Bristol HG
The Bristol HG was a truck produced by the British manufacturer Bristol Commercial Vehicles . The designation HG stands for H eavy G oods (heavy load), but is occasionally deciphered as H eavy goods ri G id to distinguish it from the semi- trailer version HA ( H eavy goods A rticulated) .
The vehicle was built exclusively for the state British Road Services (BRS). Bristol Commercial was in the wake of the nationalization of the British transport industry under the control of the British Transport Commission arrives and in 1965 a subsidiary of the holding company Transport Holding Company , which from the British Transport Commission had emerged. Bristol Commercial was only allowed to sell vehicles and chassis to other parts of the British Transport Commission or other subsidiaries of the Transport Holding Company . The British Road Services were for long distance freight traffic in the UK jurisdiction. In the immediate aftermath of World War II, Britain experienced a noticeable shortage of heavy trucks. Many small haulage companies were inadequate to source and operate long-haul trucks. The resulting problems in the transport industry were one reason for the formation of the BRS . To remedy the defect, BRS commissioned the development of a heavy, four-axle chassis with a total mass of 22 tons. Similar vehicles were the Leyland Octopus and AEC Mammoth Major 8 .
Bristol Commercial had no experience of developing heavy four-axle trucks, in particular the design of the two steerable front axles caused problems. The BRS left Bristol Commercial therefore hire three chassis different manufacturers to evaluation purposes . The tests also showed that the 8.14L AVW engine developed by Bristol Commercial was too inefficient to operate the vehicle with a trailer. Therefore the O.600 from Leyland Motors , a diesel engine with 9.8 l displacement, was used. This engine was later replaced by the O.680 , also from Leyland . Such vehicles were given the type designation HG6L ( H eavy G oods - 6 cylinder engine from L eyland). The first vehicles were delivered from 1952. The overall length of the chassis was 9093 mm (29 feet 10 inches). The engine drove through the clutch and Bristol - five-speed gearbox to the single-reduction rear axle. This was considered sufficient as the trucks were only intended to be used in the UK. As a differential gear one was Bevel of Bristol Commercial with a ratio of 6.33: 1 is installed, which was accessible through a hatch in the cargo area. The air brake of Westinghouse acted on the first, third and fourth axis. The electrical system operated at a voltage of 24 V. The tank with a capacity of 32 gallons (approx. 145 liters) allowed a range of approx. 300 miles (approx. 482 km). The front handlebar superstructures came from different manufacturers. Production of the HG ended after just four years in 1956.
In addition to the HG platform version , the HA semi- trailer was also produced from 1955 . By 1964, 653 units had been delivered to the BRS . In contrast to the HG , it only had two axes. Since the O.680 engine was problematic in practical use, the 6LX from Gardner , also a six-cylinder diesel engine, was used for the last vehicles . A six-speed gearbox was also installed along with this engine. These vehicles were given the type designation HG6G ( H eavy G oods - 6 cylinder engine from G ardner). A total of 946 were HA built that were t approved for a total mass of the 24th