A CLOSER LOOK AT CLOSE-COUPLED DRAWBARS

Current trends in coupling trailers closer to the drawing vehicle to allow a longer deck length within the overall limit are reviewed and a close examination is made of the effect on stability, manoeuvrability and ease of reversing. Examples are given of two different types of design and their performance is discussed. In one scheme, the extending-drawbar contar trombone, the effective length of the trailer drawbar is increased as the dolly turns relative to the rest of the trailer and the swing axle is flattened into a vertical straight line. Another approach used in the Bulthuis is to modify the steering geometry of the dolly causing the front axle to steer through an even greater angle permitting the front of the trailer to track behind the drawing vehicle with a much reduced cut-in of the trailer's front wheels. Both systems behaved well on the road but contact between the units could occur in reversing the Bulthuis system if the driver's concentration lapsed. The Contar-equipped outfit was foolproof but required adjustments to be made before reversing took place. The first system to be sold in Britain, the Ackermann-Fruehauf gl7, where the trailer is pulled by a single bar rather than and a' frame, is also described. (TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00203122
• Corporate Authors:

  Institute of Road Transport Engineeers

  1 Cromwell Place
  London SW1 25F,   England 
• Authors:
  • Dalzell, J
• Publication Date: 1984-4

Media Info

• Features: Figures; Photos;
• Pagination: p. 15-16
• Serial:
  • TRANSPORT ENGINEER
  • Publisher: Institute of Road Transport Engineeers
  • ISSN: 0020-3122

Subject/Index Terms

• TRT Terms: Couplers; Design; Drawbar pull; Driving; Economic efficiency; Handling characteristics; Spacing; Stability (Mechanics); Steering; Trailers
• Uncontrolled Terms: Articulated vehicles; Efficiency
• ITRD Terms: 1225: Articulated vehicle; 3876: Coupling; 9011: Design (overall design); 5911: Efficiency; 1203: Trailer; 1646: Vehicle handling
• Subject Areas: Design; Economics; Highways; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 00389490
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Oct 30 1984 12:00AM