CHAPTER IV.

CONSTRUCTION OF COMMERCIAL ICE HOUSES.

The Earliest Forms of Ice Storage--Development of the Modern Ice House--The Site and Its Requirements--Placing the House--Survey--Foundations--Size of an Ice House--Details of Construction for a House Embodying all Modern Improvements.

The earliest reference to the use of snow for cooling purposes occurs in Holy Writ, and carries us back about three thousand years. History records the custom which prevailed among the Romans, of storing snow upon the mountains during the winter, which was made use of in the summer for cooling beverages. Vaults, or pits, of circular form at the top, and tapering to a point at the bottom, were scooped out in the ground. The sides were lined, and the top thickly thatched with straw, after being filled with snow, which was tightly packed. The doorway was through the top. A modernized Roman snow cellar is shown in Figs. 44 and 45, which is taken from a cellar in use in Virginia. Its successor in the transition to more modern designs is seen in Figs. 46 and 47.

Before ice was cut and stored for commercial uses in this country it was secured, in many instances, by those who used it in their business. Brewers, dairymen, butchers, and some physicians, had ice vaults, or cellars, constructed on the Roman method. The first commercial ice houses were built below the surface of the ground. Gradually they emerged into the light and air, being only partly below the surface. Brick, stone and wood were in use for building materials. Gradually, experience leading the way, the ice dealer has evolved the modern ice house.

THE MODERN ICE HOUSE represents many years of development, and has a scientific, as well as a practical, value. Improvements may be expected in this as in other branches of the ice business. The discoveries and inquiries which scientific and practical men are continually making in this direction are rapidly adding to our store of knowledge. Ice houses, as now built and furnished, give few suggestions of their original prototype.

THE SITE.--Many features are combined in a really good site for a commercial or large ice house. Good ice in ample quantity, a porous soil, easy accessibility both from the water and land, proximity to market; also cheap and efficient transportation. Observance of the first and last of these points is imperative. Where natural drainage is lacking, the deficiency can be supplied, and access effected, in most instances, if the other features warrant the expense.

In selecting a site, when the lay of the land will permit, place the length of the house north and south, and arrange the incline and runs with as few turns as practicable. The ice cakes require assistance to keep them in motion on a crooked runway, and are constantly being jammed and spalled. On a direct run of proper pitch the cakes will travel without attention in freezing weather. On warm, sloppy days, when the ice is soft, it will require assistance. The platforms for winter shipments _via_ rail come in for attention in placing the incline, which should be conveniently disposed for supplying them with ice cakes as fast as they can be handled. System and dispatch are the watchwords of the ice dealer while ice cutting is on.

SURVEY AND FOUNDATION.--The location and size of the house being determined, a survey is made and all lines staked out. It is important to have the foundations square and of the exact size, so that dimension lumber and roof trusses will fit as designed. Levels, also, call for attention, and the entire site should be brought to grade.

In the construction of foundations practice varies. They are partly dependent upon local conditions and climatic influences. For large houses, where the wastage is readily drained off and the sills are comparatively dry, they are about as durable as the balance of the building when placed directly on the ground.

The life of an ice house varies from so many causes, that no limit can be given applicable to all cases. When the lumber is well selected and the construction thorough, fifteen years of constant service will tell plainly on the building. If repairs are made as often as required, its term of usefulness is extended.

In warm climates, also for smaller houses, and for city supply depots, foundations of stone or brick are employed to advantage. They should be put in below frost, and extend about two feet above the surface.

DETAILS OF CONSTRUCTION.--In the building illustrated in plates _A_, _B_, the sills are placed upon the ground. The house is divided into four rooms, each forty feet wide in the clear, two hundred and fifty feet deep, and forty feet high from sill to plate. The dimensions of lumber required may be:

For outside sills, 8 × 10 inches, of such lengths as can most readily be obtained.

Inside sills, 6 × 10.

Outside posts, 4 × 10 inches × 40 feet, set 12 feet apart.

Studding, 3 × 10 inches × 40 feet, with three feet centers.

Inside posts, 4 × 8 inches × 40 feet. Studding, 3 × 8 inches × 40 feet.

For outer circulating air space, the studding should be 2 × 8 inches × 40 feet, with three feet centers.

For inner dead air spaces, 2 × 6 inches × 40 feet studding are placed upright 12 feet apart, and horizontal cross studs 2 × 6 inches × 12 feet and three feet apart, are filled in between. This makes spaces 3 × 12 feet on the inside of all the outer walls.

Plates on the outer walls are 3 × 10, and on inner walls 3 × 8 inches.

The main studding is lined on both sides with moisture-proof sheathing, and boarded up with matched lumber. The inclosed space is filled with non-conducting substance, usually sawdust or spent tan bark. The filling must be dry and packed tightly.

The inner 2 × 6 studding is lined with sheathing, and then boarded up with matched lumber. The joints of this studding should be made with care and the lumber selected, no crooked stock being used. Sealing up these joints with pitch adds to their efficiency, and also to the durability of the lumber.

The outer studding is covered with weather boarding or ship siding. Twelve inches at the bottom are left open and hinged covers swung over them, which can be opened or closed as ventilation requires.

The interior walls have 4 × 8 inch × 40 feet posts, and 3 × 8 studding, which are boarded on either side with matched lumber and filled.

The lower section of these walls, to a height of ten to fifteen feet, is often left without filling, as it is more exposed to the ill effects of moisture, and requires renewal before the upper portion. This is more conveniently done where no filling is in the wall.

In the center of each room, on the end at which the ice cakes enter, an opening is left extending from the sills to the plate. As the house is filled with ice these openings are closed up. Boards are provided, when building, which will fit into place and make the walls at these openings, as near as practicable, the same as in other places. The middle section being filled and planked by the inner and outer air spaces.

