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Colliery Engineering

July, 1949

Hugh Wood & Co. Ltd.

The GTB/200 Conveyor is designed for conveying the high tonnages encountered in main trunk, drift and inclined-shaft installations. It accommodates a 36 in. or 42 in. belt, and is capable of transmitting from 100 h.p. to 230 h.p., depending on the belt speed. Drums of 42 in. diameter, are utilised for driving the belt, and power is transmitted to these through a totally enclosed steel gearbox, the driving motor being mounted outboard or inboard as required. The intermediate sections used in conjunction with the drive head are heavy, fully troughed type, these being supplied in 13 ft. 6 in. lengths, and having 6 in. diameter oil-filled rollers for supporting the carrying and return belts.

The GTB/60 Drive Unit which is designed to transmit 60h.p. and to accommodate a 36 in. or 42 in. belt, is used for heavy gate or for trunk duty. The intermediate sections used in conjunction with this drive head are fully troughed, 9 ft. long, and have 4 in. diameter oil-filled carrying rollers, and 3 in. diameter return rollers. The drive, is by electric or compressed air motor, and is taken to 27 in. diameter tandem drums through a worm reduction gearbox, and thence through totally enclosed spur gears which operate in an oil bath.

The GTB/40 Drive Head is the lightest Huwood drive unit designed primarily for gate duty and will accommodate a 24 in., 26 in., 30 in. or 36 in. belt, transmitting up to a maximum of 40 h.p. The drive is through a totally enclosed spur-reduction gearbox to two 18 in. diameter drums giving 420 deg. belt wrap. The gearbox used on this drive head is a standard unit which is also fitted to Huwood type GB/40, SL/3 and TB/30 drive heads. The sections generally used in conjunction with this head are fully troughed.

The GTB/30 Top Belt Conveyor incorporates a compact 30 h.p. drive unit, which can be used for face duty in seams 3 ft. 3 in. thick and over. This head can be fitted with an extended delivery jib for gate conveying or for gathering duty when the duty does not require or the road height does not permit the use of a larger drive unit. It is adaptable to connect to any type of face or gate-type intermediate sections.

The TB/15 Drive Unit is designed for use on faces where the height is 3 ft. or less. It can also be used for light gathering duty and for driving headings. The unit is powered by a 15 h.p. electric or compressed-air motor, and the drive is taken to tandem drums via a totally enclosed spur-reduction gearbox. The drive drums are 14 in. and 10¼ in. diameter respectively, and give a total belt wrap of 420 deg.

TB/7 Drive Unit was designed primarily for face duty in seams less than 2 ft. thick. For this application it is general to use this drive unit as a bottom-belt conveyor and run the carrying belt on the floor, but it can be used as a top-belt conveyor if required. It is powered by a 7½ h.p. electric or compressed-air motor which drives one 18 in. snubbed and slatted drum through the medium of a totally enclosed gearbox which is incorporated as part of the side frame of the head.

4FT Section 9 ft. long. — This is a rigid gate-conveyor section using 4 in. diameter fully troughed oil-filled carrying rollers at 4 ft. 6 in. centres, having a totally enclosed return belt carried on 3 in. rollers at 9 ft. centres.

4SFT Section 8-ft. Long. — This is a reversible conveyor section for use when rapid extension is required — only four bolts being used per section for fixing idler sets. 3 in. diameter oil-filled rollers, fully troughed, are spaced at 4 ft. centres, and the return belt is fully enclosed by means of split cover troughs which can easily be handled by one man.

ST Section. — This section is 6 ft. long and is designed for face duty. It is of three-piece construction, comprising bottom stool, top stool and intermediate trough fastened together without the use of nuts and bolts.

HST Section. — This is designed for heavy-duty face conveyors. It is made in 4 ft. 6in. lengths.

4LTB Tail End. — This is used on gathering conveyors which require rapid and frequent extension. Various types of hoppers are available to receive the coal from chain conveyor or face belts.

3TB Tail End. — This is for use on gate or light trunk conveyors where it is required to feed direct from a longwall face on to the gate conveyor.

The P.F. Scraper Chain Conveyor is used for face work in room and stall or shortwall faces, and can also be used as a gathering conveyor for rapid extension up to 60 yards long when driving headings. The drive head is fitted with a 5-10 h.p. motor which transmits power to the conveyor through a worm reduction gearbox, and then a precision roller chain to the headshaft. The intermediate sections are of one-piece construction 17 in. wide, connection between sections being made by two bolts. These sections are supplied in 5 ft. lengths to correspond with the lengths of the conveying chain. The conveying chain is double and is roller-borne to minimise frictional losses. The pitch is 2 in. and scrapers are fitted every 20 in. The tail end is provided with adjusting screws giving 5½ in. take-up travel for tensioning the conveying chain.

