T HE problem of the rapid transport of milk in bulk
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has received close attention by wholesalers during the past few years, and in 1931 a system of coordinating road and rail transport was developed and patented by R. A. Dyson and Co., Ltd., Grafton Street, Liverpool, being put into operation by the Co-operative Wholesale Society Ltd., 99. Leman Street, London, E.1. Particulars of the earliest six-wheeled tankers built for the conveyance of milk by road and on a railway truck were published in the issue of The Commercial Motor dated October 13, 1931, and details of the later pneumatic-tyred four-wheeled tankers were published in our
B32 'issue dated July 5, 1932. Since that time big developments of this system have taken place.
The original service operated between Bruton and London, and so successful has the system proved that the C.W.S. is now operating road-rail tankers on five services, i.e., between Cricklade and Croydon, Llanharan and Woolwich, Stowmarket and Stratford, Bruton and Woolwich, and John o'Gaunt and Woolwich. A fleet of 12 Dyson road-rail tankers is now in use and during the past 3i years nearly four million gallons of milk have been carried by this means.
The method of operation on the Stowmarket-London route exemplifies the working of the system. Early each morning the Society's own vehicles collect the milk in churns from farms within a radius of 20 miles from the 'dairy. On arrival at the dairy it is first examined, then tipped into a large receiving tank, is filtered and immediately brine-cooled to a temperature of 36 degrees F. The milk then passes into the tanker, which has a capacity of 2,000 gallons, and,_ leaving the dairy at 10 a.m., is hauled by one of the railway company's Latil tractors to Stowmarket Station, a. distance of mile.
No end-loading bay being available at the station, the London and North Eastern Railway Co. made use of
an existing siding with buffer stops and built up a concrete ramp for loading the trailer on to the railway truck. The trailer is drawn up to the ramp, uncoupled, and the tractor moves forward to a position in front gf and to one side of the railway truck. Hauling the trailer on to the truck is accomplished by wire hawser, which runs on a guide pulley on the front of the truck and is attached to a coupler on the trailer axle. The power is obtained from a Winch on the tractor.
In order to take the weight off the tyres during transit, the trailer is equipped with patented steel-drum wheels which are bolted to the inner faces of the hubs B33 and engage with guides on the truck. These drumwheels also automatically guide the trailer into its proper central position on the truck. After the trailer has been placed on the truck, steel locking bars are fixed against the rail wheels, and these keep the trailer in position, holding-down chains being hooked on as a precautionary measure. The operation of loading is accomplished in about 10 minutes and the trailer is ready for the second stage of its journey.
in order to allow for delays and for the possibility of the tractor not being available exactly when required, the truck does not leave the station until 1126 a.m., when it is coupled to a passenger train, arriving at Stratford Station, London, at 4.5 p.m. It is then shunted into an unloading bay and the railway company's tractor is able to back right up to the trailer and draw it straight off the truck.
The operation of removing thetrailer from the truck is effected in four or five minutes. The tractor, which is of International make, then tows the trailer by road to the St. Nicholas Dairy of the London Co-operative Society, Ltd. The distance to the dairy, which is situated at Manor Park, is 2i miles, and the journey is completed in about 15 minutes.
On arrival at the dairy at about 4.30 p.m. the milk is pumped straight from the trailer tank into a receiving tank in the dairy and is pasteurized and bottled ready for delivery on the following morning to the Society's members. The trailer tank is washed out and sterilized and leaves the dairy at 7 p.m. the same night, being returned to Stowmarket by rail ready for use next morning if required. Actually, two trailers are in operation on this particular service and they run on alternate days. At week-ends, however, both vehicles are used, and it is interesting to note in this connection that the sales of liquid milk in London are about 50 per cent, higher on Sundays than on any other day of the week.
A close-up view show on the trailer in pos the truck. The lock , in positio
Big Reduction in Handling Charges Effected.
Perhaps the biggest saving in the use of this system is the reduction of handling charges, and the costs on this basis alone have shown a reduction of no less than 50 per cent, on methods previously in use. The capacity of the trailer tank is equal to 120 churns, and three vehicles would be required to transport this quantity of milk in churns by road. With tank lorries of 1,250 gallons capacity, two vehicles would be needed.
We are told by Mr. W. Bird, the manager of the milk department of the Co-operative Wholesale Society, Ltd., that the reliability of the road-rail system has been exceptional, and that on no occasion in the 31 years period of operation, even under the most extreme conditions of weather, has the milk arrived at the London dairy more than 15 minutes late.
Maintenance costs have proved extremely low and, beyond daily lubrication, no other regular servicing has been required. The trailers are, however, returned to the Liverpool works of R. A. Dyson and Co., Ltd., every three years for examination and overhaul. As in • B34 some caes the tankers remain in the open, even when not in use, repainting has on several occasions been found desirable, and from the maintenance point of view this has proved to be the only important item of expenditure. The pneumatic-tyred vehicles have been in operation for some nine months and the tyre wear has been found to be negligible. The mileage on the road is, of course, very small.
The original six-wheeled solid-tyred vehicles had glass-lined tanks, but the later pneumatic-tyred trailers have tanks made from Firth's Staybrite stainless steel, which has been perfected so as to resist not only rust due to ordinary exposure, but , the effects of lactic acid, which is contained in the milk. The tanks themselves are the products of Thompson Bros.
(Bilston), Ltd., Bilston. Insulation k provided by layers of Alfol foil and the outer panelling is of aluminium sheeting.
An important feature of the insulation is that the rise in temperature of the milk during transport has been found not to exceed 2 degrees F., even in the hottest weather. When carried in churns, the temperature may increase as much as 20 degrees F., and under extreme weather conditions souring may occur when such a rise of temperature takes place.
The tare weight of the trailers is four tons and fully loaded 13 tons. The charge per gallon made by the railway company for bulk milk transport by this method is on the same basis as for milk in churns, the saving being effected by a big reduction in handling charges, as previously mentioned. There is, of course, an additional charge for the use of the railway company's tractors.
In some cases, however, this charge is not incurred, the trailers being handled by the Co-operative Wholesale Society's own 6-ton vehicles.
ing the steel drum-wheel ition on the guide rail on ing bar holding the trailer n can be seen.
Special Trucks Built for the Purpose.
The trucks used for carrying the trailers are specially built by the railway companies for the purpose under Dyson-Marenbon patents. In order to minimize the overall height the truck flooring is cut away to form a well for the guide rails. Another feature is the provision of hinged flaps at the corners for bridging the gap between the truck and the e...d-loading platform. A guide-pulley for the hawser, which is used for loading and unloading the trailer, is situated in the centre at each end of the truck, and the locking bars are arranged so as to be 'quickly adjustable. In order to prevent unnecessary bumping when stopping and starting the trucks are equipped with vacuum brakes.
Since the Co-operative Wholesale Society, Ltd., inaugurated this system of milk transport, several other important wholesale milk concerns have adopted the method, and it is safe to say that up to the present time over 10 million gallons of milk have been carried by the road-rail system.
We understand that within the next few months this form of road-rail transport is to be extended to liquids other than milk, and it is likely that, in the near future, beer, petrol and oil will be transported by this means.