[1] When the 1706 Establishment had come into effect, British naval architecture had been set on a path of conservatism that caused stagnation in the advance of shipbuilding in Great Britain.

The fiasco that was the Battle of Toulon highlighted many of the problems in British shipbuilding, with several ships unable to open gunports due to a combination of a lack of stability and insufficient height of the ports above the waterline.

'[3] Many of the fleet's problems were blamed on Sir Jacob Acworth, the Surveyor of the Navy since 1715, and an unsuccessful attempt to remove him was mounted by one of the members of the Board of Admiralty, Henry Legge.

The new Establishment of 1745 was intended to correct this situation, and at the same time solve the issues with British ships that had been the cause of complaint by sea officers for several years.

[1] The Admiralty had intended that the 80-gun ships should no longer be built, as they lacked maneuverability and stability, and their lower gunports were so close to the waterline that they could not be opened in anything above a calm sea.

Additionally, control over the Establishments was passed from the Admiralty to the Privy Council, a move intended to remove the possibility of ongoing change.

Captains complained of their poor sailing qualities, and so the Admiralty sought permission from the Privy Council to make amendments to the designs in 1750.

Although nominally ordered as 70s, these new third rates were in fact the first of the Dublin-class 74s, and represented the end of the 70-gunner as a ship type on the navy lists.