The Dublin-class ships of the line were a class of seven 74-gun third rates, designed for the Royal Navy by Sir Thomas Slade, although the design evolved during the construction period.
The Dublin-class ships were the first 74-gun ships to be designed for the Royal Navy, and marked the beginning of a more dynamic era of naval design than that in the ultra-conservative Establishment era preceding it.
Slade's original draught was approved on 26 August 1755 when the first two orders were transmitted to Deptford Dockyard. The design measured on the gundeck, some 4ý feet longer than the preceding 70-gun ships of the 1745 Establishment (although only 2 feet longer than the final 70-gun design - and ordered in 1754). The design measured on the keel and in breadth, to give a bm tonnage of 1,534<small></small>. However, before any of these ships had been begun Slade modified the design to give a revised length of on the gundeck and on the keel, resulting in an increased tonnage of 1,546<small></small>. Moreover, the final design was eventually on the keel, resulting in an increased tonnage of 1,554<small></small>.
The two 1754 orders had made provision for an additional (14th) pair of 32-pounder guns on the lower deck compared with the 13 pairs of the 70-gun ships of the 1745 Establishment, but had only mounted fourteen 9-pounder guns on the quarterdeck (12) and forecastle (2) to retain a total of 70; the Dublin class ships were actually fitted with eighteen 9-pounders on the quarterdeck (14) and forecastle (4); they were nominally ordered as 70-gun ships (although always designed to carry 74), but redesignated as 74-gun during construction beginning on 1 November 1755.
Two further units originally intended to be to the Dublin class design were ordered on 11 January 1757. These would have been of the same dimensions as the design mentioned above except that an amended draught on 17 March altered the keel length to and the BM tonnage would consequently have been 1,558<small></small> bm. However, on 21 May this was dramatically replaced by a larger design of 1,793<small></small> bm tons, derived from the draught of the ex-French prize , mounting 24-pounders instead of 18-pounders on the upper deck (but with the same armament as the Dublin class on other decks). These two ships finally emerged as and .
As with all wooden warships, these ships when completed and measured had slightly different dimensions (and hence BM tonnage) from the design dimensions, and the final measurements are listed below.