British • Enterprise in Road Transport Refrigeration
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THE Morrisons Frigmoble refrigerating container for the transport of deep-frozen or perishable goods by road, rail or water, built by Morrisons Engineering, Ltd., Rochester Airport. has already made a name for itself. That company was engaged on aircraft work throughout the war, but has since specialized in refrigerating equipment, for the construction of which light alloys are employed. This change-over has enabled the company to retain most of its skilled personnel.
Six-wheeler for Uruguay
"The Commercial Motor" was invited, last week, to inspect the latest Morrisons product before its shipment to Uruguay. It is an articulated outfit carrying an independent refrigerating unit, and the form of construction employed for the double-skinned body has points of unusual interest. Framework of the inner and outer shells is made from light-alloy angle extrusions. A minimum insulating space of 6 ins. is maintained everywhere between the two skins, and this space is filled with Isoflex.
Hydrolignum impregnated plywood distance pieces are fitted to prevent heal leakage, and there are no through metal-to-metal contacts. An interesting feature is the double floor construction. floors often being a source of heat leakage in refrigerator vans.
The upper floor, which takes the load, is of 11-in. light-alloy plate, whilst the lower one, mounted directly on the chassis, is of 16-gauge sheet. Bearers running between the two consist of Hydrolignum impregnated plywood strips, set on edge and fixed to robust lightalloy angle extrusions. Framing of the inside and 'outside containers is arranged in such a manner that expansion and contraction arising from the great difference between temperatures outside and within the body are compensated.
Birmahright sheet is used, with every joint made watertight by means of nonhardening plastic cement, and closeriveted throughout with lightalloy hollow rivets. The sheet is left with its polished surface, so that the interior can be quickly and easily cleaned by pressure hose or steam jet. There are no capillary. crevices to harbour. dirt and the body is proof against termites. •
The independent refrigerating unit is located forward in a separate compartment. completely sealed from the rest of the body. It includes a compressor driven by a small Petter petrol engine. the two being arranged on a common becIplate, mounted on rubber blocks.
Refrigerant is driven through expansion valves to a series of vacuum plates in the cold room. In the event of engine failure on the road, a warning pilot lamp lights up in the cab of the tractor.
This Frigmobile body is mounted on a Dyson drop-frame semi-trailer chassis coupled to a Leyland Comet E.C.O. 3L oil-engined tractor. It has been designed to carry a net payload of 6 tons of fresh fish. This will be maintained at a constant temperature of about 35 degrees F. in the varied atmospheric temperatures experienced in Uruguay. A remarkable point about this outfit is that the light allciy, body, together With the refilgerat.. plant and all other equipment, weighs less than .30 cwt..
Particularly.' suited for use with this vehicle re Morricraie 'containers, constructed from' the sanie.non-ctirrosive light alloys.. Convenient to. handle and easily sterilized, these neat metal boxes .an be stacked to use -every inch of floor. space within the body. Should an independent refrigerating plant not be required, the Frigmobile semi-trailer can be delivereelwith bunkers for solid CO2, or with cold hold-over plates.
Road-Rail Containers
The latest model of the Frigmobile road-rail container also has an independent refrigerating unit. The container, like the semi-trailer body just described, is built of light alloys on aircraft lines, and in this instance the compressor is driven by a small P.S.C. petrol engine.
As in the case of the semi-trailer, the two skins are of polished Fiirmabright and it is claimed that, if kept clean, this surface reflects 95 per cent. of radiant heat. It is, moreover, so thin that there can be little heat absorption.
Marine-type alloys are employed in all these Morrisons products, making them highly resistant to corrosion.