A Text-Book of Horseshoeing
by A. Lungwitz and John W. Adams Copyright 1897
All shoes whose ground-surface is provided with contrivances to prevent slipping upon snow and ice are called winter shoes.
These various contrivances are produced by several processes called “methods of sharpening.” All methods may be gathered into two groups, – namely, practical sharp-shoeing and impractical. Only the first will be considered.
The durability of sharpened shoes depends partly upon whether they are made of steel or iron, and partly upon the nature of the ground in winter. If the ground is continuously covered with a thick layer of snow, whatever method of sharpening is followed, the shoes stay sharp; if, however, the winter is open, changeable, with more bare ice than snow, no method of sharpening, whatever it may be, will last long; the shoes will not stay sharp.
For these reasons no method of sharpening which fulfills all conditions satisfactorily has yet been discovered.
The simplest and at the same time the least durable method of sharpening is: 1. That by means of ice-nails or frost-nails (fig. 158). One or two nails are drawn from each branch of the shoe and replaced with ice-nails.
2. Sharp Toe- and Heel-Calks. – The outer calk is split and a small steel wedge welded in. It is then laid upon the edge of the anvil, indented and sharpened from within to without in such a manner that the calk shall be thin from the branch to the ground, and the outer surface shall be in the same vertical plane as the outer edge. If a calk is narrow from its base to its end, and at the same time without flaw, it does not need a sharp cutting edge. The inner calk should never be sharpened except the ground be very slippery. The cutting edge of this inner calk stands at right angles to the length of the branch, and its outer corner should then be rounded to prevent its injuring the opposite foot (Figs. 159, 160).
For horses used for heavy draft purposes a toe-calk is welded to the shoe and sharpened. For this purpose we use only steel (toe-steel), which is easily welded to the shoe and remains firm. Toe-calks and steeled heel-calks are tempered, in order, as much as possible, to lengthen their period of durability. This method of sharpening is the oldest and most wide-spread, and is employed on the shoes of all horses of which we require more than light service.
Hoofs are easily damaged or even ruined by frequently repeated sharpening of the shoes, because every time this is done the shoes must be removed and replaced.
3. Shoeing with Screw Heel-Calks. – Any ordinary flat shoe not too thin and narrow at the ends of the branches can be changed to a shoe with screw heel-calks by punching holes in the ends of the branches and cutting a thread in them.
The screw heel-calk holes are made either by punching or boring. The punching is done by means of an almost cylindrical hammerpunch, afterwards finishing the holes by driving through them a round punch which tapers from the middle towards both ends. On the ground-surface of the shoe the hole is moderately counter-sunk (Fig. 162, a), so that after the thread has been cut and the calk screwed into place the shoulder of the latter will rest on the counter-sinking.
At present nearly all screw-calks are made by machinery, either of iron or toe-steel. The former is too soft and therefore not sufficiently durable; the latter, however, is quite durable when the calk is properly hardened (tempered) by heating to a cherry-red, sticking the head of the calk as far as the tap into a bed of moist sand, and allowing it to slowly cool.
The chief requirements of a good screw-calk are, further, a clean, deep, but not too coarse thread, and but one size of thread and tap for all calks, so that every calk will fit in every shoe. A calk whose tap measures one half inch (12.7 millimetres) (Whitworth) in diameter is sufficient for the heaviest shoes. The tap which is used to cut the thread in the holes for the screw-calks must be about 1/125 of an inch thicker than the head of the calk. In the German army the calks have a tap fifteen thirty-seconds of an inch in diameter. The coachman should be given four calks (sharp and blunt) for each shoe, and a small screwcalk key for placing and removing them. Screw toe-calks are also used, yet they require special security to prevent their becoming loose. Experimentation with the screw toe-calks, though not yet entirely satisfactory, cannot be said to have ended.
The advantages of shoes provided with good screw heel-calks are so manifold that they deserve marked preference over shoes sharpened by the ordinary methods. The common objections urged against screw-calks, — namely, that they loosen and are lost, or break off, are not worthy of serious consideration, since these evils are merely the result of unskillful workmanship and poor material. Shoes with screw heel-calks are the best shoes for winer, especially for horses that have to work hard and continuously.
Balling with snow is prevented by using shoes narrow in the web and concave upon the ground-surface (convex iron), and thoroughly oiling the sole and frog. Sole-pads of felt, leather, or straw serve the same purpose.
