HANDLING SHIP CARGOES BY ELECTRIC TRACTOR.
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How Economies Have Been Effected by the Use of Mechanically Propelled Vehicles at Toxteth Docks. An Ingenious Lifting Attachment.
THERE is much room tor economy in the handling processes of goods for import and export, in the dock sheds and the various ports throughout the country, and it is rather surprising that even in a port like Liverpool much of the work that could be done mechanically is still performed by hand. Old-fashioned methods seem to be venerated as nothing else under the sun, and although there are scores of devices designed to effect savings in handling charges; only a very few are adopted. -If one toes to any of the northern dock sheds at, Liverpool when liners are being unloaded he will find scores of men with hand trucks conveying produce from the ship's side to the stowing places. The weight of the loads are very light, the movements of the men slow, and the method costly.
If a reader, however, goes to Toxteth Dock, he will find an entirely different system in operation, for Messrs. Elder Dempster and Co., who run a large fleet of steamships between West Africa and other parts of the world and Liverpool, make big use of electric trucks and portable electric cranes for handling such a wide range of commodities as timber, oil palm kernels, cocoa, bales of cotton, peanuts,' etc. There are ten electric trucks and tractors in operation at this shed, with a capacity of one ton and upwards, and comprised chiefly of L,ansings. There are also Ediions, B.E.V.'s, a Hunt ma-chine, and a Walker 10 ton tractor. The uses for these vehicles are limitless, and every day new uses are being found for. them, we were told.
Solong age as in 1916, the 'Elder Dempster Co. had in mind the utilization of the electric truck, as it was then felt that the advantages of mechanical haul age as a means of dealing with indoor transport were daily becoming more manifest. The work of dealing with the transport of thousands of tons of cargo discharged from steamers in or about the dock sheds, had hitherto been under
taken by hand trucks, and up to that time no serious attempt had been made to deal with the obvious inefficiency of this method. No doubt, in some 'measure, this had been due to the difficulties presented by mixed cargoes and the sorting-out process, accompanying the handling of inward and outward freight.
Electricity, which. had already played such an important part in light, power and communication services, had made possible the advent of the electric trac
tor, which was designed especially for the, handling of goods at moderate speeds, in and about warehouses, etc. The advantages claimed were its mobility, small wheelbase and gauge, simple control, and the entire elimina-, tion of fire risk. For a particular adaptation in the company's service, as a means of hauling timber across the Toxteth dock shed to the river front, and dealing with palm 01, kernels, etc., this **stern presented many advantages.
Dealing with the transport of timber—. the old method necessitated the employment of 12 to 16 men, hauling a nonsteering bogie truck with a log, a distance of 60 'to, 80 yards in a diagonal direction. With an electric tractor; logs weighing from two to five tons carried on a bogie of a special design, it was pointed out, could be hauled across this distance in about 50 per cent. of the time and with the employment of only one manin addition to the driver of the vehicle on the journey. It was recog
_ nized that additional men would be required for the purpose of loading up at 'the dock side.
This &Teat, saving in labour constituted the main features for the adoption of the system. It was assumed that an electric tractor would accomplish three times the work undertaken by hand trucking, and estimating the average at four miles per hour for a working day of te‘n hours, a distance of 40 miles would be covered. Taking the average load at two tons, this would equal 40 ton miles, or a total number of journeys equal to 880. Considering half of this total, as loaded journeys at two tons per journey the following interesting result was obtained :— 440 x 2 = 880 tons of timber carried per working day of ten continuous hours, against the tonnage carried by -hand
trucks 880 3 293 tons per working day.
The comparison made in 1916 with hand trucks, based upon these figures was as follows:— 75 per cent., not considering any standing charges. The charge per ton carried for electric vehicles being 1.3d. as against 5d. for band trucks.
The yearly eitimated saving is £2,500.
The facilities for charging purposes were at hand inside of the ToXteth dock shed, where the batteries could be charged up at a rate which exceeded the normal discharge four times, so that very Httle delay was likely to be caused through the unexpected exhausting of a battery.
