Independent Springing for Semi-trailer
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AN independent-suspension layout for tandem-axle semi-trailers • has been developed by the Grumman Aircraft Engineering Corporation, Bethpage, New York, U.S.A. It is being incorporated in trailers built by the Grumman subsidiary, Aerobilt Bodies, Inc., of Athens, N.Y. There are four pairs of wheels in the system, each wheel being separately braked, and each pair of wheels is carried on trailing links.
The suspension is provided by Torsitastic torsion units at the upper ends of each arm, these units consisting of two concentric metal bushes with an +1;:in, layer of rubber bonded between them. The Torsilastie system is designed by the B. F. Goodrich Co., and it has a dual-rate effect similar to that provided by helper leaves in a conventional suspension layout.
Lightness is the keynote of the Acrobat all-aluminium semi-trailer. The standard Unit is 35 ft. long with 2,180 Cu. ft. usable volume, and it weighs only 3 tons 12i cwt. Integral construction is employed and aluminium wheels are fitted.
300 BUSES TO BE BOUGHT
I N 1961, Sheffield Transport Depart. ment will have to meet the cost of 300 new buses to replace those obtained shortly after the war, and which will by then be approaching the end of their useful life. The expected outlay is estimated at £1.5m., and is to be met from revenue. Next year, 49 buses are to be introduced to replace trams on the Firth Part-Brightside route, and a further 46 will be needed for the conversion of other tram services.
FERRY CHARGES UP?
OFFICIALS of the Tyne Improvement Commission are studying the question of passenger fares on the ferry service linking North and South Shields. They are expected to recommend increases to help offset the ferry's deficit. A new schedule has already been drawn up for cars and commercial vehicles.