arranged as shown on the carriage designed by Mr. F. B. Parrish (Atlas Plate No. IX.)

When this plan is adopted,-and if the law be construed literally as worded, it or a worse arrangement, that of attaching the bridle chains to a chain link connecting the swivel (when used) to the rope socket, must be adopted,the bridle chain offers no protection in case the rope breaks at or near the rope socket.

Some engineers attach the bridle chains to a clamp made in two pieces, which when bolted together firmly clamp the rope. This clamp is placed from three to five feet above the rope socket, and when properly constructed and carefully adjusted is doubtless a much better method of fastening the bridle chains; but if improperly constructed or adjusted it may injure and weaken the rope.

Bonnets.

The law provides for "a sufficient cover over-head on every carriage used for lowering or hoisting person," but the covers provided are not always "sufficient." They are frequently broken, or very much weakened by rust, and are not renewed as frequently as could be desired.

They are usually inclined, so that objects falling upon them will slide down and drop upon the cage, and to prevent objects of moderate size from wedging between the edge of the cover and the shaft lining, they are usually made shorter than the cage, so that a space of one foot or more is left between the lower edge of the bonnet and the shaft lining or buntons.

Boiler iron plate is now used to the almost entire exclusion of other materials for these cage covers, but it is an open question as to whether a covering of plank would not give as good results, longer wear, and be more easily replaced.

Detaching hooks.

Appliances for the prevention of overwinding are considered unnecessary and even mischievous by nearly all anthracite mining engineers.

Dependence must be placed upon the engineer in charge

of the winding engine, upon sufficient head-room, upon the efficiency of the brake, and the engine itself, for the prevention of accidents of this class, such is the opinion of a large majority of mining engineers and colliery superintendents; an opinion probably justified by the imperfections of the detaching hooks and other appliances that have been tried in other districts, and the dangerous feeling of security following the adoption of devices of this class.

A mechanical engineer of large practical experience in the building and operating of winding engines once remarked in my hearing that the only successful device to prevent overwinding would be one that threatened the life of the engineer in charge; as he expressed it, "a ten-ton weight suspended over the engineer so that it would fall whenever the cage passed a certain point, might decrease the number of over-winding accidents, but the adoption of detaching hooks and other appliances will increase the number of casualties."

The difficulty with nearly all of the detaching hooks that have been invented is, that, while they work successfully in trial tests when the parts are in perfect order, properly lubricated, and free from rust, they may become rusted (or frozen) and instead of unlocking and detaching the rope, the rope is broken and the cage falls or is caught by the safety catches; and in addition to this objection they introduce a new element of danger, viz: the possible accidental detaching of the rope while the cage is in the shaft or at the top or bottom landing.

A thoroughly reliable detaching hook, open to none of these objections, if used on a plant in charge of an able engineer having no faith in the appliance, would certainly constitute a valuable addition to the winding plant; but it is doubtful whether any hook yet devised is reliable at all speeds of winding and in any condition, and it is almost impossible to find an engineer who would not place too much reliance upon it.

The Pottsville plant (Page plate No. 33) is provided with detaching hooks. The detaching ring placed on top of the guide frame, and even the hook (on the right hand rope)

itself are shown by this small photographic view of the head-frame. I do not know that any other plant in the anthracite regions is provided with detaching hooks.

This plant is also provided with another safeguard against overwinding. When the indicater arm moves a certain distance beyond the landing mark, the steam brake is automatically applied and the main throttle valve closed.

The present feeling is strongly against the adoption of all devices intended (by automatic action) either to render overwinding impossible, or to decrease the risk by detaching the cage from the rope; and this feeling is grounded upon the following objections to devices of this class:

1. They inspire the engineer with a misleading feeling of security;

2. They are more or less complicated in construction, require frequent lubrication and inspection, and destroy the simplicity of the plant;

3. They may be the direct cause of accident by introducing new elements of danger;

4. Their cost;

5. They are not thoroughly reliable.

The safeguards against overwinding upon which nearly all engineers and superintendents now rely may be briefly stated:

1. The employment of a sober, reliable, and competent engineer, to be held personally responsible for overwinding accidents;

2. A good brake, and a winding engine thoroughly under the control of the engineer;

3. A reliable method of indicating the position of the cage, whether by indicator, by mark on the rope, or by both;

4. Sufficient height of sheaves to allow about two-thirds of a revolution (or more) of the drum between the landing and the sheaves.

Steam brakes and "Governors.”

The arrangement of steam brake and governor by which the brake is automatically applied whenever the speed of

winding exceeds a certain maximum, has, to my knowledge, been adopted only at the Pottsville shaft.

Probably the best arrangement is to make the steam cylinder act as an auxiliary to the hand lever, so that the latter may be successfully used when steam is shut off. At some English collieries the breaks have been operated by a weight, and the steam used only to hold the brake away from the drum, but this plan has not been adopted here, and is open to several objections.

The great difficulty with the hand brake is to multiply the pressure sufficiently and at the same time obtain sufficient movement of the brake band to throw it entirely off the brake ring. This may be obtained by abandoning the ordinary iron brake band for a brake block, and there are few reasons why this change should not be made. As the friction is independent of the surface, but varies directly with the pressure applied, it is evident that a properly constructed brake block will offer as much resistance as a band completely encircling the brake ring, and a block may be adjusted with very small clearance so that a movement of one-eighth of an inch will throw it off. If the hand lever moves through an arc of thirty inches, the pressure applied by the engine will be increased two hundred and forty times, thus a push of fifty pounds against the lever creates a pressure of twelve thousand pounds on the drum.

By locating the brake block beneath the drum the only effect is to take some of the weight of the drum off of the journals and pedestals. To attain the best results with a brake of this form it will be necessary to use materials that give a high co-efficient of friction.

Brakes of this form are coming into use at some very large English collieries, and we shall doubtless soon see them tried in this country on some large winding plants.

They require a very much stronger brake ring than the ordinary band brake.

Slope cage catches and Drags.

These are needed only on very steep slopes and may be made similar in every way to the catches used on shaft car

riages, but as the law does not especially provide for their addition to cages used in slopes, their use has seldom been suggested.

Slope cages used on moderate and even on very steep dipping slopes, are occasionally provided with a "drag" or with bars* that drop when the rope becomes slack or breaks.

These catches or drags act exactly like the drag on a heavy teaming wagon which holds the wagon and prevents it from pulling down hill while the horses are resting, or in case the harness breaks, but as the slope is usually much steeper than a road, the drags may lift the cage, barney, or car off the track and pin it against the roof of the slope.

The use of the drag is as yet confined principally to mine cars, and to a small number of collieries.

The objections advanced by those opposed to this form of safety catch, are:

1st. They are useless on the empty trip,

2nd. They may become unhooked and act on the empty trip and throw the cars off the track,

3d. They are useless on very high slopes,

4th. They are almost useless on self-acting planes, as they can only be used on the empty trip.

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If properly constructed, there should be no danger of the drag becoming accidentally detached from its fastenings and acting on the empty trip; the number of slopes so high that the cars can rise and fall over the drags is comparatively small; and as they are seldom needed on the empty trip,the rope generally breaking on the loaded trip,—these objections to their use do not seem to be well founded. The amount of money and the time saved by a successful drag in preventing the destruction of mine cars, and the protection they afford the bottom men, are advantages not to be lightly disregarded.

One of the most simple drags in use consists of an iron bar about four feet long attached to the hind axle of the car. When not in use it is suspended in a hook; when in the slope it is allowed to trail on the floor.

* Improperly called a drag.