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Type of Rope

It will be obvious to everyone that man-riding installations must be of such a standard that the maximum safety for the passengers is not only provided but is maintained. This involves planning of the roadway, design of the track, haulage engine and carriages, and the provision of adequate safety devices as well as the selection of the most suitable rope. This accident was caused by the failure of the rope. I propose to deal fully with this item and later I will make reference to devices to arrest runaways.

The size and type of rope to be selected should depend on the actual duty it has to perform and having determined the normal static load, a factor of safety should be provided of at least ten. Indeed, many installations have a greater factor of safety. The drum of the haulage and all deflecting pulleys should be of a suitable diameter to correspond to the size and design of the rope selected. Proper alignment of the pulleys with the drum of the engine should give the smallest possible angle of "fleet" and the rope should not rub against any fixed object. Unlike a winding rope, a haulage rope must be supported at intervals along its path of travel by carrying rollers, and these should be of suitable diameter. The rollers should also be light, consistent with strength, and run freely in their bearings. Rubber covered rollers might well be considered in order to reduce wear on the rope.

Mine water is often corrosive and therefore should be drained away from the rope path, and to prevent premature corrosion the wires forming the rope should be of galvanised or rust resisting steel.

Ropes are treated with lubricant during manufacture, and in order to ensure that this lubrication is maintained while they are in use, regular treatment is essential. A composition which will adhere strongly to the rope and prevent water penetrating the strands should preferably be used.

Examination of the Ropes

Examinations no less stringent than those applied to winding ropes should be carried out in the case of ropes used for hauling persons; in fact the requirements of Regulation 7 of the Coal Mines General Regulations (Winding and Haulage), 1937(a), and of Section 66 (1) (a)(b) should be applied in addition to the requirements in Section 66 (1) (b)(c) of the Coal Mines Act, 1911.

The Regulation referred to above requires that a special examination shall be made once at least in every month of every winding rope in use and that the special examination shall be done in the following manner: "The rope shall be thoroughly cleaned at all places particularly liable to deterioration and at other places not more than 100 yards apart throughout its length, and at each of these places after cleaning, examination shall be made of the circumference and surface condition of the rope and for any fractures of the wires."

Section 66 (1) (a)(a) requires that competent persons shall "once at least in every 24 hours, examine thoroughly . . . the state of the . . . ropes, chains . . . Which are in actual use for the purpose of raising or lowering persons in a mine."

I must draw the attention of managers to the requirements of the Coal Mines (Mechanics and Electricians) General Regulations, 1954(b), particularly with respect to the appointment of competent persons and their duties. These Regulations apply to the normal day to day operations at a mine but I consider that man-riding installations should be subjected in addition to a thorough examination by experts at specified periods. Such experts may be the area ropemen or engineers. This principle is by no means new and should not be regarded as lack of confidence in the men who do the routine examinations. Regular examinations by outside experts are carried out in many other industries and even in the National Coal Board itself when Insurance Engineers make regular examinations of steam boilers and air receivers.

The records of all examinations and re-cappings must be made in a book and the book preserved for a limited period depending on the type of examination recorded. This is set out in Regulation 15 of the Coal Mines General Regulations (Winding and Haulage), 1937(c).

(a) and (b) Now see Regulation 15 (2) and (3) of the Coal and Other Mines (Shafts, Outlets and Roads) Regulations, 1956.

(c) The requirement of Section 66 (1) (b) has now been superseded by the general requirement in No. 7 of the Coal and Other Mines (Mechanics and Electricians) Regulations, 1956, regarding a scheme for the systematic examination and testing of all mechanical apparatus.

Life of Man-riding Haulage Ropes

The life of a rope used on man-riding haulages varies considerably and two years has been recommended as a maximum under suitable conditions. Usually the life of a rope, particularly on long established haulages, is judged by the time previous ropes have been in use. In general this has proved satisfactory but I suspect that the period in service has been the determining factor rather than the actual rope condition. The size of rope used for man-riding can usually be the same as that used for mineral haulage, particularly so to-day where many pits are grouped into one Area. I see no reason why the period of service of new ropes on man-riding haulages should not be limited to one year, the ropes thereafter being transferred to suitable mineral haulages for the remainder of their useful lives.

Training of Ropemen

Much has been done in the past by rule of thumb, and ropemen have been selected solely because of their practical experience over a number of years. However, it has been realised for some time now that more technical information about ropes and their treatment should be made available to the industry. To this end, detailed studies of ropes, rope breakages and of the working conditions leading up to the failures have occupied the Safety in Mines Research Establishment staff for a number of years. The knowledge gained has been put at the disposal of the industry in the form of a publication "The Ropeman's Handbook", issued by the National Coal Board, and embodying conclusions drawn from extensive work at the Safety in Mines Research Establishment. The handbook should be a constant guide to ropemen. There is also a practical course which is held at Sheffield. Many ropemen have attended this course but I recommend that at least one man from each mine producing 300 tons or more of coal per day should attend. The provision of a more advanced course should be considered for senior ropemen.

(a) Now see Regulation 15 (2) and (3) of the Coal and Other Mines (Shafts, Outlets and Roads) Regulations, 1956.

(b) Now see the Coal and Other Mines (Mechanics and Electricians) Regulations, 1956.

(c) Now see Regulations 15 and 55 of the Coal and Other Mines (Shafts, Outlets and Roads) Regulations, 1956.

Means of controlling Man-Riding Carriages in the event of a Runaway

Although every care must be taken in the maintenance of properly designed man-haulages, circumstances may arise which can cause a runaway. On slight gradients, brakes to act on the wheels of the carriages should be part of the standard equipment, but on steep gradients such brakes are useless; therefore some device acting on the track or a special brake rail should be installed. Several attempts have been made to design such equipment and, up to a point, they have been successful.

The device must be capable of stopping a set of carriages on almost any gradient without causing an excessive rate of retardation. The braking device should be capable of being automatically applied as well as by persons riding on any carriage.

The problem is complicated by the unstable conditions of underground roadways causing, in time, distortion of the track.

 

A copy of this report was kindly donated by
West Cumbria Mines Research.