Firth of Forth

Firth is a cognate of fjord, a Norse word meaning a narrow inlet.

Forth stems from the name of the river; this is *Vo-rit-ia (slow running) in Proto-Celtic, yielding Foirthe in Old Gaelic and Gweryd in Welsh.[3]

It was known as Bodotria in Roman times. In the Norse sagas it was known as the Myrkvifiörd.[4] An early Welsh name is Merin Iodeo, or the "Sea of Iudeu".[5]

Geologically, the Firth of Forth is a fjord, formed by the Forth Glacier in the last glacial period.[6] The drainage basin for the Firth of Forth covers a wide geographic area including places as far from the shore as Ben Lomond, Cumbernauld, Harthill, Penicuik and the edges of Gleneagles Golf Course.[7]

Many towns line the shores, as well as the petrochemical complexes at Grangemouth, commercial docks at Leith, former oil rig construction yards at Methil, the ship breaking facility at Inverkeithing and the naval dockyard at Rosyth, along with numerous other industrial areas, including the Forth Bridgehead area, encompassing Rosyth, Inverkeithing and the southern edge of Dunfermline, Burntisland, Kirkcaldy, Bo'ness and Leven.

From left to right The Queensferry Crossing, the Forth Road Bridge and the Forth Bridge from the South Queensferry side.

The firth is bridged in two places. The Kincardine Bridge and the Clackmannanshire Bridge cross it at Kincardine, while further east the Forth Bridge, the Forth Road Bridge and the Queensferry Crossing cross from North Queensferry to South Queensferry. The Romans reportedly made a bridge of around 900 boats, probably at South Queensferry.[8]

From 1964 to 1982, a tunnel existed under the Firth of Forth, dug by coal miners to link the Kinneil colliery on the south side of the Forth with the Valleyfield colliery on the north side. This is shown in the 1968 educational film Forth – Powerhouse for Industry.[9] The shafts leading into the tunnel were filled and capped with concrete when the tunnel was closed, and it is believed to have filled with water or collapsed in places.[10]

The Fife-Edinburgh hovercraft service

In July 2007, a hovercraft passenger service completed a two-week trial between Portobello, Edinburgh and Kirkcaldy, Fife. The trial of the service (marketed as "Forthfast") was hailed as a major operational success, with an average passenger load of 85 percent.[11] It was estimated the service would decrease congestion for commuters on the Forth road and rail bridges by carrying about 870,000 passengers each year.[12] Despite its initial success, the project was cancelled in December, 2011.[13]

The inner firth, located between the Kincardine and Forth bridges, has lost about half of its former intertidal area as a result of land reclamation, partly for agriculture, but mainly for industry and the large ash lagoons built to deposit spoil from the coal-fired Longannet Power Station near Kincardine. Historic villages line the Fife shoreline; Limekilns, Charlestown and Culross, established in the 6th century, where Saint Kentigern was born.

The Ro-Pax ferry Blue Star 1 passing under the Forth Bridge in the Firth, en route from Rosyth to Zeebrugge.

The firth is important for nature conservation and is a Site of Special Scientific Interest. The Firth of Forth Islands SPA (Special Protection Area) is home to more than 90,000 breeding seabirds every year. There is a bird observatory on the Isle of May.[14] A series of sand and gravel banks in the approaches to the firth have since 2014 been designated as a Nature Conservation Marine Protected Area under the name Firth of Forth Banks Complex.[15][16]

The youngest person to swim across the Firth of Forth was 13-year-old Joseph Feeney, who accomplished the feat in 1933.[17]

In 2008, a controversial bid to allow oil transfer between ships in the firth was refused by Forth Ports. SPT Marine Services had asked permission to transfer 7.8 million tonnes of crude oil per year between tankers, but the proposals were met with determined opposition from conservation groups.[18]

Two of the three bridges across the Firth, viewed from Dalmeny, Photo taken before construction began on the Queensferry Crossing.

Satellite photo of the Firth and the surrounding area

• Bass Rock
• Craigleith
• Cramond
• Eyebroughy
• Fidra
• Inchcolm
• Inchgarvie
• Inchkeith
• Inchmickery with Cow and Calf
• Lamb
• Isle of May

• Lowest bridging point: Stirling

North shore

South shore

Map of the Firth

Wikisource has the text of the 1911 Encyclopædia Britannica article "Forth".

• Isle of May bird observatory
• Forthfast experimental hovercraft service, 16–28 July 2007
• Inchcolm Virtual Tour Take a virtual tour around some of the Inchcolm's military defences