Amalgamated Drawing Office

The Amalgamated Drawing Office was the design and engineering department of the British Motor Corporation. From the early 1950s, the resulting projects of the office were known by the initials ADO. The numbers were assigned to vehicle and engineering projects, some resulting in production models. The ADO numbering system continued well beyond BMC's absorption into British Leyland, who continued to use the convention (not, however on any former Leyland Motors marques such as Rover or Triumph) until the late 1970s.

Contrary to popular belief, ADO does not stand for Austin Drawing Office, the "amalgamation" referring back to the merger of Austin and Morris to form BMC in 1952.

Various conventions were used from the early 1970s within British Leyland and subsequently the Rover Group, even though the Austin-Morris division of BL continued to use the ADO convention until the company's collapse and subsequent Ryder Report restructuring in 1975.

The Specialist Division encompassed Rover and Triumph. Only four projects were ever pursued during its existence before the division was renamed Jaguar Rover Triumph, and integrated within Leyland Cars in 1976.

Following the various reorganisations of BMC, and the creation of the combined Leyland Cars division of British Leyland, the codes changed to LC in the mid 1970s. Following the merger of Rover's Specialist Division SD codes, these resulted in LM (Light Medium) codes.

There was also a short lived "AR" code following the renaming of BL Cars Ltd to Austin Rover in 1982. Most of the AR-designated projects were either abandoned or were renamed using the Rxx convention (see below)

After British Leyland (now BL plc) was renamed Rover Group and its subsequent re-privatisation and sale to British Aerospace (and later, BMW), project codes in the 'Rxx format were generally used, although some projects were given alternative designations or sometimes names. Projects in this series were not numbered consecutively, unlike the earlier conventions. The later RD code was used for projects undertaken by MG Rover from 2000 onward, to that company's collapse in 2005.

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