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Liquids in Notable

By P. A. C. Brockington,

A.M.I.Mech.E.

IN whose interests is produce delivered in bulk? Initially it is often for the benefit of the customer, who has estimated that the capital outlay on bulkstorage facilities and the necessary distribution system in the factory or depot, would be warranted to reduce manufacturing costs. Sometimes the suppliers would prefer bulk haulage, so that advantage could be taken of equipment already in existence for bulk loading, or would be willing to install the necessary plant to obviate packaging costs and reduce storage space.

The haulier, or the supplier's transport manager, is generally consulted after estimates have shown the expenditure to be worthwhile if suitable vehicles are available. A saving on transport costs may be a direct or secondary objective of the original plan. In practice, the transport economy achieved is frequently the most important factor.

In many industries, day-to-day deliveries must match variable consumption rates, and it is essential that the service be flexible. Transport economy is. however, mainly a function of carrying the maximum load whenever possible, and as the vehicles are costly to purchase and to run, the difference between a large profit and a severe loss on the haulage account often depends upon " mixing " the fleet in the most appropriate proportions.

The transport of liquid fuels and so on in large quantities is a long-established bulk traflic, but of more immediate interest to the transport manager who is exploring the possibilities of this method of haulage is the conveyance by tanker of produce which is normally, or for some purposes, carried in containers.

Although the bulk transport of liquid oxygen is a highly specialized traffic, the determinative and operational factors include many which are representative in an extreme sense of those in other bulk-haulage spheres.

The decision of the British Oxygen Co., Ltd., Bridgewater House, Cleveland ftow, London, S.W.1, to install costly plant for the liquefaction of oxygen at a number of centres throughout the country was made with the specific objectives of reducing transport costs and storage space and of facilitating the distribution of the gas at the customers' works. The equipment of the vehicles had had to be designed to preserve the valuable load according to the exacting temperature condition of —186 degrees C. and the fleets organized to meet the day-to-day requirements of industry.

An amount of gaseous oxygen in cylinders equal to the liquid load carried by a 7-ton bulk-haulage vehicle requires seven platform lorries of the same capacity and approximately a fourfold capital outlay on vehicles and cylinders. Moreover, with the recent increase in the use of oxygen for billet cutting, descaiing and so on, many steel makers could not handle the large number of cylinders needed.

The sphere has the smallest surface-to-volume ratio of any shape, and the majority of vehicles is equipped with this form of container to reduce evaporation losses during transit and storage. A new type of insulation may, however, enable cylindrical containers to be generally adopted, which would increase the payload for a given vehicle capacity and give better weight distribution. Some cylindrical tanks are being used experimentally.

One of the largest fleets of its kind in the country is operated by Albion Sugar Co., Ltd., Woolwich, London, S.E.18, for the bulk transport of sugar products, syrups and liquid glucose in fluid form to breweries, manufacturing confectioners and makers of preserves within a radius of 200 miles. This distance represents the practical economic limit, under existing conditions, beyond which bulk transport would not pay, but given orders of sufficiently large quantities, the radius could be increased. Long-distance deliveries require that the produce be loaded at a comparatively high temperature to ensure that the delivery viscosity be sufficiently low for easy pumping into storage tanks.

Foden 15-ton rigid eight-wheeled tankers, powered by Gardner 6LW engines, form the majority of the larger vehicles in the fleet, and these carry a 12-ton payload, which is equal to about 1,900 gallons of liquid, with variations according to specific gravity. The equipment includes 4-in. reversible-flow pumps, and although filling at the factory is by gravity, these can be employed for loading in addition to their normal use for discharging up to heads of 80 ft.

Another advantage is that the pump enables the residual liquid in the hose to be returned to the tank, which avoids any possibility of wastage when the hose is uncoupled. The tanks are of mild steel and are lined inside and lagged outside with special materials.

Other vehicles include A.E.C. and Bedford tankers, the Bedford.s being articulated units of 1,400-gallon capacity. Twoor three-compartment tanks are fitted, the largest being divided into 5-ton, 4-ton and 3-ton compartments, which discharge into a common extension. Only one type of product is carried on any given journey.

When the liquid is carried in containers, steel drums are employed, which have to he regularly reconditioned. Steaming out. inspection and filling are costly in terms

of labour, and other disadvantages include marking up the weights and grades, the large area of storage space required, the difficulties of manhandling and a 25 per cent. deadweight on delivery and return journeys. A I5-ton platform lorry loaded with drums has a genuine payload of 10 tons. The operation of road tankers on a door-to-door service is far more economic than using road-rail tankers.

Twenty years ago a porcelain-lined 1.600-gallon tanker unit, based on a Carrimore trailer and hauled by a Vulcan tractor, was purchased by Vine Products Ltd., Kingston-onThames, to meet the limited demand of customers for the delivery of wine in bulk. Since then many wholesalers and distributors have installed the necessary equipment for storing and handling wine in bulk to save labour in the handling of casks, and the use of vehicles with a larger tank capacity has become a necessary, but acceptable requirement.

Wine in Steel Tankers Following the successful operation of an E.R.F. tractor towing a Carrimore four-wheeled tandem-type semi-trailer with a Steel Barrel three-compartment 3,000-gallon stainlesssteel tank, a Scammell frameless semi-trailer is being added to the fleet, the tractor being a dual-purpose unit for alternative use with a platform trailer capable of carrying 30 hogsheads.