Balling with snow is best prevented by a rubber sole-and-frog pad, or by a “stopping” of a patent hoof cement known in Germany as “huflederkitt.”
4. Shoeing with Peg-Calks. – The calks are merely stuck into the calk-holes, hence their name. Round and square peg-calks are used, but the former are better than the latter.
The inventor of round peg-calks is Judson, an American. The shoes differ in no respect from the ordinary flat shoes. It is necessary that the tap of the calk have a moderately conical form, and exactly fit into the calk-hole of the shoe. The taper of the calk-tap is correct if for every ten thirty-seconds of an inch in length it increases or diminishes one-thirty-second of an inch in diameter (equal to one inch in every ten inches of length).
Although the calk-holes may be punched in a hot shoe, yet boring and reaming them is much better, because by this method a more perfect fit can be secured. For this purpose we require a drill (a spiral drill is the best) whose diameter is exactly the same as that of the small end of the calk-tap (Figs. 165, c, and 166, c). After the shoe has been fitted to the hoof, the provisional holes are drilled an afterwards reamed out from the ground-surface of the shoe with the reamer shown in Fig. 167. Since the tap of the reamer corresponds exactly in size to the tap of the calk, it is evident that the latter must exactly fit and be tight. The wire edge that is raised around the hole is removed with a file, and the edge then smoothed by introducing the reamer a second time. The calks are made of rolled round steel, which has the thickness of the tap-end of the calk. For this purpose we require a calk-mould or matrix, in which one or more holes have been finished with a reamer. A piece of rod steel is heated at the end for a distance nearly twice the length of the calk, is swaged, thrust into the matrix, then broken off, and backset. This will give a blunt peg-calk. If a sharp calk is desired, the upper part of the head of the calk is sharpened in the ordinary manner, although this is accomplished most easily by using a pair of tongs with short jaws that are hollowed upon the inside for seizing the tap of the calk.
Before the shoes are nailed on, the normal punch should be oiled and driven into the calkholes, and the calks passed into the holes to see that they fit perfectly.
The calks are driven into place after the shoes are nailed to the hoofs. A light blow is sufficient to fasten a calk, yet a necessary precaution is first to remove every trace of oil from the calks and calk-holes. The first calk driven into place must be held with the hand while the second is being driven, otherwise it will either spring from the calk-hole or be loosened so that it will soon afterwards be lost.
To remove such a calk we strike its head from different sides with a hammer, stone, or other hard object until it becomes loose, when a rather hard blow upon the shoe causes it to spring out. Calks which have worn down are seized by a pair of sharp nippers and loosened by blows upon the shoe. Since a calk which is firm soon rusts and is then very difficult to remove, it is recommended that all calks be removed every night.
The advantages of peg-calks over screwcalks are: 1. They do not break off. 2. They are easier to make and simpler to use. 3. They are cheaper.
Disadvantages. — 1. Peg-calks are sometimes lost, even when properly made and most carefully introduced. This evil happens much less frequently when the calks are put in by the maker (horse-shoer) than when they are stuck in by the coachman, attendant, rider, or other person. When calks are lost on the way from the shop, it is usually due to some fault in the calk-holes or in the calks, although when the feet are balled with snow the calks are easily lost, because they do not then touch the ground.
2. The removal of the calks often involves many difficulties, whence they are apt to rust into place if not removed daily, and when worn down so far that they cannot be grasped with the pincers are almost impossible to remove. By hammering upon the calks and shoe many horses are rendered not only restive, but sensitive in the feet.
3. If horses are used without the calks, a wire-edge forms around the hole on the bottom of the shoe, which interferes with the placing of the calk and lessens its security.
The hollow peg-calk (Fig. 168), made by Branscheid & Philippi, of Remscheid, has considerable merit. It holds exceedingly well, and is very durable. It is furnished in three sizes, — Nos. 12, 13, and 14, — of twenty-seven, thirtyone, and thirty-four millimetres length, and twelve, thirteen, and fourteen millimetres diameter at the end of the tap.
A punch is furnished which, when driven up to its head in the holes of the heated shoe, insures a proper width and shape of the hole and an accurately fitting calk.
The calks may be removed by an extractor (Fig. 169) having at one end a thread which is screwed into a corresponding thread on the inside of the hollow calk, when by a few hammer blows on the shoe the calk loosens. To prevent the calk becoming choked with dirt, a piece of cork is thrust into the hollow. It may be easily removed by means of the cork-screw at the other end of the extractor.