The PA/1 Scraper Chain Conveyor is designed for use as an auxiliary to a gate belt to avoid having to extend the gate belt daily. It is an enlarged version of the P.F. type of conveyor, except that the 10 h.p. driving motor and worm reduction unit are placed underneath the conveyor to avoid taking up excessive width in the gate road. The conveyor sections 2 ft. wide are designed for the large tonnages encountered in gate duty. For larger capacities the PA/2 drive head is used, which is exactly similar to the PA/1 except that a 15 h.p. motor is fitted and a fluid coupling is used between the motor and reduction unit. The greater power enables the chain speed to be increased.

The HS/6 Scraper Chain Conveyor. — The usual application of this conveyor is for room work and as a gathering conveyor from batteries of two to six rooms. It can also be used in conjunction with mobile loaders when driving headings or wherever a conveyor is required that is rapidly extensible. This conveyor is reversible to enable material to be carried inbye to the face. With this conveyor, the sections are of one-piece construction 6 ft. long connected by means of two bolts. The chain is of the single-line type with all-steel flights spaced at 18 in. intervals, and uses rollers to minimise friction. The tail end is extremely light and can be pulled forward by one man. Provision is made for 8.3/4 in. screw adjustment for tensioning the conveyor chain. This conveyor can be fitted with either a 15 h.p. type HS/6 drive unit, or 25 h.p. HS/5 drive unit depending on duties. Generally, for level work it is found that the 15 h.p. type HS/6 has ample capacity. Both these drives are of similar basic design, power being transmitted to the headshaft through a worm reduction gear unit and precision roller chain.

The HS/5 Scraper Chain Conveyor is designed for work with head-end drive, or alternatively with tail-end drive, for conveying on longwall faces up to 18 deg. (1 in 3) downhill where a belt conveyor would be unsuitable. The intermediate sections of this conveyor are made in two parts each 6 ft. long. No nuts or bolts are used for connecting the sections, a special drop-in connection being utilised which gives a positive lock and enables the conveyor to adjust itself to undulating floors. The chain used on this conveyor is similar to the chain used on the HS/6 conveyor with flights spaced every 18 in. The tail end incorporates a telescopic portion and the conveyor chain is tensioned by pulling the tail end with sylvesters. The HS/5 25 h.p. drive head, as described above, is used for this conveyor, or if required, the HS/6 15 h.p. drive head can be fitted.

The HR/2 and HR/3 Retarding Conveyors are specially designed for conveying on inclined seams and drifts where the gradient is between 18 deg. (1 in 3) and 45 deg. (1 in 1) in favour of the load. Two sizes of sections — types HR/2 and HR/3 — are available, the same drive unit being used for each. For seams above 2 ft. 6 in. thick the HR/2 conveyor is used, but for lower seams the HR/3 is recommended: The drive consists of vee-rope drive from the motor to an enclosed spur gearbox which then drives the head-shaft. A rope drum is also fitted to these drive heads for hauling the chains up to the face to assist in the assembling of the conveyor.

The intermediate sections are of two-piece construction and incorporate a special connection which avoids using nuts and bolts, and which allows the conveyor to follow undulating floors.

ML/1 Loader. — This loading machine is used on longwall faces for moving the shot coal on to the conveyor belt, woi king on the buttock end of the coal. It is hauled along the face under its own power by means of two ropes, and loads the coal while travelling in either direction. When loading, the machine advances at 30 in. per min., the flights making 80 strokes per min. The haulage and flight mechanisms are both driven by one 10 h.p. electric motor. The machine is capable of loading up to 60 tons per hour. A fast flitting gear enables the machine to flit at 12 ft. 6 in. per min.

Drills and Picks. — Hugh Wood & Co. Ltd., also have a second stand devoted to electric and compressed-air drilling machines, pneumatic picks and hammer drills, drill rods and bits, and 100 A and 30 A plugs, sockets and couplers. In connection with their electric drills a speciality is the mercury switch drill panel incorporating mercury switches for main contactors, instantaneous earth-leakage relays, instantaneous short-circuit relays and sustained-stall prevention relays. The sustained-stall prevention relay protects the drills by switching off after a few seconds stalling, and resets itself after a short delay. The DP/1 panel caters for one drill, the DP/2 for two.

Drawings and Photographs accompanying the article