The Clyde-class lifeboat was operated by the Royal National Lifeboat Institution (RNLI) from two of its stations in the United Kingdom, Kirkwall and . Only three vessels were built for the RNLI, however a fourth vessel was built in the Netherlands to the same lines as 70-001 and 70-003 as a pilot boat for Trinity House.
Following a visit in the early sixties to lifeboat societies in the Netherlands and West Germany, which successfully employed cruising lifeboats, the RNLI's Management Committee decided to sanction the construction of two such boats for RNLI service. The first two boats went on trials in 1966 and in 1968 went on station at Clovelly and Kirkwall. The third boat was built as a relief but took over as station boat at Clovelly, with the first boat becoming the relief. It eventually became apparent that cruising type boats were not really suited to the RNLI's operations and the boats were used at their respective bases as normal lifeboats until withdrawal in 1988.
The Clyde-class cruising lifeboat was the largest ever built for the RNLI and the first to have a steel hull. The first and second boats differed in hull design, ON 987 having a hull designed by the RNLI's Richard Oakley, 71feet long and with a beam of 18feet, while the second boat, ON 988, had a hull designed by Irish naval architect John Tyrrell and was 70feet long and with a beam of 17feet. Both boats had similar superstructure layouts, with a flying bridge. As crews were intended to live on board, berths and messing facilities were provided.
An inflatable inshore boat was carried forward of the wheelhouse. The boats were powered by two 230bhp Gardner 8L3B 8-cylinder diesel engines driving twin screws. Eight years after the first boat had been built, it was decided to build a third Clyde as a relief boat for the first two. This was based on the Oakley hull design, but featured a completely redesigned superstructure resembling an overgrown .
| ON | Op. No. | Name | Built | In service[1] | Principal station | Comments |
|---|---|---|---|---|---|---|
| 987 | Charles H Barrett (Civil Service No.35) | 1965 | 1968–1975 1975–1988 | Trials Relief fleet | Sold 1988. Renamed Dolphin. June 2023, tripboat at Maassluis, NL. MMSI 244070415 | |
| 988 | 70-002 | 1965 | 1966–1967 1967–1968 1968–1974 1974–1975 1975–1988 | Relief fleet Relief fleet | Sold 1989 to Iceland SAR, named Henry A. Hálfdánsson. See below, | |
| 1030 | 70-003 | City of Bristol | 1974 | 1975–1988 | Sold 1988. April 2022, Named Gemini Explorer, based Dunstaffnage Marina, Oban.[2] MMSI 235084267 | |