5. Shoeing with Peg Toe- Calks. – These are an invention of considerable worth, especially for heavy draft in hilly country. They render better service on hind than on front shoes.
Peg toe-calks, with a single tap are simpler and preferable to those with two taps. Every known contrivance to prevent the occasional loss of the peg toe-calk is impractical.
The shoe for a peg toe-calk should be of good tough material and without a flaw. The toe of the shoe should be about one-twelfth to one-tenth of an inch thicker than the branches.
The hole for the peg toe-calk, whatsoever its shape may be, must be smooth and uniform, with clean, true corners. Semicircular holes should present the convex side towards the toe.
Before punching, draw up the toe-clip. A punch-plate with a good-sized hole and a tap which will fit into the square hole in the anvil will facilitate the work. The punch-plate when in position should be flush with the front edge of the anvil. Place the toe of the shoe, hoof surface upward, over the hole of the punch-plate, and drive a hole with a punch-hammer which is perceptibly thinner than the model punch. Now turn the shoe over, punch back from the ground surface, and then file away the wire edge which the punch has raised on the ground surface. Next, take a hand-punch, the end of which should just enter the hole, punch through from the ground surface, and correct any bulging by dressing lightly over the horn of the anvil. Finally, use the model punch to give the hole the exact size and smoothness.
Should the hole in the toe of the shoe enlarge in time, as sometimes occurs, then backset when necessary on removing the shoe. Backsetting is easiest with the half-round hole, because the curved side, being turned forward, runs approximately parallel to the outer border of the toe of the shoe.
A good serviceable peg toe-calk must possess the following characteristics:
1. The tap must be of such shape as not to turn; therefore, not round.
2. The tap must be cone-shaped, and diminish in diameter about one-thirty-second of an inch for each one-fourth of an inch of its length from base to apex. If the tap has less taper it will enlarge the hole in the shoe till the head of the calk comes into contact with the shoe, when the calk will loosen and drop out.
3. The tap must be full-formed and smooth.
4. It must fit air-tight in the toe, and a single hammer-blow should be sufficient to fix it securely.
5. The head of a toe-calk must not rest on the shoe; a space of one-sixteenth of an inch should intervene.
While a shoer of average mechanical ability can make a faultless peg toe-calk, it is not profitable to do so while good machine-made calks are to be had very cheap.
The best forms in use are the quadrangular heads, with oval, half-round (Figs. 171 and 172), and with two taps (Figs. 173 and 174).
In several European countries the peg toecalks with half-round tap and with two round taps are in use. To make good peg toe-calk shoes and fit the calks properly requires more than ordinary knowledge and skill. Poor work does much harm. Therefore, work carefully and get well paid for it.
6. Removable Heel-Calks that do not Require Sharpening. – The undeniable fact that all chisel-shaped or pyramid-shaped sharp calks become dull in time, and must then either be sharpened or replaced by new calks, renders shoeing not only costly, but injurious to the hoofs and annoying to the owner. This drawback is most pronounced in large cities, where the snow never lies long upon the streets, and the horse just sharp-shod is soon obliged to travel upon bare pavements. Attempts have been made to lessen this annoyance by the use of calks that do not require sharpening, and yet which will prevent slipping even after they have been used for a long time upon bare pavements. It cannot be denied that such calks have considerable value, and, except when the ground is covered with ice, many of these calks render excellent service. Just as the ordinary sharp calks are satisfactory and very durable outside of the large cities, so now for the first time a few of these recently invented sharp calks seem to be worthy of recommendation for city use. The following are the best:
- Screw-calks and peg-calks with H-shaped cross-section (Fig. 175).
- Screw-calks with +-shaped cross-section (Fig. 176).
- Screw- and peg-calks with O-shaped cross-section (Fig. 176).
- Screw- and peg-calks with S-shaped cross-section.
- Angle-calks (Fig. 177).
- Screw- and peg-calks with rubber foot-pad.
- Screw-calks with Y star-shaped cross-section (Fig. 178).
- Hollow wedge-calks (Fig. 179).
- Perforated screw-calks (Fig. 180).
There is no doubt that the grip that these calks take upon the ground and their durability depend upon the diameter and the arrangement of their surfaces of friction. From all experiments made thus far it is shown that those calks which have narrow and comparatively few surfaces of friction are the least durable.
To introduce and remove the calks we use a calk key or wrench. For the shop, the ordinary fork key (Fig. 181), the jaws of which are tempered, is recommended. It fits all calks.