on a day in December may be 62° F in Sicily, it may be only 28° in Milan, or even 15° in Bolzano. Temperatures of 96° F in the summer are normal in Sicily, and are sometimes even encountered in the Lombardy plains. It follows that a truck travelling from the south to the north of Italy is exposed to sudden variations of temperatures or to an intensive heat during the whole voyage. We can well imagine the state in which fruit or vegetables would arrive at their destinations if the refrigerated or insulated trucks (without ice boxes) were not impervious to external heat.
The artificial temperature within the cells is produced by forced air circulation effected by two electric helicoidal fans. These take the air through ducts which are placed lengthwise below the ceiling. The air passes over electric heating resistances placed within the ducts in front of the fans. It comes out on the other side of the fans into another series of ducts situated below the former set. Subsidiary electrical heaters near the floor accelerate the heating, fans being placed near them to distribute the hot air in an even manner. When low temperatures are required within the cells, the air is made to pass over ammonia-
The automatic regulation of the temperature is effected by thermostats placed within the cells. By means of relays and contactors the thermostats cause the starting or stopping of the motors which drive the compressors and the fans. The insertion or disconnexion of the electric resistances, and the opening or closing of the circuit of the condenser water, take place at the same time.
AN INDICATOR in the machine room of the Verona cold storage warehouse. The illuminated lines and dots indicate that those cells and galleries are occupied, and also that the ventilators are in action.
The control and measurement devices are installed outside the cells in a separate chamber. They consist of indicators and controllers of temperature agreeing with the thermostats within the cells. There is also the central apparatus which indicates the temperature and humidity corresponding to that of the thermometers and hygrometers in the cells. A multiple registration apparatus gives sixty simultaneous readings derived from sixty thermo-
Certain fruits and vegetables do not require transport by refrigerated trucks. It is necessary only to load them in isothermic trucks suitably insulated against excessive heat. The insulating properties of these trucks are severely tested in the cells.
The State Railways have built many thousands of special trucks of both kinds, all of which comply with the British require-
THE APPROACH to the warehouse at Verona. A railway line connects the main hall of the building with the shunting lines which lead to a nearby goods station through a large entrance gallery. The warehouse has a total of eight galleries.
The specially built refrigerated trucks have a cross-
THE CENTRAL HALL of the Verona Cold Storage Warehouse. The floor of the hall is occupied by a turn-
The transport of fruit and vegetables by refrigerated trucks necessitates various preliminary operations which cannot be carried out by the small farmer. As Italy is pre-
Prominent among these cold storage warehouses is that of Verona, built in 1931, on an original plan. It was, and probably still is, the largest of its kind in Europe. Verona, situated in the centre of the Lombardy plains, is one of the most important railway junctions in Italy. It lies at the intersection of the trunk lines from Bologna to Brenner (for Austria) and from Milan to Venice. It is famous for its peaches and other fruit. In spring the blossoming orchards are an unforgettable sight, not less beautiful than they appeared to Romeo under “yonder blessed moon that tips with silver all these fruit-
The Verona cold storage warehouse is of circular shape, and consists of three concentric rings. The core of the building is a circular hall of 80 ft in diameter and 98½ ft high. Practically the whole floor is occupied by a turn-
These galleries have each a width of 18 ft, part of which is occupied by a loading ramp running alongside the railway track. Four of the galleries have each a length of 72 ft and hold two trucks; one gallery is 114 ft long and holds three trucks. The remaining two galleries are each 136 ft long and hold four trucks. These last two galleries communicate with the exterior and with the shunting lines. The galleries are kept at low temperatures, which can be regulated at will. Their main purpose is the pre-
To increase the storage capacity of the refrigerated cells an intermediate floor has been built about 6½ ft above the ground floor. It is constructed of wooden trestles supported by concrete girders. The trestle construction allows the free circulation of the cold air.
The first floor of the building is constructed in the form of a ring, the inner diameter of which is 82 ft and the outer 230 ft. On this floor an ice-
A COLD STORAGE CELL in the Verona warehouse. The storage cells are cooled by a combined system of circulating cold air and by radiators along the upper part of the walls; this ensures the correct degree of humidity, which is important in cooling farm products. Each cell has a volume of 50,000 cubic feet and a capacity of 200 tons.
The refrigerating machinery consists of three similar horizontal tubular compressors, running at 150 revolutions per minute. The electrical machinery comprises three 3-
In the machinery hall and in the manager's office illuminated indicators are installed which represent a diagram the whole installation. Whenever a gallery is occupied by trucks or a cell is in use this is shown on the indicator. Similarly each fan, each motor, each crane, and each transformer is shown, when working, on the indicator.
COUNTING THE CRATES during the loading of refrigerated trucks. Note how the contents of the truck have been spaced to allow for the free circulation of air.
The introduction of containers as a means of transport has partly revolutionized railway transport. The advantages of containers, which avoid transhipment and the packing of goods in separate cases, have induced the Italian State Railways to investigate their possibilities when adapted to refrigerated conveyance. Here again the great value of the isothermic chamber in scientific research work became evident. It was mainly responsible for the successful introduction of refrigerated containers, which are most certainly noteworthy for the originality of their conception and execution.
The refrigerated containers have external dimensions of 7 ft 8⅝-
READY FOR THE RAILWAY. Three refrigerator containers loaded on to a rail truck. The containers are constructed of double walls of welded steel plates. The space between these plates is occupied by cork slabs. The roof is heavily insulated and the ice tanks have a capacity of 330 lb.
The containers are built of double walls of welded steel plates, the inter-
THE ISOTHERMIC BUILDING of the Italian State Railways at Rome. This building has a length of 84 ft, a width of 36 ft, and an internal height of 18 ft 9-
When perishable goods are transported at low temperatures it is necessary for the loaded containers to be pre-
In the first container is a complete pre-
In the second container the water-
When the entire installation is required for pre-
A MOVABLE PLANT of loaded refrigerator containers. An entire refrigeration plant for pre-
THE REFRIGERATING PLANT at the Verona cold storage warehouse comprises three horizontal tubular compressors running at 150 revolutions per minute. The electrical machinery is three 3-
ANOTHER VIEW of the plant at Verona is seen in the photograph on the right. The centre photograph, supplied by the Ministry of Communication, Rome, shows the new Isothermic Building of the Italian State Railways, with a refrigerated truck inside the large cell. Each wing of the double doors weighs 3,024 lb.
SPECIAL REFRIGERATOR TRUCKS built by the Italian State Railways for direct trade between England and Italy. Many trucks of the types shown in these photographs are in service on the Zeebrugge-
A REFRIGERATED CONTAINER. Ice is loaded through the opening seen in the roof. Another opening is on the other side. These refrigerated containers, built by the Italian State Railways, have external dimensions of
7 ft 8⅝-
The centre photograph shows a hydraulic lift trolley which easily raises a loaded container on to a railway truck.
THIS SHOWS a special truck placed underneath the container. An advantage of these containers is the facility with which they can be conveyed from place to place. The containers are perfectly airtight. Goods are loaded through an opening on one side, and the door is heavily insulated with rubber tubing round the edges. The load of the container has also to be specially arranged to permit free circulation of air.