Such is the historical aspect of the electric vehicle fleet of Messrs. Elder Dempster and Co., and although the figures are now out of date, they form the basis of interesting comparison, when it is recognized that, tractors are now costing about 50 per cent, more; the motor generator set and tools would cost about 10 per cent, more; hand bogies cost about, £80; renewal of tyres is about 100 per cent_ up ; labour is 14s. a day foreight hours; renewal gears 100 per cent. up ; the cost of renewal of batteries has also advanced substantially, and electricity charges are up by about.100.per cent. The vehicles are fitted with Edison ite.el plate and Chloride cells.
When visiting the Toxteth 'dock shed, we observed a. distinctly novel vehicle in operation. It is the only one of its kind in IMO, having been designed by Mr. J. B. Wilkie, the superintendent engineer of the Elaier Dempster Co., and Mr. G. H. Rae, and is used for the transport, in the dock sheds and on the quayside, of heavy casks of palm oil weighing up to 1,800 lb. It was a Lansing box truck with an attachment consisting of an H section steel frame suitably stiffened with steel plate and secured to the underside of both axles of the electric tractor by means of extended belts. This frame carries at one end pivoted arms of a particular formation suitably stayed, the stay forming at the same time l bearing for two pairs of wire rope pulleys. A platform formed at the other end of the frame carries the small reversible electric motor and Mechanism for raising the barrel or cask. The whole of the attachment forms a complete unit, which can be assembled distinct from the tractor, and only requires to be bolted to same.
The electric motor for operating the mechanism is suitably geared by means of a spur and pinion to a screwed shaft. This screwed shaft works through a nut contained in a steel cross-head, at the extreme ends of which are attached the lifting wires, consisting of extra flexible wire rope. The wire-rope:is passed over a series of pulleys attached to pivoted arms and also contained in a steel frame, the pull on the wire ropes effecting the depression of the pivoted arms, thus lift,in the barrel.
The method of operating the truck with the barrel lifting is as follows :— The driver of the vehicle when approaching the barrel to be lifted, operates the starter of the lifting motor in the direction required to lower the pivoted arms, and, until they reach the ground. He then approaches the barrel which is flat end on, until the arms are right under the barrel, this being permissible owing to the curvature of the barrel. The motor is then reversed, this movement depressing the lever arms at one end, thus rais= lug the barrel on the other end. The barrel now being raised dear of the ground, the vehicle is free to transport it when and where required. The vehicle will run about 10 hours before the charge is exhausted.
This novel truck has only been in operation about three months. The old method of handling thisakind of cargo meant the employment -of a gang of nine men to shift barrels of palm oil, weighing 1,800 lb., say, a distance of 120 yards. Ihey worked in relays of three, the first rolling the barrel 40 yards, then returning for the next, leaving the second gang to pass the barrel on to the third, whose duty it was to see that it was stored in such a way that it would be easy to draw samples. The electric truck dispenses with all these operations; as a matter of fact it cuts out the labour almost entirely. To manoeuvre the vehicle into position for lifting a barrel and raising it about 4 ins, from the ground takes 10 seconds, 5 of which are required to raise the arms of the truck.
Logs 'up to 7 tons in weight are removed with Lansing five ton tractors. which tow them up to 350 ft. Sometimes as many as three trailers are used with the electrics. The ten ton Walker truck, with Edison steel plate cells, is one of the mast useful vehicles in the shed, and is constantly in-service hauling the portable electric cranes (of which there
are about 30 in this one shed) into position.
These portable cranes for internal use in the shed are most useful. Current is conveyed to the motor by means of a flexible wire, and, by means of gearing controlled by a man who is seated at the crane head the movements of the jib are effected. But the cranes are not capable of self-locomotion, being supported on four small wheels, one at each corner of the framework. For moving them from place to place where are situated the goods that are required to be moved, the ten tun Walker truck serves a useful purpose. When three hatches are being worked on the ship, it has been found that 15 men and six trucks can do as much work as is usually performed by 60 men.