Wednesday 14 February 2018

Approaching Liverpool from the Sea

My trips to Liverpool are normally by train but much of the city's fame arises from its importance as a sea port, situated on the River Mersey. Arriving at Liverpool by sea involves various problems for mariners - the River Mersey has the second highest tidal range in Britain, with spring tides exceeding 10 metres and entrance to the river from the sea is impeded by Coastal Bars.

Coastal Bars

Coastal bars (often referred to simply as 'Bars') are shallows or shoals in the sea bed formed by the movement of sand and sediments where the tide meets the flow of a discharging river. Navigating through these areas is called "Crossing the Bar". Apart from the risk to ships of grounding on a bar, in some weather conditions seas breaking over the bar create additional hazards, requiring good local knowledge for safe passage.

Liverpool Shipping in 1870

Commenting on the approach to Liverpool from the sea, the 'West Coast Pilot' for 1870 states "The numerous sands which encumber the entrance of the Mersey will be better understood by a reference to the chart than by reading the most elaborate description." At that time, there were various land-based lighthouses, three light vessels (North West, Formby and Crosby) and an elaborate system of buoys to identify the channels. Because of these hazards, it was compulsory for all ships to take a pilot with up-to-date local knowledge. There were 12 pilots who cruised in pilot sailing boats, ready to board ships and take charge of the navigation. The pilots were controlled by Mersey Docks and Harbour Board.

Continued dock expansion

The success of the port of Liverpool meant that expansion of the docks continued until the 1920s (see Notes on Liverpool and its Docks). During this period, steam propulsion replaced sail, iron and steel replaced wooden construction and vessel sizes increased, so that most shipping became concentrated in the dredged channel now known as Queen's Channel with the 'Bar' lightship serving as the pilot rendezvous location for inbound ships.

Liverpool 'Bar' Lightship

In 1947, the 'Bar' lightship duty was being carried out by the 'Alarm', shown in the aerial view below.


Mersey Bar Lightship 'Alarm' and SS 'Collegian', Liverpool Bay, 1947.

The firm of Philip and Son built the relacement lightship 'Planet' in 1969 which, with its crew of seven, became the Mersey 'Bar' lightship. There's a Wikipedia article on the lightship builder here. In 1972 an unmanned buoy replaced the lightship which was sold to Trinity House and continued to serve at various sites before being retired in 1989. Saved for preservation from the breakers, she eventually saw service as a cafe/bar and museum whilst moored in Canning Dock, Liverpool, where I took the photograph below.

The preserved Lightship 'Planet' in Canning Dock, Liverpool.

Following a long-running dispute between the owner of 'Planet' and the Canal and River Trust, the lightship was seized by bailiffs in 2016 and towed to Sharpness where it faces an uncertain future. There's more information about 'Planet' on the interesting Offshore Radio Museum Site.

The unmanned buoy which replaced 'Planet' in 1972 was known as a Large Automatic Navigation BuoY (LANBY buoy). The design, featuring a circular hull and central mast provided with a powerful light, originated in America and was adapted for use in Britain. According to research by the Mersey Lightvessel Preservation Society, the LANBY buoy was, in turn, replaced in 1993 by what I believe is still the current installation known as Light Float 'Bar Racon' and operated by Trinity House.

'Bar Racon'

The addition of 'Racon' to the name indicates that, in addition to the normal light signal, the installation provides an identifiable radar return (the name is a contraction of RAdar beaCON). The widespread introduction of Radar on ships represented a significant advance in safety and the addition of a radar transponder to a buoy means that, when the transponder receives a radar pulse from a ship, it transmits a return signal including a simple identity, which assists the correct identification of the radar return received by the ship.

Light float 'Bar Racon' in Liverpool Bay (Photo: Fuelcellworks).

An article in Fuelcellworks here discusses the installation of a methanol fuel cell to improve the endurance of the light float.

'Crossing the Bar'

The term is familiar to many people as the title of a short poem by Alfred, Lord Tennyson (1809-1892), a celebrated poet from the Victorian era whose works remain popular. He uses leaving harbour and sailing out to sea as a metaphor for dying.
Sunset and evening star
And one clear call for me!
And may there be no moaning of the bar,
When I put out to sea,

But such a tide as moving seems asleep,
Too full for sound and foam,
When that which drew from out the boundless deep
Turns again home.

Twilight and evening bell,
And after that the dark!
And may there be no sadness of farewell,
When I embark;

For though from out our bourne of Time and Place
The flood may bear me far,
I hope to see my Pilot face to face
When I have crossed the bar.

Alfred, Lord Tennyson with his wife Emily and sons Hallam and Lionel.

Wikipedia has an article on 'Crossing the Bar' here, suggesting that the verses were inspired by a crossing of the Solent to his home at Farringford House on the Isle of Wight. There's more about Farringford House and the famous people who settled in the area at the website Tennyson’s Celebrity Circle.

Liverpool Shipping today

Shipping in the Mersey today is very different from that in 1870 but sands remain a problem and continuous dredging operations are necessary to allow large, modern ships access and charts are still essential (although, increasingly, those charts are electronic). Although the structures of the former light houses survive, none are now active light houses but the "elaborate system of buoys" already established in 1870 has been modernised and complies with one (of two) internationally-recognised systems of navigation buoys. But, despite all the improvements brought about by the use of radio, radar, AIS and Electronic Chart Display and Information Systems (ECDIS) which I discussed in the post Watching The Ships Go By, the system of using a human pilot with hard-earned experience of the local conditions remains a vital part of bringing ships safely in and out of the Mersey.