Hydrolastic

Hydrolastic is a type of space-efficient automotive suspension system used in many cars produced by British Motor Corporation (BMC) and its successor companies. Invented by British rubber engineer Alex Moulton, and first used on the 1962 BMC project ADO16 under designer Alec Issigonis, later to be launched as the Morris 1100.

Hydrolastic is a type of space-efficient automotive suspension system used in many cars produced by British Motor Corporation (BMC) and its successor companies. Invented by British rubber engineer Alex Moulton, and first used on the 1962 BMC project ADO16 under designer Alec Issigonis, later to be launched as the Morris 1100.

Hydragas

Hydragas is a type of automotive suspension system used in many cars produced by British Leyland and its successor companies. Invented by British automotive engineer Alex Moulton, Hydragas is an evolution of the previous Hydrolastic system. Manufactured under licence by BTR AVS under the Dunlop brand at the historic Holbrook Lane site. It was first introduced in 1973 in the Austin Allegro and was later fitted to the 1975 Princess and its successor, the 1982 Austin Ambassador. Both systems attempt to address the ride-handling compromise of car suspension by interconnecting the suspension of the front and rear of the car in some way. Hydragas attempted to perform the same function and advantages as the hydropneumatic system developed by Citroën, but without its attendant complexity. The heart of the system is the displacer units, which are pressurised spheres containing nitrogen gas. These replace the conventional steel springs of a regular suspension design. The means for pressurising the gas in the displacers is done by pre-pressurising a hydraulic fluid, and then connecting the displacer to its neighbour on the other axle. This is unlike the Citroën system, which uses hydraulic fluid continuously pressurised by an engine-driven pump and regulated by a central pressure vessel. Despite early problems (the Allegro version of Hydragas was found seriously wanting), it was gradually developed into an effective and efficient alternative to steel springs on later BL/Rover Group models such as the Austin Metro and MGF. The Metro originally featured independent Hydragas units, with no fore/aft interconnection (the pipework was deleted on cost grounds, against the advice of Moulton). While the Metro was praised for its handling, and offered a significant improvement in ride quality over the Mini, it was criticised for its tendency to pitch and bounce on uneven roads - precisely the characteristics the interconnection was intended to remove. The revised Rover Metro had its suspension interconnected and went on to receive plaudits for the quality of its ride. The Austin Maxi was the only in production car to feature both systems. The Maxi featured 1100 designed Hydrolastic units with the regulator valve fitted with the interconnection pipe. However, in 1978 production of Hydrolastic bottles at Dunlop came to an end and BL modified the Princess Hydragas bottles to fit. This involved fitting a new front subframe design, with a larger diameter horizontal chamber in the subframe. MGF was the last vehicle platform to use this design. The Hydragas system was dropped in favour of conventional suspension by Rover when BTR AVS sought to increase the price of the units substantially. After servicing the spares market for some years a buyer was found and the production line was sold.

Text derived from https://en.wikipedia.org/w/index.php?oldid=1318375952 under CC BY-SA 4.0; modifications have been made.