Souter Point Lighthouse
near Whitburn, Sunderland
Now in the care of the National Trust.
1871 'LIGHTHOUSES. ... "Souter Point Lighthouse".... The tower is placed at distance of 245 yards from the edge of the cliff; it is 75 3/4 ft. high from base to vane, and shows, an elevation of 150 ft. above high water, a revolving electric white light of great brilliancy at intervals of thirty seconds; the duration of flash to interval of darkness is in the ratio of one to five, thus giving five seconds for the duration of each flash, and twenty-five seconds for each interval of darkness. Each flash will differ somewhat from that of an ordinary apparatus for oil light, inasmuch as it will appear and disappear suddenly, and be of nearly equal intensity throughout. This apparatus has been manufactured expressly for the purpose, and consists of a portion of dioptric apparatus of the third order for fixed light; around this is rotated a hexagonal drum of glass, consisting of eight panels of vertical lenses; by these lenses the divergent and continuous sheet of light from the fixed portion of the apparatus is gathered up so as to form distinct beams, which successively reach the observer as the panels pass in succession before him. It is remarkable piece of optical skill, requiring the utmost care both in mathematical calculation aud manufacture; the perfections in both are due to the scientific attainments of Mr. James Chance.
A lower light, also electric, is shown from the same tower at a distance of 22 ft. below the upper light, for marking dangers in Sunderland Bay. Directly this light is opened from seaward it will show white, and seamen will know that while it continues they are on the line of Mill Rock; standing further into the shore it will change to red, indicating that they are then in the line of the Hendon Rock and the White Stones. As Mill Rock is a very short distance from the lighthouse, it will be safe to navigate in the white beam, unless close to; but when the red beam opened, except seamen be going into Sunderland, they should not go farther in shore. If bound to Sunderland, the red beam, with the assistance of the Sunderland pier light, will enable them to avoid the Hendon Rock and White Stones.
This lower light is a novelty in lighthouse illumination, on a principle adopted by the Trinity House engineer, and is from the same electric spark as the upper light. To obtain this result the light of the land ward side of the spark, which is usually but imperfectly utilised, is collected and condensed into a small cylindrical beam of great intensity, and is sent by reflection down the centre of the tower to the required distance below the upper light, where it is again reflected, and sent through lower window over the required sector of sea surface. At this lower window a simple but important contrivance has been introduced for cleaning the glass externally in all states of the weather without the necessity of opening the window, or for the lightkeeper in charge to go outside the tower. The electricity for the production of the spark is generated by one of Professor Holmes's magneto-electric machines, worked by steam-engine of six and half indicated horse power. The magneto-electric machine contains fifty-six compound permanent steel magnets, and is driven at a speed of 400 revolutions per minute. The steam-engine, boiler, and magneto-electric machine are all duplicated, in case of accident or want of repair to any part; and during such states of the atmosphere lights are imperfectly visible both magneto-electric machines will be worked, thus doubling the power of the current of electricity, and consequently the intensity of the light. But, as a further precaution against accident, an oil-lamp is placed in position, and is always in readiness to take the place of the electric light at any moment. The machinery was exhibited at the International Exhibition held at Paris in 1867, with which an electric light was shown every night during five months of the period during which the Exhibition was open, the light receiving high commendation from the international jury.
During foggy weather a powerful fog-horn, also the invention of Mr. Holmes, will be sounded. This horn is placed 97 ft. seaward of the lighthouse, at an elevation of 80 ft above high water, and is blown by air compressed by the steam-engine, and sent through a pipe underground to an iron receiver, on which is placed an automatic apparatus which causes the horn to traverse and fro, and send its sound to every part of the adjacent sea, and regulates the number and duration of the blasts. It is arranged that the number of blasts be two per minute, the duration of each blast being five seconds, with an interval of twenty-five seconds, corresponding with the flashes and intervals of the light. The buildings comprise dwellings for five light-keepers (one principal, who is a duly qualified mechanical engineer, and four assistants).
The works were designed by Mr. Douglas, and were executed by the following firms—viz., Electrical apparatus and fog-horn, Professor Holmes and Messrs. Buckett Brothers, London; optical apparatus, Messrs. Chance Brothers and Co., near Birmingham ; steam engines and boilers, Sir Joseph Whitworth and Co., and the Fairbairn Engineering Company, Manchester; and buildings, Mr. Robert Allison, builder, Whitburn. The whole of the scientific portion of the work was carried out under the advice and personal inspection of Professor Tyndall, who took a great interest in the undertaking.'
1879 '....The improvements of late years have now, however, rendered it as trustworthy on this point as any of the other illuminants employed. Thus the electric light has been used in Souter Point Lighthouse on the Durham coast since January 1871 from sunset to sunrise, and down to the present time that is , for about 36,000 hours — it has only been interrupted twice , and that merely for a few minutes. ...'
One of the generators, made by Buckett Brothers in 1867, is preserved in the Science Museum. R. H. Parsons describes the engines as being of the Allen type (i.e. Porter-Allen engines made by J. Whitworth & Co). Each generator absorbed 32 HP. For a light of 1520 cp, this represents very poor efficiency.
Sources of Information
- Illustrated Times, 4 November 1871
- The Scotsman, 5 May 1879: article about the new Eddystone Lighthouse
- 'Early Days of the Power Station Industry' by R. H. Parsons, 1939