At the opposite end of the rooms a similar opening is provided. For closing it a slightly different plan is adopted. The outer section is divided into doors five or six feet high, swung on hinges; these take the place of the weather boarding. The interior wall is then arranged the same as the one at the opposite end of the room. These doors can be opened as the ice is coming out, and remain closed at other times.

Interior partition walls are sometimes of value. It is thought they add to the durability of the house, and also effect a saving in wastage. In the majority of houses they are dispensed with.

The construction of the roof will be found convenient and substantial, if the plans shown in Plate _B_ are followed. Light-colored roofing composition should be used, avoiding tar and gravel, or tin, as these both attract and absorb the heat. Gable roofs, with good shingles laid four or five inches to the weather, are the best roofs for ice houses. They are cooler and more durable than most composition coverings.

The posts in Diagram _B_ can be extended and additional bracing put in. The increased area and weight will require a proportional addition to the strength of roof timbers. In the sizes of timbers for ice house construction, noted in this chapter, consideration has been given to durability, and while lighter material is employed, in some instances, the houses are sooner racked and sprung out of place.

The ventilator on top is about twenty feet square and two feet high, with slats on all sides. It will not be required on high gable roofs, an opening in each gable end being sufficient to carry off the moisture and heated air. The gable ends should be well braced against the wind.

At the center of roof trusses a floor is laid through the building, dividing the space above the ice. Trap doors are cut through this floor about seventy-five feet apart, four to six feet in size; these doors are for ventilating the space between the ice and the floor, and for dumping the sawdust through on top of the ice. It also affords a convenient place in which the sawdust can be stored and dried, when the houses are cleaned in the fall.

The outer circulating air-spaces are continued to the level of the loft floor, discharging the air into the loft, where it finds vent through the ventilator.

The eaves project about two feet, and are provided with ample gutters, which are furnished with large conductor pipes every fifty feet. On the side of the house where galleries are placed, the roof is extended to cover them, or, if at a gable end, a special roof is provided.

Lightning rods are especially required on ice houses. Being often the most prominent object in their locality, the electric fluid finds its readiest path through them, and the escaping vapor and much of the material used in their construction add to their exposure. Copper strips, terminating in forked points, raised above the cone of the roof, fifty or seventy-five feet apart each way, provide ample protection. A line of points across the house should be connected, and the copper strips extended, without any break or interruption, into the ground. They should be buried several feet below the surface, and if they terminate in a drain or other damp place, their efficiency is increased.

The floor of each room is graded slightly toward the center, and a trench dug through the center from end to end. It should have a grade toward the front of the house of about two inches in a rod. At the rear of the house it may be nine inches square, gradually increasing to double this size at the front of the house. Lateral drains, alternating on either side, are desirable. If the surface drainage sets toward the house, it should be intercepted and conducted away. After the trenches are made they are filled with broken stone or cobbles about nine inches deep at the start, and double the depth at the front of the house. The side trenches may be six or eight inches wide, and filled about the same depth.

On top of the stones, shavings, straw, reeds, or other porous filling, is placed, to the level of the floor. The entire floor is now covered with a layer of charcoal, or with coal ashes placed several inches deep. On top are laid boards, not too closely placed, with length toward the main drain. The spaces between the boards form channels to conduct the waste water to the drains. Where the drains emerge from the house they are trapped, to prevent any air currents from entering through them, and collected into one or more main channels.

Plate _A_ illustrates the drainage plan, and a section view is presented in Plate _B_. In porous soils, which can be depended on to carry off the wastage, drains are not so necessary. For very large houses, however, they should not be entirely neglected. In warm climates and for city supply houses, cement floors are the best.

For loading cars for winter shipments, the platforms illustrated in plates _A_, _C_ and _D_ are used for handling large quantities. The ice cakes are elevated on the incline to runways (see _R_, in Plates _A_, _C_ and _D_), and slide by gravity until landing on the platform. An endless chain with cross-bars passes over the top of this platform, carrying a cake before each bar. Where a railroad siding is placed on both sides of the platform the work is expedited, as no delay is occasioned by waiting for cars, a loaded train being pulled out and empty cars run in on one track, while loading continues on the other.

THE INCLINED WAYS shown in Plate _C_ are rigged with endless chains, which carry cross-bars. In filling the house, the ice cakes are floated to the foot of the incline, and fed on to it, one or two cakes at a time in front of each bar, and thus is made to travel up the incline. The cakes are passed through gates on to the runways at the various levels desired, and pass over these, by gravity, into the ice house.

There are two methods of arranging the chains--called the over-shot and the under-shot. The first named is mostly used, and is the one shown in Plate _C_. The power required varies with the length of the incline and with the style of the elevators, which are arranged for one or two cakes on a bar. The smaller rigs are operated with an eight or ten horse power engine, and the larger plants up to one hundred horse power, where several elevators and platform conveyors are coupled on to one engine. For filling smaller houses there are several methods in use, a choice depending on the surroundings and size of the room or house.

Next in importance to the endless chain system, are the jack grapples by which large quantities of ice are annually stored. An incline is used which is similar to the one shown on Plate _C_, but of lighter build. These grapples are operated with horses, or with steam power, when winding drums are employed. By using friction-winding drums, the jack grapples readily accomplish the work of a single elevator, and are less expensive. This plan is shown in Plate _E_. An ordinary threshing engine furnishes ample power, and this method is rapidly growing in favor. Where the ice house is placed at the edge of the water and there is no room in which to place an incline, the gigs are very convenient. When they are operated by means of a winding drum run by a reversing engine, and large enough to handle four cakes at a time, they are very efficient. Economy of power, simplicity and ease of management, are all in their favor.

Small houses and cooling rooms are filled with the aid of hoisting tongs.