The overall length of this vehicle is about 5 ft. less than that of the E.R.F. unit and the weight saved is nearly a ton. Each vehicle is powered by a Gardner 6LW engine; the Scammell is fitted with a five-speed-and-overdrive gearbox and a specially designed wine pump driven from the power take-off,

By carrying in bulk, the useful wine load is increased by about 30 per cent., and the cost of cooperage and of returning the empties is obviated. A hogshead has a long life, but it must be inspected, and possibly repaired, after every delivery. The wine from a tanker is pumped straight into the vats without loss, and the turn-round time is greatly reduced. Division of the tank into three compartments enables a variety of wines to be carried, and lengths of " sweetened " hose up to 240 ft. provide for delivery to vats remote from the unloading point

Oil in 200-gallon Lots

The regular delivery of small quantities of lubricating oil in bulk has lately been adopted by the Vacuum Oil Co., Ltd. as a method of distribution to garages in many parts of the country. Although the bulk delivery of 200 gallons and larger amounts has been practised for many years, it was not until the steel shortage caused packaging difficulties that the possibility of using multi-compartment tankers for lesser consignments was considered. The method has now been fully established as a means for promoting distribution economy and for facilitating handling at the garages, and will be progressively extended to new areas.

Typical of the vehicles employed is a Bedford rigid 5-tonner on which is mounted an A.P.V. light-alloy tank. This has three compartments and a total capacity of 1,200 gallons, which represents a gain in payload of approximately 200 gallons compared with a packaged load in a van of similar weight capacity. The oil is discharged by gravity.

Included in the fleet operated by Edgar Vaughan and Co., Ltd., Legge Street, Birmingham, is a Leyland Comet tractor with two Tasker semi-trailers, one of which is a 2,000-gallon tanker with four 500-gallon compartments and the other a drop-sided platform vehicle. This combination enables the concern to take full advantage of limited bulk orders for machine-tool lubricants and cutting oils, and despite the division of duties, the lower cost of delivery by tanker and the saving on filling, weighing, stencilling and so on allows a reduction in purchase price of 21d. to 31d. a gallon. The tractor with one driver is employed on bulk transport for about half the normal running hours.

A time-saving feature of the tanker equipment is the grodbing of the discharge valves and controls at the side of the vehicle, and the use of a common delivery extension. The tank is of steel and is cleaned internally with mineral oil and a squeegee. The oils are sold by weight in amounts

of not less than 500 gallons, and, when required, may be discharged through a long pipe to a distant workshop. The saving on barrel costs is about fl 5s. a drum for every three return journeys.

When the draught beer is delivered to a licensed house in casks from the brewery of Mitchells and Butlers Ltd., Smethwick, Birmingham, two draymen accompany the driver to unload the containers. The cost of cooperage is heavy, and casks take up valuable storage space.

Two 10+-barrel tanks of 378-gallon capacity, mounted on Austin 5-ton chassis, and four 10-barrel tanks on Thornycroft 5-ton chassis, are used for deliveries to those houses equipped with storage tanks and compressors when they were built before the war, and the saving on transport and handling costs is substantial. The system would be expanded but for the high capital cost of installing tanks in existing establishments.

The A.P.V. tanks are of stainless steel and each has two compartments with separate pressure gauges and discharge cocks. Air at a pressure up to 15 lb. per sq. in. is supplied by the compressor on the premises, so that storage tacks located at any normal height can rapidly be filled.

Preventing Corrosion by Chemicals The main problem associated with the transport of chemicals in bulk is the provision of a tank material, or lining, which is resistant to corrosion. Stainless steel of various kinds is suitable for some of the many hundreds of chemicals carried, whilst others often require a rubber or synthetic lining. A recent development is a p.v.c. lining supplied by the Dunlop Rubber Co., Ltd., which can accommodate a wide range of chemicals.

Of a fleet of 27 C-licence vehicles operated by Synthitc Ltd., West Bromwich, for the transport of formaldehyde. 25 are tankers and two platform lorries are equipped to accommodate 1.000-gallon demountable tanks. The majority of the fleet comprises Vulcan rigid four-Wheelers, powered by Perkins P6 engines, which have a payload of 5 tons (1,000 gallons). The remainder are E.R.F. tankers of 7-71-ton capacity for loads up to 1,400 gallons. The size of the tankers is dictated by the capacity of the customers' storage tanks.

The tanks of the 5-tonners are of aluminium to keep the vehicle weight down to the 30 m.p.h. classification. The larger tanks are of copper, which is preferred because it is not attacked by the formaldehyde and has an indefinite life. None of the tanks is lagged, except a special copper tank for carrying low-alcohol fluid. An E.R.F. 11+-tonner is engaged on a run to Northern Ireland by the PrestonLarne or Preston-Belfast ferry.

Tanker Replaces Bottles

A concern operating a large C-licence tanker fleet employs a 15-ton rigid eight-wheeler to do the work previously performed by three tractor-trailer platform units carrying the liquid in bottles. The fleet also includes smaller tankers, some of which arc articulated, and the large savings which have been obtained are partly the result of selecting a range of vehicles to meet changing demands without undue disorganization or the maintenance of surplus vehicles at normal times.

Cost figures provided by the concern are of interest, particularly as the comparative costs of road-rail transport and hired road tankers are included. For delivering approximately 470,000 gallons a year by the 3.000-gallon tanker a distance of slightly more than 100 miles, the cost is approximately £2,400. If hired transport were used, the cost would be £2,764 a year and by road-rail tanker the annual cost would be £9,210. By using C-licence vehicles instead of road-rail tankers, the concern is, therefore, saved 3.47d. a gallon.

On a run where bulk transport is particularly advantageous, another concern has saved nearly 8d. a gallon by adopting this method, but on some runs the gain is much smaller.

Next week I will deal with the operation of vehicles engaged on the bulk haulage of solids and powdered materials.